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Home My WebLink AboutMS 04-06; MAY MINOR SUBDIVISION; IMPROVEMENT PLAN REVIEW; 2019-11-11HETHERINGTON ENGINEERING, INC. (t SOIL & FOUNDATION ENGINEERING • ENGINEERING GEOLOGY • HYDROGEOLOGY November 11, 2019 Project 89941 Log No 20752 Ms Mary May 5258 Silkwood Diive Oceanside, California 92056 Subject: IMPROVEMENT PLANS REVIEW El Camino Real, A.P.N. 167-080-36 Carlsbad, California References: 1. "Preliminary Geotechnical Investigation, Proposed Two-Lot Development, El Camino Real, Carlsbad, California, A.P.N. #167-080- 36", by Vinje & Middleton Engineering, Inc, dated October 17, 2003. 2. "Improvement Plans for: Private Joint Access Road, A.P.N. 167-080- 36, Carlsbad, California", by The Sea Bright Company, undated. Dear Ms. May: In accordance with the request of Mr. Robert Sukup, we have reviewed the referenced report and plans. Based on our review, it appears that the plans (Reference 2) generally conform to the recommendations contained in the geotechnical report (Reference 1). This opportunity to be of service is appreciated. If you have any questions, please contact our office. Sincerely, HEM Hetherin INEERING, IN Ma on Civg48 Geotechnical Engineer 397 (expires 3/31/20) Distribution: 2-Addressee 1-via e-mail (Sukup@roadrunner.com) *i VV RE1J EC I NOV 2 12019 LAND DEVELOPMENT ENGINEERING 5365 Avenida Encinas, Suite A • Carlsbad, CA 92008-4369 • (760) 931-1917 • Fax (760) 931-0545 - 333 Third Street, Suite 2 • Laguna Beach, CA 92651-2306 • (949) 715-5440 • Fax (760) 931-0545 www.hetheringtonengineering.com HETHERINGTON ENGINEERING, INC. SOIL & FOUNDATION ENGINEERING • ENGINEERING GEOLOGY • HYDROGEOLOGY March 22, 2006 Project No. 5431.1 Log No. 9920 Ms. Mary Humphrey 18627 Brookhurst Street, Suite 332 Fountain Valley, California 92708 Subject: GEOTECHNICAL CONSULTANT OF RECORD Proposed Two-Lot Residential Development El Camino Real, APN 167-080-36 Carlsbad, California References: 1) "Preliminary Geotechnical Investigation, Proposed Two-Lot Development, El Camino Real, Carlsbad, California, A.P.N. #167- 080-36," by Vinje & Middleton Engineering, Inc., dated October 17, 2003. 2) Grading and Erosion Control Plans For Humphrey Residence, El Camino Real," by The Sea Bright Company, undated Dear Ms. Humphrey: In accordance with your request, we are submitting this letter concerning geotechnical consultant of record with respect to the proposed two-lot residential development at the subject site. We have reviewed the report by Vinje Middleton and Associates (Reference 1) and generally concur with the findings and conclusions of this report. Based our review of the referenced report and plans, Hetherington Engineering, Inc. will assume the role of geotechnical consultant of record for site grading and construction. Please call if you have any questions. Sincere'y, HETIR1NGTON ENGINEERING, LNC fa J4tz S. Geldert LU Civil Engineer 63912 (expires 9/30/06) oFESS/o,7. No. 63912 Exp. Date- Distribution: 4-Addressee L 5205 Avenida Encinas, Suite A • Carlsbad, CA 92008-4369 • (760) 931-1917 • Fax (760) 931-0545 32242 Paseo Adelanto, Suite C • San Juan Capistrano, CA 92675-3610 • (949) 487-9060 • Fax (949) 487-9116 www.hetheringtonengineering.com I Preliminary Geotechnical Investigation I Proposed Two-Lot Residential Development El Camino Real, Carlsbad, California I (A.P.N. #167-080-36) I October 17, 2003 I Prepared For: I Ms. MARY HUMPHREY 18627 Brookhurst Street, #332 Fountain Valley, California 92708 I Prepared By: VINJE & MIDDLETON ENGINEERING, INC. I 2450 Vineyard Avenue, Suite 102 Escondido, California 92029 I Job #03-390-P LI JE & MIDDLETON ENGINEERING, INC. S Job #03-390-P 2450 Vineyard Avenue Escondido, California 92029-1229 S Phone (760) 743-1214 Fax (760) 739-0343 October 17, 2003 Ms. Mary Humphrey 18627 Brookhurst Street, #332 Fountain Valley, California 92708 PRELIMINARY GEOTECHNICAL INVESTIGATION, PROPOSED TWO-LOT RESIDENTIAL DEVELOPMENT, EL CAMINO REAL, CARLSBAD, CALIFORNIA (A.P.N. #167-080-36) Pursuant to your request, Vinje and Middleton Engineering, Inc., has completed the Preliminary Geotechnical Investigation Report for the above-referenced project site. The following report summarizes the results of our research and review of pertinent geotechnical maps and reports, subsurface field investigation and soil sampling, laboratory testing, engineering analyzes and provides conclusions and construction recommendations for the proposed development as understood. From a geotechnical engineering standpoint, it is our opinion that the site is suitable the proposed two-lot residential development and the associated 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 the construction costs. If you have any questions or need clarification, please do not hesitate to contact this office. Reference to our Job #03-390-P will help to expedite our response to your inquiries. We appreciate this opportunity to be of service to you. VINJE & MIDDLETON ENGINEERING, INC. ennis Middleton CEG #980 TABLE OF CONTENTS PAGE NO. I. INTRODUCTION .................................................. II. SITE DESCRIPTION ...............................................i III. PROPOSED DEVELOPMENT .......................................i IV. SITE INVESTIGATION .............................................2 V. GEOTECHNICAL CONDITIONS ......................................2 Earth Materials .................................................2 Groundwater and Surface Drainage ................................3 Slope Stability .................................................3 Faults I Seismicity ..............................................3 Geologic Hazards ..............................................6 Laboratory Testing / Results .....................................6 VI. CONCLUSIONS ..................................................9 VII. RECOMMENDATIONS ............................................10 Remedial Grading and Earthworks ...............................10 * Foundations and Slab-on-Grade Floors ...........................16 Exterior Concrete Slabs I Flatworks ...............................17 Soil Design Parameters ........................................18 Asphalt and PCC Pavement Design ..............................'19 General Recommendations .....................................20 VIII. LIMITATIONS ...................................................23 TABLE NO. FaultZone .......................................................... Site Specific Seismic Parameters .......................................2 SoilType ...........................................................3 Maximum Dry Density and Optimum Moisture Content .....................4 Moisture-Density Tests (Undisturbed Chunk Samples) .....................5 I Expansion Index Test .................................................6 Direct Shear Test .....................................................7 TABLE OF CONTENTS (continued) Grain Size Analysis . 