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Home My WebLink AboutCT 06-13; TABATA 10; GEOTECHNICAL PLAN REVIEW UPDATE; 2011-12-13GEOTECHNICAL PLAN REVIEW UPDATE PROPOSED 26-LOT (TABATA 10) SUBDIVISION CAMINO HILLS DRIVE, CARLSBAD (A.P.N.'s 212-050-32 & -33) December 13, 2011 Prepared For: TABATA FAMILY TRUST do Mr. Gregg Harrington P.O. Box 679 Carlsbad, California 92018 Ni Prepared By: VINJE & MIDDLETON ENGINEERING, INC. 2450 Auto Park Way Escondido, California 92029 Job #06-210-P LN dON CIO? 0 NV7 cr1 I I GEOTECHNICAL PLAN REVIEW UPDATE PROPOSED 26-LOT (TABATA 10) SUBDIVISION CAMINO HILLS DRIVE, CARLSBAD (A.P.N.'s 212-050-32 & -33) INTRODUCTION The most current project Grading Plans prepared by REC Consultants, Inc. (not dated) for the proposed 26-lot residential development referenced above, also known as Tabata 10 subdivision, were provided to us for review and comments. The plans are reproduced herein and enclosed with this transmittal as Plates 1-3. The approximate site coordinates are 33.1452°N latitude and 117.2880°W longitude. The subject property was originally studied with respect to surface and subsurface .I geotechnical conditions performed by this office with findings, conclusions and recommendations summarized in the following written technical report: Preliminary Geotech nical Investigation Proposed 26-Lot Subdivision Camino Hills Drive, Carlsbad, California (A.P.N.'s 212-050-32 & -33) Job #11-210-P, report dated June 23, 2006 The reference report was reviewed in connection with the preparation of this update study and a copy is attached herein as Appendix A. The purpose of this work was to review the referenced report and confirm compatibility of the project current grading plans with the site indicatedgeotechnical conditions. Additional updated and/or amended recommendations consistent with current codes and engineering standards are also provided in the following sections and will supplement or supersede those given in the referenced report, where specifically indicated. Our efforts in connection with the preparation of this report included a recent site visit conducted by our Engineering Geologist on December 5, 2011. SITE DESCRIPTION Existing topographic conditions and proposed development at the project property are shown the enclosed Plate 3. Based on our recent observations, site conditions primarily have remained substantially the same as discussed in the referenced report. In general, much of the study property consists of gently sloping terrain that descends in a northeasterly direction to El Camino Real. Previous grading activities for off-site developments have modified the property to include large graded slopes that ascend to residential developments along the southerly and easterly site margins. An anomalous hill VINJI & MlDoLlnoN ENGINEERING, INC. • 2450 Auro Park Way Escondido, California 92029-1229 • Phone (760) 743-1214 1 0 ,I GEOTECHNICAL PLAN REVIEW UPDATE DECEMBER 13, 2011 TABATHA 10 SUBDIVISION, CAM INO HILLS DRIVE, CARLSBAD PAGE 2 marks the northwest property margin adjacent to Camino Hills Drive. The hill rises nearly 30 feet above surrounding areas with slope gradients that generally approach 2:1 (horizontal to vertical) maximum. The large graded slopes that mark the southerly and easterly site margins were constructed at 2:1 gradients maximum and range to nearly 50 feet high. Drainage terraces were noted in south and northeast portions of the graded embankments. S Available pre-development topography indicate the perimeter slopes are largely fill embankments with some fill-over-cut slopes. The previous residential dwelling located on the hilltop in the northwesterly area of the I property has been removed. Elsewhere, the property is characterized by grass covered gently sloping terrain previously utilized for agricultural purposes. Perimeter graded slopes are well landscaped with large trees, shrubs, and assorted groundcover plants. Site drainage sheetlfows in a northeasterly direction towards El Camino Real. Excessive scouring or erosion is not in evidence. GEOTECHNICAL CONDITIONS Geotechnical conditions at the project property have remained substantially unchanged from those discussed in the details in the referenced report (see Appendix A). In general, previous grading has modified much of the project site and altered the original surface contours. Old topographic maps of the area indicate that lower, level areas of the site were previously characterized by a natural canyon that drained northward toward El Camino Real. Grading of the area in the late 1960's leveled the site for agricultural purposes. Graded perimeter slopes in the south and east margins were constructed at a later date in support of the off-site development above. ' The project site exposes natural formational and Terrace Deposit units that are mantled by surficial alluvial and fill deposits. Eocene age formational rock units are present at . shallow to modest depths in south and east portions of the property and found at depth beneath younger soil deposits in northerly areas. Natural Terrace Deposit soils are present in the north and west portions of the property and thicken northward and pinch out atop a' formational rocks to the south. Undifferentiated fill and alluvial soils occupy lower elevations of the project site and compacted fill sections mark the south and east perimeter areas of the project site. a' Groundwater conditions, as encountered during the original site investigation, occur at depths of 32 and 33 feet below ground surfaces in the northwest portions of the property a' (see Boring Logs B-2 and B-3 in Appendix A). The noted groundwater is sufficiently deep and is not expected to impact the proposed grading or the future stability of the developed property provided our recommendations are followed. 1 VINIIi & MIDI:LETON ENGINEERING, INC. • 2450 Auto ParkWay Escondido, California 92029-1229 • Phone (760) 743-1214 1 S GEOTECHNICAL PLAN REVIEW UPDATE DECEMBER 13, 2011 TABATHA 10 SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD PAGE 3 P1 Details of project earth materials are given in the Test Trench and Boring Logs included in Appendix A (Plates 3-11). Approximate locations of the Test Trench excavations and lIP1 Boring explorations are transferred and are shown on the enclosed Plate 3. IV. PROPOSED DEVELOPMENT P1 The project current Grading Plan (Plate 3) proposes a substantially similar development scheme to the earlier reviewed project Preliminary Site Plan used as a basis of our P1 geotechnical study in 2006 (see Plate 2, Appendix A). The grading plans outline the creation of a 26-lot residential subdivision with associated interior public roadways and improvements using minor to relatively significant cut-fill grading. Current plans, however, depict new building pad elevations for some lots. Elevated pad elevations on the order of 4 feet are now proposed for perimeter southeastern lots. Similar grades or minor elevation changes are noted for the remaining lots. Minor graded slopes provide ground elevation ,I transitions between uneven pad surfaces. Additional Cross-Sections showing the proposed new pad elevations and associated new graded embankments are included as _I Plate 4. Based on the project plans, nearly 26,000 yards of import soil will be required to complete grading and achieve final design grades. A modest sound earthen berm, incorporating relatively short retaining walls, is proposed along the north/northwest margin of the property adjacent to El Camino Real. Proposed hydro-modification consists of a self-contained vegetated bio-retention/detention area with impermeable liners on sides and bottom, engineered soils, and perforated and header pipes surrounded with aggregate or crushed rocks, along the northern property margins. The treated stormwater from the bio- retention/detention area is discharged via a new 24-inch RCP storm drain pipe into the existing 36-inch RCP pipe beneath the El Camino Real. _I Future residential construction is anticipated to consist of single and/or two story conventional wood-frame buildings with exterior stucco supported on shallow stiff concrete foundations with stem-walls and slab-on-grade floors, slab-on-ground with turned-down footings, or post-tension slab foundations. V. SEISMIC GROUND MOTION VALUES For design purposes, site specific seismic ground motion values were determined as part of this investigation in accordance with the California Building Code (2010 CBC). The following parameters are consistent with the indicated project seismic environment and our experience with similar earth deposits in the vicinity of the project site, and may be utilized for project design work: S. VINu & MIotDLEroN ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029-1229 • Phone (760) 743-1214 GEOTECHNICAL PLAN REVIEW-UPDATE DECEMBER 13, 2011 TABATHA 10 SUBDIVISION, CAM INO HILLS DRIVE, CARLSBAD PAGE 4 TABLE I Site Class I Ss I Si I Fa I Fv I SMs I SMi I SDs SDi D 1.158 0.439 1 1.037 1. 1.561 J 1.201 1 0.685 0.801 0.457 According to Chapter 16, Section 1613 of the 2010 California Building Code. Explanation: Ss: Mapped MCE, 5% damped, spectral response acceleration parameter at short periods. Si: Mapped MCE, 5% damped, spectral response acceleration parameter at a period of 1-second. Far Site coefficient for mapped spectral response acceleration at short periods. Fv: Site coefficient for mapped spectral response acceleration at 1-second period. SMS: The MCE, 5% damped, spectral response acceleration at short periods adjusted for site class effects (SMS=FaSs). SM1: The MCE, 5% damped, spectral response acceleration at a period of 1-second adjusted for site class effects (SM1=FvS1). SDS: Design, 5% damped, spectral response acceleration parameter at short periods (SDS= %SMS). SD1: Design, 5% damped, spectral response acceleration parameter at period of 1-second (SD1 ½SM1). Site peak ground accelerations (PGA) based. on 2 percent probability of exceedance in 50 years defined as Maximum Considered Earthquake (MCE) with a statistical return period of 2,475 years is also evaluated herein in accordance with the requirements of CBC Section 1613 and ASCE Standard 7-05. Based on our analysis, the site PGAMCE was estimated to be 048.g using the web-based United States Geological Survey (USGS) ground motion calculator. The design PGA determined as two-thirds of the Maximum Considered Earthquake (MCE) was estimated to be 0.32g. VI. HYDRO-MODIFICATIONS Project stormwater management should be designed and constructed considering the site indicated geotechnical conditions. The implemented management practice(s) should also have no short and long term impacts on the site building pad surfaces, graded slopes and natural embankments, fills and backfills, structures, and onsite and nearby off improvements and properties. Site hydro-modification, as currently proposed consist of a self-contained vegetated bio- retention/detention area with impermeable liners on sides and bottom, engineered soils filter medial and perforated and header pipes surrounded with aggregates or crushed rocks, along the northern property margins. Treated waterfrom the bio-rètention/detention area is captured and discharged via a new 24-inch RCP pipe into the existing 36-inch RCP storm drain pipe under El Camino Real. The proposed hydro-modification system represent a feasible design and is considered acceptable from a geotechnical viewpoint. VINjI & MDDLETON ENcINIrIuNc, INC. • 2450 Auto Park Way Escondido, California 92029-1229 • Phone (760) 743-1214 1. . GEOTECHNICAL PLAN REVIEW UPDATE DECEMBER 13, 2011 TABATHA 10 SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD PAGE 5 VII. CONCLUSIONS AND RECOMMENDATIONS 1 Project most current Grading Plans reproduced herein as Plates 1 through 3 represent feasible designs and development schemes from .a geotechnical viewpoint. The most significant change from the original plans include minor to moderate elevations changes 1 in final pad grades for some lots, the addition of an earthen sound wall adjacent toEl Camino Real, and a vegetated bio-retention/detention area as a part of the project hydro- modification. The site mostly remains substantially unchanged from conditions presented in the referenced Preliminary Geotechnical Investigation report (Appendix A). All conclusions and recommendations provided in the referenced report (Appendix A) remain valid and should be incorporated into the final plans and implemented during the construction phase except where specifically amended or superseded below. Additional site-specific conclusions and recommendations consistent with the enclosed plans, and current codes, standards and engineering practice are also provided below and should be considered where ever appropriate and as applicable: Landslides, faults or significant shear zones are not present at the project property and are not considered a geotechnical factor in the planned developments. The study site is not located near or within the Alquist - Priolo earthquake fault zone established by the State of California. Soil collapse, liquefaction and seismically induced settlements will not be a factor in the development of the project property provided our remedial grading and foundation recommendations are followed. All existing underground waterlines, sewer lines, storm drains, utilities, tanks, structures, and improvements at. or nearby the project construction site should be throughly potholed, identified, and marked prior to the initiation of the actual excavations, grading and earthworks. Specific geotechnical engineering recommendations may be required based on-the- actual field locations, invert elevations, backfill conditions and proposed grades in the event of a grading conflict. Utility lines may need to be temporarily redirected, if necessary, prior to earthwork operations and reinstalled upon completion. Alternatively, permanent relocations may be appropriate as shown on the approved plans. Abandoned lines, irrigation pipes, and conduits should be properly removed, capped or sealed off to prevent any potential forfuture water infiltrations into the embankments, foundation bearing and subgrade soils. Voids created by the removals of the abandoned underground pipes, tanks and structures should be properly backfilled with compacted fills in accordance with the requirements of this report. VINJE & MlLEToN ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029-1229 • Phone (760) 743-1214 I GEOTECHNICAL PLAN REVIEW UPDATE DECEMBER 13, 2011 TABATHA 10 SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD PAGE 6 4. Remove all existing surface and subsurface improvements, old foundations and concrete slabs, vegetation, trees, roots, stumps, construction debris, and all other unsuitable materials and deleterious matter from all areas of proposed new fills, embankments, improvements, and structures plus 10 feet outside the perimeter, where possible and as approved in the field. Trash, vegetation, and construction debris shall not be allowed to occur or contaminate new site fills and backfills. The prepared grounds should be inspected and approved by the project geotechnical consultant or his designated field representative prior to grading and earthworks. 'I 5. Earthwork and remedial grading operations should be completed as specified in the Remedial Grading and Earthworks section of the referenced report (Page 17 of Appendix A). Site upper fill and alluvium deposits in the areas of planned new fills, embankments, structures, and improvements plus 10 horizontal feet outside the perimeter should be removed (stripped) to the underlying competent natural soils, I Terrace Deposits, and Formational Rock as approved in the field, and recompacted. Ground stabilization techniques using Tensar Geogrid BX-1 100 (orgreaterfrom the same series) earth reinforcement may be required at the yielding bottom of 1 :removals, and within the compacted fill mass, in the case of unsuitable exposure and should be anticipated as specified and directed in the field. Actual removal depths should be established by the project geotechnical consultant 1 at the time of earthwork operations based on exposed field conditions. Typical removal depths in the vicinity of the subsurface are given in the referenced report ' (Table 15, Appendix A) and also depicted on the attached Plate 3. Locally deeper removals may be necessary as directed in the field and should be anticipated. 6. Current plans indicated minor to moderate changes in the final pad elevations. Elevated pad grades are now proposed for the south/southeastern lots with Lots 3-5 raised up to 4 feet above the prior elevations (see Plate 2, Appendix A). Ground transitioning will be accomplished with new graded cuts on the order of 5-8 feet high. Reconstruction of lower sections of the exposed slope in these areas (Lots 4 and 6-10) with stabilization fills, or a toe retaining wall support, as recommended in a referenced report (see Plate 20, Appendix A) may still be necessary. Final recommendations for slope reconstructions for new graded embankments constructed within or at the toe of existing graded slopes will be provided in the field by the project geotechnical engineer based upon actual developed exposures. VINJE & MIDDLEioN ENGINEERING, INC. 2450 Auto Park Way Escondido, California 92029-1229 Phone (760) 743-1214 GEOTECHNICAL PLAN REVIEW UPDATE DECEMBER 13, 2011 TABATHA 10 SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD PAGE 7 The project is an unbalanced grading operation and nearly 26,000 yards of import soil will be required to achieve final design grades. Onsite soils may also may be expected to shrink approximately 10% to 20% on a volume basis when compacted as specified herein. Import soils required to complete grading, should be good quality non-corrosive, very low expansive sandy granular D.G. type soils (100% passing 1 -inch sieve, more than 50% passing #4 sieve and less than 18% passing #200 sieve with expansion index less than 21), inspected, tested as necessary, and approved by the project geotechnical consultant prior to delivery to the site. Import soils should also meet or exceed the design parameters given in the following sections. Good quality sandy granular D.G. type import soils should be placed within the upper pad grades. Attempts should also be made to bury site potentially expansive clays in deeper fills below the upper 4 feet and place better quality sandy onsite soils within the upper grades using select grading techniques, as specified in the referenced report. The cut portions of cut-fill transition pads should be undercut to a minimum depth of 3 feet or-at least 12 inches below the bottom of the deepest footing(s), whichever is more and reconstructed to design pad grades with compacted fills, as specified. In the roadways, driveway, parking and on-grade slabs/improvement transition areas, there should be a minimum of 12 inches of compacted soils below rough finish subgrade. Fill materials, processing, spreading and placement in thin horizontal lifts (less than 8 inches maximum), moisture conditioning above the optimum levels and compaction procedures, and minimum compaction levels (95% within the upper 3 feet and where specified, and 90% below the upper 3 feet) will remain the same as specified. All grading and earthworks should be completed in accordance with the Chapter 18 and Appendix "J" of the California Building Code (CBC), City of Carlsbad Grading Ordinances, the Standard Specifications for Public Works Construction, and the requirements of the referenced soil report (Appendix ) and this update transmittal. New graded slopes, berms, and embankments constructed in connection with the site development are expected minor features on the order of 10 feet high maximum. Graded slopes and embankments should be programmed for 2:1 gradients and constructed as spiffed in the referenced report (see Appendix A). VINE' & MDDLETON ENGINEERING, INC. • 2450 Auto PirkWay Escondido, California92029-1229 Phooc (760) 743-1214 GEOTECHNICAL PLAN REVIEW UPDATE DECEMBER 13, 2011 TABATHA 10 SUBDIVISION, CAM INO HILLS DRIVE, CARLSBAD PAGE-8 Excavations and removals of onsite existing fills and alluvium are expected to predominantly generate marginal quality plastic silty to clay-rich deposits which typically require additional processing, mixing and moisture conditioning. efforts in orderto manufacture a uniform homogeneous mixture suitable for reuse as new site fills. Site potentially expansive soils should be buried in deeper fills and better quality sandy soils generated from the excavations of site Terrace Deposits, and good quality sandy import soils place within upper pad grades, as specified. Plastic silty to clayey soils are also not suitable for wall and trench backfills and good quality sandy soils should be used for this purpose. For foundation design purposes, however, sandy clay to silty clayey sand (SC/CL) bearing soils with low to high expansion potential (Expansive Index less than 131) based on ASTM D-4829 classification should be considered. Remedial grading and geotechnical foundation design recommendations specified herein are provided to also mitigate adverse affects of site potentially expansive soils. Soil design parameters, and foundations and slabdesigns will remain the same as specified in the referenced report. However, the following revised parameters are appropriate based on the anticipated bearing soils properties and supercede those previously given where specifically applicable: * Design edge moisture variation distance for edge lift (em.) .........4.9 feet. * Design edge moisture variation distance for center lift (em) ........9.0 feet. * Design differential swell occurring at the perimeter of slab for edge lift condition (Ym) ...............................1 .32 inches. * Design differential swell occurring at the perimeter of slab for center lift condition (Ym) .............................2.91 inches. I . In case of post-tensioned slab foundation system, undersiab moisture control should consist of a well-performing vapor barrier/moisture retardant (minimum. 