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HomeMy WebLinkAboutCDP 00-29; Trautman Residence; Soil Investigation; 2000-03-13REPORT OF SOIL INVESTIGATION Proposed Trautman Residence 3530 Holley Brae Lane Carlsbad, California Geotechnical Exploration, Inc. REPORT OF SOIL INVESTIGATION Proposed Trautman Residence 3530 Holley Brae Lane Carlsbad, California JOB NO. 00-7688 13 March 2000 Prepared for: The Trautmans c/o MOSAIC ARCHITECTURE GEOTECHNICAL EXPLORATION, INC. SOIL & FOUNDATION ENGINEERING • GROUNDWATER HAZARDOUS MATERIALS MANAGEMENT • ENGINEERING GEOLOGY 13 March 2000 The Trautmans Job No. 00-7688 c/o MOSAIC ARCHITECTURE 3568 Sydney Place San Diego, CA 92116 Attn: Ms. Carolyn LaPrance Subject: Report of Soil Investigation Proposed Trautman Residence 3530 Holly Brae Lane Carlsbad, California Dear Mr. and Mrs. Trautman: In accordance with your request and our proposal of January 26, 2000, Geotechnical Exploration^ Inc. has performed an Investigation of the soil conditions at the existing undeveloped residential lot. The field work was performed on February 14, 2000. It is our understanding that a two-story residence and associated improvements are proposed for the subject property. These improvements include several patio areas, an extensive driveway, and parking areas. Because of the moderately sloping nature of the lot, imported fill soils will be required to construct a level building pad. Our investigation revealed that the site is underlain by medium dense to dense, slightly silty to clayey sand formational soil overlain by shallow silty sand topsoil up to V/2 feet thick. The formational soils have good-bearing strength characteristics, are of low to medium expansion potential and are suitable for support of imported fill soils and the proposed residence and improvements. However, the encountered topsoils are of low density and are not suitable for support of the proposed structure in their existing condition. These soils will need to be excavated and recompacted if utilized as support for new foundations and slab areas. Such soil preparation can be accomplished during the process of preparing the site to receive imported fill soils. In our opinion, if the conclusions and recommendations presented in this report are implemented during site preparation, the site will be suited for the new residential improvements. 7420 TRADE STREET • SAN DIEGO, CA 92121 • (858) 549-7222 • FAX: (858) 549-1604 . E-MAIL: geoteck@pacbell.net This opportunity to be of service is sincerely appreciated. Should you have any questions concerning the following report, please do not hesitate to contact us. Reference to our Job No. 00-7688 will expedite response to your inquiries. Respectfully submitted, GEOTECHNICAL EXPLORATION, INC. LesliH5. Reed, l^fesi^nt C.E.G.[exp. 3-31-01]/R.G. 3391 Jaime A. Cerros, P.E. R.C.E. 34422/G.E. 2007 Senior Geotechnical Engineer DCV/LDR/JAC/pj TABLE OF CONTENTS PAGE I. SCOPE OF WORK 1 II. SITE DESCRIPTION 2 III. FIELD INVESTIGATION 3 IV. DESCRIPTION OF SOILS 3 V. GROUNDWATER 3 VI. LABORATORY TESTS AND SOIL INFORMATION 4 VII. CONCLUSIONS AND RECOMMENDATIONS 6 VIII. GRADING NOTES 13 IX. LIMITATIONS 14 FIGURES la. Site Map Ib. Plot Plan Ila-d. Exploratory Logs III. Laboratory Data IV. Foundation Requirements Near Slopes APPENDICES A. Unified Soil Classification System B. General Earthwork Specifications REPORT OF SOIL INVESTIGATION Proposed Trautman Residence 3530 Holly Brae Lane Carlsbad, California JOB NO. 00-7688 The following report presents the findings and recommendations of Geotechnical Exploration, Inc. for the subject project. I. SCOPE OF WORK It is our understanding, based on communications with Ms. Carolyn LaFrance of Mosaic Architecture, that a two-story residence and associated improvements, including patio areas and driveway and parking areas, are proposed for the existing undeveloped residential lot. We have reviewed preliminary plans prepared by Mosaic Architecture, dated January 28, 2000. With the above in mind, the Scope of Work is briefly outlined as follows: 1. Identify and classify the surface and subsurface soils in the addition areas to the explored depth, in conformance with the Unified Soil Classification System (refer to Appendix A). 2. Recommend possible site preparation procedures. 3. Recommend the allowable bearing capacity and wall active and passive pressures for the encountered site bearing soils. 4. Provide a preliminary estimate of the anticipated settlement of the on-site, properly prepared soils under the new proposed structural loads. 3^ Proposed Trautman Residence Job No. 00-7688 Carlsbad, California Page 2 The scope of this investigation did not include geologic and seismic studies for the site. Should these be required by the governing agencies (i.e.. City of Carlsbad), this office can perform the required studies at your request. II. SITE DESCRIPTION The property is known as: Assessor's Parcel No. 207-063-55, Parcel C (ex. doc. 97- 063913) Parcel B in doc. 063916, per Map No. 17539, in the City of Carlsbad, County of San Diego, State of California. The site, consisting of approximately 0.36-acre, is located on the southwest side of Holly Brae Lane, in the northern portion of the City of Carlsbad. The property is currently undeveloped. The property is bordered on the northwest, southwest and southeast by single-family residential properties, and on the northeast by Holly Brae Lane. The property is part of a moderately sloping natural hillside descending to the northeast from an approximate elevation of 327 feet above mean sea level (MSL) at the southwest property corner, to 296 feet above MSL at the southeast property corner. The lower 5- to 6-foot portion of the slope appears to have been modified by grading and is a "cut" slope. Access to the proposed residence is anticipated to be via a long concrete driveway from Holly Brae Lane. The proposed residential structure is to be of wood frame construction with a concrete perimeter foundation and slab on-grade floors. Retaining walls are planned to provide level areas for patio improvements. It is our understanding that a swimming pool and associated improvements are planned for the lower elevation, eastern portion ofthe lot. Vegetation on the site consists primarily of native shrubbery, grass, and some iceplant. Proposed Trautman Residence Job No. 00-7688 Carlsbad, California Page 3 III. FIELD INVESTIGATION Four exploratory excavations were logged by our field representative in areas where new foundations and/or improvements are planned. Samples were taken of the predominant soils throughout the field operation. Excavation logs are presented here as Figure No. II. The predominant soils have been classified in conformance with the Unified Soil Classification System (refer to Appendix A). Bulk soil samples were obtained. IV. DESCRIPTION OF SOILS In general, the site is underlain by medium dense to