8 SulfateTest .........................................................9 Removals and Over-excavations .......................................10 PLATE NO. Regional Index Map ..................................................i Preliminary Siting and Grading Study ...................................2 Geologic Cross-Section ................................................3 Test Trench Logs (with key) ..........................................4-6 Fault - Epicenter Map ..................................................7 Retaining Wall Drain Detail ............................................8 Isolation Joints and Re-entrant Corner Reinforcement .....................9 0 I PRELIMINARY GEOTECHNICAL INVESTIGATION PROPOSED TWO-LOT RESIDENTIAL DEVELOPMENT EL CAMINO REAL, CARLSBAD, CALIFORNIA INTRODUCTION The property investigated in this work includes partially developed hillside terrain located on the west side of El Camino Real approximately 650 feet south of Chestnut Avenue in the City of Carlsbad. The property location is depicted on a Regional Index Map enclosed with this report as Plate 1. We understand that the property is planned for a two-lot residential development with associated structures and improvements. Consequently, the purpose of this study was to determine soil and geotechnical conditions at the property and evaluate their influence upon the planned construction. Geologic mapping, test trench digging, soil sampling and testing were among the activities conducted in conjunction with this effort which has resulted in the geotechnical development and foundation recommendations presented herein. II. SITE DESCRIPTION Existing topographic conditions and a preliminary development scheme are shown on a Preliminary Siting and Grading Study, provided by Vista Engineering, Inc., included with this report as Plate 2. The property is bordered by El Camino Real to the east, residential properties to the south and west, and undeveloped terrain to the north. The largest site slope ascends approximately 25 feet on the west side of the existing pad onto off-site terrain above. Slope gradients locally approach 1.5:1 (horizontal to vertical) at their steepest. Previous cut/fill grading in the westerly portion of the site resulted in an existing nearly level pad area. The existing pad area extends north into the adjacent property. Approximate limits of existing site fills associated with the grading are shown on Plate 2. Site drainage sheetfiows in an easterly direction to El Camino Real. Some minor erosion was noted in the existing fills and on the westerly graded slope. Elsewhere, excessive scouring or erosion from uncontrolled run-off is not in evidence. Ill. PROPOSED DEVELOPMENT We understand the study property is planned for the support of two three-story dwellings with associated structures and improvements as shown on Plate 2. The lower basement level for both dwellings will be entirely or partially subterranean. Basement retaining walls are incorporated into the designs to accommodate ground transitioning and achieve final grades. A Geologic Cross-Section through the planned development is enclosed as Plate 3. Minor to moderate cut grading is planned for the creation of new level building and basement pads. Maximum 10 feet of cut excavations are anticipated in the proposed basement areas. VINJE & MIDDLETON ENGINEERING, INC. 2450 Vineyard Avenue, Escondido, California 92029-1229 • Phone (760) 743-1214 • Fax (760) 739-0343 EOTECHNLCAL INVESTIGATIONS GRADING SUPERVISION 1'ERC TESTING ENVIRONMENTAL INVESTIGATION PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 2 EL CAMINO REAL, CARLSBAD, CALIFORNIA OCTOBER 17, 2003 Pavement improvements consist of PCC driveways with longitudinal gradients that range from 10% maximum for the lower easterly dwelling to 20% maximum for the upper westerly dwelling. Detailed building plans are unavailable. However, it is anticipated that building construction will consist of a lower masonry block basement wall, and upper wood-frame and stucco structures supported on shallow stiff continuous strip and spread pad concrete footings with slab-on-grade floor foundations. SITE INVESTIGATION Subsurface conditions at the site were chiefly determined by the excavation of 6 test trenches dug with a tractor-mounted backhoe. All trenches were logged by our project geologist who also retained rock/soil samples for laboratory testing. Test trench locations are shown on Plate 2. Logs of the trenches are enclosed with this report as Plates 4-6. Laboratory test results are summarized in a following section. GEOTECHNICAL CONDITIONS ,. The study property is underlain by formational bedrock units mantled by a modest cover of fill and topsoil. Terrace Deposits are exposed in the slope along the western margin of the site. Instability is not indicated at the property. A. Earth Materials Terrace Deposits - Pleistocene age Terrace Deposits are exposed on an existing ascending slope along the west property margin. Exposures consist of dark- colored sandstone units that are typically fine to medium grained and massive. The sandstone was found in a cemented condition overall. Minor erosion mark portions of the slope face. However, no evidence of shallow or deep-seated slope instability is indicated. Formational Bedrock - The proposed building pad and improvement areas are underlain by Eocene age sedimentary bedrock units typically designated Santiago Formation. At the project site, the formational rock units typically consist of light- colored clayey to silty sandstone units with interbeds of cobble conglomerate and siltstone. As exposed in our test trenches, site formational units are weathered friable near the surface becoming cemented at depth. Project formational rocks are competent units that will adequately support the planned dwellings and improvements. VINJE & MIDDLETON ENGINEERING, INC. 2450 Vineyard Avenue, Escondido, California 92029.1229 • Phone (760) 743-1214 • Fax (760) 739-0343 GEOTECHNICAL INVESTIGATIONS GRADING SUPERVISION PERC TESTING ENVIRONMENTAL INVESTIGATION PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 3 EL CAMINO REAL, CARLSBAD, CALIFORNIA OCTOBER 17, 2003 Topsoil - A modest cover of topsoil mantles much of the formational rock units at the study site. The topsoil typically consists of sandy to clay-rich deposits that were found in loose to soft conditions near the surface becoming medium dense to stiff at depth. Project topsoils, as exposed in Test Trench 2 (T-2), reached a maximum thickness of 9 feet. Fill - Artificial fills largely occupy the western portion of the subject site. Existing site fill deposits consist of silty sands which were likely generated during the on-site grading operations when the existing pad was created. Documentation for the fill placement is not available. Existing fills are anticipated to reach a maximum thickness of 5 feet. Estimated limits of the existing fill deposits at the site are shown on Plate 2. Details of the underlying earth materials at the site are presented on the enclosed Test Trench Logs, Plates 4-6. Groundwater and Surface Drainage Groundwater conditions were not encountered in our test excavations to the depths explored and are not expected to impact site development. However, like all graded building sites, the proper control of surface drainage is an important factor in the continued stability of the property. Irrigation and meteoric water should not be allowed to pond on lot surfaces and over-watering of site vegetation should be avoided. Project site and building basement retaining walls should be provided with adequate back drain systems. Slope Stability Landslides or other forms of geologic slope instability are not in evidence at the project site. The western site slope is performing well with no evidence of surficial or deep-seated instability. Cemented Terrace Deposits exposed on the slope face and underlying formational rock materials are flat-lying to massive sandstone units which characteristically perform well with regard to gross stability and are expected to remain stable. Faults I Seismicity Faults or significant shear zones are not indicated on or near proximity to the project site. VINJE & MIDDLETON ENGINEERING, INC. 2450 Vineyard Avenue, Escondido, California 92029.1229 • Phone (760) 743-1214 • Fax (760) 739-0343 çEOTECHNICAL INVESTIQATIONS 9RADINQSUPERVISION PERC TESTING ENVIRONMENTAL INVESTIGATION I PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 4 EL CAMINO REAL, CARLSBAD, CALIFORNIA OCTOBER 17, 2003 40 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 I 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 I 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 I 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 11 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 0.91g 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 EQ FAULT VERSION 3.00 updated) typically associated with the fault is also tabulated. TABLE I V Maximum Probable Fault Zone Distance From Site Acceleration (R.H.) Rose Canyon fault 6.0 miles 0.169g Newport-Inglewood fault 6.3 miles 0.164g Coronado Bank fault 22.1 miles 0.136g Elsinore fault 23.2 miles 0.112g 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 7. 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. VINJE & MIDDLETON ENGINEERING, INC. 2450 Vineyard Avenue, Escondido, California 92029.1229 • Phone (760) 743-1214 • Fax (760) 739-0343 cEOTECHNICAI. INVESTIGATIONS GRADING SUPERVISION PERC TESTING ENVIRONMENTAL INVESTIGATION PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 5 EL CAMINO REAL, CARLSBAD, CALIFORNIA OCTOBER 17, 2003 Most of the earthquakes are thought to have been generated along offshore faults. For the most part, the recorded events remain moderate shocks which typically 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 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 1992 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 Uniform Building Code. The following parameters are consistent with the indicated project seismic environment and may be utilized for project design work: VINJE & MIDDLETONENGINEERINc, INC. 2450 Vineyard Avenue, Escondido, California 92029.1229 • Phone (760) 743.1214 • Fax (760) 739-0343 qEOTECHNICAL INVESTIGATIONS QRADINQ SUPERVISION PIRC TESTING ENVIRONMENTAL INVESTIGATION PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 6 EL CAMINO REAL, CARLSBAD, CALIFORNIA OCTOBER 17, 2003 TABLE 2 Site Soil Profile Type Seismic Zone Seismic Zone Factor Source Type Seismic I Seismic Response Coefficients Na Nv Ca Cv Ts To [ Sc I 4 0.4 I B I 1.0 11.0 I 0.40 0.57 I 0.569 I 0.114 According to Chapter 16, Division IV of the 1997 Uniform Building Code. Geologic Hazards Geologic hazards are not presently indicated at the project site. Exposed slopes do not indicate gross geologic 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 not anticipated. LaboratoryTesting I Results Earth deposits encountered in our exploratory test excavations were closely examined and sampled for laboratory testing. Based upon our test trench data and field exposures, site soils have been grouped into the following soil types: TABLE 3 Soil Type, I Description j 1 palebrownsiltyfinetomediumsand(Fill/Topsoil/TerraceDeposit) 2 dark brown to blue-grey sandy clay/clayey sand (Topsoil/Fill) 3 tantooff-whitesiltysandstone,locallyclayey(FormationalRock) 4 red-brown cobble conglomerate with clayey sand matrix (Formational Rock) 5 red-brown silty sand/cobble mix (Fill) The following tests were conducted in support of this investigation: 1. Maximum Dry Density andOptimumMoistureContent: The maximum dry density and optimum moisture content of Soil Types 2 and 3 were determined in accordance with ASTM D-1557. The test results are presented in Table 4. VINJE & MIDDLETON ENGINEERING, INC. 2450 Vineyard Avenue, Escondido, California 92029.1229 • Phone (760) 743.1214 • Fax (760) 739-0343 QEOTECHNICAL INVESTIGATIONS GRADING SUPERVISION PERC TESTING ENVIRONMENTAL INVESTIGATION PRELIMINARY GEOTECHNICAL INVESTIGATION EL CAMINO REAL, CARLSBAD, CALIFORNIA TABLE 4 PAGE 7 OCTOBER 17. 