15- mil Stego) placed mid-height in a minimum of 4 inches of clean sand (SE of 30 or greater). However, interior underslab moisture control requirements per CGC Section 4.505.2.1 consisting of a minimum 4-inch thick base of 1A-inch or larger clean aggregate, provided with a vapor barrier (minimum 15-mil Stego) in direct .I contact with concrete, and a concrete mix design which address bleeding, shrinkage, and curling may also be considered. .I 13. All exterior concrete slabs and flatwork (walkways, and patios) should also be constructed as specified in the referenced report (Appendix A). Slab subgrade soils should be compacted to minimum 90% compaction levels. Subgrade soils should .I be tested for proper moisture and specified compaction levels and approved by the project geotechnical consultant prior to the placement of concrete. VINJE & MIDDLETON ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029-1229 • Phone (760) 743-1214 GEOTECHNICAL PLAN REVIEW UPDATE DECEMBER 13, 2011 TABATHA 10 SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD PAGE 9 Slab reinforcements lying on subgrade will be ineffective and shortly corrode due to lack of adequate concrete cover. Reinforcing bars should be correctly placed extending through the construction joints tying the slab panels. In construction practices where the reinforcements are discontinuous or cut the construction joints, slab panels should be tied together with minimum 16 inches long #3 dowels (dowel baskets) at 18 inches on centers placed near the mid-height in the slab (9 inches on either side of the joint). Provide thickened slab edge and "tool joint" or "softcut" contraction/control joints for exterior slabs as specified. The larger dimension of any panel shall not exceed 125% of the smaller dimension. All exterior slab designs should be confirmed in the final as-graded compaction report. Preliminary structural section estimates for the asphalt and PCC paving will remain the same as specified. The minimum asphalt pavement structural section presented in Table 16 of the referenced report (see Page 32 of Appendix A), or the minimum section required by the City of Carlsbad, whichever is greater, should be considered. Provide "tool joint" or "softcut" contraction/control joints for all PCC paving surfaces also as specified. The larger dimension of any panel shall not exceed 125% of the smaller dimension. Joints shall intersect free edges at a 900 angle and shall extend straight for a minimum of 11/2 feet from the edge. The minimum angle between any two intersecting joints shall be 800. Align joints of adjacent panels. Also, align joints in attached curbs with joints in slab panels. Provide adequate curing using approved methods (curing compound maximum coverage rate = 200 sq. ft./gal.). The proposed bio-retention area within the project development is a self- contained system which incorporates timely removal Of the captured water by the perforated subdrain pipe and discharging the treated water into the storm water drainage facilities, without allowing accumulation or saturation of the surrounding soils. The proposed bio-retention system is considered acceptable from a geotechnical point of view and may be installed at the designated site locations as shown on the project plans. Added care, however, will be required during the bio-retention constructions to void puncturing the impermeable liner and assure positive outflow of the perforated subdrain pipe. Control of site surface drainage and potential for post construction subsurface water caused by surface water infiltrations is one of the most significant geotechnical factors at the project building sites. Surface flow, run-off drainage and subsurface water should not impact graded surface, saturate wall backfills, bearing and subgrade soils or cause erosion. All retaining walls should be provided with a back drain as specified. Drainage ditches should be provided at the top and toe of slopes and behind site retaining walls with collected water directed to approved disposal VINJI & MIoDLlnoN ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029-I229 Phone (760) 743-1214 GEOTECHNICAL PLAN REVIEW UPDATE DECEMBER 13, 2011 TABATHA 10 SUBDIVISION, CAM INO HILLS DRIVE, CARLSBAD PAGE 10 location via adequate area inlets. All wall back drains, tight pipes and outlet locations should also be shown on the final plans. '1 17. Final grading and foundation plans should reflect preliminary recommendations given in this report and reviewed and approved by the project geotechnical P1 .consultant. Additional or more specific recommendations may be necessary and should be provided at that time, as required. GEOTECHNICAL ENGINEER OF RECORD (GER) Vinje & Middleton Engineering, Inc. is the geotechnical engineer of record (GER) for a specific scope of work or professional service under a contractual agreement unless it is terminated or, canceled by either the client or our firm. In the event a new geotechnical consultant or soils engineering firm is hired to provide added engineering services, professional consultations, engineering observations and compaction testing, Vinje & Middleton Engineering, Inc. will no longer be the geotechnical engineer of record. Project transfer should be completed in accordance with the California Geotechnical Engineering Association (CGEA) Recommended Practice for Transfer of Jobs Between Consultants. The new geotechnical consultant or soils engineering firm should review all previous geotechnical documents, conduct an independent study, and provide appropriate confirmations, revisions or design modifications to his own satisfaction. The new geotechnical consultant or soils engineering firm should also notify in writing Vinje & Middleton Engineering, Inc. and submit proper notification to the City of Carlsbad for the assumption of responsibility in accordance with the applicable codes and standards (1997 UBC Section 3317.8). LIMITATIONS This geotechnical plan review update is not a "Plan Check Review" and does not relieve the responsibility of the project design consultant(s) and contractor(s) to get completely .I familiarized with the requirements of the project soil report(s) and fully incorporate its recommendations into the projectdesign, plans and construction works, where appropriate, and as applicable. Our review and comments are for general geotechnical conformance Wi of the project plans with the intent of the project soil report and design recommendations. Review of structural and civil engineering calculations, architectural intent and structural and civil engineering design modeling and basis, verification of set back requirements, SI easements and right-of-ways, as well as code, city and county compliance are beyond geotechnical engineering services. It is the owner's or his (her) representative's responsibility to provided copies of all pertinent soil report(s), updates, addendum letters SI and plan review letters to respective design consultant(s), and general contractor and his (her) subcontractor(s) for full compliance. V I NJ E& MIDDLETON ENGINEEIUNG, INC. • 2450 Auto PirkWy Escondido, Cahforna 92029-1229 • Phone(760)743-1214 GEOTECHNICAL PLAN REVIEW UPDATE DECEMBER 13, 2011 TABATHA 10 SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD PAGE 11 This opportunity to be of service again is sincerely, appreciated. Should any questions arise concerning this report, please do not hesitate to contact this office. VINJE & MIDDLETON ENGINEERING, INC. -7 - - -- GEV2885 Exp. 12134.112 No. 2362 FIE C EG # ENNEERS ç GEOLOGIST EXRsJiJ13j/ Distribution: Addressee (2, e-mail) REC Consultants Inc., Atten1tyri-ix Parra (3, e-mail) Attachments: Plates 1 - 4 Appendix A VlNJl & MIDDLInoN ENGINEERING, INC. • 2450 Auro Park Way Escondido, CaIforna 92029-1229 • Phone (760) 743-1214 AREAS SLOPED LESS THAN 6:I SHALL BE IRRIGATED AS APPROVED BY THE CITY ENGINEER, PRIOR TO H1OROSEEDING THE DEVELOPER SHALL SUBMIT A PROPOSED "DECLARATION OF RESPONSIBLE CHARGE" SCHEME TO PROVIDE IRRIGATION TO THE CITY ENGINEER. THE PROPOSAL SHALL BE I HEREBY DECLARE THAT I AM THE ENGINEER OF WORK FOR THIS PROJECT. THAT I SPECIFIC REGARDING THE NUMBERS TYPES AND,COSTS OF THE ELEMENTS OF THE HAVE EXERCISED RESPONSIBLE CHARGE OVER THE DESIGNOF THE PROJECT AS DEFINED THE PROPOSED SYSTEM. IN SECTION 670.3 OF THE BUSINESS AND PROFESSIONS CODE. AND THAT THE DESIGN IS IRRIGATION SHALL MAINTAIN THE MOISTURE LEVEL OF THE SOIL AT THE OPTIMUM CONSISTENT WITH CURRENT STANDARDS - LEVEL FOR THE GROWTH OF THE HYDROSEEDED GROWTH. I UNDERSTAND THAT THE CHECK OF PROJECT DRAWINGS AND SPECIFICATIONS BY THE C C. HYDROSEEDINO MIX SHALL CONSIST OF ALL OF THE FOLLOWING.- - CITY OF CARLSBAD DOES NOT RELIEVE ME. AS ENGINEER OF WORK, OF MY I SEED MIS SHALL CONSIST OF NO LESS THAN: - RESPONSIBILITIES FOR PROJECT DESIGN. ' ' 20 lbs PER ACRE OF ROSE CLOVER FIRM: NEC CONSULTANTS. OC V. 20 lbs PER ACRE OF ZORRO FESCUE ADDRESS 2442 SECOND AVENUE - s 3 lb. PER ACRE OF E SCHOOL CIA CBLIFORNICA SItED, CA CITY, STATE_SAN - A. 4 lbs PER ACRE OF ACHILLEA MILLEFOLIA TELEPHONE 619.232.9200 C. 3 lbs. PER ACRE OF ALYSSUM (CARPET OF SNOW) F. 1/2 lb. PER ACRE OF DIM'ORPHOLECA 61' BRUCE ROBERTSON DATE______________ 9. ITEMS cctp, AND (OF THIS SUBSECTION MAY BE OMITTED ON (NAME OF ENGINEER) - LOCASOVIS WHERE THE AREA BEING HYDROSEEDED IS NOT VISIBLE R.CE. NO.: 48329 FROM EITHER A PUBLIC STREET OR RESIDENTIAL STRUCTURES V. ITEM -o OF THIS SUBSECTION MUST BE INOCULATED WITH A REGISTRATION EXPIRATION DATE: 6130112 NITROGEN FIXING BACTERIA AND APPLIED DRY EITHER BY DRILLING • OR BROADCASTING BEFORE HEDROSEEDING SOILS ENGINEER'S CERTIFICATE ALL SEED MATERIALS SHALL BE TRANSPORTED TO THE ,W2BSITE IN UNOPENED CONTAINERS WITH THE CALIFORNIA DEPARTMENT OF FOOD AND AGRICULTURE CERTIFICATION TAO ATTACHED TO, OR I 00015(WEIRETIIN . A REGISTERED (CIVIL/ PRINTED ON SAID CONTAINERS OECITECHNICAL) ENGINEER OF THE STATE OF CALIFORNIA. PRINCIPALLY DOING. , j NON-PHYTO- TOXIC (WETTING AGENTS MAY BE ADDED TO THE BUSINESS IN THE FIELD OF APPLIED SOILS MECHANICS. HEREBY CERTIFY THAT - HYSROSEED SLURRY AT THE DISCRETION OF THE CONTRACTOR. A SAMPLING AND STUDY OF THE SOIL CONDITIONS PREVALENT WITHIN THIS - SITE WAS MADE BY ME OR UNDER MY DIRECTION BETWEEN THE DATES OF 2. TIRE I MULCH APPLIED AT THE RATE OF NO LESS THAN 2000 lbs PER ACRE. JUNE . 2006 AND MARCH . 2000,,.,. TWO TIRE B MULCH (STRAW) MAY BE SUBSTITUTED. ALL OR PART. FOR COPIES OF THE SOILS REPORT COMPILED FROM THIS STUDY. PATH MY HYDRAULICALLY APPLIED FIBER MATERIAL WHEN STRAW IS USED IT MUST BE RECOMMENDATIONS HAS BEEN SUBMITTED TO THE OFFICE OF THE CITY ANCHORED TO THE SLOPE BY MECHANICALLY PUNCHING NO LESS THAN 50% OF ENGINEER. THE STRAW INTO THE SOIL SIGNED: S. FERTILIZER CONSISTING OF AMMONIUM PHOSPHATE SULFATE I6-20-0. WITH 15% G.E./P.E. Na' 080 SULPHUR APPLIED AT THE RATE OF 500 lbs PER ACRE. - EN YE: ________________________________ 0. AREAS TO BE HYDROSEEDED SHALL BE PREPARED PRIOR TO HYDROSEEDING BY: I. ROUGHENING THE SURFACE TO BE PLANTED BY ANY OR A COMBINATION OF: LICENSE EXPIRATION DATE: ___________ a TRACK WALKING SLOPES STEEPER THAN &I b. HARROWING AREAS 6:1 OR FLATTER THAT ARE SUFFICIENTLY FRIABLE. OWNER'SCERTIFICATE °' RIPPING AREAS THAT WILL NOT BREAK UP USING ITEMS o OR ABOVE, I ( WE ) HEREBY CERTIFY THAT A REGISTERED SOILS ENGINEER OR 2. CONDITIONING THE SOILS SO THAT IT IS SUITABLE FOR PLANTING BY: GEOLOGIST HAS BEEN OR WILL BE RETAINED TO SUPERVISE OVER-AU a ADJUSTING THE SURFACE SOIL MOISTURE TO PROVIDE A DAMP GRADING ACTIVITY AND ADVISE ON THE COMPACTION AND STABILITY OF BUT NOT SATURATED SEED BED. THIS SITE. - 6. THE ADDITION OF SOIL AMENDMENTS PH ADJJSTIJENT, LEACHING COVERING SALINE SOILS TO PROVIDED VIABLE CONDITIONS FOR NOBURU TABATA . DATE GROWTH. 0. HYDROSEEDED AREAS SHALL BE MAINTAINED TO PROVIDE A VIGOROUS GROWTH UNTIL THE THE PROJECT IS PERMANENTLY LANDSCAPED OR, FOR AREAS WHERE HYEIROSEEDINC IS THE SOURCE _OFTOPOGRAPHY THE PERMANENT LANDSCAPING. UNTIL THE PROJECT IS COMPLETED AND ALL BONDS WTOPOGRAPHY SHOWN ON THESE PLANS WAS GENERATED BY AERIAL RELEASED. - I - METHODS FROM INFORMATION GATHERED ON__________ - LEGAL _DESCRIPTION TOPOGRAPHY SHOWN HEREON CONFORMS TO NATIONAL MAP ACCURACY STANDARDS BERG A SUBDIVISION OF PARCELS I AND 207 PARCEL MAP Na 2481, IN TIlE CITY OF CARLSBAD, COUNTY OF SAN "GO, STATE OF CALIFORNIA FILED IN THE OFFICE GE THE COUNTY RECORDER OF PROJECT LOCATION . - SAN DIEGO COUNTY ON MARCH 21. 1974 AS FILE NO. 74-071006. OFFICIAL RECORDS THIS PROJECT IS LOCATED WITHIN ASSESSORS PARCEL NUMBER(S) 212-050-32 A 33 THE CAUFNIACOORDINATEINDEXOFTIIPROJECT IS - - E VICINITY MAP CITY OF OCEANSIDE CITY OF EIICINITAS INDEX OF SHEETS SHEET I - TITLE SHEET SHEET 2 - SECTIONS AND DETAILS SHEET 3 - ROUGH GRADING PLAN REFERENCE DRAWINGS CT 83-25 OPAL 246 CASIO 83-202 Cr Al-S DEG 335 CMWO 85-309 Cr 91-2 OVAL 328 C.MWSI 90-503 ('1.1. 6/30/IS GRADING NOTES (IN ADDITION To THE REQUIREMENTS OF CHAPTER 15.16 OF THE CARLSBAD MUNICIPAL CODE.) THIS PLAN SUPERSEDES ALL OTHER PLANS PREVIOUSLY APPROVED BY THE CITY OF CARLSBAD REGARDING GRADING SHOWN ON THIS SET OF PLANS APPROVAL OF THIS PLAN DOES NOT LESSEN OR WAIVE ANY PORTION OF THE CARLSBAD MUNICIPAL CODE. RESOLUTION OF CONDITIONAL APPROVAL. CITY STANDARDS OR OTHER ADDITIONAL DOCUMENTS LISTED HEREON AS THEY MAY PERTAIN TO THIS PRO.ECT. THE ENGINEER IN RESPONSIBLE CHARGE SHALL RE WSE THESE PLANS BIER NON-CONFORMANCE IS DISCOVERED. CITY APPROVAL OF PLANS DOES NOT RELIEVE THE DEVELOPER OR ENGINEER-OF-WORK FROM RESPONSIBLUTY FOR THE CORRECTION OF ERRORS AND OMISSIONS DISCOVERED DURING CONSTRUCTION. ALL PLAN REWSIONS SHALL BE PROMPTLY SUBMITTED TO THE CITY ENGINEER FOR APPROVAL A REDlY-OF-WAY PERMIT FROM THE CITY ENGINEER WILL BE REQUIRED FOR ANY (WORK IN THE PUBLIC RIGHT OF WAY. PRIOR TO PERMIT ISSUANCE. A CERTIFICATE OF INSURANCE AS WELL AS ADDITIONAL INSURED ENDORSEMENT MUST BE FILED NAMING THE CITY OF CARLSBAD AS AN ADDITIONAL INSURED ON THE PERMITTEES POLICY IN THE MINIMUM AMFIIINT OF BT.000OOISOO FOR EACH UI.LIJNNANCE OF UABILITY. THE INSURANCE COMPANY (WRITING THE PO, MUST HAVE A RATING OF A- OR BETTER AND A SIZE CATEGORY OF CLASS WI DR BETTER AS ESTABLISHED BY BESTS KEY RATING GUIDE, UNLESS EXEMPTED BY SECTION 30I.(b)5 OF THE UNIFORM BUILDING CODE. RETAINING WALLS OUTSIDE OF PUBLIC RIGHT OF WAY REQUIRE SEPARATE PERMITS FROM THE BUILDING DEPARTMENT. & NO WORK SHALL BE COMMENCED UNTIL ALL PERMITS HAVE BEEN OBTAINED FROM THE CITY AND OTHER APPROPRIATE AGENCIES 7. APPROVAL OF THESE PLANS BY THE CITY ENGINEER DOES NOT AUTHORIZE ANY WORK OR GRADING TO BE PERFORMED UNTIL THE PROPERTY OWNERS PERMISSION HAS BEEN OBTAINED AND A VAUD GRADING PERMIT HAS BEEN ISSUED. & NO REVISIONS WILL BE MADE TO THESE PLANS WITHOUT THE WRITTEN APPROVAL OF THE CITY ENGINEER, NOTED WITHIN THE REVISION BLOCK. ON THE APPROPRIATE SHEET OF THE PLANS AND THE TITLE SHEET. 9. ORIGINAL DRAWINGS SHALL BECOME THE PROPERTY OF THE CITY UPON BEING SIGNED BY THE CITY ENGINEER. TO. THE ORIGINAL DRAWING SHALL BE REVISED TO REFLECT AS-BUILT CONDITIONS BY THE ENGINEER-OF-WORK PRIOR TO FINAL ACCEPTANCE OF THE PORK BY THE CITY. IT. ACCESS FOR FIRE AND OTHER EMERGENCY VEHICLES SHALL BE MAINTAINED TO THE PROJECT SITE AT ALL TIMES DURING CONSTRUCTION. 12. WHERE TRENCHES ARE WITHIN CITY EASEMENTS. A SOILS REPORT COMPRISED 071 (A) SUMMARY SHEET. (B) LABORATORY WORK SHEETS AND (C) COMPACTION CURVES. SHALL BE SUBMITTED BY A PROFESSIONAL ENGINEER OF THE STATE OF CALIFORNIA. PRINCIPALLY DOING BUSINESS IN THE FIELD OF APPLIED SOILS MECHANICS THE SOILS REPORT WILL BE SUBMITTED TO THE CITY ENGINEERING INSPECTOR WITHIN TWO WORKING DAYS OF THE COMPLETION OF FIELD TESTS IS. A SOILS COMPACTION REPORT AND COMPLIANCE VERIFICATION REGARDING ADHERENCE TO RECOMMENDATIONS OUTLINED IN THE SOILS REPORT IS REQUIRED PRIOR TO THE ISSUANCE OF A BUILDING PERMIT. ALL CONTROLLED GRADING SHALL BE DONE UNDER THE DIRECTION OF A PROFESSIONAL ENGINEER OF THE STATE OF CALIFORNIA PRINCIPALLY DOING BUSINESS IN THE FIELD OF APPLIED SOILS MECHANICS ALL FILL OR FUTURE FILL AREAS SHALL BE CONSTRUCTED IN ACCORDANCE 16TH THE CITY OF CARLSBAD STANDARD SPECIFICATIONS AND THE EARTHWORK SPECIFICATIONS ATTACHED TO THE PRELIMINARY SOILS INVESTIGATION. DAILY FIELD COMPACTION REPORTS WILL BE SUBMITTED TO THE PRCT INSPECTOR. I O.JE d. A PRECONSTRIJCTION MEETING SHAlE BY ((FED AT THE SITE PRIOR TO THE BFTINN(NO OF WORK AND SHAll AT ATTTNIIEI) BY ALL RFPRYSENTATIVES RESPONBLE FOR CONSTRUCTION. INSPECTION. SUPERVISION. TESTING AND ALL OTHER ASPECTS OF THE WORK THE CONTRACTOR SHALL REQUEST A PRECOFLSTRUCTION MEETING BY CALLING THE INSPECTION LINE AT (760) 438-3891 AT LEAST FIVE(S) WORKING DAYS PRIOR TO STARTING CONSTRUCTION. THE CONTRACTOR WILL THEN BE CONTACTED BY THE PROJECT INSPECTOR TO COORDINATE A DATE AND TIME FOR THE PRECLWSTRUCTION MEETING. APPROVED DRAWINGS MUST BE AVAILABLE PRIOR TO SCHEDULING. THE GRADING PERMIT WILL BE PRO WOED BY THE PROJECT INSPECTOR AT THE MEETING IS. All INSPECTION RFC4JYSTS OTHER THAN FOR PRYCONSTRUCTVW MEETING WI I BY MAST BY FAIlING THY FNISNYFRING 24-HOUR IWSPFYII(IN RFTRJFcT lINE AT (7601 J_ INSPECTION REQUEST MUST BE RECEIVED PRIOR TO 2OD PM ON THE OAT BEFORE THE INSPECTION IS NEEDED. INSPECTIONS WILL BE MADE THE NEXT WORK DAY UNLESS YOU REQUEST OTHERWISE. REQUESTS MADE AFTER 200 P.M. WILL BE SCHEDULED FOR TWO FULL WORK DAYS LATER. lB. THE OWNER AND/OR APPLICANT THROUGH THE DEVELOPER AND/OR CONTRACTOR SHALL DESIGN. CONSTRUCT AND MAINTAIN ALL SAFETY DEVICES. INCLUDING SHORING AND SHALL BE SOLELY RESPONSIBLE FOR CONFORMING TO ALL LOCAL STATE AND FEDERAL SAFETY AND HEALTH STANDARDS LAWS AND REGULATIONS Ti. THE CONTRACTOR SHALL CONFORM TO LABOR CODE SECTION 6705 BY SUBMITTING A DETAIL PLAN TO THE CITY ENGINEER AND/OR CONCERNED AGENCY SHOWING THE DESION OF SHORING, BRACING SLOPING OR OTHER PROVISIONS TO BE MADE OF WORKER PROTECTION FROM THE HAZARD OF CAVING GROUND DURING THE EXCAVATION OF SUCH TRENCH OR TRENCHES OR DURING THE PIPE INSTALLATION THEREIN. THIS PLAN MUST BE PREPARED FOR ALL TRENCHES FIVE FEET (5) OR MORE IN DEPTH AND APPROVED BY THE CITY ENGINEER AND/OR CONCERNED AGENCY PRIOR TO EXCAVATION. IF THE PLAN VARIES FROM THE SHORING SYSTEM STANDARDS ESTABLISHED BY THE CONSTRUCTION SAFETY ORDERS. TITLE 8 CALIFORNIA ADMINISTRATIVE CODE, THE PLAN SHALL BE PREPARED WY A REGISTERED ENGINTYR AT THE CONTRACTORS EXPENSE A COPY OF THE OSHA EXCAVATION PERMIT MUST BE SUBMITTED TO THE INSPECTOR PRIOR TO EXCAVATION. 18. NO BLASTING SHALL BE PERFORMED UNTIL A VALID BLASTING PERMIT HAS BEEN OBTAINED FROM THE CITY OF CARLSBAD. SUBMIT APPLICATION FOR BLASTING PERMIT WELL IN ADVANCE OF THE SCHEDULING OF BLASTING OPERATIONS IN. IF ANY ARCHAEOLOGICAL RESOURCES ARE OISCOVERED WITHIN ANY I4RL7RK AREA DURING CONSTRUCTION. OPERATIONS (WILL CEASE IMMEDIATELY AND THE PERMITTEE WILL NOTIFY THE CITY ENGINEER. OPERATIONS WILL NOT RESTART UNTIL THE PERMITTEE HAS RECEIVED (WRITTEN AUTHORITY FROM THE CITY ENGINEER TO DO SEE ALL OPERA SONS CONDUCTED ON THE SITE OR ADJACENT THERETO, INCLUDING WARMING UP. REPAIR. ARRIVAL DEPARTURE OR OPERATION OF TRUCKS EAR THMO WNG EQUIPMENT, CONSTRUCTION EQUIPMENT AND ANY OTHER ASSOCIATED GRADING EQUIPMENT SHALL BE LIMITED TO THE PERIOD BETWEEN 7100 AU. AND SUNSET EACH DAY. MONDAY THRU FRIDAY AND NO EARTHUOWNG OR GRADING OPERATIONS SHALL BE CONDUCTED ON WEEKENDS OR HOLIDAYS (A LIST OF CITY HOLIDAYS IS AVAILABLE AT THE ENGINEERING DEPARTMENT COUNTER.) ALL OFF-SITE HAUL ROUTES SHALL BE SUBMITTED BY THE CONTRACTOR TO THE CITY ENGINEER FOR APPROVAL 1140 FULL WORKING DAYS PRIOR TO BEGINNING OF WORK. IMPORT MATERLAL SHALL BE OBTAINED FROM. AND WASTE MATERIAL SHALL BE DEPOSITED AT. A SITE APPROVED BY THE CITY ENGINEER. THE CONTRACTOR SHALL BE RESPONSIBLE FOR AN DEBRIS OR DAMAGE OCCIIRRTNG ALONG THE HAUL ROUTES OR ADJACENT STREETS AS A RESULT OF THE ERASING OPERATION. BRUSH SHALL BE REMOVED ONLY WITHIN THE AREA TO BE GRADED. NO TREES ARE TO BE REMOVED UNLESS SPECIFICALLY NOTED ON THE PLAN. ALL AREAS SHALL BE GRADED TO DRAIN. GRADING RESULTING IN THE PONDING OF WATER IS NOT PERMITTED. ALL EARTHEN S WALES AND DITCHES SHALL HAVE A MINIMUM ONE PERCENT SLOPE. THESE PLANS ARE SUBJECT TO A SIGHED AND APPROVED SET GE EROSION CONTROL PLANS EROSION CONTROL SHALL BE AS SHOWN AND AS APPROVED BY THE CITY ENGINEER OR AS DIRECTED BY THE PROJECT INSPECTOR. ALL SLOPES SHALL BE TRIMMED TO A FINISH GRADE TO PRODUCE A UNIFORM SURFACE AND CROSS SECTION. THE SITE SHALL BE LEFT IN A NEAT AND ORDERLY CONDITION. ALL STONES ROOTS OR OTHER DEBRIS SHALL BE REMOVED AND DISPOSED OF AT A SITE APPROVED OF BY THE CI TY ENGINEER. ALL SLOPES SHALL BE IRRIGATED. STABILIZED, PLANTED AND/OR HYDROSEEDED WITHIN TEN (ID) DAYS OF THE TIME WHEN EACH SLOPE IS BROUGHT TO GRADE AS SHOWN ON THE APPROVED GRADING PLANS LANDSCAPING SHALL BE ACCOMPLISHED ON ALL SLOPES AND PADS AS REQUIRED BY THE CITY OF CARLSBAD LANDSCAPE MANUAL THE LANDSCAPING PLANS FOR THIS PROJECT. DRAWING NO. AND/OR AS DIRECTED BY THE CITY ENGINEER OP PLANNING DIRECTOR. l'AcOa\OA 00050 lusUroo.ngsLA'.U_UI.00g IUAWIAUII 1140.31 AM PAl 29. THE OWNER/APPLICANT SHALL INSURE THAT ALL CONTRACTORS SHALL COORDINATE THE WORK OF THESE GRADING PLANS WITH THAT SHOWN ON BOTH THE LANDSCAPE AND IRRIGATION PLANS AND THE IMPROVEMENT PLANS AS REQUIRED FOR THIS WORK IN ACCORDANCE WITH THE LANDSCAPE MANUAL TIME REQUIREMENTS 30. WHERE AN EXISTING PIPE LINE IS TO BE ABANDONED AS A RESULT OF THE GRADING OPERATION. IT SHALL BE REMOVED WITHIN TWENTY FEET OF BUILDING OR STREET AREAS AND REPLACED WITH PROPERLY COMPACTED SOILS IN OTHER AREAS THE PIPE WILL BE PLUGGED WITH CONCRETE OR REMOVED AS APPROVED BY THE CITY ENGINEER. 31. THE CONTRACTOR SHALL VERIFY THE LOCATION OF ALL EXISTING FACILITIES (ABOVE GROUND AND UNDER GROUND) WITHIN THE PROJECT SITE SumCIENrLY AHEAD OF GRADING TO PERMIT THE REVISION OF THE GRADING PLANS IF IT IS FOUND THAT THE ACTUAL LOCATIONS ARE IN CONFLICT WITH THE PROPOSED WORK. 32. THE CONTRACTOR SHALL NOTIFY AFFECTED UTSITY COMPANIES (SEE BELOW) AT LEAST 2 FULL WORKING DAYS PRIOR TO STARTING GRADING NEAR THEIR FACILITIES AND SHALL COORDINATE THE WORK WITH A COMPANY REPRESENTA DIAL - UNDERGROUND SERVICE ALERT 800 1806-9809 422-413.3 SOGRIE . 800 660-7343 PACIFIC BELL . 800892-0123 TIME WARNER CABLE - - 760438-7741 COX COMMUNICA SONS 760 CITY OF CARLSBAD(STREETS RI STORM DRAIN) 760 434-2980 'CITY OF CARL SBAD(SElWER.WATER RI RECLAIMED WATER) 760 438-2722 'SAN DIEGUITO WATER DISTRICT 760 633-2650 "LEUCADIA WASTEWATER DISTRICT . 760 753-0155 'VALLECITOS WATER DISTRICT 760 744-0460 'OLIVENHAIN WATER DISTRICT 760 753-6466 'BUENA SANITATION DISTRICT 760 726-1340 'AS APPROPRIATE 33. PERMIT COMPLIANCE REQUIREMENTS A, FOR CONTROLLED GRAOIN5 - THE APPLICANT HIRES A OWL ENGINEER. SOILS ENGINEER. AND/OR GEOLOGIST TO GIVE TECHNICAL ADVICE. OBSERVE AND CONTROL THE WORK IN PROGRESS 115.18.120 A.BJ CARLSBAD MUNICIPAL CODE. B. PRIOR TO FINAL APPROVAL OF A GRADING PERMIT - THE FOLLOWING REPORTS MUST BE SUBMITTED TO THE CITY ENGINEER WA THE PROJECT INSPECTOR 115.18.120 A. 101 CARLSBAD MUNICIPAL CODE (I) FINAL REPORT BY SUPERVISING GRADING ENGINEER STATING ALL GRADING IS COMPLETE. ALL EROSION CONTROL. SLOPE PLANTING AND IRRIGATION ARE INSTALLED IN CONFORMANCE WITH CITY - CODE AND THE APPROVED PLANS ( OBTAIN SAMPLE OF COMPLIANCELETTER FROM CITY ENGINEERING DEPARTMENT). AS-BUILT GRADING PLAN. REPORT FROM THE SOILS EN GI NEER. P14101 INCLUDES RECOMMENDED SOIL BEARING CAPACITIES A STATEMENT AS TO THE EXPANSIVE QUALITY OF THE SOIL. AND SUMMARIES OF FIELD AND LABORATORY TESTS THE REPORT SHALL ALSO INCLUDE A STATEMENT BY THE SOILS ENGINEER THAT THE GRADING WAS DONE IN ACCORDANCE WITH THE REQUIREMENTS AND RECOMMENDATIONS OUTLINED IN THE PRELIMINARY SOILS REPORT AND ANY SUPPLEMENTS THERETO. REPORT WITH AS-BUILT GEOLOGIC PLAN. IF REQUIRED BY THE CITY. 34. UNLESS A GRADING PERMIT FOR THIS PROJECT IS ISSUED WITHIN ONE (I) YEAR AFTER THE CITY ENGINEER'S APPROVAL THESE PLANS MAY BE REQUIRED TO BE RESUBMITTED FOR PLARCHEOC. PLANCHECI( FEES WILL BE REQUIRED FOR ANY SUCH RECHECK. 