dense, native/formational, slightly clayey to clayey silty sand/sandstone. The upper portion (1 to 2 feet) of these materials can be clayey. These materials were encountered in all our exploratory pits. The formational materials are overlain by shallow depths of loose silty sand topsoils. Depth to the underlying formational soils ranges up to Vh feet. The formational soils have excellent bearing strength characteristics and are suitable for support of the proposed foundation and slabs and imported fill soils. The formational soils are of low to moderate expansion potential (based on our experience with these clayey sandy soils in this area of the County of San Diego). The topsoils are of low density and are not suitable for bearing in their in situ condition. Due to their shallow depth, the topsoils can be easily improved during planned grading operations. V. GROUNDWATER No groundwater was encountered during the course of our relatively shallow field investigation and we do not expect significant groundwater problems to develop in Proposed Trautman Residence Carlsbad, California Job No. 00-7688 Page 4 the future - if the property is developed with proper surface drainage and that proper surface and subsurface drainage are maintained on the property. We note that imported fill soil will be required to achieve planned surface elevations. Placement of fill soil on dense formational material can create perched water conditions, specifically at the toe area ofthe proposed fill slope and behind retaining walls. In addition, it should be kept in mind that any required grading operations may change surface drainage patterns and/or reduce permeabilities due to the densification of compacted soils. Such changes of surface and subsurface hydrologic conditions, plus irrigation of landscaping or significant increases in rainfall, may result in the appearance of minor amounts of surface or near-surface water at locations where none existed previously. The damage from such water is, in general, expected to be minor and cosmetic in nature, if good positive drainage is implemented at the completion of construction. Corrective action should be taken on a site-specific basis if, and when, it becomes necessary. VI. LABORATORY TESTS AND SOIL INFORMATION Laboratory tests were performed on the typical encountered natural soil materials in order to evaluate their physical and mechanical properties and their ability to support the proposed additions. The following tests were conducted on the sampled soils: 1. Moisture/Density Relations (ASTM D1557-91, Method A) 2. Mechanical Analysis (ASTM D422-90) 3. Expansion Index Test (UBC Test Method 29-2, Table 18-1-B) Proposed Trautman Residence Job No. 00-7688 Carlsbad, California Page 5 The relationship between the moisture and density of soil samples gives qualitative information regarding soil strength characteristics and soil conditions. The Mechanical Analysis Test was used to aid in the classification of the soils according to the Unified Soil Classification System. The expansion potential of the on-site soils was determined utilizing the Uniform Building Code Test Method for Expansive Soils (UBC Standard No. 29-2). In accordance with the UBC (Table 18-1-B), expansive soils are classified as follows: 0 to 20 Very low 21 to 50 Low 51 to 90 Medium 91 to 130 Hiqh Above 130 Very high According to the UBC Test Method for Expansive Soils, the sampled and tested soils on the site have a medium expansion potential. Based upon our experience with formational materials in this area of Carlsbad, our observations ofthe primary soil types on the project, and our previous experience with laboratory testing of similar soils, our Geotechnical Engineer has utilized conservative values for friction angle and cohesion for those formational soils which will have significant lateral support or bearing functions on the project. These values have been utilized in recommending the allowable bearing value as well as the active and passive earth pressures for wall and footing designs should they be utilized as such in site development. Limited occurrences of up to moderately expansive soils were encountered during field exploration. Proposed Trautman Residence Job No. 00-7688 Carlsbad, California Page 6 Currently, we understand imported soils are planned for the site. These soils will require laboratory analysis for soil strength properties, expansion indices, passive and active pressures, bearing capacity, etc., at the time they are brought to the site or before. VII. CONCLUSIONS AND RECOMMENDATIONS The following conclusions and recommendations are based upon the field investigation conducted by our firm, in conjunction with our knowledge and experience with the soils in the City of Carlsbad. Our investigation revealed that the site is underlain at shallow depths by medium dense to dense formational materials consisting primarily of slightly silty to clayey sandstone. These soils are locally overlain by a limited thickness of silty sand topsoils. The topsoils range up to IV2 feet thick. The encountered topsoils are not suitable as bearing materials and, in our opinion, are not suitable for support of structural loads without proper recompaction. It is recommended that the loose topsoils be removed and recompacted prior to placement of imported fill soils. The prevailing formational materials encountered on the site are medium dense to dense and of low to medium expansion potential (expansion index up to 70 per UBC). It is our opinion that the formational materials will provide adequate support for the proposed imported fill soils and/or the new residence and improvements. Foundation excavations shall extend into properly compacted fill soils into dense natural soils. 0 Proposed Trautman Residence Job No. 00-7688 Carlsbad, California Page 7 A. Preparation of Soils for Site Additions 1. We understand that imported fill soils will be utilized to reach planned grades at the site. Prior to fill soil placement, the existing site topsoils shall be removed. If desired, these soils can be cleaned, recompacted and mixed with imported soils as part of the proposed fill at the site. Compacted fill placement shall be per the attached grading specifications in Appendix B. A representative of our office shall observe topsoil removal prior to approving fill soil placement. 