2003 2. Moisture-Density Tests (Undisturbed Chunk Samples): In-place dry density and moisture content of representative soil deposits beneath the site were determined from relatively undisturbed chunk samples using the water displacement test method. The test results are presented in Table 5 and tabulated on the enclosed Test Trench Logs (Plates 4-6). TABLES Sample Location Soil Type Field Moisture Content (w-%) Field Dry Density (Yd-pcf) D Max. ry Density (Ym-pcf) Ratio Of In-Place Dry Density To Max. Dry Density (YdIYm X 100) T-1 @1W 2 9.3 111.6 125.4 89.0 T-1 @4' 2 13.2 109.5 125.4 87.3 T-1 @ 7W 3 10.8 109.1 123.4 88.4 T-2@2' 1 1.6 104.0 - - T-2 @ T 2 8.8 105.2 125.4 83.9 T-2 @8W 2 7.2 114.0 125.4 90.9 T-4@6' 3 10.2 126.6 123.4 100+ 1-5 @ 1' 2 9.4 126.7 123.4 100+ * Designated as relative compaction for structural fills. Required relative compaction for structural fill is 90% or greater. 3.. Expansion Index Test: Two expansion index tests were performed on representative samples of Soil Types 2 and 3 in accordance with the Uniform Building Code Standard 18-2. The test results are presented in Table 6. VINJE & MIDDLETON ENGINEERING, INC. 2450 Vineyard Avenue, Escondido, California 92029-1229 • Phone (760) 743.1214 • Fax (760) 739-0343 QEOTECHNICAL INVESTIGATIONS GRADING SUPERVISION I'ERC TESTING ENVIRONMENTAL INVESTIGATION 1* PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 8 EL CAMINO REAL, CARLSBAD, CALIFORNIA OCTOBER 17, 2003 TABLE 6 Sample Location Soil Type Remolded w (%) Saturation (%) Saturated W:0/0) Expansion Index (El) Expansion Potential 1-1 @4' 2 10.9 49.8 20.2 45 low T-5 @ 1' 3 10.4 50.8 18.8 7 very low (w) = moisture content in percent. 4. Direct Shear Test: Two direct shear tests were performed on representative samples of Soil Types 2 and 3. 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 7. TABLE 7 S 5. Grain Size Analysis: Grain size analyzes were performed on representative samples of Soil Types 1, 2, and 3. The test results are presented in Table 8. TABLE 8 Sieve Size 1/z" 1" I 6" I 1/s" #4 I #10 J #20 #40 #200 Location Soil Type Percent Passing T-1 @4' 2 100 100 100 100 100 98 85,.'64 32 T-2@2' 1 7-7 100 100 100 100 98 94 78 57 17 1-5 @ 1' 3 100 100 100 100 100 95 73 59 44 6. Sulfate Test: One sulfate test was performed on a representative sample of Soil Type 2 in accordance with the California Test 417. The test result is presented in Table 9. VINJE & MIDDLETON ENGINEERING, INC. 2450 Vineyard Avenue, Escondido, California 92029-1229 • Phone (760) 743-1214 • Fax (760) 739.0343 QEOTECHNICAL INVESTIGATIONS GRADING SUPERVISION I'ERC TESTING ENVIRONMENTAL INVESTIGATION PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 9 EL CAMINO REAL, CARLSBAD, CALIFORNIA OCTOBER 17, 2003 TABLE 9 Sample Location Soil Type Amount of Water Soluble Sulfate (s04) In Soil (% by Weight) F---T-1 @4' 2 I 0.013 VI. CONCLUSIONS Based upon the foregoing investigation, development of the project site substantially as proposed, is feasible from a geotechnical viewpoint. The property is underlain by dense and stable formational bedrock units which are mantled by a thin to modest section of loose to medium dense sandy to clayey fill / topsoils. Geotechnical factors presented below are unique to the project site and will influence grading procedures and associated development costs: Instability is not indicated at the project site. Landslides or other forms of geologic instability within the onsite natural Terrace and Formational deposits are not indicated. * Modest basement excavations up to 10 feet maximum are planned to achieve lower level pad grade elevations. Elsewhere, relatively minor grade modifications are proposed to construct the planned design elevations. Unusual excavation difficulties within the onsite bedrock units are not anticipated. Site existing fills, topsoils, and upper weathered bedrock are not suitable for support of the planned construction and improvements in their present condition. Removal and recompaction of these deposits will be necessary in order to construct stable ground surfaces suitable for the support of the proposed structures and improvements. Added removals of cut ground will also be necessary in the case of cut/fill transition pads which expose bedrock units so that uniform bearing soil conditions are created throughout the building surfaces. * The overall stability of graded building pads developed over sloping terrain is most dependent upon adequate keying and benching of fill into the undisturbed bedrock during grading operations. At the project site, added care should be given to proper construction of keyways and benching during grading. VINJE & MIDDLETON ENGINEERING, INC. 2450 Vineyard Avenue, Escondido, California 92029.1229 • Phone (760) 743.1214 • Fax (760) 7390343 QEOTECHNICAL INVESTIGATIONS QRADINQ SUPERVISION PERC TESTING ENVIRONMENTAL INVESTEATION PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 10 S EL CAMINO REAL, CARLSBAD, CALIFORNIA OCTOBER 17, 2003 Site soils are generally very low expansive silty sandy deposits. Some clay bearing soils with low expansive potential also occur at the site. Site potentially expansive soils may be first removed from the site in the case of an export operations. Potentially expansive soils may also be selectively buried in deeper fills or thoroughly mixed with an abundant very low expansive soils generated from the onsite excavations. Based on the anticipated development scheme and grading recommendations given herein, finish grade soils are expected to consist chiefly of clayey to silty sand deposits (SM/SC) with very low to low expansion potential (expansion index less than 51). Actual classification and expansion characteristic of finished grade soil mix can only be provided in the final as-graded compaction report based on appropriate testing. * Groundwater conditions are not expected to impact grading activities or the long term performance of the developed areas. Adequate site surface drainage control, however, remains a critical factor in the future stability of the developed property as planned. S Well-constructed back drains should be provided behind the planned site and building basement retaining walls as recommended in the following sections. * Soil collapse, liquefaction and seismically induced settlements will not be a factor in the development of the project site. Post construction settlements will not be a factor in construction of the planned new structures provided our remedial grading and foundation recommendations are