35. THE SOILS REPORT TITLED PRELIMINARY C(OTECIWRE.IL OWESTBLATRIN PREPARED BY '(WIlL MIDOLETON EI40RTERDIT. 18.. - DATED lOWE 23 .20,00-. SHALL BE CONSIDERED AS A PART OF THIS GRADING PLAN. ALL GRADING SHALL BE DONE IN ACCORDANCE WITH THE RECOMMENDATIONS AND SPECIFICATIONS CONTAINED IN SAID SOILS REPORT. EROSION_CONTROL_NOTES I. IN CASE EMERGENCY (WORK IS REQUIRED, CONTACT BRUCE_ROBERTSON_AT 619,921.9451 (PHONE NUMBER) 2. EQUIPMENT AND WORKERS FOR EMERGENCY WORK SHALL BE MADE AVAILABLE AT ALL TIMES DURING THE RAINY SEASON. ALL NECESSARY MATERIALS SHALL BE STOCKPILED ON SITE AT CONVENIENT LOCATIONS TO FACILITATE RAPID CONSTRUCTION OF TEMPORARY DEVICES WHEN RAIN IS EMINENT. S. DEVICES SHOWN ON PLANS SHALL NOT BE MOVED OR MODIFIED WITHOUT THE APPROVAL OF THE ENGINEERING INSPECTOR. THE CONTRACTOR SHALL RESTORE ALL EROSION CONTROL DEVICES TO (WORKING ORDER TO THE SATIOFACTION OF. THE CITY ENGINEER AFTER EACH RUN-OFF PRODUCING RAINFALL. THE CONTRACTOR SHALL INSTALL ADDITIONAL EROSION CONTROL MEASURES AS MAY BE REQUIRED BY THE CITY ENGINEER DUE TO UNCOMPLETED GRADING OPERATIONS OR UNFORESEEN CIRCUMSTANCES WHICH MAY ARISE, & THE CONTRACTOR SHALL BE RESPONSIBLE AND SHALL TAKE NECESSARY PRECAUTIONS TO PREVENT PUBLIC TRESPASS ONTO AREAS WHERE IMPOUNDED WATERS CREATE A ,HAZARDOUS CONDITION.. 7. ALL EROSION CONTROL MEASURES PROVIDED PER THE APPROVED GRADING PLAN SHALL BE INCORPORATED HEREON. R. GRADED AREAS AROUND THE PROJECT PERIMETER MUST DRAIN AWAY FROM THE FACE OF SLOPE AT THE CONCLUSION OF EACH WORKING DAY. 9. ALL REMOVABLE PROTECTIVE DEVICES SHOWN SHALL BE IN PLACE AT THE END OF EACH WORKING DAY WHEN THE FIVE (5) DAY RAIN PROBABILITY FORECAST EXCEEDS FORTY PERCENT (402). SILT AND OTHER DEBRIS SHALL BE REMOVED AFTER EACH RAINFALL ILl ALL GRAVEL BASS SHALL BE BURLAP TYPE WITH 3/4 INCH MINIMUM AGGREGRA SE. IT. SHOULD GERMINATION OF HYDROSEEDED SLOPES FAIL TO PROVIDE EFFECTIVE COVERAGE OF GRADED SLOPES (90% COVERAGE) PRIOR TO NOVEMBER IS, THE SLOPES SHAh.. BE STABILIZED BY PUNCH STRAW INSTALLED IN ACCORDANCE WITH SECTION 35.023 OF THE EROSION AND SEDIMENT CONTROL HANDBOOK DY THE DEPARTMENT OF CONSERVATION, STATE OF CALIFORNIA. TEMPORARY EROSION CONTROL PLANTING AND _IRRIGATION ALL PERMANENT AND TEMPORARY EROSION CONTROL PLANTING AND IRRIGATION SHALL BE INSTALLED AND MAINTAINED AS REQUIRED IN SECTION 212 OF THE STANDARD SPECIFICATIONS AND THE FOLLOWING A HYDROSEEDING SHALL BE APPLIED ER I. ALL SLOPES THAT ARE GRADED BIT (HORIZONTAL TO VERTICAL) OR STEEPER WHEN THEY ARE: a THREE FEET OR MORE IN HEIGHT AND ADJACENT TO A PUBLIC WALL OR STREET. ALL SLOPES 4 FEET OR MORE IN HEIGHT. 2. AREAS GRADED FLATTER THAN 6:1 WHEN ANY OF THE FOLLOWING CONDITIONS EXIST: 0. NOT SCHEDULED FOR IMPROVEMEHTS(CONSTRUCSON OR GENERAL LANDSCAPING) WITHIN 60 OATS OF ROUGH GRADING 6. IDENTIFIED BY THE PARKS AND RECREATION DIRECTOR AS HIGHLY - VISIBLE TO THE PUBLIC a HAVE ANY SPECIAL CONDITION IDENTIFIED BY THE CITY ENGINEER THAT WARRANTS IMMEDIATE TREATMENT. B. HYDROSEEDED AREAS SHALL BE IRRIGA TO IN ACCORDANCE WITH THE FOLLOWING CRITERIA: I. AU SLOPES THAT ARE GRADED B: T OR STEEPER AND THAT ARE: THREE TO EIGHT FEET IN HEIGHT SHALL BE IRRIGATED BY HAND WATERING FROM OUICI( COUPLERS/HOSE BIBS OR A CONVENTIONAL SYSTEM OF LOW PRECIPITATION SPRINKLER HEADS PROVIDING lODE COVERAGE. 6. GREATER THAN B FEET IN HEIGHT SHALL BE WATERED BY A CONVENTIONAL SYSTEM OF LOW PREOPITA DON SPRINKLER HEADS PROVIDING 7002 COVERAGE. -h WORK TOBEDONE GRADING PLANS THE GRADING WORK SHALL CONSIST OF THE CONSTRUCTION OF ALL CUTS AND FILLS. REMEDIAL GRADING. DRAINAGE FACILITIES EROSION CONTROL FACILITIES AND FOR PLANTING OF PERMANENT LANDSCAPING AND PREPARATION OF AS-BUILT GRADING PLANS TABATA 10 CT 06-13 OF NS AND THE CITY STANDARDS SPECIFICATIONS REQUIREMENTS RESOLUTIONS AS-BUILT GEOLOGIC MAPS AND REPORTS ALL AS SHOWN OR REQUIRED ON THIS SET AND ORDINANCES CITED ON THESE PLANS CITY OF CARLSBAD ': THE GRADING WORK SHALL BE PERFORMED IN ACCORDANCE WITH THE FOLLOWING DOYLIUFNTIL CURRENT AT THE TIME OF CONSTRUCTION, AS DIRECTED BY THE CITY ENGINEER. I. CARLSBAD MUNICIPAL CODE 2. CITY OF CARLSBAD ENGINEERING STANDARDS S. THIS SET OFPLANS RESOLUTION NO._ 6605 DATED_ .OILY 11 =9 - THE STANDARD SPECIFICATIONS FOR PUBLIC (WORKS CONSTRUCTION (GREEN BOOK). 1 6. SOILS REPORT AND RECOMMENDATIONS BY_WRI MIDDLE TON ENGINEERING. INC. NOT TO DATED JUNE 2.1 2006 SCALE - 7. THE SIN DIEGO REGIONAL STANDARD DRAWINGS AND AS MAY BE MODIFIED BY THE CITY OF CARLSBAD STANDARDS R. CALIFORNIA COASTAL COMMISSION DEVELOPMENT PERMIT CONDITIONS CITY OF VISTA DATED JULY IS, 2009 ENVIRONMENTAL APPROVAL DOCUMENTS DATED .PJLY 75, 2009 STORM WATER POLLUTION PREVENTION (SW II-287) PLAN PREPARED BY REC CONSULTANTS, INC DATED MARCH 2011 CITY OF - -. WDIO NO. 9 375 1l SAN I,WARCOS II, STORM WATER MANAGEMENT PLAN (SWAP Il-OW) PREPARED BY_REC CONSULTANTS INC DATED MARCH 2DTI 12, CALIFORNIA STORM WATER QUALITY ASSOCIATION BMP CONSTRUCTION HANDBOOK AND CAL TRANS CONSTRUCTION SITE BMP MANUAL ' LEGEND DESCRIPTION DWG.NO. SYMBOL QUANTITY BOUNDARY - - - - - 96 PROPOSED EVEVATION - PROPOSED CONTOURS - BROW DITCH ISPA' SI' 0-75 940 LF FLOW DIRECTION - - PROPOSED SLOPE EXISK SLOPE .SW.41(FEOWE(NE - . - -------- - STORM GRAIN (24' ICR) - OSUEMW - 187 If STOPM DRAIN (Fa' - (CALF .tFIP( A-A CLEAN OUT 0-9 El F (A - ,M00I/IE0 nr c 06 0-8 El - 2 (A 1A1P RAP 0-40 - . (.4 - 1BIOREFENFTON AREA - 20,000 EF RETAINING WALLS C-.SC-2 4,400 SI" - EXISTING: EXIST.CONTOURS - BENCH MARK - I EXIST. OVERHEAD ELECTRIC LINE -( ---- DESCRIPTION: EXIST. STORM DRAIN LOCATION: SEWER MAiN U - -' SEWER MANHOLE RECORDED: _________________________________________- WATER MAIN 0. ELEVATION: DATUM: GAS LINE C - - TELEPHONE LINE 111111 REQUIRED TREATMENT CONTROL BMP TABLE TYPE DESCRIPTIONOWNRHSHIP DESCRIPTION MAINTENANCE AGREEMENT SHEET ND. I MAINTENANCE I FREQUENCY BIORMN611 LIN SIDE OF ROAD WJJ BIOP.%TBNTIEN (IDA - TED EVERY S MONThS AMR RAIN EVENT PUTRATTON (3(40,43 swi.o OWNER no 9 I_OR 2 I_SAKE ASLANDSCAPE FLETRATION PERMEABLE PAVER HEWER no 2 EVERY YEAR 000141' PROJECT PRIORITY HIGH EARTHWORKQUANTITIES IMPORT: 26.003 CY (SPORT: _________ CT REMEDIAL.'_CT CT GUT: 30080_CF P1W 56.CY PLANNING DEPARTMENT APPROVAL IBGNSH PLANNING DIRECTOR DATE / / - (BOIlED) - RR8OIl I ED: ____________ (P6045 K-1 - AS BUILT" ECE,..................... EXP._________ DATE REVIEWED BY INSPECTOR DATE SHEET CITY OF CARLSBAD ENGINEERING _DEPARTMENT 3- GRADING PLANS PURl TABATA 10 TITLE SHEET - APPROVED: GLEN K. VAN PESKI - - - - - - NONEERINC MANAGER PE 41204 EXPIRES 3/31/l3 DATE A\ 10 TWIll BY: PROJECT NO. DRAWING NO CHKD BY:.,,,_._.... RWID BY: ..,_,II CT o6-13J472-7AI DAIS 01111W. EIIISKELR OF WORK REVISION DESCRIPTION ,DAIE 15111 AL DAIS 0115W. OTHER DIV (PPROVBL f PLATE 1 LV&M JOB #06-21O-J — (14/W) 5'p66 SIDEWALK \ (S/E). 1K SOW C-2 WIN 2' WDE CURB 13 EWRY to LF CURB & GLITTER aIRS . PB C'/ \ CL 2X 5. 13 17 PROP. B'PVC HA TER MAIN SEWER MAIN /7 /3 i 30' 1 30' 60' R/W - LOOP STREET /E(Q eAc/rAB NOT TO SCALE TA-6.0 COLLECTOR STREET ,I FROM STA.15#11.65 TO STA. 19+7787 (SEE CITY OW Na 472-7) 5' PLC SIOTWALK fI (N/w) 5' PCC SIDEWALK SPR50 C-2 \ (S/E) SORB) C-I 2X 1 PROP. 10" PW 10, 60'R/W 1 STREET 'MINIMUM LOOP 4AC/6A8 NOT TO SCALE 7.I.=50 COLLECTOR STREET PROM STA./9#77.87 TO STA. 27+72.27 1 (SEE CITY ON NO. 472-7) 'I P*4O57tn IO/,2/OI,,,-,t:t P0! 'I. (S/ E) (91w) EX GROUND RET WALL / 5' PX SIDEWALK PCC SIDEWALK NORSO G-2 C r-2 t/RB & C/IT/ER Z5-Ox I Ilk WI __ __ 5155 I 'I I (X8PIS(v.fRMAIN 05 / PER 245-1 TO BE NfL OCA AU 5 'I . to' 20' SlAIN 20' 00 PROP. 0.5 10, 30' 50' R/W PER 245-I (LoCS DON CAUINO HILLS DRIVE 'MINIMUM STRUCTURAL ,I EX /2' STEEL WA TER MAIN SECTION. 4 AC/6 SB NOT TO SCALE T.L6.0 COLLECTOR STREET PROM srA.FO56.72 TO STA. /2*14.12 VARIES) CO BE RELOCATED i RFLOCALKO 121 (SEE CITY OW NO. 472-7) 5/EEL MAIN 1 5'PCC SIDEWALK (S/E) (N/W) 5'PCC SIDEWALK SORB/C-I RET /CuRa SORB) 6-2 a. CURS & C/iT/OR 2Z 57 'I 2z 55'I 8' ES BPVC SEWER MAIN ___ 0.5' 0.5.jd_o 0 PROP. BPVC / PER 245-I TO BE RELOCATED /0' I 20' SE/HER MAIN - 20' jO - 3D' 60' R/W PROM STA.12#14.12 TO STA. /5#17.65 CAMINO HILLS DRIVE 'MINIMUM STRUCTURAL SECTION: 4 AC/6 AS ES. 12' STEEL WATER MAIN NOT TO SCALE T1-6.0PER 246-I (LOCATION COLLECTOR STREET VARIES) TO BE RELOCATED RELOCATED (SEE CITYOW Na 472-7) STEEL MAIN R/W CL 30' WIDTH VARIES - 3' 1416/4 FLOW COLLECTION INLET - TO OPERATE AS A 9,5' /5' 2' 17' SHARP CREST HTER FOR TOO-YR FLOW CONTROL RETENTION AREA SHILL BE DEEP ROOTED. DENSE. DROUGHT LEVEL AND DEPRESSED A MINIMUM OF FROM THE TOLERANT PLANTING SUITABLE SURROUNDING GRADE INSTALL CURB CUSS PER DETAIL I FOR WELL DRAINED SOIL COLLECTION POINT CLEANOUT EVERY 10 LINEAR FEET FOR StORETEMN 2% UNDERDRAWS CURB PER SDRSD 10)0 WSE 18" ENGINEERED SOIL IMPERMEABLE LINER SIDES AND BOTTOM .D GUTTER DEPTH \\ 2.5' LIVE LOAD LINE OF INFLUENCE 6, U H COT/C CURB 4' PERFORATED PVC Pil .0: OPENING a V2 PER BROWN AND CALOWE Ul TIE HYDROMINNnCATION CONTROL OUTLET PVC PIPE TO STORM CR4/N 7"'" Ivi HYDROUODIFICATION/UD CALCULATOR IllIllIllIll I II I III I IIIIIlIlIIIIII4,IIH HIGH FLOWS OUTLET PIPE "- ASPHALT SECTION A—A CURB OPENING DETAIL (SEE SHEET 3) N.T.S. STREET "A" / BIORETENTION CROSS SECTION N.T.S. PUBLIC STREET r1J "AS BUILT" HIP /TOE OF BL_ — — — — — — — — - RCE EXP.— DATE I ).SLOPE RENEWED 9',' - - — — — - - . . INSPECTOR DATE SHEET CITY OF CARLSBAD SHEETS SUBDIVISION BOUNDARY - — - 2 ENGINEERING DEPARTMENT 3 2/ACRID ABS FOR: TABATA 10 NOSES AND DETAILS APPROVED: GLEN K. VAN PESKI PLAN — TYPICAL LOT GRADING PER GS-15 - _________________________ ENGINEERING MANAGER PC 41204 EXP. 3/31/13 OATS - - - - OWN BY: PROJECT NO. DRAWING NO.1 - . . REVISION DESCRIPTION g CT 06-13 472-7A [ PLATE L&M JOB 4o6_21O_PJ I REQUIRED TREATMENT CONTROL RI/P TABLE DESCRIPTION QUANTITY GRASS ORATE EDO IF 616.1 PER LOT PERMEABLE PAYER DRIVEWAY UP TO ROW 'T•--•-' BROWNING ROAD REP PER CT 83-25 .4' ----- EXISTING WATER - MASt-PER 246-I - - - - - - - I II I 1 .. I - -i. ::-::;>'- I OPEN -- -: I LOT 15 :- • sw-, Il ,/' BEGW - .• / RETAINING WALL PER SDRSO C-2 I ' 1o1 223 jiH fr - PERMISSION TO GRADE ._ •• LETTER DATED I.-. •- -----•- ------- "S. I.LOT .13 - I NEW 12 WATER WIN I SEGIN PROPOSED 1 I RETAINING WALL.- 1 N - - -pth2Pso c- EXISTING, 11' S + I-M-M PER CARL - - ! I , . I EXISTING STAA&..OIN 1. : SYSTEMPERCT1.. I,i . LOT 80 I: MAIN PER CT 83-2 .; - FGIII • - -;: : DI • EXISTING 8 PVC sóE -' EXISTING 24 I EXISTING IMPROVCMENTS-- I.. 1 PER Cr 83-25 LOT3O_.; OPEN N~ LXII I P\COA857 IcbatO I0Gad1,g\GRD_03 IQfl2/TIU I:4141 PM PDT PROPOSED GROUND R/W —...._L..__ PROPOSED RET W4 — .. - - - - PROPOSED - WTJIALTEN lION/GE TEN NON ui AREA I. CL ELCAM(NOREAL POUMIT .3.- O LGROUND It LOT 10 _ 4l T1iL EMSTING 0-75 DRoVMICX DITCH (A Mcp : cr a., tjl± I LINE "A-" PROFILE ScAL ( i4Ojh', 14 (v) NOTE FOR STQRU DRAIN IN PUp STREET SEE IMPROVEMENTS PtANSIDRCTO6-13 - - LOT 15 GEOTECHNICAL LEGEND ______ -------- Test Trench (4/11/2006) - S --------- - Test Boring (5/25/2006) LOT 15 - - - - Estimated Geologic Contact I I - - - Geologic Cross-Section LOT 54 10 Recommended Removal Depth - Caf -------Compacted Fill Slope 1T - af-Qat-----Old Fill-Alluvium -LOT 13 - Qt --------- - Terrace Deposit (Pleistocene) Li ) Ts- - -------Formational Rock (Eocene) BUILT I - RCE............... EXP. ________ DATE -- ---0 2040 - 80 120 - :INcT. I DATE - • CITYOF CARLSffAD1 SVIEETS S •3 I ll TABATAIO - - - -. APPR?VEO - GLEN N. VAN PESK11 £NDTAGEFANG UAVIATER PG .41204 GYP. 3/31/13 OATS I _I [U8n .__i_ I 2----- PROJECT NO. CT 06-13 IIG 472-7PJ _JJINIT1N. EMENEVDTW*M REVISION DESCRIPTION DATE _MOTTM. _DATE __PATTAI. I ©L©I[C CIOICTEON rSCALE: .1" = 20'] I COMPACTED FILL 130 - PROPOSED I GRADE [LOT 4] 120 ,T ------- ____ I __- 110 FORMATIONAL ROCK I ''I 14~~ 1 I.Y. 1 PROPOSED GRADE [LOT 7] 110 FILL_ALLUJM ... 'S - 110 100 L FORMATIONAL ROCK 1 1 1 100 El PLATE 4 V&M JOB #06-210-P APPENDIX A T 1T fl I PNTcTNTP1P TNT(Z 2450 Auto Park Way Job #06-210-P Escondido, California 92029-1229 Phone (760) 743-1214 June 23, 2006 Fax (760) 739-0343 Tabata Family Trust do Mr. Gregg Harrington P.O. Box 943 Carlsbad, California 92018 PRELIMINARY GEOTECHNICAL INVESTIGATION, PROPOSED 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD (A.P.N.'s 212-050-32 & 33) Pursuant to your request, Vinje and Middleton Engineering, Inc. has completed the enclosed Preliminary Geotechnical Investigation Report for the subject site. The following report summarizes the results of our field investigation, including laboratory analyses and conclusions, and provides recommendations for the proposed development as understood. From a geotechnical engineering standpoint, it is our opinion that the site is suitable for the planned residential subdivision and associated paving and underground improvements provided the recommendations presented in this report are incorporated into the design and construction of the project. The conclusions and recommendations provided in this study are consistent with the indicated site geotechnical conditions and are intended to aid in preparation of final development plans and allow more accurate estimates of development costs.. If you have any questions or need clarification, please do not hesitate to contact this office. Reference to our Job #06-210-P will help to expedite our response to your inquiries. We appreciate this opportunity to be of service to you. VINJE & MIDDLETON ENGINEERING, INC. Dennis Middleton CEG #980 DM/jt (I CEGØ * CERTIFIED * E N G :NEE1.I!r.G Preliminary Geotechnical Investigation Proposed 26-Lot Subdivision Camino Hills Drive Carlsbad, California (A.P.N.'s 212-050-32 & 33) June 23, 2006 Prepared For: TABATA FAMILY TRUST do Mr. Gregg Harrington P.O. Box 943 Carlsbad, California 92018 Prepared By: VINJE & MIDDLETON ENGINEERING, INC. 2450 Vineyard Avenue, Suite 102 Escondido, California 92029 Job #06-210-P TABLE OF CONTENTS PAGE NO. INTRODUCTION . I SITE DESCRIPTION . I HI. PROPOSED DEVELOPMENT ........................................2 IV. SITE INVESTIGATION ..............................................2 V. GEOTECHNICAL CONDITIONS ......................................2 Earth Materials ................................................3 Groundwater and Surface Drainage ...............................4 Slope Stability .................................................4 Faults I Seismicity ..............................................4 Geologic Hazards ...............................................7 Laboratory Testing I Results .....................................7 VI. SITE CORROSION ASSESSMENT ....................................13 VII. CONCLUSIONS ...................................................14 VIII. RECOMMENDATIONS ............................................17 Remedial Grading and Earthworks ................................17 Foundations and Interior Floor Slabs .............................26 Post-tensioned I Structural Slab-on-Ground Foundations ............28 -Exterior Concrete Slabs I Flatworks ..............................30 Soil Design Parameters ........................................31 Asphalt and PCC Pavement Design ..............................32 General Recommendations .....................................34 IX. LIMITATIONS ...................................................36 TABLE NO. FaultZone ..........................................................I Site Specific Seismic Parameters .......................................2 SoilType ...........................................................3 Grain Size Analysis ..................................................4 TABLE OF CONTENTS (continued) Liquid Limit, Plastic Limit and Plasticity Index .............................5 Maximum Dry Density and Optimum Moisture Content .....................6 Moisture-Density Tests (Undisturbed Chunk and Ring Samples) .............7 Expansion Index Test .................................................8 Direct Shear Test .....................................................9 pH and Resistivity Test ..............................................10 SulfateTest ........................................................11 Chloride Test ........................................................12 R-value Test ........................................................13 Years to Perforation of Steel Culverts ..................................14 Removals and Over-excavations .......................................15 Asphalt and PCC Pavement Design ....................................16 PLATE NO. Regional Idea Map ...................................................i SitePlan ...........................................................2 Test Trench Logs I Boring Logs (with key) .............................3-11 Geologic Cross-Sections ...........................................12-14 Fault - Epicenter Map .................................................15 Grain Size Analysis ...............................................16-17 Consolidation Tests ...............................................18-19 Typical Stabilization Fill or Retaining Wall ...............................20 Isolation Joints and Re-entrant Corner Reinforcement ....................21 Retaining Wall Drain Detail ...........................................22 REFERENCES PRELIMINARY GEOTECHNICAL INVESTIGATION PROPOSED 26-LOT SUBDIVISION CAMINO HILLS DRIVE, CARLSBAD (A.P.N. 121-050-32 & 33) INTRODUCTION The property investigated in this work includes an approximate 10-acre parcel located at the east terminus of Camino Hills Drive, adjacent to El Camino Real, within the City of Carlsbad. The site location is shown on a Regional Index Map enclosed with this report as Plate 1. We understand that the property is proposed for a 26-lot residential subdivision with associated interior streets and underground improvements. Consequently, the purpose of this investigation was to determine soil and geotechnical conditions at the site and to evaluate their influence upon the planned development. Geologic mapping, test trench and boring excavations, as well as soil sampling and testing were among the activities conducted in conjunction with this effort which has resulted in the geotechnical grading and foundation recommendations presented herein. SITE DESCRIPTION A Preliminary Review Site Plan depicting existing topographic conditions and the proposed development scheme has been prepared by Pasco Engineering and is reproduced herein as Plate 2. As shown, much of the study property consists of gently sloping terrain that descends in a northeasterly. direction to El Camino Real. An anomalous hill marks the northwest property margin adjacent to Camino Hills Drive. Previous grading activities for off-site developments have modified the property to include large graded slopes that ascend to residential developments along the southerly and easterly site margins. The anomalous hill rises nearly 30 feet above surrounding areas with slope gradients that generally approach 2:1 (horizontal to vertical) maximum. The large graded slopes that mark the southerly and easterly site margins were constructed at 2:1 gradients maximum and range to nearly 50 feet high. Drainage terraces were noted in south and northeast portions of the graded embankments. Pre-development topography from San Diego Topographical Survey Maps No.'s 354-1677 and 354-1683 dated 1975 indicate the perimeter slopes are largely fill embankments with some fill-over-cut slopes. This was confirmed by shallow hand-dug test pits in selected areas of the slopes. Documentation pertaining to slope construction is not available for review. The symetrical hill in the northwesterly portion supports a residential dwelling and associated improvements. Portions of the southwest corner of the property are currently utilized for stockpiling irrigation supplies. Gently sloping areas of the property appear to have been previously used for agricultural purposes, but presently support a modest cover of grass and weeds. Perimeter graded slopes are well landscaped with large trees, shrubs, and assorted groundcover plants. VINE & MII)DLET0N ENcINEiiuNG, INC. • 2450 Auto Park Way-Escondido, California 92029-1229 • Phone (760)743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 2 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 Site drainage sheetlfows in a northeasterly direction towards El Camino Real. Excessive scouring or erosion is not in evidence. PROPOSED DEVELOPMENT The existing dwelling and associated structures and improvements are planned for demolition to allow for the development of a 26-lot residential subdivision with interior roadways and underground improvements. Cut-fill grading techniques will be used to construct level building pads and roadway surfaces. Soils generated from the cutting of the northwest hill will be used as compacted fills placed in lower areas of the site. Vertical cut and fill depths will approach 30 feet and 15 feet maximum respectively. Planned new graded cut and fill slopes will be modest embankments approaching 10 feet high maximum and are programmed for 2:1 gradients. Perimeter slopes will also be extended at the same gradients (2:1) below the existing toe levels to achieve adjacent pad grades that are approximately up to 6 feet lower. pub1sc. Interior roadway improvements include a horseshoe-shaped private street that will provide access to individual lots from Camino Hills Drive at two locations. Construction plans are not available. However, future, residential, constructions .are anticipated to consist of conventional wood-framed with exterior stucco buildings supported on shallow foundations with stem-walls and slab-on-grade floors, or slab-on-ground with turned-down footings. SITE INVESTIGATION Subsurface conditions were chiefly determined by the excavation of 10 test trenches dug with a tractor-mounted backhoe and the excavation of 4 small-diameter test borings drilled with a truck-mounted rotary auger drill. A Geotechnical Boring Permit (#LM0N103949 dated May 3, 2006) was issued by the