2. Should removal and recompaction be chosen, the existing loose topsoils shall be removed to expose underlying dense formational soils. Anticipated removal depths are 1 to Vh feet, to a minimum of 5 feet outside of the proposed residence and improvements or per the recommendations of our field personnel. For fill soils, the horizontal distance of rework beyond the toe of the slope shall be at least three times the depth ofthe key ofthe slope. The minimum depth of compacted fill shall be at least 2 feet below the bottom of foundations, if they are placed on fill. 3. Any buried objects or particular soft soil areas which might be discovered on the site in areas to receive new foundations or improvements shall be removed and the excavation shall be properly backfilled with approved on- site or imported fill soils. Imported soils shall be low-expansive and shall be compacted to at least 90 percent of Maximum Dry Density. On-site clayey soils shall be placed with a moisture content at least 4 percent over the Optimum Moisture. Proposed Trautman Residence Job No. 00-7688 Carlsbad, California Page 8 B. Desiqn Parameters for Existinq and Proposed Foundations 4. For preliminary foundation design of new footings founded in on-site formational soils, based on the assumption that the new footings will be placed at least 18 inches into dense natural (formational) soils or properly compacted on-site soils, we provide a preliminary allowable soil bearing capacity equal to 2,500 pounds per square foot (psf). This applies to footings at least 18 inches into formation and at least 12 inches in width. For wider and/or deeper footings, the allowable soil bearing capacity may be calculated based on the following equation: Qa = 1500D-I-1000W where "Qa" is the allowable soil bearing capacity (in psf); "D" is the depth of the footing (in feet) as measured from the lowest adjacent grade; and "W" is the width ofthe footing (in feet). The allowable soil bearing capacity may be increased one-third for analysis including wind or earthquake loads. A maximum of 6,000 psf may be allowed for vertical bearing capacity for foundations in dense, sound formational material. Floors consisting of slabs on-grade shall be at least 4 inches thick and be reinforced with at least No. 3 steel bars spaced no farther than 18 inches apart in both directions. The slabs shall be underlain with a 4-inch-thick Proposed Trautman Residence Carlsbad, California Job No. 00-7688 Page 9 layer of clean sand (SE equal to 30 or higher) and a reinforced moisture barrier at mid-height. Conventional shallow foundations and footings of proposed structures, walls, etc., when founded 5 feet and farther away from the top of allowable slopes, may be of standard design in conformance with the recommended load- bearing capacities. If the proposed foundations and footings are located closer than 5 feet inside the top of allowable slopes, they shall be deepened to 11/2 feet below a line beginning at a point 5 feet horizontally inside the slopes and projected outward and downward, parallel to the face ofthe slope (see Figure No. IV). Footings on slopes or close to slopes greater than 15 feet in height shall have a horizontal distance to the face ofthe slope not less than one-third the slope height. The horizontal distance shall be measured from the top ofthe footing. The following table summarizes site-specific seismic design criteria to calculate the base shear needed for the design of the residential structure. The design criteria was obtained from the Uniform Building Code (1997 edition). Parameter Value Reference Seismic Zone Factor, Z 0.40 Table 16-1 Soil Profile Type Sc Table 16-J Seismic Coefficient, Ca 0.40Na Table 16-Q Seismic Coefficient, Cv 0.56Nv Table 16-R Near-Source Factor, Na 1.0 Table 16-S Near-Source Factor, Nv 1.0 Table 16-T Seismic Source Type B Table 16-U Proposed Trautman Residence Job No. 00-7688 Carlsbad, California Page 10 7. The passive earth pressure of the encountered medium dense to dense, natural-ground formational soils and properly recompacted topsoils (to be used for design of shallow foundations and footings to resist the lateral forces) shall be based on an Equivalent Fluid Weight of 275 pounds per cubic foot. This passive earth pressure shall only be considered valid for design if the ground adjacent to the foundation structure is essentially level for a distance of at least three times the total depth of the foundation and is properly compacted or dense native soil. 8. A Coefficient of Friction of 0.40 times the dead load may be used between the bearing soils and concrete foundations, walls, or floor slabs. C. Retaining Walls The following design criteria is provided for proposed site retaining walls: 9. The active earth pressure (to be utilized in the design of any cantilever walls, allowed to rotate at the top) shall be based on an Equivalent Fluid Weight of 38 pounds per cubic foot (for level backfill only and low-expansive, on-site or low-expansive imported soils). We recommend that very low-expansive to low expansive soils be used as wall backfill material. Retaining wall plans shall indicate that walls shall be backfilled with very low to low expansive soils (EI less than 50 only). Retaining walls with 2.0:1.0 gradient (horizontal to vertical) in the backfill shall be designed with an equivalent fluid weight of 52 pcf. Any applicable surcharge loads within the potential failure wedge behind the retaining walls shall be included in the retaining wall design loads. In the event that a retaining wall is to be designed for a restrained condition (not allowed to rotate at the top), a uniform pressure equal to 9xH (nine Proposed Trautman Residence Job No. 00-7688 Carlsbad, California Page 11 times the total height of retained wall, considered in pounds per square foot) shall be considered as acting everywhere on the back ofthe wall in addition to the design Equivalent Fluid Weight. Any other surcharge loads applied within a horizontal distance measured from the face of the wall equal to its height shall be considered in the structural design. The wall backfill area shall be measured from the back of the wall to the inclined plane, passing through the heel ofthe retaining wall at an inclination of 30 degrees from vertical. D. Site Drainage Considerations 10. Adequate measures shall be taken to establish proper site drainage after completion of the proposed residential project. Drainage waters from this site must be directed away from foundations, floor slabs, and footings, and toward the natural easterly drainage direction for this area or into properly designed and approved drainage facilities. Roof gutters and downspouts should be installed on the structure, with runoff directed away from the foundations via closed drainage lines. Proper subsurface and surface drainage will help reduce the potential for waters to seek the level of the bearing soils under the foundations and footings. Failure to observe this recommendation could result in undermining, uplifting and differential settlement of the structure or other improvements on the site. Currently, the Uniform Building Code requires a minimum 2 percent surface gradient for proper drainage of building pads, unless waived by the building official. Concrete pavement may have a minimum gradient of 0.5 percent. 