followed. VII. RECOMMENDATIONS The following recommendations are provided based on the planned construction as shown on the enclosed Plate 2. Added or modified recommendations may also be appropriate and can be provided at the final plan review phase when detailed construction plans are finalized: A. Remedial Grading and Earthworks Cut/fill and remedial grading techniques should be used in order to achieve final design grades and improve soil conditions beneath the new structures and . improvements. All grading and project construction should be completed in accordance with the Appendix Chapter 33 of the Uniform Building Code, City of VINJE & MIDDLETON ENGINEERING, INC. 2450 Vineyard Avenue, Escondido, California 92029.1229 0 Phone (760) 743.1214 • Fax (760) 739-0343 flcfl-rrcun,,r-A, rnn,rrrinam,nMc no A fl,Mfl CI lPI.0V,CIfl. -- PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE II I. EL CAMINO REAL, CARLSBAD, CALIFORNIA OCTOBER 17, 2003 Carlsbad Grading Ordinances, the Standard Specifications for Public Works Construction, and the requirements of the following sections: I. Clearing and Grubbing: Existing vegetation, deleterious materials and debris should be removed from areas to receive new fills, structures, and improvements plus 10 feet where possible, and as directed in the field. Prepared ground should be inspected and approved by the project geotechnical engineer or his designated field representative prior to the remedial grading work. Existing underground utilities in the construction areas should be pot-holed, identified and marked prior to the actual work. Inactive lines should be properly removed or abandoned as approved. Abandoned underground structures should also be removed and the generated voids properly backfilled with compacted soils in accordance with the recommendations provided herein. 2. Removals and Over-excavations: Existing site loose to soft fills, topsoils, and upper weathered soft bedrock units at the project site should be removed to the underlying competent bedrock, or firm native ground as approved in the field by the project geotechnical engineer, and placed back as properly compacted fill. Typical removal depths in the vicinity of individual exploratory test sites are shown in Table 10. Locally deeper removals may also be necessary based on the actual field exposures and should be anticipated: TABLE 10 Location Total Depth - (ft) Estimated Depth to Ground- water Estimated Removal Depths (ft) Comments T-1 8' n/e 2' Parcel B driveway areas T-2 10' n/e - 8' Parcel A building pad areas T-3 31/2' We 2W Parcel A building pad areas (see note 1) T-4 8' n/e 5W slope areas, remove all existing fill/topsoil T-5 2' n/e - 1' Parcel B building pad areas (see note 1) T-6 3' n/e 11/2' Parcel B driveway areas ExDlanations: - Depth of cut or undercut may govern. All depths are measured from the existing ground levels. VINJE & MIDDLETON ENGINEERING, INC. 2450 Vineyard Avenue, Escondido, California 92029.1229 • Phone (760) 743.1214 • Fax (760) 739-0343 çEOTECI-INICAL INVESTIGATIONS QRADINQ SUPERVISION PERC TESTIN( ENVIRONMENTAL INVESTIQATION I PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 12 EL CAMINO REAL, CARLSBAD, CALIFORNIA OCTOBER 17, 2003 Actual depths may vary at the time of construction based on actual subsurface exposures. Firm native ground is defined as undisturbed natural ground with in-place densities of 87% or greater. Bottom of all removals should be additionally prepared and recompacted as directed in the field. 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 project grading operations. n/e not encountered. Bearing Soils Transitioning: Project building/wall foundations should be uniformly supported on compacted fill soils. Foundation transitioning from compacted fills to cut ground or undisturbed Formational units should not be allowed. The cut or undisturbed ground portions of the bearing soils in the transition pads should be undercut a minimum of 3 feet below rough finish grades or 12 inches below the bottom of the deepest footing(s), whichever is more, and placed back as properly compacted fills. There should also be at least 12 inches of compacted subgrade soils below all onsite pavings and improvements. Temporary Construction Slopes: Temporary slopes necessary for the project basement excavations may be constructed at near vertical gradients to a maximum of 5 feet. Construction slopes greater than 5 feet and less than 12 feet may be constructed at near vertical gradients within the lower 3 feet and ½: 1 gradients maximum within the upper sections. The wall backfills should be properly benched and tightly keyed into the temporary slope as the backfill placement progresses and as directed in the field by the project geotechnical consultant. Additional recommendations including flatter construction slopes and the need for temporary shoring should be given by the project geotechnical consultant at the time of earthwork operations based on actual field exposures. Fill Materials and Compaction: Soils generated from the removals of the existing fills and topsoils may be suitable for reuse as new compacted site fills provided all trash, debris and unsuitable materials are selectively removed and properly disposed of to the satisfaction of the project geotechnical engineer. Earth deposits at the site range from sandy soils to some potentially expansive clay-bearing materials. Project potentially expansive soils may be first removed is from the site in the case of an export operation. Select grading techniques may VINJE & MIDDLETON ENQZNEERING, INC. 2450 Vineyard Avenue, Escondido, California 92029.1229 • Phone (760) 743.1214 • Fax (760) 739-0343 GEOTECI-IN1CAL INVESTIGATIONS ()RADINQ SUPERVISION I'ERC TESTING ENVIRONMENTAL INVESTICAT10N I. PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 13 EL CAMINO REAL, CARLSBAD, CALIFORNIA OCTOBER 17, 2003 also be considered to bury the site potentially expansive soils in deeper fills at least 3 feet below rough finish grades or mix with an abundant very low expansive soils generated from the onsite excavations. Typically, clayey soils also require additional processing and moisture conditioning efforts in order to manufacture a uniform soil mixture suitable for reuse as compacted fill. The clay-bearing soils should be moisture conditioned to slightly (2% to 3%) above the optimum levels and compacted as specified. Import