County of San Diego Health Department for the two deep borings. All trenches and borings were logged by our project geologist who also retained representative soil and rock samples at selected locations and intervals for subsequent laboratory testing. Locations of exploratory excavations are shown on the enclosed Preliminary Site Plan, Plate 2. Logs of the excavations are included with this report as Plates 3-11. Laboratory test results are summarized in following sections of this report. GEOTECHNICAL CONDITIONS Much of the project site is modified by previous grading which has altered the original surface contours. Old topographic maps of the area indicate that lower, level areas of the site were previously characterized by a natural canyon that drained' northward toward El VINJE & M,Dr)LlEToN ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 3 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 Camino Real. Grading of the area in the late 1960's leveled the site for agricultural ' purposes. Graded perimeter slopes in the south andeast margins were constructed at a later date in support of the off-site development above. Consequently, the project site exposes natural formational and Terrace Deposit units that are mantled by surficial alluvial and fill deposits. A. Earth Materials The following earth deposits are recognized at the project site: Formational Rock (Ts) - Eocene age formational rock units are present at shallow to modest depths in south and east portions of the property and found at depth beneath younger soil deposits in northerly areas. As exposed in our test excavations site formational rock consists predominantly of pale grey colored siltstone with local interbeds of sandstone. The rocks were typically found weathered soft in upper exposures and grade uniformly dense at depth. Project formational rocks are competent deposits with no indication of instability, and will adequately support planned fills, structures, and improvements. Terrace Deposit (Qt) - Natural Terrace Deposit soils were encountered in north and west portions of the property. The Terrace Deposits thicken northward and pinch out atop formational rocks to the south. Site Terrace Deposits largely consist of dark-colored clayey sands and were found in moist and loose to soft conditions near the surface grading more dense at depth. Noted exposures are stable units that will adequately support new fills, structures, and improvements. Fill - Alluvium (af-Qal) - Undifferentiated fill and alluvial soils occupy lower elevations of the project site approximately as shown on Plate 2. These soils consists chiefly of silty sands with clay and occur in a loose, and soft to medium dense condition. Compacted Fill (Caf) - Structural fill sections mark the south and east perimeter areas of the project site as shown on Plate 2. The fills are locally derived compacted sections that support off-site improvements above. Noted fill slopes at• the site are provided with a good plant cover and do not evidence instability. Details of project earth materials are given on the enclosed Test Trench Logs and Boring Logs (Plates 3-11) and further defined in a following section herein. The indicated subsurface relationship is depicted on Geologic Cross-Sections enclosed herein as Plates 12-14. VINJE & MIDDLETON ENGINEERING, INC. 2450 Auto Park Way Escondido, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 4 26-LOT SUBDIVISION. CAMINO HILLS DRIVE. CARLSBAD JUNE 23. 2006 B. Groundwater and Surface Drainage Subsurface water was encountered at depths of 33 and 32 feet below ground surfaces in borings B-2 and B-3 respectively. Elsewhere, groundwater conditions were not encountered to the depths explored. The noted groundwater is sufficiently deep and is not expected to impact the proposed grading as currently planned or the future stability of the developed property provided our recommendations are followed. However, the control of surface run-off and storm water is critical to the continuing stability of the property and graded surfaces. Water should not be allowed to pond on pad surfaces and over-watering of site vegetation may create overly moist to wet ground conditions near finish pad grades. Development of the property shOuld include improved site drainage and construction of engineered surface drainage and storm runoff control facilities as indicated on the project drainage improvement plans. Slope Stability Southerly and easterly site perimeters are marked by 2:1 gradient graded slopes constructed to support residential developments above. Documentation pertaining 7 to the slope construction is not available for review. Older topographic maps indicate the slopes range from fill slopes to fill over cut slopes. These slopes are well landscaped and were carefully inspected by our project engineering geologist. The graded embankments are performing well and do not evidence slope instability. Pad constructions will lower the grades adjacent to the southerly and easterly embankments where slopes will continue to descend at 2:1 gradients to an additional maximum height of 6 feet. The new toe embankment should be reconstructed as a graded stabilization fill slope as recommended in the following sections. Alternatively, a retaining wall may be constructed at the base of the slope in order to achieve design grades and assure stability of the existing embankments. New graded slopes planned in connection with the site development are generally minor to modest embankments programmed for 2:1 gradients. New graded slopes will be grossly stable with respect to shallow and deep-seated failures provided slope construction recommendations, specified in the following sections, are followed. Faults I Seismicity Faults or significant shear zones are not indicated on or near proximity to the project site. VINJE & MIDDLETON ENGINEERING, INC. 2450 AtitoPatkWay Escondido, California 92029-1229 Phone (760) 743-1214 PRELIMINARY .GEOTECHNICAL INVESTIGATION PAGE 5 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 As with most areas of California, the San Diego region lies within a seismically active zone; however, coastal areas of the county are characterized by low levels of seismic activity relative to inland areas to the east. During a 40-year period (1934-1974), 37 earthquakes were recorded in San Diego coastal areas by the California Institute of Technology. None of the recorded events exceeded a Richter magnitude of 3.7, nor did any of the earthquakes generate more than modest ground shaking or significant damages. Most of the recorded events occurred along various offshore faults which characteristically generate modest earthquakes. Historically, the most significant earthquake events which affect local areas originate along well known, distant fault zones to the east and the Coronado Bank Fault to the west. Based upon available seismic data, compiled from California Earthquake Catalogs, the most significant historical event in the area of the study site occurred in 1800 at an estimated distance of 10.0 miles from the project area. This event, which is thought to have occurred along an off-shore fault, reached an estimated magnitude of 6.5 with estimated bedrock acceleration values of 0.129g at the project site. The following list represents the most significant faults which commonly impact the region. Estimated ground acceleration data compiled from Digitized California Faults (Computer Program EQFAULT VERSION 3.00 updated) typically associated with the fault is also tabulated: TABLE I Maximum - Probable FaultZàhe! . ' Distance from.Site.. - ..Accelération.(R.1b) Rose Canyon 6.6 miles 0.2 lOg Newport-Inglewood 8.2 miles 0.182g Coronado Bank 22.6 miles 0.175g Elsinore-Julian 22.6 miles 0.150g The location of significant faults and earthquake events relative to the study site are depicted on a Fault - Epicenter Map enclosed with this report as Plate 15. More recently, the number of seismic events which affect the region appears to have heightened somewhat. Nearly 40 earthquakes of magnitude 3.5 or higher have been recorded in coastal regions between January 1984 and August 1986. Most of the earthquakes are thought to have been generated along offshore faults. V IN) I: & MIDI)LEroN ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029-1229 Phonc (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION. PAGE 6 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 For the most part, the recorded events remain moderate shocks which typically oil resulted in low levels of ground shaking to local areas. A notable exception to this pattern was recorded on July 13, 1986. An earthquake of magnitude 5.3 shook I County coastal areas with moderate to locally heavy ground shaking resulting in $700,000 in damages, one death, and injuries to 30 people. The quake occurred - along an offshore fault located nearly 30 miles southwest of Oceanside. A series of notable events shook County areas with a (maximum) magnitude 7.4 shock in the early morning of June 28, 1992. These quakes originated along related segments of the San Andreas Fault approximately 90 miles to the north. Locally high levels of ground shaking over an extended period of time resulted; however, significant damages to local structures were not reported. The, increase in earthquake frequency in the region remains a subject of speculation among geologists; however, based upon empirical information and the recorded seismic history of County areas, the 1986 and'i 992 events are thought to represent the highest levels of ground shaking which can be expected at the study site as a result of seismic activity. In recent years, the Rose Canyon Fault has received added attention from geologists. The fault is a significant structural feature in metropolitan San Diego which includes a series of parallel breaks trending southward from La Jolla Cove through San Diego Bay toward the Mexican border. Test trenching along the fault in Rose Canyon indicated that at that location the fault was last active 6,000 to 9,000 years ago. More recent work suggests that segments of the fault are younger having been last active 1000 - 2000 years ago. Consequently, the fault has been classified as active and included within an Alquist-Priolo Special Studies Zone established by the State of California. Fault zones tabulated in the preceding table are considered most likely to impact the region of the study site during the lifetime of the project. The faults are periodically active and capable of generating moderate to locally high levels of ground shaking at the site. Ground separation as a result of seismic activity is not expected at the property. For design purposes, site specific seismic parameters were determined as part of this investigation in accordance with the California Building Code. The following parameters are consistent with the indicated project seismic environment based on site specific study and our experience with similar earth deposits in the vicinity of the project site, and may be utilized for project design work: VINE & MlDDLIToN ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 7 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 TABLE 2 Sit U Vsdismic-.pSeismic Seismic Response Coefficients Profile Seismic Zone Source Type Zone Factor Type Na Nv Ca Cv Ts To SD 4 0.4 L B 1.0 1.0 0.44 0.64 0.582 0.116 According to Chapter 16, Divisions IV & V of the 2001 California Building Code. A site specific probabilistic estimation of peak ground acceleration was also performed using the FRISKSP (T. Blake, 2000) computer program. Based upon Boore et al (1997) attenuation relationship, a 10 percent probability of exceedance in 50 years was estimated to produce a site specific peak ground acceleration of 0.32g (Design-Basis Earthquake, DBE). The results were obtained from the corresponding probability of exceedance versus acceleration curve. Geologic Hazards Geologic hazards are not presently indicated at the project site. Perimeter graded slopes are performing well with no indication of gross shallow or deep-seated instability. The most significant geologic hazards at the property will be those associated with ground shaking in the event of a major seismic event. Liquefaction or related ground rupture failures are considered remote to none provided our remedial grading and ground stabilization recommendations are followed. Laboratory Testing I Results Earth deposits encountered in our exploratory test excavations were closely examined and sampled for laboratory testing. Based upon our test trench and borings, standard performing penetration tests (SPT), field exposures and site soils have been grouped into the following soil types: TABLE 3 Description . 1 pale brown sandy clay I clayey sand (Fill/Topsoil) 2 red-brown clayey sand (Alluvium) 3 red-brown medium to coarse sand wl trace clay (Fill/Topsoil/Alluvium) 4 grey silty clay / siltstonel claystone (Topsoil/Formational Rock 5 grey / yellow-tan fine sand w/ trace clay (Topsoil/Formational Rock/Terrace) VlNII & MIDDLETON ENGINEERING INC. • 2450 Auto Park Way Escondido, California 92029-1229 Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 8 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 The following tests were conducted in support of this investigation: 1. Standard Penetration Test: Standard penetration tests (SPT) were performed at the time of borehole drilling in accordance with the ASTM standard procedure D-1586. The procedure consisted of a standard 51 MM outside diameter sampler, 457 MM in length and 35 MM in inside diameter, sampler driven by a 140-pound hammer mechanically dropped 30 inches using 5-foot long AW drill rods. The bore hose was 200 MM (8 inches) in diameter and water was added for bore hole support and aiding drilling. The test results are indicated at the corresponding locations on the Boring Logs. 2. Grain Size Analysis: Grain size analyses were performed on representative samples of Soil Types 1, 2, 4, and 5. The test results are presented in Table 4 and graphically presented on the enclosed Plates 16 and 17. TABLE 4 Sieve Size 1_ I #4 I #10 I #20 1 #40 #200 Location Soil Type Percent Passing T-1 @ 1' 1 100 99 97 94 89 64 T-1 @4' 2 100 100 97 88 76 41 T-3 @ 3' 4 100 100 100 991, 98 70 T-2@5' 5 100 100 99 97 86 .32 3. Liquid Limit, Plastic Limit and Plasticity Index: Liquid limit, plastic limit and plasticity index tests were performed on representative samples of Soil Types 1, 2, 4, and 5 in accordance with ASTM D-4318. The test results are presented in Table 5. TABLE 5 Location Soil Type Liquid Limit . (LL-%) Plastic Limit Plasticity Index (P1LL T-1@1' 1 45 24 21 T-1@4' 2 32 16 16 T-3@3' 4 49 27 22 T-2@5' 5 36 25 11 VINJE & MII))LtToN ENGINEERING, INC. • 2450 Auto Park Way Escondido California 92029-1229 1 Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 9 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 4. Maximum Dry Density and Optimum Moisture Content: The maximum dry density and optimum moisture contents of Soil Types 2, 4 and 5 were determined in accordance with ASTM D-1 557. The test results are presented in Table 6. TABLE 6 Soil Maximum Dry Optimum Moisture Location . Type - Density (Ym-cfl Content (Wopt-%) T-1 @ 4' 2 129.6 10.4 T-3@3' 4 110.5 19.8 T-2@5' 5 119.5 - 12.5 5. Moisture-Density Tests (Undisturbed Chunk and Ring Samples): In-place dry density and moisture contents of representative soil deposits beneath the site were determined from relatively undisturbed chunk samples using the water displacement test method, and undisturbed ring samples using the weights and measurements test method. The test results are presented in Table 7 and tabulated on the enclosed Test Trench Logs and Boring Logs. TABLE 7 Sample . Location Soil . Type : Field Moisture Content .. (w-%) . Field Dry Density (Yd-pcf) Max. Dry. Density . (Ym.pcf) Ratio Of In-Place Dry Density To Max. Dry Pensity* (YdIYm x 100) T-1 @2' 1 18.5 100.8 - - T-1 @4' 2 12.9 104.1 129.6 80.4 1-1 @ 7' 2 15.4 103.4 129.6 79.8 T-1 @9' 2 8.2 112.3 129.6 86.7 T-1@11' 2 7.8 119.3 129.6 92.1 T-1 @ 13' 3 9.7 102.8 - - T-1 @ 15' 3 14.1 103.5 - - T-2 @3' 5 16.6 101.0 119.5 84.5 T-2 @5' 5 23.6 89.8 119.5 75.1 T-2 @8' 5 18.8 107.8 119.5 90.2 VINJE & MIDDLETON ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029-1.229 Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 10 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 TABLE 7 (continued) T-2 @10' 5 17.4 114.3 119.5 95.6 1-3 @ 3' 4 28.6 88.0 110.5 79.6 T-3@5' 4 27.8 88.8 110.5 80.4 1-3 @ 7' 5 18.4 100.6 119.5 84.2 T-4@5' 4 22.0 106.0 110.5 95.9 T-4@8' 4 22.4 108.0 110.5 97.7 T-4@10' 4 21.2 106.9 110.5 96.7 T-5@5' 2 11.9 109.0 129.6 84.1 T-5@8' 2 13.1 110.8 129.6 85.5 T-5 @ 10' 2 13.9 106.8 129.6 82.4 T-5 @ 14' 2 13.5 108.5 129.6 83.7 T-5@16' 5 16.0 102.5 119.5 85.8 T-6@7' 5 13.3 105.5 119.5 88.3 T-7@4' 1 26.1 88.9 - - T-7@7' 5 18.9 99.3 119.5 83.1 T-7 @10' 5 25.2 92.8 119.5 77.6 T-7@12' 1 22.5 98.3 - - T-7 @ 14'. 1 25.7 95.7 - - T-8@5' 2 11.9 101.6 129.6 78.4 T-8@8' 2 12.7 113.9 129.6 87.9 T-8@11' 2 12.2 104.1 129.6 80.3 T-8@ 12W 5 23.7 94.9 119.5 79.4 T-9@5' 5 18.3 96.1 119.5 80.4 T-9@7' 5 12.2 110.6 119.5 92.6 T-9@ 10' 5 13.1 110.9 119.5 92.8 T-9@ 12 5 16.9 99.1 119.5 83.0 T-9@ 14' 5 17.9 99.3 119.5 83.1 T-9@ 15' 4 24.3 97.3 110.5 88.1 I VI NJ I: & M DLETON ENcINEEiING, INC. • 2450 Auto Park Way Escondido California 92029-1229 Phonc (760) 743-121.4 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 11 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 TABLE 7 (continued) B-1 @4' 2 17.4 113.8 129.6 87.8 B-2 @14' 2 18.3 110.1 129.6 84.9 B-2@24' 5 16.9 114.6 119.5 95.8 B-3@4' 2 9.0 113.2 129.6 87.3 B-3 @ 14' 2 9.7 113.8 129.6 87.8 B-3@24' 5 16.2 109.5 119.5 91.6 B-3@34' 5 20.3 110.7 119.5 92.6 @9' 5 11.7 106.2 119.5 88.8 @19' EB 5 5.8 109.5 119.5 91.6 * Designated as relative compaction for structural fills. Minimum required relative compaction for structural fill is 90% unless otherwise specified. 6. Expansion Index Test: Three expansion index tests were performed on representative samples of Soil Types 1, 4, and 5 in accordance with the California Building Code Standard 18-2. The test results are presented in Table 8. TABLE 8 Sample Location Soil I Type Remolded to (%) Saturation (%) Saturated to (%) Expansion Index (El) Expansion Potential T-1 @1' 1 14.8 51.2 31.8 112 high T-3 @ 3' 4 16.3 50.0 40.1 103 high T-2 @ 5' 5 11.5 49.7 24.4 46 low T-6@6' 5 9.6 51.0 21.2 59 medium (w) = moisture content in percent. 7. Direct Shear Test: Three direct shear tests were performed on representative samples of Soil Types 2, 4, and 5. The prepared specimens were soaked overnight, loaded with normal loads of 1, 2, and 4 kips per square foot respectively, and sheared to failure in an undrained condition. The test results are presented in Table 9. VINIE & MIDDIInON ENGlNlIIuNc, INC. • 2450 Auto Park Way . Escondido, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 12 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 TABLE 9 Sample Location Soil Type Sample Condition Wet Density (Yw-pcf) mt. Fric. (0-Deg.) Angle of-,-Apparent Cohesion (c-psf) T-1 @4' 2 remolded to 90% of Ym @ % wopt 127.8 32 75 T-3 @ 3' 4 remolded to 90% of Ym @ % wopt 117.9 23 280 T-2 @5' 5 remolded to 90% of Ym @ % wopt 120.9 28 166 pH and Resistivity Test: pH and resistivity of representative samples of Soil Types 1 and 4 were determined using " Method for Estimating the Service Life of Steel Culverts," in accordance with the California Test Method (CTM) 643. The test results are presented in Table 10. TABLE 10 Sample Location [_Soil Type I._Minimum Resistivity (OHM-CM) I_pH T-1@1' 1 504 6.2 T-3 @ 3' 4 381 6.5 Sulfate Test: Sulfate tests were performed on representative samples of Soil Types 1 and 4 in accordance with the California Test Method (CTM) 417. The test results are presented in Table 11. TABLE 11 Chloride Test: Chloride tests were performed on representative samples of I Soil Types 1 and 4 in accordance with the California Test Method (CTM) 422. The test results are presented in Table 12. SI SI 'a VINJE & MIDDLETON ENG!NEERING, INC. • 2450 Auto Park Way Escondido, California 92029-1229 Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 13 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 TABLE 12 Amount of Water SolübleChloridé (CI) Sample Location Soil Type In Soil (% by Weiciht) T-1 @ 1' T-3@3' 1 4 [IZsIII1 11. Consolidation Tests: Consolidation tests were performed on a representative 'I remolded sample of on-site Soil Type 2. The test result is graphically presented on the enclosed Plate 19-20. ' 12. R-value Test: One R-value test was performed on a representative sample of Soil Type 1 in accordance with the California Test 301. The test result is - presented in Table 13. TABLE 13 I:LOca*iOn 77 1 De-77777777-77- scription 1k I T-1 @ 1' I 1 I brown sandy clay/clayey sand I 5 VI. SITE CORROSION ASSESSMENT A site is considered to be corrosive to foundation elements, walls and drainage structures if one or more of the following conditions exists: * Sulfate concentration is greater than or equal to 2000 ppm (0.2% by weight). * Chloride concentration is greater than or equal to 500 ppm (0.05 % by weight). * pH is less than 5.5. For structural elements, the minimum resistivity of soil (or water) indicate the relative quantity of soluble salts present in the soil (or water). In general, a minimum resistivity value for soil (or water) less than 1000 ohm-cm indicates the presence of high quantities of soluble salts and a higher propensity for corrosion. Appropriate corrosion mitigation measures for corrosive conditions should be selected depending on the service environment, amount of aggressive ion salts (chloride or sulfate), pH levels and the desired service life of the structure. Laboratory test results performed on selected representative site samples indicated that the minimum resistivity is less than 1000 ohm-cm suggesting a potential for presence of high quantities of soluble salts. However, test results further indicated pH is greater than VINJE & MIDDLETON ENGINEERING, INC. • 2450 Auto Park \Miy Escondido, California 92029-1229 Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 14 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 5.5, sulfate concentration is less than 2000 ppm, and chloride concentration is less than 500 ppm. Based on the results of the corrosion analyses, the project site may be considered non-corrosive. Conformation testing should be completed during the actual earthworks and grading operations to further verify site corrosion conditions. The project site is not located within 1000 feet of salt or brackish