11. Due to the possible buildup of perched water (derived primarily from rainfall and irrigation), minor amounts of surface or near-surface water may appear Proposed Trautman Residence Job No. 00-7688 Carlsbad, California Page 12 at locations where none existed previously. The damage from such water is expected to be minor and cosmetic in nature if good positive drainage is implemented at the completion of construction. In order to reduce the potential for moisture-related problems to develop at the site, proper drainage must be maintained. Corrective action should be taken on a site- specific basis, if and when it becomes necessary. 12. Planter areas, flower beds, and planter boxes shall be sloped to drain away from the perimeter foundations, footings, and floor slabs. Planter boxes shall be constructed with a closed bottom and a subsurface drain, installed in gravel, with the direction of subsurface and surface flow away from the foundations, footings, and floor slabs, to an adequate drainage facility. Any planter areas adjacent to the building or surrounded by concrete improvements shall be provided with sufficient area drains to help for quick runoff disposal. No water shall be allowed to pond adjacent to the building or other improvements. 13. Retaining walls shall be provided with a continuous backdrain (either gravel or geocomposite such as Miradrain 6000), waterproofing membrane, and a subdrain system. The subdrain system shall consist of a perforated 4-inch- diameter PVC schedule 40 pipe or SDR 35 pipe in an envelope of crushed rock gravel and shall be wrapped with geofabric such as Mirafi 140N or equivalent. The subdrain shall be founded a minimum of 18 inches below interior floor slab elevations and discharge into an approved drainage facility. CW Proposed Trautman Residence Job No. 00-7688 Carlsbad, California P^Qe 13 VIII. GRADING NOTES Any required grading operations shall be performed in accordance with the General Earthwork Specifications (Appendix B) and the requirements of the County of San Diego Grading Ordinance. 14. Geotechnical Exploration, Inc. recommends that we be asked to verify the actual soil conditions revealed during site grading work and/or footing excavations to be as anticipated in this "Report of Soil Investigation." In addition, the compaction of any fill soils placed during site grading work must be tested. It is the responsibility of the grading contractor to comply with the requirements on the grading plans and the local grading ordinance. 15. It is the responsibility of the owner and/or developer to ensure that the recommendations summarized in the report are carried out in the field operations and that our recommendations for design of the project are incorporated in the building and grading plans. It is recommended that we review the grading and foundation plans prior to construction operations to verify that our recommendations are incorporated in the plans, and to verify that any additional or modified recommendations that are warranted are included in the plans. 16. This firm does not practice or consult in the field of safety engineering. We do not direct the contractor's operations, and we cannot be responsible for the safety of personnel other than our own on the site; the safety of others is the responsibility ofthe contractor. The contractor should notify the owner if he considers any ofthe recommended actions presented herein to be unsafe. CH Proposed Trautman Residence Job No. 00-7688 Carlsbad, California Page 14 IX. LIMITATIONS Our conclusions and recommendations have been based upon all available data obtained from our field investigation and laboratory analysis, as well as our experience with the soils and native materials located in the Carlsbad area of the County of San Diego. Of necessity, we must assume a certain degree of continuity between exploratory excavations and/or natural exposures. It is, therefore, necessary that all observations, conclusions, and recommendations be verified at the time grading operations begin or when footing excavations are placed. In the event discrepancies are noted, additional recommendations may be issued, if required. The work performed and recommendations presented herein are the result of an investigation and analysis that meet the contemporary standard of care in our profession within the County of San Diego. This report should be considered valid for a period of two (2) years, and is subject to review by our firm following that time. If significant modifications are made to the building and/or grading plans, especially with respect to the height and location of the proposed structure, this report must be presented to us for immediate review and possible revision. The firm of Geotechnical Exploration, Inc. shall not be held responsible for changes to the physical condition of the property, such as addition of fill soils or changing drainage patterns, which occur subsequent to issuance of this report, or any work done without our observations and testing. CH 0 Proposed Trautman Residence Carlsbad, California Job No. 00-7688 Page 15 This opportunity to be of service is sincerely appreciated. Should you have any questions, please feel free to contact our office. Reference to our Job No. 00- 7688 will help expedite a reply to your inquiries. Respectfully submitted, GEOTECHNICAL EXPLORATION, INC. Dorl4ld C. Vaughi^ Pro j ecLGoo rd i n ato r Jaime A. Cerros, P.E. R.C.E. 34422/G.E. 2007 Senior Geotechnical Engineer DCV/LDR/JAC/pj \ Leslie'D. Ree^dTPresident C.E.G. 999[exp. 3-31-01]/R.G. 3391 lio 002CC.7 CH^ SITE MAP Proposed Trautman Residence 3930 Holly Brae Lane Carlsbad, Ca. Figure Number la Job Number 00-7688 Proposed Very low mported expansion (per UBC) (Proposed) Site Profile SCALE: 1" - 20 (approximate) NOTE: TWB Plot Plan h not to be uMd for 1^ purpoBM. Locotlorw and dimeniions ore app note. •" '— moto. Actuol property dlmenilone ond locotlone of utlllUea may be obtained from the Approved Building Plane or the •Ae-Bullt" Groding Plane. Piot Plan (showing proposed location) HP-3 APPROXIMATE LOCATION OF EXPLORATORY EXCAVATION EXISTING TOPOGRAPHY Approximate Property Boundary Trautman Residence 3930 Holly Brae Lano Carisbad. Ca. Figure Number Ib Job Number CX)-7688 Geotechnical Exploration, Inc. '^EQUIPMENT Hand Tools DIMENSION & TYPE OF EXCAVATION 3' X 2.5' X 3' Pit DATE LOGGED 02-14-2000 SURFACE ELEVATION Not Available GROUNDWATER DEPTH Not encountered LOGGED BY DV o m FIELD DESCRIPTION AND CLASSIFICATION DESCRIPTION AND REMARKS (Grain size. Density, Moisture, Color) ci c/i =5 -Lo lu— O 2 cn o ri o m CJ SILTY SAND. Loose-moist, gray brown-brown, TOPSOIL SM 1 - - becomes slightly clayey -f '.