soils, if required to complete grading or wall backfiuing, should be very low expansive (expansion index less than 21) granular sandy deposits inspected and approved by the project geotechnical consultant prior to delivery to the site. Uniform bearing soil conditions should be constructed at the site by the grading operations. Site soils should be adequately processed, thoroughly mixed, moisture conditioned to slightly above the optimum moisture levels as directed in the field, placed in thin uniform horizontal lifts and mechanically compacted to a minimum of 90% of the corresponding laboratory maximum dry density per ASTM D-1557, unless otherwise specified. A minimum of 90% compaction levels will be required for all structural fills and• wall backfills. In the improvement areas, fills should also be compacted to a minimum 90% with the exception of the upper 12 inches under the asphalt paving surfaces where a minimum of 95% compaction levels will be required. 6. Permanent Graded Slopes - Graded slopes should be programmed for 2:1 gradients maximum. Graded slopes constructed at 2:1 gradients will be grossly stable with respect to deep seated and surficial failures for the anticipated design maximum vertical heights. Fill slopes shall be provided with a lower Keyway. The Keyway should maintain a minimum depth of 2 feet into competent formational units with a minimum width of 12 feet as approved by the project geotechnical engineer or his designated field representative. The Keyway should expose competent formational units throughout with the bottom heeled back a minimum of 2% into the natural hillside. Additional level benches should be constructed into the natural hillside as the fill slope construction progresses. Fill slopes should also be compacted to 90% (minimum) of the laboratory standard out to the slope face. Over-building and cutting back to the compacted core, or backrolling at a maximum of 4-foot vertical increments-and "track-walking" at the completion VINJE & MIDDLETON ENGINEERING, INC. 2450 Vineyard Avenue, Escondido, California 92029.1229 • Phone (760) 743-1214 • Fax (760) 739-0343 GEOTECHNICAL INVESTIGATIONS GRADING SUPERVISION PERC TESTING - ENVIRONMENTAL INVESTIGATION PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 14 EL CAMINO REAL, CARLSBAD, CALIFORNIA OCTOBER 17, 2003 of grading, is recommended for site fill slope construction. Geotechnical engineering inspections and testing will be necessary to confirm adequate compaction levels within the fill slope face. Shrinkage and Bulking: Based upon our analyzes, on-site existing fills and topsoil deposits may be expected to shrink approximately 5% to 10%, and the soils generated from the excavations of the onsite Formational units may be anticipated to bulk nearly 10% to 15% on a volume basis when compacted to at least 90% of the corresponding maximum density. C Wall Back Drainage System: All site retaining and building basement walls should be provided with adequate back drainage system. The wall back drain system should consist of a minimum 18-inches wide trench excavated to the depths of the wall foundation level. A minimum 4-inch diameter, Schedule 40 (SDR 35) perforated pipe surrounded with a minimum of 2.25 cubic feet per foot of %-crushed rocks wrapped in filter fabric (Mirafi 140 N), or Caltrans Class 2 permeable aggregate should be used. The perforated drain pipe should be installed at suitable elevations to allow for adequate fall via non-perforated solid pipe to an approved outlet. Filter fabric can be eliminated if Class 2 permeable material is used. Typical wall back drain system is depicted on the enclosed Plate 8. Appropriate waterproofing should be provided behind the walls. Protect pipe outlet as necessary. Drainage and Erosion Control: A critical element to the continued stability of the graded building pads is an adequate surface drainage system. This can most effectively be achieved by installation of appropriate surface drainage facilities. Building pad surface run-off should be collected and directed away from the planned buildings and improvements to a selected location in a controlled manner. Drainage swales should be provided at the top and toe of the slopes per project civil engineer design. Concrete brow ditches should be considered on the back side of basement walls. Area drains should be installed. 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. Engineering Inspections: All grading operations including removals, suitability of earth deposits used as compacted fills, and compaction procedures should be continuously inspected and tested by the project geotechnical consultant and presented in the final as-graded compaction report. The nature of finished subgrade soils should also be confirmed in the final compaction report at the completion of remedial grading. VINJE & MIDDLETON ENGINEERING, INC. 2450 Vineyard Avenue, Escondido, California 92029.1229 • Phone (760) 743-1214 • Fax (760) 739-0343 QEOTECHNICAL INVESTIQATIONS çRADINq SUPERVISION PERC TESTING INVrP0N7ANTAI 1NVF1Z1l(AT,(Th' I PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 15 EL CAMINO REAL, CARLSBAD, CALIFORNIA OCTOBER 17, 2003 U Geotechnical engineering inspections shall include but not limited to the following: * Initial Inspection - After the grading / brushing limits have been staked but I before grading / brushing starts. * Bottom of keyway/over-excavation inspection - After the natural ground or i bedrock is exposed and prepared to receive fill but before fill is placed. * Excavation inspection - After the excavation is started, but before the vertical depth of excavation is more than 5 feet. Local and CAL-OSHA safety requirements for open excavations apply. * Fill I backfill inspection - After the fill I backfill placement is started but before the vertical height of fill / backfill exceeds 2 feet. A minimum of one test shall be required for each 100 lineal feet maximum with the exception of wall backfills where a minimum of one test shall be required for each 25 lineal feet maximum. Wall backfills shall also be mechanically compacted to at least 90% compaction levels unless otherwise specified. Finish rough and lie final pad grade tests shall be required regardless of fill 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 I slab steel inspection - After steel placement is completed but before the scheduled concrete pour. Subdrain / wall back drain inspection - After the trench excavations, but during the actual placement. All material shall conform to the project material specifications and approved by the project soils engineer. Underground utility I plumbing trench inspection - After the trench excavations, but before placement of bedding or installation of the underground facilities. Local and CAL-OSHA safety requirements for open excavations apply. Inspection of pipe bedding may also be required by the project geotechnical engineer. * Underground utility / plumbing trench backfill inspection - After the backfill placement is started above the pipe zone but before the vertical height of VINJE & MIDDLETON ENGINEERING, INC. 2450 Vineyard Avenue, Escondido, California 92029-1229 • Phone (760) 743-1214 • Fax (760) 739-0343 QEOTEC}INICM. INVESTIGATIONS QRADINQ SUPERVISION PERC TESTING PNJIPflMMF?.JTAJ IN]TJ(TfTh 1 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 16 EL CAMINO REAL, CARLSBAD, CALIFORNIA OCTOBER 17, 2003 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 governing agencies requirements and project soils report if applicable. All trench backfills shall be mechanically compacted to a minimum of 90% compaction levels unless otherwise specified. Plumbing trenches over 12 inches deep maximum under the interior floor slabs should also be mechanically compacted and tested for a minimum of 90% compaction levels. Flooding or jetting techniques as a means of compaction method shall not be allowed. * Pavement/improvements subgrade and basegrade inspections - Prior to the placement of concrete or asphalt for proper moisture and specified compaction levels. B. Foundations and Slab-on-Grade Floors I The following recommendations are consistent with very low to low expansive (expansion index less than 51) clayey to silty sand (SM/SC) foundation bearing soil and site specific geotechnical conditions. Additional recommendations may be 1 required and should be given at the plan review phase. All design recommendations should also be further confirmed and/or revised at the completion of remedial grading based on the expansion characteristics of the I foundation bearing soils and as-graded site geotechnical conditions, and presented in the final as-graded compaction report: Continuous strip wall foundations should be sized at least 18 inches wide and 24 inches deep. Spread pad footings should be at least 36 inches square and 18 inches deep. Footing depths are measured from the lowest adjacent ground surface, not including the sand/gravel layer beneath the floor slabs. Exterior continuous footings should enclose the entire building perimeter. 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. Reinforcement details for isolated pad footings should be provided by the project architect / structural engineer. I 3. All interior slabs should be a minimum of 5 inches in thickness, reinforced with #3 reinforcing bars spaced 16 inches on center each way placed mid-height in the slab. Slabs should be underlain by 4 inches of clean sand (SE 30 or I greater) which is provided with a 6-mil plastic moisture barrier placed mid-height in the sand. V!NJE & MIDDLETON ENQINEERIN, INC. 2450 Vineyard Avenue, Escondido, California 92029.1229 • Phone (760) 743-1214 • Fax (760) 739-0343 GRADINQ SUPERVISION 1'ERC TESTINq ENVIRONMENTAL INVEST1QATION I I PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 17 EL CAMINO REAL, CARLSBAD, CALIFORNIA OCTOBER 17. 2003 Provide "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 1-inch in depth but not to exceed 1 1/4. inches 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. The enclosed Plate 9 may be used as a general guideline. Foundation bearing and slab subgrade soils should not be allowed to dry below the as-graded moisture contents prior to pouring the concrete or additional ground preparations and moisture re-conditioning will be required as directed in the field. Foundation trenches and slab subgrade soils should be inspected and tested S for proper moisture and specified compaction levels, and approved by the project geotechnical consultant prior to the placement of concrete. C. Exterior Concrete Slabs I Flatworks All exterior slabs (walkways, and patios) should be a minimum of 4 inches in thickness reinforced with 6x6/10x10 welded wire mesh carefully placed mid- height in the slab. 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 1-inch but should not exceed 1 1h-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. All exterior slab designs should be confirmed in the final as-graded compaction report. VINJE & MIDDLETON ENGINEERING, INC. 2450 Vineyard Avenue, Escondido, California 92029-1229 • Phone (760) 743.1214 • Fax (760) 739.0343 QEOTECHNICAL INVESTtATlONS GRADING SUPERVISION PENC TESTING I PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 18 EL CAMINO REAL, CARLSBAD, CALIFORNIA OCTOBER 17, 2003 4. Subgrade soils should be tested for proper moisture and specified compaction I levels, and approved by the project geotechnical consultant prior to the placement of concrete. D. Soil Design Parameters The following soil design parameters are based upon tested representative samples of on-site earth deposits. All parameters should be re-evaluated when the characteristics of the final as-graded soils have been specifically determined: * Design wet density of soil = 124 pcf. * Design angle of internal friction of soil = 30 degrees. * Design active soil pressure for retaining structures = 41 pcf (EFP), level backfill, cantilever, unrestrained walls. * Design active soil pressure for retaining structures = 67 pcf (EFP), 2:1 sloping backfill surface, cantilever, unrestrained walls. * Design at-rest soil pressure for retaining structures = 62 pcf (EFP), non- yielding, restrained walls. * Design passive soil pressure for retaining structures 374 pcf (EFP), level surface at the toe. * Design coefficient of friction for concrete on soils = 0.36 * Net allowable foundation pressure (minimum 18 inches wide by 24 inches deep footings) = 2500 psf. * Allowable lateral bearing pressure (all structures except retaining walls) for certified on-site soils = 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 walls. When combining passive pressure and frictional resistance, the passive component should be reduced by one-third. The indicated net allowable foundation pressures provided herein were