water. Based upon the result of the tested soil sample, the amount of water soluble sulfate (SO4) was found to be 0.052 to 0.060 percent by weight which is considered negligible according to the California Building Code Table No. 19-A-4. Portland cement Type II may be used. Table 14 is appropriate based on the pH-Resistivity test result: TABLE 14 I Design17.9"SoilType Gage f 18 116 [14 I 12 101 '8 1 Years to Perforation of Steel Culverts 5 La: 8 11 14 17 4 Years to Perforation of Steel Culverts 6 9 13 16 20 VII. CONCLUSIONS Based upon the foregoing investigation, development of the study site into an 26-lot residential subdivision with the associated internal roadway and underground improvements is feasible from a geotechnical viewpoint. Adverse geologic conditions which could preclude site development were not indicated at the property. The following factors are unique to the property and will most impact project development procedures from a geotechnical viewpoint: * Slope instability or geologic hazards are not present at or near the project site and will not be a factor in site devolvement. * The property is chiefly a graded site developed to its existing lines and grades for agricultural purposes in the late 1960's. Grading documents including engineering observations and compaction testing records of prior earthworks operations at the site, are not available. Much of the property is occupied by a modest to thick section of undifferentiated fill/alluvial soil (see mapped areas "af-Qal" on Plate 2). These soils occur in a loose to soft condition particularly in near-surface exposures. Post construction compression and settlement of the these deposits are considered to be the primary geotechnical concern at the study site. Consequently, ground stabilization and VINJE & MIDDLETON ENGINEERING, INC. • 2450 Auto Rwk Way Escondido, California 92029-1229 Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 15 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 remedial grading earthworks mitigation of the underlying loose to soft soils will be required as a part of project development in order to create safe and stable building surfaces as detailed in the following sections. Post construction settlement of site fills/alluvium after development is not expected to exceed approximately 1% inches, and should occur below the heaviest loaded footings. The magnitude of post construction differential settlements of site fills/alluvium (as expressed in terms of angular distortion) is not anticipated to exceed 1A-inch between similar elements, in a 20-foot span. Remaining areas of the site are mostly underlain by formational rocks or Terrace Deposit units (see mapped areas "Ts" and "Qt" on Plate 2). These are suitably dense units and will provide adequate support for the planned new fills, structures and improvements. Perimeter embankments at the project property are predominantly compacted fill slopes (designated as "Caf" in Plate 2) constructed as a part of upper development. The existing perimeter embankment slopes are provided with a well-established cover of vegetation, and have performed well since their construction with no evidence' of gross instability. Some additional undercutting is proposed to a maximum height of 6 feet in the south corner of the project (see Plate 20). The lower exposed slopes should be constructed as stabilization fills as recommended in a following section herein. Alternatively, a retaining wall may be constructed in the impacted areas in order to achieve final design grades and enhance the overall gross stability of site embankments. Soils generated from project fills/alluvium excavations will predominantly consist of marginal quality plastic clay soils which can be detrimental to site structures and improvements if they occur within upper finish pad grades. Excavations of site Terrace Deposits underlaying the northwestern hill are expected to generate better quality low expansive sandy soils. Site marginal quality plastic clayey soils should be buried within deeper fills, and better quality sandy soils available from the excavation of project Terrace Deposits may be placed at finish pad grades using select grading techniques. Alternatively, good quality sandy granular import soils may also be considered to cap the building pad areas. Plastic clayey soils typically require added processing, moisture conditioning and mixing efforts in order to manufacture a uniform mixture suitable for reuse as new site compacted fills. Potentially expansive clayey soils typically result in thicker pavement sections and will require special geotechnical engineering mitigation and foundations/slab designs which may include presaturation of subgrade soils, deeper foundations and thicker slab-on-grade floors, or post-tensioned / structural VINpI & MrI)LlToN ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 16 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 slab-on-ground foundations if they occur within upper pad grades. Capping the site With better quality on-site sandy soils or good quality sandy granular import soils will allow the use of more conventional foundations/slab designs and improve pavement structural sections. Moisture sensitive expansive soils and related periodic soil heaving-shrinkage is also considered a major geotechnical concern at the study site. Based on the available laboratory test results and noted site conditions, final bearing and subgrade soils may be anticipated to consist of silty sandy clay to clayey silty sand (SC/CL) with low to high expansion potential (expansion index less than 131) according to the California Building Code classification (Table 18A-1-B). Actual classification and expansion characteristic of the finished grade soil mix can only be provided in the final as-graded compaction report based on proper testing of foundation bearing and subgrade soils when rough finish grades are achieved. Foundation bearing and subgrade soils at finish pad grades should be additionally tested at the completion of rough grading to evaluate actual expansion characteristic of final soil mixture and confirm foundations and slab designs. * Uniform bearing conditions should be constructed under the proposed buildings, structures and improvements. For this purpose, added removals of cut ground will be necessary in the case of cut-fill pads which expose formational rock or natural soils, so that uniform soil conditions are constructed throughout the buildings and improvement surfaces. Groundwater was encountered at the depth of 33 feet below the planned Lot 24 and 32 feet within the alluvial soils (B-3) feet along the easternmost portions of the site below the planned street improvements measured from the existing ground surfaces. Elsewhere at the site, groundwater was not encountered in our exploratory excavations to the depths explored. Natural groundwater conditions at the site occur at depth and is not expected to impact project grading or long term stability of the developed property. However, the proper control of surface drainage and storm water is an important factor in the continued stability of the property. Ponding should not be allowed on graded surfaces, and over-watering of site vegetation should be avoided. Subsurface drains should be provided in stability fills and behind retaining walls(if any planned) as recommended below. Site grading and earthwork constructions will not impact the adjacent properties provided our recommendations are incorporated into the final designs and implemented during the construction phase. Appropriate setbacks shall be maintained, and temporary excavation slope constructions completed as recommended below. Added field recommendations, however, may also be VINJIE & MIDDLETON ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029-1229 Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 17 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 necessary and should .be given by the project geotechnical consultant for the protection of adjacent properties and should be anticipated. * Local groundwater conditions were found to be deep, and a thick section of overburden soils surcharges the impacted areas. Elsewhere over the majority of the property, groundwater was not recorded to the depths explored and formational units occur at the surface or at shallow to modest depths. Additionally, ground stabilization techniques using earth reinforcement Geogrid, and removal and recompaction of foundation, bearing and subgrade soils are recommended in connection with the site development as specified below. Consequently, liquefaction of the locally saturated alluvial soils below the water table (primarily. areas of boring-B-73, see Plate 2) is not considered a major geotechnical concern at the project property. Liquefaction and secondary affects such as seismically induced settlements, lateral spreading and flow slides are considered unlikely to remote provided our ground stabilization and remedial grading recommendations specified in the following sections are followed. * Loose to soft surface fill/alluvial deposits are potentially collapsible and compressible, and should be regraded as recommended below. VIII. RECOMMENDATIONS The following recommendations are consistent with the indicated geotechnical conditions at the project site and should be reflected in final plans and implemented during the construction phase. Added or modified recommendations may also be appropriate and can be provided at the final plan review phase: A. Remedial Grading and Earthworks The most effective method to mitigate upper loose to soft soils and accelerate compression of the underlying untreated deposits during the construction phase periods is remedial grading removal and recompaction techniques, and compacted fill surcharging as recommended below. All grading and earthworks should be completed in accordance with the Appendix Chapter 33 of the California Building Code, City of Carlsbad Grading Ordinances, the Standard Specifications for Public Works Construction and the requirements of the following sections: VINJE & MiDDLIToN ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029-1229 • Phonc (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 18 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 Clearing and Grubbing - Surface vegetation, trash, deleterious materials, and construction debris generated from the demolition of existing structures / improvements and other unsuitable materials should be removed from the areas proposed for grading, new fills, structures and improvements plus 10 feet outside the perimeter, or as directed in the field, and properly disposed of. Construction debris and site vegetation shall be allowed to contaminate the new site fills. not. All irrigation lines and existing leach lines, septic tanks, pipes and structures should be properly removed from the construction areas. Existing underground utilities in the construction areas should also be pot-holed, identified and marked prior to the actual work. Abandoned irrigation lines should be properly capped and sealed off to prevent any future water infiltrations into the foundation bearing and subgrade soils. Voids created by the removals of the abandoned underground pipes, tanks and structures should be properly backfilled with compacted fills in accordance with the requirements of this report. r' The prepared ground should be inspected and approved by the project geotechnical engineer or his designated field representative prior to remedial grading work. Removals and Over-excavations - Uniform and stable bearing soils conditions should be constructed under the planned new buildings and site improvements and limit potential fill soil settlements within tolerable limits as specified. For this purpose, removal and recompaction of the upper fills/alluvium to firm native ground or competent formation units where these deposits occur at shallower depths and removal and recompaction with ground stabilization techniques using earth reinforcement Geogrid placed at the bottom of over-excavations, should be considered. Approximate removal depths in the vicinity of individual exploratory excavations are summarized in Table 15 and depicted on the enclosed Plate 2 based upon site soil conditions and proposed grades. The tabulated values are typical and• subject to field changes by the project geotechnical consultant based on actual field exposures. Locally deeper removals may be necessary and should be anticipated. VINJE & MrDDLInoN ENGINEERING, INC. • 2450 Auto Pk Way Escondido, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 19 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 TABLE 15 Estimated - Estimated Total Depth to Removal • Depth Ground- Depths . - Comments. T-1 161/2' not encountered 9' Lot 13 - private street improvement areas. T-2 10%' not encountered 7' Lot 8 areas. Depth of undercut may govern. 1-3 9' not 8' Lot 5 areas. Depth of undercut may govern. encountered Reconstruct toe slope as a stability fill. T-4 101/2 not' encountered 6' Lot 2 areas. Depth of undercut may govern. T-5 16W not encountered 9' Lot 25 areas. Depth of undercut may govern. not Lot 22 areas. Depth of undercut may govern. Stockpile T-6 8' encountered 3' better quality sandy soils from Terrace Deposit excavations for capping the pads. Fill slope/private street improvement areas. Toe not keyway should be a minimum of 3 feet below adjacent 1-7 14%' encountered 7' ground level. Place Tensar Geogrid earth reinforcement at bottom of slope keyway excavations as specified herein UOA. not Lots 16,17 areas. Place Tensar Geogrid earth T-8 15' encountered 10' reinforcement at soft and yielding bottom of removals in the impacted areas as specified herein UOA. T-9 15% ' not encountered 7' Private street improvement areas. not Private street improvement areas. Depth of undercut T-10 15' encountered 4%' may govern. Stockpile better quality sandy soils from Terrace Deposit excavations for capping the pads. B-i 191/2' not encountered 5' Lot ii areas. Depth of undercut may govern. Lot 24 areas. Place Tensar Geogrid earth B-2 401/2' 33' 10' reinforcement at soft and yielding bottom of removals in the impacted areas as specified herein UOA. Private street improvement areas. Place Tensar B-3 39' 32' 7' Geogrid earth reinforcement at bottom of removals in the impacted areas as specified herein UOA. B-4 20' not encountered 8' Lot 26 areas. Private street improvements. VINJE & MIDDLETON ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION . . PAGE 20 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 Notes:. 'I . 1. UOA = Unless Otherwise Approved. 2. All depths are measured from the existing ground levels. 3. Actual depths may vary at the time of construction based on subsurface exposures. I 4. Bottom of all removals should be additionally prepared and recompacted to a minimum depth of 6 inches as directed in the field. 5. Firm native ground is defined as undisturbed natural exposures with in-place densities of 85% or greater as approved in the field. 6. In the case of deeper storm drain or utility trenches where the proposed inverts are below the recommended depths, removals shoUld be further extended a minimum of 12 inches below the bottom of pipe (or pipe bedding) unless otherwise approved. RI 7. Exploratory trenches excavated in connection with our study at the indicated locations were backfilled with loose and uncompacted deposits. The loose/uncompacted backfill soils within these trenches shall also be re-excavated and placed back as properly compacted fills as a part of the .I project grading operations. 8. All grounds steeper than 5:1 receiving fills/backfills should be properly benched and keyed as directed in the field. I 3. Ground Stabilization - Fills can only be placed over firm stable native and non-yielding ground (in-place densities of 85% or greater). Ground stabilization techniques using earth reinforcement Geogrid should be used in the areas of RI the site where yielding soft bottom of removals are exposed at the specified over-excavation depths. Removal and recompaction grading with ground stabilization techniques will also limit potential fill soil settlements within 1 tolerable limits as specified. For this purpose, a layer of Tensar Geogrid BX-1 100 (or greater from the same series) earth reinforcement should be placed at the impacted bottom of over- excavations prepared as directed in the. field. Initial fill lifts should then be carefully placed over the Geogrid and compacted. Subsequent fill lifts can continue until design grades are achieved. Additional layers of Geogrid may also be necessary within the compacted fill mass as directed in the field, and should be anticipated. - 4. Excavations Characteristics - Proposed cut excavations will approach 25 feet I deep in the existing hill knob areas of the property underlain by Terrace Deposit units. The cuts and recommended undercuts are expected to be achieved with moderate efforts using larger bulldozers (Caterpillar D-8 or equal). Some hard RI units, and cemented beds may also be locally encountered requiring added ripping and more concentrated efforts. However, difficult excavations or the need for special techniques is currently not anticipated. 1 5. Cut-Fill Transitions and Undercuts - Ground transition from excavated cut to compacted fills should not be permitted underneath the proposed structures RI and irñprovements. Transition pads will require special treatment. The cut portion of cut-fill pads plus 10 feet outside the perimeter, where possible and VINJF & 1v1lDDuToN ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 21 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 as directed in the field, should be undercut to a sufficient depth to provide for a minimum of 3 feet of compacted fill mat below rough finish grades, or at least 12 inches of compacted fill beneath the deepest footing(s) whichever is more. In the roadways, driveway, parking and on-grade slabs/improvement transition areas there should be a minimum of 12 inches of compacted soils below rough finish subgrade. Cut pad exposing loose to soft soils at final grades should also be undercut to a minimum depth of 3 feet (or 12 inches below the bottom of deepest footing whichever is more unless otherwise specified) and reconstructed to design grades with compacted fills as specified herein. 6. Temporary Construction Slopes - Excavations and removals adjacent to existing improvements and graded embankments should be performed under inspection of the project geotechnical engineer. Undermining existing improvements, underground utilities to remain, and perimeter graded slopes should not be allowed by the removal operations. Temporary construction slopes should maintain adequate setbacks (minimum of 2 feet) from the toe of existing ascending slopes and adjacent improvements, as directed and approved in the field. Construction slopes, temporary excavations and trenching less than 3 feet high maximum may be constructed at near vertical gradients. Temporary excavations and trenching greater than 3 feet and less than 12 feet high maximum should be laid back at 1:1 gradient unless Otherwise specified or approved. Temporary slopes greater than 12 feet and less than 20 feet high maximum may be constructed at 1:1 within the lower 7 feet and laid back at 1%:1 gradient within the upper portions. The remaining wedge of soil should then be properly benched out and new fills/backfills tightly keyed-in as the backfilling progresses. Temporary trench and construction slopes greater than 3 feet maximum constructed at near vertical gradients will require shoring/trench shield support unless otherwise approved. All temporary construction slopes require continuous geotechnical inspections during the grading operations. Additional recommendations including revised slope gradients, setbacks and the need for temporary shoring/trench shield support should be given at that time as necessary. The project contractor shall also obtain appropriate permits, as needed, and conform to Cal-OSHA and local governing agencies' requirements for trenching/open excavations and safety of the workmen during construction. Permissions to perform off site grading should also be obtained if necessary and as appropriate. VINJE & MIDDLETON ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 22 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 Soil Properties and Select Grading - Soils generated from the excavations of site existing fills, alluvium and formational rock units (map symbols af-Qal and Ts) will consist of marginal quality plastic silty to clayey deposits with high expansion potential which can be detrimental to structures and improvements, if they occur at or near finish grades. Plastic silty to clayey soils also required added processing, mixing and moisture conditioning efforts in order to manufacture a uniform mixture suitable for reuse as site new compacted fills. However, better quality sandy earth deposits which generally work well as compact fills are expected from the excavations of site Terrace Deposits (map symbol Qt). Adverse effects of site highly expansive plastic silty to clayey soils should be mitigated by selective burial of these deposits, placed a minimum of 4 feet below rough pad grades (or 12 inches below the deepest footing, whichever is more) and a minimum of 10 feet away from the face of slopes within the fill mass. Better quality sandy soils available from the site Terrace Deposit excavations should to stockpiled and selectively used within the upper pad grades and outer fill embankment slope surfaces. Improvement areas should be provided with a minimum 18 inches of better quality sandy soils. On-site plastic clayey soils should also not be used for wall or trench backfills. Shrinkage and Import Soils - Based upon our analyses and experience with similar earth deposits, site soils may be expected to shrink approximately 10% to 20% on a volume basis when compacted to at least the minimum compaction levels specified herein. Import soils, if required to complete grading and achieve final pad grades, should be good quality sandy non-corrosive granular deposits (SM/SW) with very low expansion potential (100% passing 3,4-inch sieve, more than 50% passing #4 sieve and less than 20% passing #200 sieve with expansion index less than 21). Import soils should be inspected, tested as necessary, and approved by the project geotéchnical engineer prior to delivery to the site. Sandy granular soils should also be considered for wall and trench backfills. Fill Materials and Compaction - Soils generated from the site removals and over-excavations are considered suitable for reuse as site new fills provided they are processed, prepared and placed in accordance with the requirements of this report. Project fill soils should be clean deposits free of roots, stumps, vegetation, deleterious matter, trash, demolition debris, and unsuitable materials as approved in the field by the project geotechnical consultant. Uniform bearing soil conditions shOuld be constructed at the site by the remedial grading and earthwork operations. Site soils should be adequately processed, thoroughly mixed, moisture conditioned to slightly above I VINJE & MIDDLETON ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029J229 Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION . PAGE 23 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 (approximately 2% for sandy 'soils and 3% to 5% for clayey soils) the optimum moisture levels as directed in the field, placed in thin (8 inches maximum) uniform horizontal lifts and mechanically compacted to a minimum 90% of the corresponding laboratory maximum dry density below 3 feet from the rough finish grades, and minimum 95% of the corresponding laboratory maximum dry density within the upper 3 feet of final grades per ASTM D-1557, unless .p otherwise specified. 