-f.,l'-,fL CLAYEY SAND. Medium dense, damp, dark orange brown. Qlv SC 4.0 101.5 Bottom of Excavation © 3' 6 - y WATER TABLE ^ LOOSE BAG SAMPLE Q] IN-PLACE SAMPLE • DRIVE SAMPLE s SAND CONE/F.D.T. ^ STANDARD PENETRATION TEST JOB NAME PROPOSED TRAUTMAN RESIDENCE y WATER TABLE ^ LOOSE BAG SAMPLE Q] IN-PLACE SAMPLE • DRIVE SAMPLE s SAND CONE/F.D.T. ^ STANDARD PENETRATION TEST SITE LOCATION 3930 Holly Brae Lane, Carlsbad, Ca. y WATER TABLE ^ LOOSE BAG SAMPLE Q] IN-PLACE SAMPLE • DRIVE SAMPLE s SAND CONE/F.D.T. ^ STANDARD PENETRATION TEST JOB NUMBER 00-7688 HGURE NUMBER lla REVIEWED BY|^|^|^ LOG No. HP-1 '^EQUIPMENT Hand Tools DIMENSION & TYPE OF EXCAVATION 3' X 3' X 3" Pit DATE LOGGED ^ 02-14-2000 SURFACE ELEVATION Not Available GROUNDWATER DEPTH Not encountered LOGGED BY DV o m 1 - 2 - 4 - FIELD DESCRIPTION AND CUSSIFICATION DESCRIPTION AND REMARKS (Grain size, Densiiy, Moisture, Color) SILTY SAND. Loose-moist, brown-gray brown, c/5 cJ C/5 SM TOPSOIL - slightly clayey SUGHTLY SILTY SAND/SANDSTONE. Medium dense/dense, damp, dark orange brown. Qlv Bottom of Excavation @ 3' -Lo SC LiJ^ a.l/' So O 2 LLI a o o C/> O -I- I X C3 LLI O 11 V WATER TABLE [3 LOOSE BAG SAMPLE Q] IN-PLACE SAMPLE • DRIVE SAMPLE s SAND CONE/F.D.T. JOB NAME PROPOSED TRAUTMAN RESIDENCE V WATER TABLE [3 LOOSE BAG SAMPLE Q] IN-PLACE SAMPLE • DRIVE SAMPLE s SAND CONE/F.D.T. SITE LOCATION 3930 Holly Brae Lane, Carlsbad, Ca. V WATER TABLE [3 LOOSE BAG SAMPLE Q] IN-PLACE SAMPLE • DRIVE SAMPLE s SAND CONE/F.D.T. JOB NUMBER 00-7688 RGURE NUMBER Ilb REVIEWED BY^j^j^ LOG No. HP-2 ^ STANDARD PENETRATION TEST JOB NUMBER 00-7688 RGURE NUMBER Ilb LOG No. HP-2 '^EQUIPMENT Hand Tools DIMENSION & TYPE OF EXCAVATION 3' X 2.5' X 3' Pit DATE LOGGED ^ 02-14-2000 SURFACE ELEVATION Not Available GROUNDWATER DEPTH Not encountered LOGGED BY DV FIELD DESCRIPTION AND CLASSIFICATION UJ liJ 4— u a. LLI"^— ON_ 5S Q a. 2 ^ Y M.D.D.) + 1 _i Vl SAMPLE O.D. (INCHES) DEPTH 1 SYMBOL SAMPLE DESCRIPTION AND REMARKS (Grain size. Density, Moisture, Color) tn cJ c/j Q- xn OPTIMU MOISTU MAXIMl DENSIT c/3 O Is EXPAN CONSC li m o SAMPLE O.D. (INCHES) -: jv". t SILTY SAND. Loose-moist, brown. SM ' ••. TOPSOIL 1 - 2 - - CLAYEY SAND. Medium dense, moist, dark orange brown. Qlv SC <v4' r/.y.j.. 3 Bottom of Excavation @ 3' 4 - 5 6 - V WATER TABLE LOOSE BAG SAMPLE [3 IN-PLACE SAMPLE • DRIVE SAMPLE [s] SAND CONE/F.D.T. ^ STANDARD PENETRATION TEST PROPOSED TRAUTMAN RESIDENCE SITE LOCATION 3930 Holly Brae Lane, Carlsbad, Ca. JOB NUMBER 00-7688 RGURE NUMBER lie REVIEWED BY, LDR LOG No. HP-3 EQUIPMENT Hand Tools DIMENSION & TfPE OF EXCAVATION 3" X 2.5' X 3' Pit DATE LOGGED 02-14-2000 SURFACE ELEVATION Not Available GROUNDWATER DEPTH Not encountered LOGGED BY DV FIELD DESCRIPTION AND CLASSIFICATION DESCRIPTION AND REMARKS (Grain size. Density, Moisture, Color) t/3 c/i \n lo alv} I s El O 2 2 O c/) o il + I _i X S3 LlJ CJ t: : Z m CJ CJ ^1. 1 - 2 -^^"•!:' SILTY SAND. Loose-moist, dork brown. TOPSOIL SM CLAYEY SAND. Medium dense, moist, dark orange brown. Qlv SC Bottom of Excavation @ 3' y WATER TABLE LOOSE BAG SAMPLE Q] IN-PLACE SAMPLE • DRIVE SAMPLE SAND CONE/F.D.T. ^ STANDARD PENETRATION TEST JOB NAME PROPOSED TRAUTMAN RESIDENCE SITE LOCATION 3930 Holly Brae Lane, Carlsbad, Co. JOB NUMBER 00-7688 RGURE NUMBER lid REVIEWED BY, LDR LOG No. HP-4 140 LABORATORY SOIL DATA SUMMARY 130 120 110 100 90 80 MAXIMUM DRY DENSITY (pcf) OPTIMUM MOISTURE CONTENT (X) 123 11 100 80 S 6C y 40 Gravel Sand Fines Gravel Cofit Tc Hei i uit T\rit Cli/ • U.S. o o c slancird ^ o < '. ° ' a o < X j sieve si2«s 3 : 20 o *o . " O ^ ^ *f 00 «<• — o o 10 20 30 LABORATORY COMPACTION TEST oooo GRAIN O',*ME:-:J. W 2.70 2.60. 2.50^ SPECIFIC GRAVITY ZERO AIR VOIDS CURVES SOIL TYPE SOIL CLASSIFICATION BORING No. HANDPIT Ho. DEPTH 1 Dark orange clayey silty sand HP-1 2 3 EXPANSION INDEX 1 2 . 3 FIGURE NUMBER Ilia JOB NUMBER 00-7688 4D 10 FOUNDATION REQUIREMENTS NEAR SLOPES PROPOSED STRUCTURE CONCRETE FLOOR SLAB TOP OF COMPACTED FILL SLOPE (Any loose soils on the slope surface shall not be considered to provide lateral or vertical strength for the footing or for slope stability. Needed depth of imbedment shall be measured from competent soil.) COMPACTED FILL SLOPE WITH MAXIMUM INCLINATION AS PER SOILS REPORT. REINFORCEMENT OF FOUNDATIONS AND FLOOR SLABS FOLLOWING THE RECOMMENDATIONS OF THE ARCHITECT OR STRUCTURAL ENGINEER. CONCRETE FOUNDATION 12" MINIMUM OR AS DEEP AS REQUIRED FOR LATERAL STABILITY. TOTAL DEPTH OF FOOTING MEASURED FROM FINISH SOIL SUB-GRADE OUTER MOST FACE N,^ OF FOOTING TYPICAL SECTION (SHOWING PROPOSED FOUNDATION LOCATED WITHIN 5 FEET OF TOP OF SLOPE) 12" FOOTING/5' SETBACK TOTAL DEPTH OF FOOTINC O ^ £ 3 LU (/) U u. z o U o 5 1.5:1.0 SLOPE # 2.0:1.0 SLOPE f 0 52" 42" 1' 45" 36" 2' 36" 30" 3' 28" 24" 4' 20" 18" 5' 12" 12" # when applicable FIGURE NUMBER IV JOB NUMBER OO-7688 (ID ID APPENDIX A UNIFIED SOIL CLASSIFICATION CHART SOIL DESCRIPTION COARSE-GRAINED More than half of material Is larger than a No. 200 sieve GRAVELS, CLEAN GRAVELS More than half of coarse fraction is larger than GW Well-graded gravels, gravel and sand mix- No. 4 sieve size, but smaller than 3" tures, little or no fines. GP Poorly graded gravels, gravel and sand mix- tures, little or no fines. GRAVELS WITH FINES GM Silty gravels, poorly graded gravel-sand-silt (appreciable amount) mixtures. GC Clay gravels, poorly graded gravel-sand-silt mixtures. SANDS, CLEAN SANDS SW Well-graded sand, gravelly sands, little or no More than half of coarse fraction is smaller than a no fines. No 4 sieve SP Poorly graded sands, gravelly sands, little or no fines. SANDS WITH FINES SM Silty sands, poorly graded sand and silty (appreciable amount) mixtures. SC Clayey sands, poorly graded sand and clay mixtures. FINE-GRAINED IMore than half of material is smaller than a No. 200 sieve SILTS AND CLAYS ML Inorganic silts and very fine sands, rock flour, sandy silt and clayey-silt sand mixtures with a slight plasticity. Liquid Limit Less Than 50 CL Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, silty clays, clean clays. OL Organic silts and organic silty clays of low plasticity. MH Inorganic silts, micaceous or diatomaceous fine sandy or silty soils, elastic silts. Liquid Limit Greater Than 50 CH Inorganic clays of high plasticity, fat clays. OH Organic clays of medium to high plasticity. HIGHLY ORGANIC SOILS PT Peat and other highly organic soils. APPENDIX B GENERAL EARTHWORK SPECIFICATIONS General The objective of these specifications is to properly establish procedures for the clearing and preparation of the existing natural ground or properly compacted fill to receive new fill; for the selection of the fill nnaterial; and for the fill compaction and testing methods to be used. Scope of Work The earthwork includes all the activities and resources provided by the contractor to construct in a good workmanlike manner all the grades of the filled areas shown in the plans. The major items of work covered in this section include all clearing and grubbing, removing and disposing of materials, preparing areas to be filled, compacting of fill, compacting of backfills, subdrain installations, and all other work necessary to complete the grading of the filled areas. Site Visit and Site Investigation 1. The contractor shall visit the site and carefully study it, and make all inspections necessary in order to determine the full extent of the work required to complete all grading in conformance with the drawings and specifications. The contractor shall satisfy himself as to the nature, location, and extent of the work conditions, the conformation and condition of the existing ground surface; and the type of equipment, labor, and facilities needed prior to and during prosecution of the work. The contractor shall satisfy himself as to the character, quality, and quantity of surface and subsurface materials or obstacles to be encountered. Any inaccuracies or discrepancies between the actual field conditions and the drawings, or between the drawings and specifications, must be brought to the engineer's attention in order to clarify the exact nature of the work to be performed. 