10. Permanent Graded Slopes - Project graded slopes are programmed for 2:1 or flatter gradients maximum. Engineered graded slopes constructed at 2:1 or flatter gradients will 'be grossly stable with respect to deep seated and surficial failures for the anticipated design maximum vertical heights provided our recommendations are followed. Engineered slopes should be constructed as follows. I Fill Slope Construction - Road embankment fills are planned at the site in connection with the private street improvements along the eastern margins. The planned fill slopes should be provided with a lower keyway. The keyway I ' should maintain a minimum depth of 3 feet below the adjacent ground surface at the toe into with a minimum width of 12 feet as approved by the project geotechnical engineer or his designated representative. Deeper keyway depths 1 may also be required based on actual exposures and should be anticipated. Loose to soft soils may be anticipated at the bottom of keyway excavations I requiring mitigation and stabilization. Stable bottom of keyway excavations can be achieved by placing a layer of Tensar Geogrid BX-1 100 (or greater from the same series) earth reinforcement at the impacted bottom prepared as directed I in the field. Initial-fill lifts should then be carefully placed over the Geogrid and compacted followed with subsequent lifts. I All keyways should be heeled back a minimum of 2% into the hillside and inspected and approved by the project geotechnical engineer. Additional level benches should be constructed into the natural hillside as the fill slope I . construction progresses. Fill slopes should also be compacted to a minimum 90% (or 95%) of the laboratory standard out to the slope face unless otherwise specified. Over-building and cutting back to the compacted core, or backrolling .I at a minimum of 4 feet vertical increments and "track-walking" at the completion of grading is recommended for site fill slope construction. ' Geotechnical engineering inspections and testing will be necessary to confirm adequate I compaction levels within the fill slope face. MI ' I Vit'jE & M113DI-ETON ENGINEERING, INC. • 2450 Auto ParkWay Escondido, Cdiforna 92029-1229 Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 24 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 PS Cut Slope Construction - Proposed graded cut slopes are expected to expose stable, competent Terrace Deposits which will be grossly stable at the planned. 2:1 gradients. Small cut slopes are also proposed in the form of lowering the existing toe of fill embankments in the south and east perimeter areas to adjacent pad levels are planned at the site. The slopes planned at the rear of Lots 3-6 should be reconstructed as stabilization fills with a minimum bottom equipment-width of 15 feet extended at least 2 feet into the underlying competent formational rock as approved in the field. Temporary construction slopes for the stabilization fill should be no steeper than %:1. The stability fill should then be reconstructed to design .grades soon after by placing fill soils tightly keyed into the construction slopes as the fill placement progress. Recommended Typical 'Stabilization Fill slope is schematically depicted on the enclosed Plate 16. Alternatively, a retaining wall may be constructed at the base of the perimeter slopes as shown. All cut slopes should be inspected and approved by the project geotechnical consultant during the grading to further confirm stability. More specific or revised recommendations will be provided at that time as necessary and should be anticipated. 11. Surface Drainage and Flood I Erosion Control - A critical element to the continued stability of the graded building pads is adequate surface drainage and flood control. This can most effectively be achieved by installation of appropriate flood and drainage control structures. Building pad surface run-off should be collected in approved drainage facilities, and 'directed to selected locations in a controlled manner. Area drains should be installed. Surface and flood waters should not be allowed to impact site embankments, fills, structures and improvements, or penetrate into the underlying bearing soils. Storm water and surface run-off shall be diverted from entering the site. The finished slope should be planted soon after completion of grading. Unprotected slope faces will be subject to severe erosion 'and should not be. allowed. Over-watering of the slope faces should also not be allowed. Only the amount of water to sustain vegetation should be provided. Temporary erosion control facilities and silt fences should be installed during the construction phase periods and until landscaping is established as indicated and specified on the approved project erosion plans. VINJE & .MIDDLET0N ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029-1229 Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 25 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 12. Engineering Inspections - All grading operations including removals, suitability of earth deposits used as compacted fill, and compaction procedures should be continuously inspected and tested by the project geotechnical consultant and presented in the final as-graded compaàtion report. The nature of finished subgrade soils should. also be confirmed in the final compaction report at the completion, of grading. . Geotechnical engineering inspections shall include, but not limited to the following: . . * Bottom of over-excavation/keyway inspection - After the bottom of over- excavation or keyway is exposed and prepared to receive fill but before fill placement is started * Ground stabilization Geogrid placement - During the actual placement. Geogrid shall conform to the specified specifications. * Excavation inspection - After the excavation is started but before the vertical depth of excavation is more than 3 feet. This, includes all temporary excavation slopes and trenching. Safety requirements enforced by the governing agencies for open excavations apply. Fill/backfill inspection - After the fill/backfill placement is started but before' the vertical height of fill/backfill exceeds 2 feet. There should be a minimum of 1-foot in every 100 lineal, feet for each 2 feet of vertical gain. Final rough and finish pad grade tests shall be required regardless of the fill/backfill thickness. * Foundation trench inspection - After the foundation trench excavations but before steel placement. * Foundation bearing/slab subgrade soils inspection - Prior to the placement of concrete for proper moisture and specified compaction levels. * Foundation/slab steel inspection - After steel placement is completed but before the scheduled concrete pour. * Subdrain/back drain inspection - During the actual placement. All material shall conform to the project material specifications and approved by the project soils engineer. VINJE & MIDDLETON ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029-1229 Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 26 26-LOT SUBDIVISION, CAMINQ HILLS DRIVE, CARLSBAD JUNE 239 2006 Underground utility/plumbing trench inspection - After the trench excavations but before installation of the underground facilities. Safety requirements enforced by Cal-OSHA, and governing agencies for open excavations apply. Inspection of the pipe bedding may also be required by the project soils engineer. Underground utility/plumbing trench backfill inspection - After the backfill placement is started above the pipe zone but before the vertical height of backfill exceeds 2 feet. Testing of the backfill within the pipe zone may also be required by the governing agencies. Pipe bedding and backfill materials shall conform to the requirements of governing agencies and project soils report if applicable. All trench backfills shall be mechanically compacted to the minimum specified compaction levels per ASTM D-1557, unless otherwise superseded. Plumbing trenches over 12 inches deep maximum under the interior floor slabs should also be mechanically compacted and tested for the minimum specified compaction levels. Flooding or jetting techniques as a means of compaction method shall not be allowed. Pavement/improvements base and subgrade inspections - Prior to the placement of concrete or asphalt for proper moisture and specified compaction levels. B. Foundations and Interior Floor Slabs Proposed buildings may be supported on conventional concrete footings and slab- on-grade floor type foundations. The following recommendations and geotechnical mitigation are consistent with silty sandy clay to clayey silty sand (SC/CL) foundation bearing and subgrade soils with low to high expansion potential (expansion index less than 131) anticipated at finish grade levels. Added or modified recommendations may also be necessary and should be given at the time of foundation plan review phase. All foundations and floor slab recommendations should also be further confirmed and / or revised as necessary at the completion of rough grading based on the actual expansion characteristics of the foundation bearing and subgrade soils: Perimeter and interior continuous strip foundations should be sized at least 15 inches wide and 24 inches deep for single and two-story structures. Exterior spread pad footings, if any, should be at least 30 inches square and 18 inches deep and structurally tied to the perimeter strip footings with tie beams at least in one direction. Tie beams should be a minimum of 12 inches wide by 12 inches deep. Footing depths are measured from the lowest adjacent ground surface, not including the sand/gravel layer beneath floor slabs. 1 VINJE & MIILEToN ENGINEERING, INC. • 2450 AUtO PikWay Escondido, California 92029-1229 • Phone (760)743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 27 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 Exterior continuous footings should enclose the entire building perimeter. Flagpole footings also need to be tied together if the footing depth is less than 4 feet below rough finish grade. 2 Continuous interior and exterior foundations should be reinforced with a minimum of four #5 reinforcing bars. Place 245 bars 3 inches above the bottom of the footing and 245 bars 3 inches below the top of the footing. Tie beams should also be reinforced with 244 bars top and bottom and #3 ties at 30 inches on center maximum. Reinforcement details for spread pad footings should be provided by the project architect/structural engineer. Theslab subgrade and foundation bearing soils should not be allowed to dry prior to pouring the concrete, as additional ground preparations, moisture. re- conditioning and presaturation will be necessary as directed in the field. The required moisture content of the bearing soils is approximately -3% to 5% over the optimum moisture content to the depth of 24 inches below slab subgrade. Attempts should be made to maintain as-graded moisture contents in order to preclude the need for presaturation of the subgrade and bearing soils. In the case of presaturation of the slab subgrade and/or non-monolithic pour (two-pour) system, dowel the slab to the footings using #4 reinforcing bars spaced 18 inches on center extending at least 20 inches into the footings and 20 inches into the slab. The dowels should be placed mid-height in the slab. Alternate the dowels each way for all interior footings. After the footings are dug and cleaned, place the reinforcing steel and dowels and pour the footings. This office should be notified to inspect the foundation trenches, and reinforcing prior to pouring concrete. Once the concrete for the footings has cured and underground utilities tested, place 4 inches of 3/a-inch rock over the slab subgrade. Flood with water to the top of the 3/8-inch rock, and allow the slab subgrade to soak until moisture testing indicates that the required moisture content is present. After the slab subgrade soils have soaked, notify this office and schedule for appropriate moisture testing. When the required moisture content has been achieved, place a well- performing moisture barrier/vapor retardant (minimum 15-mil plastic) over the 3/8-inch rock, and place 2 inches of clean sand (SE 30 or greater) on top of the plastic. VINJI & MocLEToN ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 28 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 If sufficient moisture is present, flood ing/p resatu ration will not be required. The dowels may be deleted, slab underlayment may consist of 2 inches of clean sand over a well performing moisture barrier/vapor'retardant (minimum 15-mu plastic) over 2 inches of clean sand, and the footings and slab may be poured monolithically. This office should be notified to inspect the sand, slab thickness, and reinforcing prior to concrete pour. All interior slabs should be a minimum of 5 inches in thickness reinforced with #4 reinforcing bars spaced 18 inches on center each way placed 11/2 inches below the top of slab. Interior slabs should be provided with "softcut" contraction/control joints consisting of sawcuts spaced 10 feet on center maximum each way. Cut as soon as the slab will support the weight of the saw, and operate without disturbing the final finish which is normally within 2 hours after final finish at each control joint location or 150 psi to 800 psi. The softcuts should be a minimum of %-inch in depth, but should not exceed 1-inch deep maximum. Anti-ravel skid plates should be used and replaced with each blade to avoid spalling and raveling. Avoid wheeled equipment across cuts for at least 24 hours. Provide re-entrant corner reinforcement for all interior slabs. Re-entrant corners will depend on slab geometry and/or interior column locations. Plate 21 may be used as a general guideline. Foundation trenches and slab subgrade soils should be inspected and tested for proper moisture and specified compaction levels and approved by the project geotechnical consultant prior to the placement of concrete. C. Post-tensioned I Structural Slab-on-Ground Foundations Post-tensioned 'or structural slab-on-ground foundations consistent with the anticipated silty to clayey expansive bearing soils may also be 'considered. Remedial grading and foundation bearing/slab subgrade soil preparations will remain the same and should be completed as specified. - Post-tensioned or structural slab-on-ground foundation design should be completed by the project structural engineer or design/build contractor. The following are appropriate: 1. The foundation design should consider slabs with stiffening beams (ribbed foundation). In the case of uniform slab thickness foundation, the design shall satisfy all requirements of the design procedure for ribbed foundation. The fully I VINJE & MIDDLETON ENGINEERING. INC. • 2450 Auto Park Way Escondido, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION . PAGE 29 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE. 23, 2006 conformant ribbed foundation is then converted to an equivalent uniform thickness foundation. In this case, however, perimeter edge beams shall be required as specified in the following sections. All designs shall conform to the latest addition of the California Building Code (CBC), specifications of the Posttensioning Institute (P11), local standards, and the specifications given in this report. Foundation bearing soils should be inspected and tested as necessary prior to trenching and actual construction by the project geotechnical engineer. The required foundation bearing soils in-place densities, and specified moisture contents should be confirmed prior to the foundation pour. A minimum 4 inches of clean sand (SE greater than 30) should be placed over the approved slab subgrade soils. A well performing moisture barrier/vapor retardant (minimum 15-miI plastic) shall be placed mid-height in the sand. At the completion of ground and subgrade preparations as.specified, and approval of the project soil engineer, the post-tensioned or structural slab-on- ground foundations should be constructed as detailed on. the structural/construction drawings. Based upon our experience on similar projects, available laboratory testing and analysis of the test results, the following soil design parameters are appropriate: . * Design predominant clay mineral type ................Montmorillonite. * Design percent of clay in soil ................................60%. * Design effective plasticity index .................................45. * Design depth to constant soil suction .......................7 feet. * Design constant soil suction ............................... Pf 3.6. * Design velocity of moisture flow .................... 0.70 inch/month. * Design edge moisture variation distance for edge lift (em) .......3.0 feet. * Design edge-moisture variation distance for center lift (em) ......6.0 feet. * Design differential swell occurring at the perimeter of slab for edge lift condition (Ym) ........................... 1.095 inches. * Design differential swell occurring at the perimeter of slab for center lift condition (Ym) ............................5.677 inches. * Design soil subgrade modulus (k) .........................100 pci. * Design net allowable bearing pressure for Post-tensioned or structural slab-on-ground foundations ......1000 psf. VINJE & MIDDLETON ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 30 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 Notes: The net allowable foundation pressure provided herein applies to dead plus live loads and may be increased by one-third for wind and seismic loading. Provide a minimum of 15 inches wide by 24 inches deep perimeter edge beam. Perimeter edge beam should enclose the entire building circumference and reinforced with at least 145 continuous bar near the bottom. Provide adequate interior stiffening ribs as necessary. Posttension slab should be a minimum of 5% inches thick. Use minimum f'c=3000 psi concrete. We recommend to consider pre-tensioning in order to preclude early concrete shrinkage cracking. D. Exterior. Concrete Slabs / Flatworks All exterior slabs (walkways, patios, etc.) should be a minimum of 4 inches in thickness, reinforced with #3 bars at 16 inches on centers in both directions placed 1% inches below thetop of slab. Use 6 inches of 90% compacted clean sand beneath all exterior slabs. Provide "tool joint" or "softcut" contraction/control joints spaced 10 feet on center (not to exceed 12 feet maximum) each way. Tool or cut as soon as the slab will support weight and can be operated without disturbing the final finish which is normally within 2 hours after final finish at each control joint location or 150 psi to 800 psi. Tool or softcuts should be a minimum of %-inch but should not exceed 1-inch deep maximum. In case of softcut joints, anti-ravel skid plates should be used and replaced with each blade to avoid spalling and raveling. Avoid wheeled equipments across cuts for at least 24 hours. In order to enhance performance of exterior slabs and flatworks supported on potentially expansive and moisture sensitive subgrade soils, a minimum 8 inches wide by 12 inches deep thickened edge reinforced with a minimum of 144 continuous bar near the bottom may be considered along the free-ends. All exterior slab designs should be confirmed in the final as-graded compaction report. / 5. Subgrade soils should be tested for proper moisture and specified compaction . levels and approved by the project geotechnical consultant prior to the placement of concrete. VINJE & MlDDLI1oN ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029-1229 Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION . PAGE 31 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 E. Soil Design Parameters The following soil design parameters are based upon tested representative samples of on-site earth deposits. Expansive clayey soils should not be used for wall backfills. Sandy site soils or. good quality granular import soils should be considered within the active zone. Design parameters for import soils can only be given based on actual testing when a representative sample is available. All parameters should be re-evaluated when the characteristics of the final as-graded soils have been specifically determined: * . Design wet density of soil = 121 pcf. * Design angle of internal friction of soil = 28 degrees. * Design active soil pressure for retaining structures = 44 pcf (EFP), level backfill, cantilever, unrestrained walls. * Design active soil pressure for retaining structures = 69 pcf (EFP), 2:1 sloping backfill surface, cantilever, unrestrained walls. * Design at-rest soil pressure for retaining structures = 64 pcf (EFP), non- yielding, restrained walls. * Design passive soil pressure for retaining structures = 335 pcf (EFP), level surface at the toe. * Design coefficient of friction for concrete on soils = 0.34. * Net allowable foundation pressure (minimum 15 inches wide footings extended a minimum of 24 inches into compacted fill) = 2000 psf. * Allowable lateral bearing pressure (all structures except retaining walls) = 150 psf/ft. . Notes: Use a minimum safety.factor of 1.5 for wall over-turning and sliding stability. However, because large movements must take place before maximum passive resistance can be developed, a minimum safety factor of 2 may be considered for sliding stability particularly where sensitive structures and improvements are planned near or on top of retaining/basement walls. When combining passive pressure and frictional resistance the passive component should be reduced by one-third. * The indicated net allowable foundation pressure provided herein was determined based on a minimum 15 inches wide by 24 inches deep footing and may be increased by 20% for each additional foot of depth and 10% for each VINJE & MII)DLEToN ENGINEERING, ]NC. • 2450 Auto P.rkWay Escondido, California 92029-1229 • Phone (760) 743-1214 11 11 1 I PRELIMINARY GEOTECHNICAL INVESTIGATION ,.• PAGE 32 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 ....additional foot of width to a maximum of 4500 psf. The allowable foundation pressures provided herein also apply to dead plus live loads and may be increased by one-third for wind and seismic loading. The lateral bearing earth pressures may be increased by the amount of designated value for each additional foot of depth to a maximum of 1500 pounds per square foot. F. Asphalt and PCC Pavement Design 1. Asphalt Paving: A new pubho pFffiva street improvement is planned, and widening of Camino Hills Drive is proposed in connection with the site development. All roadway improvements and paving constructions shall be completed in accordance with the City of Carlsbad ordinances. The following asphalt pavement structural sections are based on a tested R- value of 5 performed on selected on-site earth materials and the indicated assumed traffic indices (TI), and may be considered for initial planning phase cost estimating purposes. A minimum section of 3 inches asphalt (AC) over 6 inches of Class 2 aggregate base (AB) or the minimum structural section required by City of Carlsbad, whichever is more, will be required and shall govern when a lesser pavement section is indicated by design calculations: TABLE 16 F)esign.Traffic Index (TI) . ' . Design R-value 4.5 5.0 6.0 6.5 5 3" AC over 8" AB J_3" AC over 10" AB 3" AC over 14" AB 4" AC over 14" AB The Class 2 aggregate base shall meet or exceed the current Caltrans specifications. Final pavement sections will depend on the actual R-value test results performed on finish subgrade soils, design TI and approval of the City of Carlsbad. All design sections should be confirmed and/or revised as necessary at the completion of rough pavement subgrade preparations. Revised pavement sections should be anticipated. Base materials should be compacted to a minimum 95% of the maximum dry density. Subgrade soils beneath the pavement base layer should also be compacted to a minimum 95% of the Corresponding maximum dry density within the upper 12 inches. Base materials and subgrade soils should be VINJE & M!t)DLIToN ENGINlEIuNG, INC. • 2450 Auto Park Way Escondido, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 33 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 'I .tested for proper moisture and minimum 95% compaction levels and approved by the project geotechnical consultant prior to the placement of the base or. asphalt layers. 2. PCC Paving: PCC driveways and parking supported on expansive subgrade soils should be a minimum of 51/2 inches in thickness, reinforced with #3 reinforcing bars at 16 inches on center each way, placed 2 inches below the top of slab. Subgrade soils beneath the PCC driveways and parking should also be compacted to a minimum 90% of the corresponding maximum dry density within the upper 6 inches, unless otherwise specified. In order to enhance performance of PCC pavements supported on expansive subgrade, a minimum 8 inches wide by 12 inches deep thickened edge reinforced with a minimum 144 continuous bar placed near the bottom is recommended to be considered along the outside edges. I Provide "tool Joint" or "softcut" contraction/control joints spaced 12 feet on center (not to exceed 15 feet maximum) each way. Tool or cut as soon as the I slab will support weight and can be operated without disturbing the final finish which is normally within 2 hours after final finish at each control joint location or 150 psi to 800 psi. Tool or softcuts should be a minimum of 1-inch but should not exceed I %-inches deep maximum. In case of softcut joints, anti- ravel skid plates should be used and replaced with each blade to avoid spalling - . and raveling. Avoid wheeled equipments across cuts for at least 24 hours. 'a 11 3. General Paving: Base section and subgrade preparations per structural section design, will be required for all surfaces subject to traffic including roadways, N travelways, drive lanes, driveway approaches and ribbon (cross) gutters. Driveway approaches within the public right-of-way should have 12 inches subgrade compacted to a minimum of 95% compaction levels, and provided with a 95% compacted Class 2 base section per the structural section design. In the case of potentially expansive subgrade (expansion index greater than 20), provide 6 inches of Class 2 base under curb and gutters and 4 inches of I Class 2 base (or 6 inches of Class III) under sidewalks with a thickened edge along the free-end as specified. Base layer under curb and gutters should be compacted to a minimum 95%, while subgrade soils under curb and gutters, and base and subgrade under sidewalks should be compacted to a minimum 90% compaction levels unless otherwise specified. Specific recommendations should be given in the final as-graded compaction report. 1. N VINJE & MIDDLETON ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029-I229 Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION' PAGE 34 --S 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23. 2006 ' Base and subgrade should be. tested for proper moisture and specified compaction levels, and approved by the project geotechnical consultant prior to the placement of the base or asphalt/PCC finish surface. G. General Recommendations The minimum foundation design and steel reinforcement provided herein are based on soil characteristics and are not intended to be in lieu of reinforcement necessary for structural considerations. Adequate staking and grading control is a critical factor in properly completing the recommended remedial and site grading operations. Grading control and staking should be provided by the project grading contractor or surveyor/civil engineer, and is beyond the geotechnical engineering services. Inadequate staking and/or lack of grading control may result in unnecessary additional grading which will increase construction costs. Footings located on or adjacent to the top of slopes should be extended to a sufficient depth to provide a minimum horizontal distance of 7 feet or one-third of the slope height, whichever is greater (need not exceed 40 feet maximum) between the bottom edge of the footing and face of slope. This requirement applies to all improvements and structures including fences, posts, pools, spas, etc. Concrete and AC improvements should be provided with a thickened edge to satisfy this requirement. Open or backfilled trenches parallel with a footing shall not be below a projected plane having a downward slope of 1-unit vertical to 2 units horizontal (50%) from a line 9 inches above the bottom edge of the footing, and not closer than 18 inches frOm the face of such footing. Where pipes cross under-footings, the footings shall be specially designed. Pipe sleeves shall be provided where pipes cross through footings or footing walls, and sleeve clearances shall provide for possible footing settlement but not less than 1-inch all around the pipe. Foundations where the surface of the ground slopes more than 1-unit vertical in 10 units horizontal (10% slope) shall be level or shall be stepped so that both top and bottom of such foundations are level. Individual steps in continuous footings shall not exceed. 18 inches in height and the slope of a series of such steps shall not exceed 1-unit vertical to 2 units horizontal (50%) unless otherwise specified. The steps shall be detailed on the structural drawings. The local effects due to the discontinuity of the steps shall also be considered in the design of foundations as appropriate and applicable. VINJE & MIDDLETON ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 35 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 Expansive clayey soils should not be used for backfilling of any retaining structure. All retaining/basement walls should be provided with a 1:1 wedge *of granular, compacted backfill measured from the base of the wall footing to the finished surface, and a well constructed back drainage as shown on Plate 22. All underground utility and plumbing trenches shOuld be mechanically compacted to a minimum 90% of the maximum dry density of the soil unless otherwise specified. Care should be taken not to crush the utilities or pipes during the compaction of the soil. Non-expansive, granular backfill soils should be used. Trench backfill materials and compaction beneath pavements within the public right-of-way shall conform to the City of Carlsbad requirements. On-site soils are expansive clayey deposits subject to continued swelling and shrinkage upon wetting and drying. Maintaining a uniform as-graded soil moisture during ,-the post construction periods, is essential in the future performance of the site structures and improvements. In no case should water be allowed to pond or accumulate adjacent to the improvements and structures. Due to sensitive expansive plastic clayey soils present at the site, construction of swimming pools, spas, patios, etc. should only be allowed based on a review and specific recommendations provided by the project geotechnical consultant. Planting large trees hear the building foundations should be avoided. Site drainage over the finished pad surfaces should flow away from structures onto the street in a positive manner. Care should be taken during the construction, improvements, and fine grading phases not to disrupt the designed drainage patterns. Roof lines of the buildings should be provided with roof gutters. Roof water should be collected and directed away from the buildings and structures to a suitable location. Final plans should reflect preliminary recommendations given in this report. Final foundations and grading plans may also be reviewed by the project geotechnical consultant for conformance with the requirements of the geotëchnical investigation report outlined herein. More specific recommendations may be necessary and should be given when final grading and architectural/structural drawings are available. All foundation trenches should be inspected to ensure adequate footing embedment and confirm competent bearing soils. Foundation and slab reinforcements should also be inspected and approved by the project geotechnical consultant. VINJE & Mn)!)LIroN ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029-1229 1 Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 36 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 ' 13. The amount of shrinkage and related cracks that occurs in the concrete slab- on-grades, flatworks and driveways depend on many factors the most important of which is the amount of water in the concrete mix. The purpose of the slab I reinforcement is to keep normal concrete shrinkage cracks closed tightly. The amount of concrete shrinkage can be minimized by reducing the amount of water in the mix. To keep shrinkage to a minimum the following should be mI .considered: S * Use the stiffest mix that can be handled and consolidated satisfactorily. '1 * Use the largest maximum size of aggregate that is practical. For example, concrete made with /8-jflCh maximum size aggregate usually requires about 40-lbs. more (nearly 5-gal.) water per cubic yard than concrete with 17inch aggregate. U * Cure the concrete as long as practical. $ - The amount of slab reinforcement provided for conventional slab-on-grade construction considers that good quality concrete materials, proportioning, craftsmanship, and control tests where appropriate and applicable are S I provided. 14. A preconstruction meeting between representatives of this office, the property owner or planner, city inspector as well as the grading contractor/builder is recommended in order to discuss grading/construction details associated with site development. S S S IX. LIMITATIONS S The conclusions and recommendations provided herein have been based on available data obtained from the review of pertinent reports and plans, subsurface exploratory 'IS excavations as well as our experience with the soils and formational materials located in the general area. The materials encountered on the project site and utilized in our laboratory testing are believed representative of the total area; however, earth materials 'I may vary in characteristics between excavations. Of necessity we must assume a certain degree of continuity between exploratory 1' excavations and/or natural exposures. It is necessary, therefore, that all observations, conclusions, and recommendations be verified during the grading operation. In the event discrepancies are noted, we should be contacted immediately so that an inspection can be made and additional recommendations issued if required. 11, V I NJ E & MloDLIToN ENGINItIurjG, INC. • 2450 Auto Park Way Escondido, California 92029-1229 . Phone (760) 743-1214 I PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 37 - 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 The recommendations made in this report are applicable to the site at the time this report was prepared. It is the responsibility of the owner/developer to ensure that these recommendations are carried out in the field. It is almost impossibleto predict with certainty the future performance of a property. The future behavior of the site is also dependent on numerous unpredictable variables, such as earthquakes, rainfall, and on-site drainage patterns. The firm of VINJE & MIDDLETON ENGINEERING, INC., shall not be held responsible for changes to the physical conditions of the property such as addition of fill soils, added cut slopes, or changing drainage patterns which occur without our inspection or control. The property owner(s) should be aware that the development of cracks in all concrete surfaces such as floor slabs and exterior stucco are associated with normal concrete shrinkage during the curing process. These features depend chiefly upon the condition of concrete and weather conditions at the time of construction and do not reflect detrimental ground movement. Hairline stucco cracks will often develop at window/door corners, and floor surface cracks up to 1/8-inch wide in 20 feet may develop as a result of normal concrete shrinkage (according to the American Concrete Institute). This report should be considered valid for a period of one year and is subject to review by our firm following that time. If significant modifications are made to your tentative development plan, especially with respect to the height and location of cut and fill slopes, this report must be presented to us for review and possible revision. This report is issued with the understanding that the owner or his representative is I responsible to ensure that the information and recommendations are provided to the project architect/structural engineer so that they can be incorporated into the plans. Necessary steps shall be taken to ensure that the project general contractor and subcontractors carry out such recommendations during construction. The project soils engineer should be provided the opportunity for a general review of the project final design plans and specifications in order to ensure that the recommendations I provided in this report are property interpreted and implemented. The project soils engineer should also be provided the opportunity to verify the foundations prior the placing of concrete. If the project, soils engineer is not provided the opportunity of making these I reviews, he can assume no responsibility for misinterpretation of his recommendations. . Vinje & Middleton Engineering, Inc., warrants that this report has been prepared within the limits prescribed by our client with the usual thoroughness and competence of the engineering profession. No other warranty or representation, either expressed or implied, is included or intended. I 1 VINJE & MIDIDLEToN ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 38 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 Once again, should any questions arise concerning this report, please do not hesitate to contact this office. Reference to our Job #06-210-P will help to expedite our response to your inquiries. .' . We appreciate this opportunity to be of service to you. S VINJE & MIDDLETON ENGINEERING, INC. Dennis Middleton #980 Mehdi S. E #46174 '--- Steven J. Meizer CEG#2362 DM/SMSS/SJM/jt Distribution: Addressee (5) c:/jt/myfiles/prelilms .06/06-2 10-P çED MID 0<. G CEG98O * CERTIFIED * ENGINE INC Op -41 No. 9362 CERTIFIED - . NEEAING % GEOL FxP. s-31-07 ra OGIST VINJE & MIDILEToN ENGINEERING, INC. • 2450 Auto Park Way Escondido, California 92029-1229 Phone (760) 743-1214 REFERENCES - Annual Book of ASTM Standards, Section 4 - Construction, Volume 04.08: Soil And Rock (I); II D420 - D 5611, 2005. - Annual Book of ASTM Standards, Section 4 - Construction, Volume 04.09: Soil And Rock (II); D 5714- Latest, 2005. 1 - Highway Design Manual, Caltrans. Fifth Edition. - Corrosion Guidelines, Caltrans, Version 1.0, September 2003. - California Building Code, Volumes 1 & 2, International Conference of Building Officials, 2001. - "Green Book" Standard Specifications For Public Works Construction, Public Works 1 .Standards, Inc., BNi Building News, 2003 Edition. - California Department of Conservation, Division of Mines and Geology (California Geological Survey), 1997, Guidelines for Evaluating and Mitigating Seismic Hazards in California, DMG 'I Special Publication 117, 71p. - California Department of Conservation, Division of Mines and Geology (California Geological Survey), 1986 (revised), Guidelines for Preparing Engineering Geology Reports: DMG Note II 44. - California Department of Conservation, Division of Mines and Geology (California Geological Survey), 1986 (revised), Guidelines to Geologic and Seismic Reports: DMG Note 42. - EQFAULT, Ver. 3.00, 1997, Deterministic Estimation of Peak Acceleration from Digitized Faults, Computer Program, T. Blake Computer Services And Software. - EQSEARCH, Ver 3.00, 1997, Estimation of Peak Acceleration from California Earthquake I Catalogs, Computer Program, T. Blake Computer Services And Software. - Tan S.S. and Kennedy, M.P., 1996, Geologic Maps of the Northwestern Part of San Diego County, California, Plate(s) 1 and 2, Open File-Report 96-02, California Division of Mines and Geology, 1:24,000. I - UBCSEIS, Ver. 1.03, 1997, Computation of 1997 Uniform Building Code Seismic Design Parameters, Computer Program, T. Blake Computer Services And Software. - "Proceeding of The NCEER Workshop on Evaluation of Liquefaction Resistance Soils," Edited 1 by T. Leslie Youd And Izzat M. Idriss, Technical Report NCEER-97-0022, Dated December 31, 1997. - "Recommended Procedures For Implementation of DMG Special Publication 117 Guidelines I For Analyzing And Mitigation Liquefaction In California," Southern California Earthquake center; USC, March 1999. "Soil Mechanics," Naval Facilities Engineering Command, DM 7.01. , - "Foundations & Earth Structures," Naval Facilities Engineering Command, DM 7.02. - "Introduction to Geotechnical Engineering, Robert D. Holtz, William D. Kovacs. - "Introductory Soil Mechanics And Foundations: Geotechnical Engineering," George F. Sowers, I Fourth Edition. - "Foundation Analysis And Design," Joseph E. Bowels. - Caterpillar Performance Handbook, Edition 29, 1998. - Jennings, C.W., 1994, Fault Activity Map of California and Adjacent Areas, California Division of Mines and Geology, Geologic Data Map Series, No. 6. I I - Kennedy, M.P., 1977, Recency and Character of Faulting Along the Elsinore Fault Zone in Southern Riverside County, California, Special Report 131, California Division of Mines and Geology, Plate 1 (East/West), I2p. - Kennedy, M.P. and Peterson, G.L., 1975, Geology of the San Diego Metropolitan Area, California: California Division of Mines and Geology Bulletin 200, 56p. - Kennedy, M.P. and Tan, S.S., 1977, Geology of National City, Imperial Beach and Otay Mesa Quadrangles, Southern San Diego Metropolitan Area, California, Map Sheet 24, California Division of Mines and Geology, 1:24,000. - Kennedy, M.P., Tan, S.S., Chapman, R.H., and Chase, G.W., 1975, Character and Recency of Faulting, San Diego Metropolitan Areas, California: Special Report 123, 33p. Caterpillar Performance Handbook, Edition 29, 1998. - Jennings, C.W., 1994, Fault Activity Map of California and Adjacent Areas, California Division of Mines and Geology, Geologic Data Map Series, No. 6. - Kennedy, M.P., 1977, Recency and Character of Faulting Along the Elsinore Fault Zone in Southern Riverside County, California, Special Report 131, California Division of Mines and Geology, Plate 1 (East/West), 12p. - Kennedy, M.P. and Peterson, G.L., 1975, Geology of the San Diego Metropolitan Area, California: California Division of Mines and Geology Bulletin 200, 56p. - Kennedy, M.P. and Tan, S.S., 1977, Geology of National City, Imperial Beach and Otay Mesa Quadrangles, Southern San Diego Metropolitan Area, California, Map Sheet 24, California Division of Mines and Geology, 1:24,000. - Kennedy; M.P.,. Tan, S.S., Chapman, R.H., and Chase, G.W., 1975, Character and Recency of Faulting, San Diego Metropolitan Areas, California: Special Report 123, 33p. - "An Engineering Manual For Slope Stability Studies," J.M. Duncan, A.L. Buchignani And Marius De Wet, Virginia Polytechnic Institute And State University, March 1987. C_ , en S ICO 101 XP to 1AU VE PLATE .1 Is V&M JOB #66.2-10-P / cr f aAFcT CT / CIHOS WAY OP / TILOS FOocfR,-• •• • - -S. ( SITE S -- 5- S \ /'V 44,I Jr- - \ I Mono Canyon 00 Mc c'T PAL - V / CO 0 LA NA Co CT - ETRR dR I \\ '•PAL R W 'ALMAS OR I t ••• P$ •.• I Scale 1:25,Q00 TN 2002 DeLorin.. Topo USA ®. Data copyright of content owner. j -° www.d(crme.00m :00 a eoo aoo LAT:33.1452 LONG: 117.2880 PRIMARY DIVISIONS GROUP SECONDARY DIVISIONS SYMBOL -.1 GRAVELS CLEAN GRAVELS GW Well graded gravels, gravel-sand mixtures, little or no fines. 0 W 0 - I— c'j MORE THAN HALF OF COARSE (LESS THAN GP Poorly graded gravels or gravel-sand mixtures, little or no fines. 