2. A soils investigation report has been prepared for this project by GEI. It is available for review and should be used as a reference to the surface and subsurface soil and bedrock conditions on this project. Any recommendations made in the report of the soil investigation or subsequent reports shall become an addendum to these specifications. Authority of the Soils Engineer and Engineering Geologist The soils engineer shall be the owner's representative to observe and test the construction of fills. Excavation and the placing of fill shall be under the observation of the soils engineer and his/her representative, and he/she shall give a written opinion regarding conformance with the specifications upon completion of grading. The soils engineer shall have the authority to cause the removal and replacement of porous topsoils, uncompacted or improperly compacted fills, disturbed bedrock materials, and soft alluvium, and shall have the authority to approve or reject materials proposed for use in the compacted fill areas. The soils engineer shall have, in conjunction with the engineering geologist, the authority to approve the preparation of natural ground and toe-of-fill benches to receive fill materiai. The engineering geologist shall have the authority to evaluate the stability of the existing or proposed slopes, and to evaluate the necessity of remedial measures. If any unstable condition is being created by cutting or filling, the engineering geologist and/or soils engineer shall advise the contractor and owner immediately, and prohibit grading in the affected area until such time as corrective measures are taken. B2 The owner shall decide all questions regarding: (1) the interpretation of the drawings and specifications, (2) the acceptable fulfillment of the contract on the part of the contractor, and (3) the matter of compensation. Clearing and Grubbing 1. Clearing and grubbing shall consist of the removal from all areas to be graded of all surface trash, abandoned improvements, paving, culverts, pipe, and vegetation (including - but not limited to - heavy weed growth, trees, stumps, logs and roots larger than 1-inch in diameter). 2. All organic and inorganic materials resulting from the clearing and grubbing operations shall be collected, piled, and disposed of by the contractor to give the cleared areas a neat and finished appearance. Burning of combustible materials on-site shall not be permitted unless allowed by local regulations, and at such times and in such a manner to prevent the fire from spreading to areas adjoining the property or cleared area. 3. It is understood that minor amounts of organic materials may remain in the fill soils due to the near impossibility of complete removal. The amount remaining, however, must be considered negligible, and in no case can be allowed to occur in concentrations or total quantities sufficient to contribute to settlement upon decomposition. Preparation of Areas to be Filled 1. After clearing and grubbing, all uncompacted or improperly compacted fills, soft or loose soils, or unsuitable materials, shall be removed to expose competent natural ground, undisturbed bedrock, or properly compacted fill as indicated in the soiis investigation report or by our field representative. Where the unsuitable materials are exposed in final graded areas, they shall be removed and replaced as compacted fill. 2. The ground surface exposed after removal of unsuitable soils shall be scarified to a depth of at least 6 inches, brought to the specified moisture content, and then the scarified ground compacted to at least the specified density. Where undisturbed bedrock is exposed at the surface, scarification and recompaction shall not be required. 3. All areas to receive compacted fill, including all removal areas and toe-of-fill benches, shall be observed and approved by the soils engineer and/or engineering geologist prior to placing compacted fill. 4. Where fills are made on hillsides or exposed slope areas with gradients greater than 20 percent, horizontal benches shall be cut into firm, undisturbed, natural ground in order to provide both lateral and vertical stability. This is to provide a horizontal base so that each layer is placed and compacted on a horizontal plane. The initial bench at the toe of the fill shall be at least 10 feet in width on firm, undisturbed, natural ground at the elevation of the toe stake placed at the bottom of the design slope. The engineer shall determine the width and frequency of all succeeding benches, which will vary with the soil conditions and the steepness of the slope. Ground slopes flatter than 20 percent (5.0:1.0) shall be benched when considered necessary by the soils engineer. B3 Fill and Bankfill Material Unless otherwise specified, the on-site material obtained from the project excavations may be used as fill or backfill, provided that all organic material, rubbish, debris, and other objectionable material contained therein is first removed. In the event that expansive materials are encountered during foundation excavations within 3 feet of finished grade and they have not been properly processed, they shall be entirely removed or thoroughly mixed with good, granular material before incorporating them in fills. No footing shall be allowed to bear on soils which, in the opinion of the soils engineer, are detrimentally expansive - unless designed for this clayey condition. However, rocks, boulders, broken Portland cement concrete, and bituminous-type pavement obtained from the project excavations may be permitted in the backfill or fill with the following limitations: 1. The maximum dimension of any piece used in the top 10 feet shall be no larger than 6 inches. 2 Clods or hard lumps of earth of 6 inches in greatest dimension shall be broken up before compacting the material in fill. 3. If the fill material originating from the project excavation contains large rocks, boulders, or hard lumps that cannot be broken readily, pieces ranging from 6 inches in diameter to 2 feet in maximum dimension may be used in fills below final subgrade if all pieces are placed in such a manner (such as windrows) as to eliminate nesting or voids between them. No rocks over 4 feet will be allowed in the fill. 4. Pieces larger than 6 inches shall not be placed within 12 inches of any structure. 5. Pieces larger than 3 inches shall not be placed within 1 2 inches of the subgrade for paving. 6. Rockfills containing less than 40 percent of soil passing 3/4-inch sieve may be permitted in designated areas. Specific recommendations shall be made by the soils engineer and be subject to approval by the city engineer. 7. Continuous observation by the soils engineer is required during rock placement. 8. Special and/or additional recommendations may be provided in writing by the soils engineer to modify, clarify, or amplify these specifications. 9. During grading operations, soil types other than those analyzed in the soil investigation report may be encountered by the contractor. The soils engineer shall be consulted to evaluate the suitability of these soils as fill materials. Pianino and Compacting Fill Material 1. After preparing the areas to be filled, the approved fill material shall be placed in approximately honzontal layers, with lift thickness compatible to the material being placed and the type of equipment being used. Unless otherwise approved by the soils engineer, each layer spread for compaction shall not exceed 8 inches of loose thickness. Adequate drainage of the fill shall be provided at all times during the construction period. OD B4 2. When the moisture content of the fill material is below that specified by the engineer, water shall be added to it until the moisture content is as specified. 3. When the moisture content of the fill material is above that specified by the engineer, resulting in inadequate compaction or unstable fill, the fill material shall be aerated by blading and scarifying or other satisfactory methods until the moisture content is as specified. 4. After each layer has been placed, mixed, and spread evenly, it shall be thoroughly compacted to not less than the density set forth in the specifications. Compaction shall be accomplished with sheepsfoot rollers, multiple-wheel pneumatic-tired rollers, or other approved types of acceptable compaction equipment. Equipment shall be of such design that it will be able to compact the fill to the specified relative compaction. Compaction shall cover the entire fill area, and the equipment shall make sufficient trips to ensure that the desired density has been obtained throughout the entire fill. At locations where it would be impractical due to inaccessibility of rolling compacting equipment, fill layers shall be compacted to the specified requirements by hand- directed compaction equipment. 5. When soil types or combination of soil types are encountered which tend to develop densely packed surfaces as a result of spreading or compacting operations, the surface of each layer of fill shall be sufficiently roughened after compaction to ensure bond to the succeeding layer. 6. Unless otherwise specified, fill slopes shall not be steeper than 2.0 horizontal to 1.0 vertical. In general, fill slopes shall be finished in conformance with the lines and grades shown on the plans. The surface of fill slopes shall be overfilled to a distance from finished slopes such that it will allow compaction equipment to operate freely within the zone of the finished slope, and then cut back to the finished grade to expose the compacted core. Alternate compaction procedures include the backrolling of slopes with sheepsfoot rollers in increments of 3 to 5 feet in elevation gain. Alternate methods may be used by the contractor, but they shall be evaluated for approval by the soils engineer. 7. Unless otherwise specified, all allowed expansive fiil material shall be compacted to a moisture content of approximately 2 to 4 percent above the optimum moisture content. Nonexpansive fill shall be compacted at near-optimum moisture content. All fill shall be compacted, unless otherwise specified, to a relative compaction not less than 95 percent for fill in the upper 12 inches of subgrades under areas to be paved with asphalt concrete or Portland concrete, and not less than 90 percent for other fill. The relative compaction is the ratio of the dry unit weight of the compacted fill to the laboratory maximum dry unit weight of a sample of the same soil, obtained in accordance with A.S.T.M. D-1557 test method. 8 The observation and periodic testing by the soils engineer are intended to provide the contractor with an ongoing measure of the quality of the fill compaction operation. It is the responsibility of the grading contractor to utilize this information to establish the degrees of compactive effort required on the project. More importantly, it is the responsibility of the grading contractor to ensure that proper compactive effort is applied at all times during the grading operation, including during the absence of soils engineering representatives. 85 Trench Backfill 1. Trench excavations which extend under graded lots, paved areas, areas under the influence of structural loading, in slopes or close to slope areas, shall be backfilled under the observations and testing of the soils engineer. All trenches not falling within the aforementioned locations shall be backfilled in accordance with the City or County regulating agency specifications. 2. Unless otherwise specified, the minimum degree of compaction shall be 90 percent of the laboratory maximum dry density. 3. Any soft, spongy, unstable, or other similar matenal encountered in the trench excavation upon which the bedding matenal or pipe is to be placed, shali be removed to a depth recommended by the soils engineer and replaced with bedding materials suitably densified. Bedding material shall first be placed so that the pipe is supported for the full length of the barrel with full bearing on the bottom segment. After the needed testing of the pipe is accomplished, the bedding shall be completed to at least 1 foot on top of the pipe. The bedding shall be properly densified before backfill is placed. Bedding shall consist of granular matenal with a sand equivalent not less than 30, or other material approved by the engineer. 4. No rocks greater than 6 inches in diameter will be allowed in the backfill placed between 1 foot above the pipe and 1 foot below finished subgrade. Rocks greater than 2.5 inches in any dimension will not be allowed in the backfill placed within 1 foot of pavement subgrade. 5. Matenal for mechanically compacted backfill shall be placed in lifts of horizontal layers and properly moistened prior to compaction. In addition, the layers shall have a thickness compatible with the material being placed and the type of equipment being used. Each layer shall be evenly spread, moistened or dried, and then tamped or rolled until the specified relative compaction has been attained. 