0 < 5% FINES) b O Z LU FRACTION IS ______ GRAVEL GM Silty gravels, gravel-sand-silt mixtures, non-plastic fines. W 0zN LARGER THAN WITH NO. 4 SIEVE FINES GC Clayey gravels, gravel-sand-clay mixtures, plastic fines. < -JIW Ir < I- > SANDS CLEAN SW O i W SANDS Well graded sands, gravelly sands, little or no fines. Ui z LU Fn 0) <0 ct MORE THAN HALF OF COARSE (LESS THAN SP Poorly graded sands or gravelly sands, little or no fines. 5% FINES) SANDS SM Silty sands, sand-silt mixtures, non-plastic fines. O W -I FRACTION IS 0 SMALLER THAN WITH NO. 4 SIEVE FINES Sc Clayey sands, sand-clay mixtures, plastic fines. LU N ML Inorganic silts and very fine sands, rock flour; silty or clayey fine 0 3 j SILTS AND CLAYS sands or clayey silts with slight plasticity. 0 < > LIQUID LIMIT IS CL Inorganic clays of low to medium plasticity, gravelly clays, sandy 1 w LESS THAN 50% clays, silty clays, lean clays. OL Organic silts and organic silty clays of low plasticity. g . < . MH Inorganic silts, micaceous or diatomaceous fine sandy or silty o SILTS AND CLAYS soils, elastic silts. LU CC LU Z z0z LIQUID LIMIT IS CH ___ Inorganic clays of high plasticity, fat clays. LL GREATER THAN 50% OH Organic clays of medium to high plasticity, organic silts. HIGHLY ORGANIC SOILS PT Peat and other highly organic soils. GRAINSIZES U.S. STANDARD SERIES SIEVE - - CLEAR SQUARE SIEVE OPENINGS 200 40 10 4 3/4" 3" 12" SAND GRAVEL I I SILTS AND CLAYS COBBLES BOULDERS I FINE MEDIUM I COARSE I FINE I COARSE I RELATIVE DENSITY SANDS, GRAVELS AND NON-PLASTIC SILTS BLOWS/FOOT VERY LOOSE 0 - 4 LOOSE 4-10 MEDIUM DENSE 10 -30 DENSE 30 -50 VERY DENSE OVER 50 CONSISTENCY CLAYS AND PLASTIC SILTS STRENGTH BLOWS/FOOT VERY SOFT 0-¼ 0-2 SOFT ¼-'/2 2-4 FIRM '/2-1 4-8 STIFF 1-2 8-16 VERY STIFF 2-4 16-32 HARD OVER 4 OVER 32 I I Blow count, 140 pound hammer falling 30 inches on 2 inch O.D. split spoon sampler (ASTM D-1 586) Unconfined compressive strength per SOILTEST pocket penetrometer CL-700 Sand Cone Test Bulk Sample j 246 = Standard Penetration Test (SPT) (ASTM ID- i 586) with blow counts per 6 inches 0 Chunk Sample 0 Driven Rings 246 = California Sampler with blow counts per 6 inches VINJE & MIDDLETON . KEY TO EXPLORATORY BORING LOGS ENGINEERING, INC. Unified Soil Classification System (ASTM D-2487) 2450 Vineyard Ave., #102 Escondido, CA 92029-1229 PROJECT NO. KEY Date: 4-11-06 Logged by: SJM T FIELD DEPTH (ft) SAMPLE USCS SYMBOL FIELD MOISTURE (%) DRY DENSITY (pci) RELATIVE COMPACTION (%) I I DESCRIPTION -0- FILL: I - - Sandy clay. Pale brown color. Moist to very moist. Soft. CL/OH - Plastic. ST-1 18.5 100.8 - - -Clayey tj TERRACE DEPOSIT (Q&): sand. Red-brown color. Moist. Somewhat blocky. SC/CL 12.9 104.1 80.4 - - Loose to medium dense. Includes sub-angular pebbles. I - - ST-2 15.4 103.4 79.8 - 10 - Silty fine to medium sand with clay. Dark brown color. Medium dense to dense. Grades fine to coarse grained at SM/SC 8.2 112.3 86.7 -10'. Trace of clay. ST-2 7.8 119.3 92.1 I - - - -Red-brown Coarse sand. Clay binder. Some gravel and small rock. color. Moist. Medium dense. ST-3 SC/GC ______ 9.7 102.8 - -15- I- Ii 14.1 103.5 - - - Clay fine to medium sand. Brown color. Moist. Somewhat SC - - blocky. Medium dense. ST-2 - - End Test Trench at 161/2 - extent of backhoe. -20 - No caving. No groundwater. Date: 4-11-06 DEPTH SAMPLE (ft) -0- _______________________________________ Logged by: SJM T-2 FIELD USCS SYMBOL FIELD MOISTURE DRY DENSITY RELATIVE COMPACTION DESCRIPTION (%) (pci) (%) FILL I TOPSOIL: Sandy clay. Pale brown color. Moist. Soft. Plastic. ST-1 CL 'FORMATIONAL ROCK (Ts): 116.6 101.0 84.5 Claystone. Grey color. Weathered. "Popcorn' texture. CL/OH ST-4 23.6 89.8 75.1 Silty sandstone. Fine grained. Trace of clay. Tan with rust-colored staining. Includes clasts of claystone. SM/SC 18.8 107.8 90.2 Weathered. Friable. Moderately to poorly cemented. No - discernable structure. ST-5 17.4 114.3 95.6 End Test Trench at 101/2. No caving. No groundwater. E El VINJE & MIDDLETON ENGINEERING, INC 2450 Vineyard Avenue, Suite 102 Escondido, California 92029-1229 Office 760-743-1214 Fax 760-739-0343 Y Sand Cone Test 0 Bulk Sample .1ESTTRENHLOGS. . CAMINO HILLS DRIVE, CARLSBAD - PROJECT NO. 06-210-P PLATE 3 D Chunk Sample 0 Driven Rincis Date: 4-11-06 Logged by: SJM T-3 USCS FIELD FIELD DRY RELATIVE DEPTH (ft) SAMPLE SYMBOL MOISTURE (%) DENSITY (pci) COMPACTION (%) DESCRIPTION - 0 - FILL /ALLUVIUM (af-Qal): Sandy clay. Pale brown color. Moist. Soft. ST-1 CL/CH - - - - MCI 28.6 88.0 79.6 Silty clay. Dark grey color. Moist. Soft to stiff. Plastic. ST-4 CL/CH - 5 - 27.8 88.8 80.4 - - - - Fine sand. Trace of clay. Off-white to grey color. Somewhat hIrw.ky Medium dense. ST-5 SC 18.4 10.6 84.2 FORMATIONAL ROCK (Ts): -10- - - Fine sandy siltstone/claystone. Grey color. Weathered. MH/CH - - Fractured. Blocky. ST-4 -15 - End Test Trench at 9. - - No caving. No groundwater. -20- 1 1 Date: 4-11-06 Logged by: SJM TA USCS FIELD FIELD DRY RELATIVE DEPTH (ft) SAMPLE SYMBOL MOISTURE (%)• DENSITY (pci) COMPACTION (%) . DESCRIPTION - 0 - FILL (af): Sandy clay. Brown color. Moist. Soft. ST-1 CL \ i FORMATIONAL ROCK (Ts): -- \ Fine sandy siltstone. Grey color. Deeply weathered. Soft. MH — 5 -ST-4 0 106.0 95.5 - - . Pinch-out lens of medium sand. Trace of clay. Red-brown color. Friable. Some gravel and small rock. SCIGC r22.4 108 0 97 7 - - ST-3 -10- 21.2 106.9 96.7 Fine sandy siltstone I claystone. Grey color. Maroon MH/CH - - - - colored staining. Polished surfaces. Fractured. Grades - - blocky at 9. ST-4 -15- - - End Test Trench at bY2. - - No caving. No groundwater. - 20- VINJE & MIDDLETON ENGINEERING, INC 2450 Vineyard Avenue, Suite 102 Escondido, California 92029-1229 Office 760-743-1214 Fax 760-739-0343 V Sand Cone Test M Bulk Samole TEST.TRENCH LOGS. CAMINO HILLS DRIVE, CARLSBAD - PROJECT NO. 06-210-P PLATE 4 0 Chunk SamDle 0 Driven Rinas Date: 4-11-06 Logged by: SJM T-5 USCS FIELD FIELD DRY RELATIVE DEPTH (ft) SAMPLE SYMBOL MOISTURE (%) DENSITY (pcf) COMPACTION (%) DESCRIPTION - 0 - FILL - ALLUVIUM (af-Qal): - - Sandy clay. Pale brown color. Moist. Soft. ST-1 CL - - Clayey sand. Fine grained. Dark brown color. Moist. Loose SC to medium dense. ST-2 - - 11.9 109.0 84.1 __________________________________________ TERRACE DEPOSIT (Qt): - - - - Clayey sand. Red-brown color. Moist. Medium dense. Sc White carbonate stringers and 3"-6" diameter sub-angular 13.1 110.8 85.5 rock below 11'. ST-2 -10- - - FORMATIONAL ROCK (Ts): - - Clayey sandstone. Fine grained. Off-white color. SC 13.9 106.8 82.4 - - Moderately cemented. Somewhat blocky. No apparent - - U structure. ST-2 13.4 108.5 83.7 -15- - El 16.0 1 102.5 85.5 End Test Trench at 16W - extent of backhoe. LO-- No caving. No groundwater. I Date: 4-11-06 Logged by: SJM FIELD USCS FIELD DRY RELATIVE I DEPTH SAMPLE DESCRIPTION SYMBOL MOISTURE DENSITY COMPACTION (ft) (%) (pcf) (%) - 0 -F!LL(af): 1 - - Clayey sand. Tan color. Moist. Loose. ST-2 SC - - TERRACE DEPOSIT (R+) I - 5 - Fine sand. Silty. Yellow-tan color. Somewhat blocky. SM/S P - - Friable. Moderately cemented. No structure. - ST-5 13.3 105.5 88.3 -10- - - End Test Trench at 8. - - No caving. No groundwater. 20- 11 VINJE & MIDDLETON ENGINEERING, INC TEST TRENCH LOGS 2450 Vineyard Avenue, Suite 102 Escondido, California 92029-1229 CAMINO HILLS DRIVE, CARLSBAD PROJECT NO. 06-210-P PLATE 5 I Office 760-743-1214 Fax 760-739-0343 V Sand Cone Test N Bulk Sample U Chunk Sample - 0 Driven Rings I Date: 4-11-06 Logged by: SJM T-7 FIELD DEPTH SAMPLE USCS SYMBOL FIELD MOISTURE DRY DENSITY RELATIVE COMPACTION (ft) DESCRIPTION (%) (pcf) (%) - 0 - FILL - ALLUVIUM (af-Qal): - - Sandy clay. Pale brown color. Moist. Soft. Stiff at 3'. CL - - ST-1 26.1 88.9 -5- - - Li TERRACE DEPOSIT (Qt): - - Fine sand. Trace of clay. Tan color. Somewhat blocky. SM/SC 18.9 99.3 83.1 - - Loose to medium dense. Local clean sand lenses. -10- Li ST-5 . 25.2 92.8 . 77.6 - - Li Sandy clay I clayey sand. Brown color. Some rust - colored SC/CL 22.5 98.3 - - - staining. Blocky. Medium dense. - - ..LJ ST-1 25.7 95.7 - -15- - - End Test Trench at 141/2'. - - No caving. No groundwater. -20 - Date: 4-11-06 DEPTH I SAMPLE (ft) T-8 DESCRIPTION FILL- ALLUVIUM (af-Qal): Clayey sand. Fine to medium grained. Red-brown color. Moist. Very loose to loose. ST-2 Clayey sand. Dark brown color. Moist. Blocky. Medium dense. Color changes to red-brown color at 10'. ST-2 FORMATIONAL ROCK (Ts): Sandstone. Fine grained. Trace of clay. Grey to yellow- tan. Deeply weathered. Weakly to moderately cemented. Friable. Local rust-colored staining. ST-5 End Test Trench at 15'. No caving. No groundwater. Logged by: SJM FIELD USCS FIELD DRY RELATIVE SYMBOL MOISTURE DENSITY COMPACTION (%) (pcf) Sc SC 11.9 101.6 78.4 12.7 113.6 87.9 SC 12.2 104.1 1 80.3 13.7 94.9 1 79.4 VINJE & MIDDLETON ENGINEERING, INC 2450 Vineyard Avenue, Suite 102 Escondido, California 92029-1229 Office 760-743-1214 Fax 760-739-0343 V Sand Cone Test E Bulk Sample TEST TRENCH LOGS CAMINO HILLS DRIVE, CARLSBAD - PROJECT NO. 06-210-P PLATE 6 Li Chunk SamDle 0 Driven Rinas Date: 4-11-06 Logged by: SJM DEPTH (ft) SAMPLE T_9 USCS SYMBOL FIELD MOISTURE (%) FIELD DRY DENSITY (pd) RELATIVE COMPACTION (%) - DESCRIPTION - 0 - FILL- ALLUVIUM (af-Qal): - - Sandy clay. Pale brown color. Moist. Soft. CL ST-1 - - Fine sandy silt. Grey color. Moist. Soft. ST-4 MH 18.3 96.1 80.4 - - - - TERRACE DEPOSIT (Qt): Sandstone. Fine grained with clay. Yellow-tan color. Moist. 12.2 110.6 92.6 - - _10 - - - Weakly cemented. Weathered. Becomes somewhat blocky at 7'. Local rust - colored staining below 11'. ST-5 Sc 13.1 16.9 110.9 99.1 92.8 83.0 lj FORMATIONAL ROCK (Ts): MH 17.9 99.3 83.1 Fine sandy siltstone. Grey color. Deeply weathered. Plastic ST-4. -15- - - 1 Li U - 24.3 97.3 88.1 - - End Test Trench at 151/2'. - - No caving. No groundwater. -20 - Date: 4-11-06 Logged by: SJM DEPTH (ft) SAMPLE T -' 10 USCS SYMBOL FIELD MOISTURE (%) FIELD DRY DENSITY (pcf) RELATIVE COMPACTION (%) DESCRIPTION - 0 - - - - - FILL/TOPSOIL: Clayey sand. Red-brown color. Moist. Loose. ST-2 CL TERRACE DEPOSIT (Qt): Silty fine sand. Trace of clay. Red-brown color. Locally blocky. Friable. Some rust-colored staining. ST-5 SM/SC - 5 - - - Clayey medium to coarse sand. Red-brown color. Medium dense. ST-3 Sc - 10— CH Sandy clay. Dark grey color. Moist. Blocky. Moderately plastic. Polished surfaces. ST-4 - - I' Clayey sand. Brown color. Rust-colored staining. Local polished surfaces. Blocky. Medium dense. ST-2 SC 15 - - - - - 20 - Fine sandy silt. Grey color. Blocky. Polished surfaces. Medium dense. ST-4 MH End Test Trench at 15'. No caving. No groundwater. I VINJE & MIDDLETON ENGINEERING, INC 2450 Vineyard Avenue, Suite 102 Escondido, California 92029-1229 I Office 760-743-1214 Fax 760-739-0343 TEST TRENCH LOGS CAMINO HILLS DRIVE, CARLSBAD PROJECT NO. 06-210-P PLATE 7 V Sand Cone Test 0 Bulk Sample IJ Chunk Sample 0 Driven Rincis BORING LOG B-I -Description DRY RELATIVE DEPTH SAMPLE USGS MOISTURE DENSITY COMPACTION FT SYMBOL (%) (PCF) (%) - 0 - FILL (af): Clayey sand. Brown color. Slightly moist. Loose. ST-2 SC - - 17.4 113.8 87.8 I5 :Q - - 12,20 TERRACE DEPOSIT (Qt): - - Medium to coarse sand: Clay binder. Red-brown SC - - color. Moist. ST-3 10 - - Sandy clay. Olive-brown color. Moist. Stiff. CL/CH - - Plastic. Local grey-colored staining.. Weathered reflection of underlying siltstone. ST-4 -15- 6,10,13 - - FORMATIONAL ROCK (Ts): -. - Sandy siltstone. Pale grey color. Weathered. MH - - Friable. Firm. - - 51013 ' ' \ ST-4 . -20- -25- End Boring at 19%'. - - No caving. No groundwater. -30 - -35 - _40- Bulk Sample • Project: CAMINO HILLS DRIVE, CARLSBAD Ring Sample 0 SPT Sample II Project No:06-210-P Date Drilled: 5-25-06 Logged By: SM Groundwater ..2.. Truck-mounted rotary drill. 8" hollow-stern auger. PLATE 8 Drill, Sample Method: 140-lb. Hammer, 30" hydraulic drop. 5'AW Rods. VINJE & MIDDLETON ENGINEERING, INC. BORING LOG B-2 4. Description DRY RELATIVE DEPTH SAMPLE USGS' MOISTURE DENSITY COMPACTION FT SYMBOL (%) (PCF) (%) - 0 - FILL-ALLUVIUM (af-Qal): - - Clayey sand / sandy clay. Brown color. Slightly SC/CL - - moist. Soft. ST-1 - - Clayey silt. Grey color. Moist. Soft. ST-5 MH 3,2,2 - - . CL/CH - - Sandy clay. Red-brown color. Moist to very moist. - 10 - Soft. Plastic. ST-1 -15- 98 Clayey send. Red-brown color. Moist. Loose to 18.3 110.1 84.9 - medium dense. SC - - Color Chang - . es to pale brown at 18'. ST-2 -20- II - - 4,4,6 -25- 0 TERRACE DEPOSIT (Qt): 16.9 114.6 95.8 - - 12,24 Sandy clay. Dark brown color. Moist. Stiff. CL/CH - - Plastic. ST-1 130= II - - 8,13,18 FORMATIONAL ROCK (Is): - - Sandy siltstone. Pale grey color. Weathered soft MH - - and plastic in upper exposures. Fractured and - - friable below. Local rust-colored staining. Medium -35 - dense. - -. 10,11,14 - - Groundwater encountered at approximately 33'. - - Becomes somewhat blocky and dense at 39'. - - Continued rust-colored staining. ST-4 -40- 11 End Boring at 401/2'. - - 19,20,24 No caving. Groundwater encountered at 33'. Project: CAMINO HILLS DRIVE, CARLSBAD Bulk Sample • Ring Sample 0 Project No: 06-210-P Date Drilled: 5-25-06 Logged By:SM SPT Sample Groundwater Truck-mounted rotary drill. 8" hollow-stem auger. Drill, Sample Method: 140-lb. Hammer, 30" hydraulic drop. 5' AW Rods. PLATE 9 BORING LOG B-3 DEPTH FT SAMPLE Description USGS SYMBOL MOISTURE (%) DRY DENSITY (PCF) RELATIVE COMPACTION (%) - 0 - FILL-ALLUVIUM (af-Qal): - - Clayey sand. Brown color. Slightly moist. Loose. SC - - ST-2 - 5 - p 13,20 Medium to coarse sand. Clay binder. Red-brown color. Friable. Medium dense. ST-3 SC 9.0 ' 113.2 97.3 - - - S - SM Silty fine sand. Tan color. Firm to medium dense. ST-5 10 - 11,12,13 Medium sand. Trace of clay. Red-brown color. - - SC - - Friable. Medium dense. ST-3 - - 0 SC Clayey fine sand. Red-brown to tan color. Medium 15 dense. Local rust and grey colored staining. 9.7 18,20 113.8 87.8 - - Massive. - ST-5 Medium to coarse sand. Includes gravel and -20 - 6,10,14 - - pebbles. Red-brown color. Very moist. - - SP/GP - - Groundwater at approximately 32. Loose to firm. - - 0 Blow counts for 34' sample inflated due to pebbles. 16.2 109.5 91.6 -25 - 13,22 Water added to aid drilling. Caving below 32' - - prohibited further sampling. S ST-3 -3°- 1 o -7,13,14 ______________________________________ ______ 20.3 - - 735- 110.7 92.6 12,35, - - End Boring at 39'. - - Caving 35'- 39'. Groundwater at 32'. -40- Bulk Sample Project: CAMINO HILLS DRIVE, CARLSBAD Ring Sample 0 Project No:06-210-P Date Drilled: 5-25-06 Logged By: SM SPT Sample 11 Groundwater Truck-mounted rotary drill. 8" hollow-stem auger. Drill,SampleMethod:140-lb.Hammer,30"hydraulicdrop.5'AWRods. PLATE 10 VINJ= & MIIJLJLt I ON ENUINEEKING, INC. BORING LOG .PLion B-4 Descri DRY RELATIVE DEPTH SAMPLE USGS MOISTURE DENSITY COMPACTION FT SYMBOL (%) (PCF) (%) - 0 - FILL-ALLUVIUM (af-Qal): - - Clayey sand. Brown color. Slightly moist. Loose. SC - - ST-2 - 5 - II Medium to coarse sand. Clayey sand. Red-brown sc - - 9,8,5 color. Loose to firm. ST-3 - -. Fine sand. Red-brown color. Weakly cemented. SP - - Friable. Massive. Medium dense. ST-5 11.7 106.2 88.8 -10- 11,14 - - TERRACE DEPOSIT (Qt): Clayey sand. Includes gravel and pebbles. Red-SC/GC - - brown color. Medium dense. ST-2 115: 9,10,14 —20— Medium to coarse sand with gravel and pebbles. GP 5.8 109.5 91.6 81217 , - - Red-brown color. Medium dense. -. - ST-3 -25- 1301 ' - - End Boring at 20'. -. - No caving. No groundwater. - . -40- Bulk Sample • Project: CAMINO HILLS DRIVE, CARLSBAD Ring Sample 0 SPT Sample 11 Project No:06-210-P Date Drilled: 5-25-06 Logged By: SM Groundwater Truck-mounted rotary drill. 8" hollow-stem auger. Drill, Sample Method:140-lb. Hammer, 30" hydraulic drop. 5'AW Rods. , PLATE 11 VINJE & MIDDLETON ENGINEERING, INC. A EXISTING STJ'UCTURE To BE DEMOifsNED V&M JOB #06-210-p SCALE: 1 "=30' ©LOQI[C C=CTIfON PLATE: 12 - - 1201 QPnSED GRADE - ..._.-- ... . B-3roj.) PROPOSED GRADE - - I / I - - - - - N - 80J — I -- ) - - - - - LL 2. 4L V4' '' - • — - '-'' 1s7_ - • d.& 4/_,/ - ,L 60 IN PROPOSED GRADE B-4(proi.) 1711 _E'PEP GRADE --..- - - - - FILL POAIONAL ROCK T—, cz DPOI! - • . ... ....--- --. .. I .-.. .- )• A TIONL lQOCK 100-I G' A° 80 60 120 100 80 60 80 60 IOILOi[C PLATE 13 PROPOSED GRADE C UN 120 FOJI1A T)TONAL ROCK —i-- 100 RI. 160- P ::: chff2 _PROPOSED GRADE 120( 100 FOPJAfONAL)OCZ 100• RI: -r -- SCALE: 1"=30' V&M JOB #06-210-P Original ground suthice approximated from County of San Diego Topographic Survey Map No.'s .954-167'1'& 354-1683. dated 1975. 1©L©IC (ICTI[©N PLR1:E 14 I 150-1 F. )2 [ —proj. - I JPll[hJJ GRADE B - am - --- - - ________ - I - - - - - -- - p - -- - - I r- - ___________ - - - - - - I - - - - - - - - - - ----- - - - gym SCALE: 1=50 II 100 50 0:2 T -' ¶\\ • \or:\. Ns -. ___ o •• \ : \.,C..:::::::::::::::\" j - / Ap ON t O0ØØ 5 el 7. E? centr6 \._ ------ :-------- U \ 30 20 10 0 30 MILES 1 FAULT - EPICENTER MAP SAN DIEGO COUNTY REGION INDICATED EARTHQUAKE EVENTS THROUGH 75 YEAR PERIOD (1900-1974) Map data is compiled from various sources including California Division of Mines and Geology, California Institude of. Technology and the National Oceanic and Atmospheric Administration. Map is reproduced from California Division of Mines and Geology, "Earthquake Epicenter Map of California; Map Sheet 39." arthquake Magnitude I..............4.0 TO 4.9 PROJECT Job #06-210-P 5.0T05.9 - - ED ............6.0 TO 6.9 CAMINO HILLS DRIVE, CARLSBAD lu ..........7.0 TO 7.9 PLATE: 15 Fault. 10 20 30 40 . Ill C, m a 50 —i 31 60 iii 70 80 90 100 500 100 50 10 5 1 0.5 0.1 0.05 0.01 0.005 0.001 GRAIN SIZE MILLIMETERS • lu IIIIIIIIIlUuIliiiijiijjiiiiiuuijiifliuiiu Illiulu _______ 0 IV IhIIIUNuIIIIIIIui;!!u.uI, IIIIIV_IIIIIIIU uiu_IuIIIIuIiiuiiiiiniu_i;inuiuiiiiiiiuu_1111I11• au_IIIIIIluuuIIIIuIu_ilhuluuullllulu_liii....____ au_IIIIIIIlIIuIIoIIliau_iIIiIi'IuiuIIIIII..u_____ au_llhIIIlVIIIIHIV_uIIuuiII.Iuau_uiiii___ ia• lu IIoIIIuIIIu.IIIIII.0 111111111 iiiivau iiiinau_ioiiiauauiiiiiau_1111111U___ IV_IIllhIIIIIIVIIIIIIiIV_IIJIIItIuuIIOhuIl•_IIIIUIU___ au__UIUaiiuuhIuhlaUjnhIIrauiiohiiiu_liii.... au_oiuONE iiiuiiau_iiiaiuuouiiau_iuiiiuu___ au_IhIllINIUlIlIlIlU_hIIUIVlIhIIIIU_IlilUlu___ lu_IIOUhIItUUIIIutIlU_iiiiiiiiuiuiiiiuuau_iiiiiiuu_ au_IllIllINU1011Illu_IllIUlUlUIlNIllU_IlilUlU___ 20 10 0 I I I I I - S. S•ARD !IN I lid I U. S. STANDARD ir Imp Ed Ed ad Ed Ind 00 lot Ed SIEVE NUMBERS HYDROMETER 9 2 Cobbles Gravel Sand SILT OR CLAY I Coe Fine Coaese to medium Fine SAMPLE # DEPTH (FEET) SYMBOL CLASSIFICATION NAT W% LL PL P1 PROJECT: 06-210-P T-1 1 CL/CH - 45 24 23 ADDRESS: CAMINO HILLS DRIVE T-1 4 SC/CL 12.9 32 16 16 CARLSBAD DATE: JUNE, 2006 PLATE 16 VINJE AND MIDDLETON ENGINEERING, INC. U U S141) SIEVE IN INCHES U. S. STANDARD SIEVE NUMBERS HYDROMETER - -s o IM F Ed =OF = 0 0 0 0 0 — 100 11111111 III I I iiiiii I I 1111111 I 10 9C 80 20 70 30 60 50 -i M z 60 m 0 70 20 80 WHH Hil..90 100 50 10 5 1 0.5 0.1 0.05 0.01 0.005 0.001 GRAIN SIZE MILLIMETERS Cobbles Gravel Sand SILT OR CLAY Coarse Fine Coaese to medium Fine SAMPLE # DEPTH (FEET) SYMBOL CLASSIFICATION NAT W% LL PL P1 PROJECT: 06-210-P T-2 5 • SC/SM 23.6 36 25 11 ADDRESS: CAMINO HILLS DRIVE T-3 3 A .CL/CH 28.6 49 27 22 CARLSBAD DATE: JUNE, 2006 PLATE 17 VlN RFIIJ MILJIJLC I IJI'l IJcIlrn,, 10 0 500 'I 1 • 1 1.070 1.060 1.050 1.040 1.030 1 1.020 1.010 WI 1.000 0.990 0.980 IIPI 0.970 up1 0.960 0.950 0.940 0.930 SAMPLE JDPTh (FEET) SYMOOL EXPLANATOON T-1 4 FIELD MOISTURE = = SAMPLE SATURATED REBOUND Sample -. 0 0 _C-1 0 000 0 0 000 0 0 0 0 00 0 0 0 00 Cl cm qq Co 0 0 00 Co 0 10 C'l C') 10 NORMAL LOAD (PSF) 000 c2l CD 0 C20 CD VB 4 06-2 1 0-P LOAD CONSOLIDATION TEST PLATE PLATE 18 VNJE & MIDDLETON ENGINEERING,INC: 1 I' 1 1.070 1 1.060 1.050 1 1.040 1.030 1.020 1.010 1.000 0.990 '1 0.980 0.970 0.960 0.950 0.940 0930 SAMPLE DEPTH (FEET) SYMBOL EXPLANATION T-3 3 FIELD MOISTURE SAMPLE SATURATED REBOUND Sample condition DI 0 0 000 0 0 000 0 0 000 0 40 CD 0 e 0 o 00 0 0 0 00 2 o e oe 0 0 0 00 N () • 0 0 0 0 00 Cl C) qw I0 NORMAL LOAD (PSF) #06_21Op LOAD CONSOLIDATION TEST PLATE PLATE 19 VINJE & MIDDLETON ENGINEERING, INC; Temporary backcut Remove and recom pact loose fill-alluvium (see report) Proposed grade I Remove and recompact / 2' 7 ii RETAINING WALL (See report for backcut 7 specifications and bearing soil preparation) - J ••---- Wall drain Li - -- - - Bench as directed in the field 1-4—Minimum equiptment width 15min. TYPICAL STABRUZATROH FELL OR 1TA1INEN 'WALL EL CAMINO REAL AT CAMINO HILLS DRIVE, CARLSBAD CONSTRUCTION NOTES * Construct back-cut at 1/2:1 gradient Heel keyway into hillside 2916 * Recompact soil to minimum 9096 of laboratory standard * Trim excess soil to finish grade SI PLATE 20 ISOLATION JOINTS AND RE-ENTRANT CORNER REINFORCEMENT Typical - nO scale (b) TION JOINTS RE-ENTRANT C RE I NFORCEMEN NO. 4 BARS PL BELOW TOP OF RACTION JOIN ORNER (c) RE- COR ACED 1.5" SLAB ENTRANT NER CRACK NOTES: Isolation joints around the columns should be either circular as shown in (a) or diamond shaped as shown in (b). If no isolation joints are used around columns, or if the corners of the isolation joints do not meet the contraction joints, radial cracking as shown in (c)may occur (reference Ad). In order to control cracking at the re-entrant corners (±2700 corners), provide reinforcement as shown in (c). Re-entrant corner reinforcement shown herein is provided as a general guideline only and is subject to verification and changes by the project architect and/or structural engineer based upon slab geometry, location, and other engineering and construction factors. I .' VNJE & NUDDLETON ENGINEERING, INC. PLATE 21 1. LAJNb I KUTION SPECIFICATIONS: ri Provide granular, non-expansive backfill soil in 1:1 gradient wedge behind wall. Compact backfill to minimum 90% of laboratory standard: -. 2. Pràvide back drainage for wall to prevent build-up of hydrostatic pressures. Use drainage openings along base of wall or back drain system as outlined below. [, 3. Backdrain should consist of 4" diameter PVC pipe (Schedule 40 or equivalent) with perforation down.. Drain to suitable outlet at minimum 1%. Provide %fl - 1%" crushed gravel fitter wrapped in filter fabric (Mirafi 140N or equivalent). Delete filter fabric wrap if Caltrans Class 2 permeable material is used. Compact Class 2 material to minimum 90% of laboratory standard. . 4. Seal back of wall with waterproofing in accordance with architects specifications. ' 5.' Provide 'positive drainage to disallow ponding of water above wall Lined drainage ditch to minimum 2% flow away from wall is recommended 4 * Use 1% cubic foot per foot with granular backfill soil and 4 cubic foot per foot if expansive backfill soil is used . . -. VINJE & MIDDLETON ENGINEERING, INC .i. - ., t . p - . . • -.- .,.- p . . - i-p -. ., 4 - PLATE 22 - - . - :- - p - •. - - •- - . . . ' . - J4 - Pp.t._ - p--p.