6. Backfill shall be mechanically compacted by means of tamping rollers, sheepsfoot rollers, pneumatic tire rollers, vibratory rollers, or other mechanical tampers. Impact-type pavement breakers (stompers) will not be permitted over clay, asbestos cement, plastic, cast iron, or nonreinforced concrete pipe. Permission to use specific compaction equipment shall not be construed as guaranteeing or implying that the use of such equipment will not result in damage to adjacent ground, existing improvements, or improvements installed under the contract. The contractor shall make his/her own determination in this regard. 7. Jetting shall not be permitted as a compaction method unless the soils engineer allows it in writing. 8. Clean granular material shall not be used as backfill or bedding in trenches located in siope areas or within a distance of 10 feet of the top of slopes unless provisions are made for a drainage system to mitigate the potential buildup of seepage forces into the slope mass. 86 Observations and Testing 1. The soils engineers or their representatives shall sufficiently observe and test the grading operations so that they can state their opinion as to whether or not the fill was constructed in accordance with the specifications. 2. The soils engineers or their representatives shall take sufficient density tests during the placement of compacted fill. The contractor should assist the soils engineer and/or his/her representative by digging test pits for removal determinations and/or for testing compacted fill. In addition, the contractor should cooperate with the soils engineer by removing or shutting down equipment from the area being tested. 3. Fill shall be tested for compliance with the recommended relative compaction and moisture conditions. Field density testing should be performed by using approved methods by A.S.T.M., such as A.S.T.M. D1556, D2922, and/or D2937. Tests to evaluate density of compacted fill should be provided on the basis of not less than one test for each 2-foot vertical lift of the fill, but not less than one test for each 1,000 cubic yards of fill placed. Actual test intervals may vary as field conditions dictate. In fill slopes, approximately half of the tests shall be made at the fill slope, except that not more than one test needs to be made for each 50 horizontal feet of slope in each 2-foot vertical lift. Actual test intervals may vary as field conditions dictate. 4. Fill found not to be in conformance with the grading recommendations should be removed or otherwise handled as recommended by the soils engineer. Site Protection It shall be the grading contractor's obligation to take all measures deemed necessary during grading to maintain adequate safety measures and working conditions, and to provide erosion-control devices for the protection of excavated areas, slope areas, finished work on the site and adjoining properties, from storm damage and flood hazard originating on the project. It shall be the contractor's responsibility to maintain slopes in their as-graded form until all slopes are in satisfactory compliance with the job specifications, all berms and benches have been properly constructed, and all associated drainage devices have been installed and meet the requirements of the specifications. All observations, testing services, and approvals given by the soils engineer and/or geologist shall not relieve the contractor of his/her responsibilities of performing the work in accordance with these specifications. After grading is completed and the soils engineer has finished his/her observations and/or testing of the work, no further excavation or filling shall be done except under his/her observations. Adverse Weather Conditions 1. Precautions shall be taken by the contractor during the performance of site clearing, excavations, and grading to protect the worksite from flooding, ponding, or inundation by poor or improper surface drainage. Temporary provisions shall be made during the rainy season to adequately direct surface drainage away from and off the worksite. Where low areas cannot be avoided, pumps should be kept on hand to continually remove water during periods of rainfall. 87 During periods of rainfall, plastic sheeting shall be kept reasonably accessible to prevent unprotected slopes from becoming saturated. Where necessary dunng periods of rainfall, the contractor shall install checkdams, desilting basins, rip-rap, sandbags, or other devices or methods necessary to control erosion and provide safe conditions. During periods of rainfall, the soils engineer should be kept informed by the contractor as to the nature of remedial or preventative work being performed (e.g. pumping, placement of sandbags or plastic sheeting, other labor, dozing, etc.). Following periods of rainfall, the contractor shall contact the soils engineer and arrange a walk- over of the site in order to visually assess rain-related damage. The soils engineer may also recommend excavations and testing in order to aid in his/her assessments. At the request of the soils engineer, the contractor shall make excavations in order to evaluate the extent of rain-related damage. Rain-related damage shall be considered to include, but may not be limited to, erosion, silting, saturation, swelling, structural distress, and other adverse conditions identified by the soils engineer. Soil adversely affected shall be classified as Unsuitable Materials, and shall be subject to overexcavation and replacement with compacted fill or other remedial grading, as recommended by the soils engineer. Relatively level areas, where saturated soils and/or erosion gullies exist to depths of greater than 1.0 foot, shall be overexcavated to unaffected, competent material. Where less than 1.0 foot in depth, unsuitable materials may be processed in place to achieve near-optimum moisture conditions, then thoroughly recompacted in accordance with the applicable specifications. If the desired results are not achieved, the affected materials shall be over-excavated, then replaced in accordance with the applicable specifications. In slope areas, where saturated soils and/or erosion gullies exist to depths of greater than 1.0 foot, they shall be overexcavated and replaced as compacted fill in accordance with the applicable specifications. Where affected materials exist to depths of 1.0 foot or less below proposed finished grade, remedial grading by moisture-conditioning in place, followed by thorough recompaction in accordance with the applicable grading guidelines herein presented may be attempted. If materials shall be overexcavated and replaced as compacted fill, it shall be done in accordance with the slope-repair recommendations herein. As field conditions dictate, other slope- repair procedures may be recommended by the soils engineer.