determined based on a minimum 18 inches wide by 24 inches deep footings VINJE & MIDDLETON ENQINEERINQ, INC. 2450 Vineyard Avenue, Escondido, California 92029.1229 • Phone (760) 743-1214 • Fax (760) 739.0343 QEOTECHNICAL INVESTIGATIONS GRADING SUPERVISION I'ERC TESTING ENVIRONMENTAL INVESTIgATION PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 19 EL CAMINO REAL, CARLSBAD, CALIFORNIA OCTOBER 17, 2003 and may be increased by 20% for each additional foot of depth and 20% for each 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. E. Asphalt and PCC Pavement Design Specific pavement designs can best be provided at the completion of rough grading based on R-value tests of the actual finish subgrade soils; however, the following structural sections may be considered for cost estimating purposes only (not for construction): A minimum section of 3 inches asphalt on 6 inches Caltrans Class 2 aggregate base may be considered for the on-site asphalt paving surfaces. In the areas where the longitudinal grades exceed 10%, one-half inch asphalt should be added to the design asphalt thickness for each2% increase in grade or portions thereof. PCC paving is recommended for longitudinal grades over 15% and will be required when longitudinal grades are 20% or more. Actual designs will also depend on the design TI and approval of the City of Carlsbad. Base materials should be compacted to a minimum of 95% of the corresponding maximum dry density (ASTM D-1 557). Subgrade soils beneath the asphalt paving surfaces should also be compacted to a minimum of 95% of the corresponding maximum dry density within the upper 12 inches. Residential PCC driveways and parking supported on low expansive (expansion index less than 51) subgrade soils should be a minimum of 51/2 inches in thickness, reinforced with #3 reinforcing bars at 18 inches on center each way placed 2 inches below the top of slab. Subgrade soils beneath the FCC driveways and parking should be compacted to a minimum of 90% of the corresponding maximum dry density within the upper 6 inches. For grades over 15%, provide a minimum 6 inches wide by 8 inches deep shear key perpendicular to the longitudinal profile, monolithically poured at the base of the VINJE & MZDDLETON ENGINEERING, INC. 2450 Vineyard Avenue, Escondido, California 92029.1229 • Phone (760) 743.1214 • Fax (760) 739-0343 qEOTECHNICAL INVESTIGATIONS GRADING SUPERVISION PERC TESTING ENVIRONMENTAL INVESTIGATION I I I PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 20 P EL CAMINO REAL, CARLSBAD, CALIFORNIA OCTOBER 17, 2003 PCC paving section at 15 feet on centers maximum. Use a minimum 560-C- 3250 concrete per Standard Specifications for Public Works Construction I (Green Book) for all PCC paving surfaces. Provide "tool joint" or "softcut" contraction / control joints spaced 10 feet on center (not to exceed 15 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 1-inch but should not exceed 1 %-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. Subgrade and basegrade soils 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. Base section and subgrade preparations per structural section design, will be required for all surfaces subject to traffic including roadways, 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. Provide 6 inches of Class 2 base under curb and gutters and 4 inches of Class 2 base (or 6 inches of Class Ill) under sidewalks. Base layer under curb and gutters should be compacted to a minimum of 95%, while subgrade soils under curb and gutters, and base and subgrade under sidewalks should be compacted to a minimum of 90% compaction levels. Base section may not be required under curb and gutters, and sidewalks in the case of very low expansive subgrade soils (expansion index less than 21). Appropriate recommendations should be given in the final as-graded compaction report. F. General Recommendations 1. The minimum foundation design and steel reinforcement provided herein is based on soil characteristics only and is not intended to be in lieu of reinforcement necessary for structural consideration. All recommendations should be evaluated and confirmed by the project architect / structural engineer. VINJE & MIDDLETON ENqtNEERINc, INC. 2450 Vineyard Avenue, Escondido, California 92029-1229 • Phone (760) 743.1214 • Fax (760) 739-0343 EOTECHN1CAL INVESTIGATIONS GRADING SUPERVISION PERC TESTING. ENVIRONMENTAL INVESTIGATION I I PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 21 EL CAMINO REAL, CARLSBAD, CALIFORNIA OCTOBER 17, 2003 I Adequate staking and grading control is a critical factor in properly completing the recommended remedial and site grading operations. Grading control and I 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 1 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. Expansive clayey soils should not be used for backfilling of any retaining structure. All retaining 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. All underground utility and plumbing trenches should be mechanically compacted to a minimum of 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. Based upon the results of the tested soil sample, the amount of water soluble sulfate (SO4) in the soil was found to be 0.013 percent by weight which is considered negligible according to California Building Code Table No. 19-A-4. Portland cement Type II may be used. Potentially expansive clayey deposits are subject to continued swelling and shrinkage upon wetting and drying. At the site, 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. Site drainage over the finished pad surface 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. Rooflines of the buildings should be provided with VINJE & MIDDLETON ENGINEERING, INC. 2450 Vineyard Avenue, Escondido, California 92029-1229 • Phone (760) 743-1214 • Fax (760) 739-0343 QEOTECHNICAL INVESTIGATIONS GRADING SUPERVISION PERC TESTING ENVIRONMENTAL INVESTIGATION PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 22 EL CAMINO REAL, CARLSBAD, CALIFORNIA OCTOBER 17, 2003 roof gutters. Roof water should be collected and directed away from the buildings and structures to a suitable location. Consideration should be given to adequately damp-proof/waterproof the basement walls / foundations and provide the planter areas adjacent to the foundations with an impermeable liner and a subdrainage system. Final plans should reflect preliminary recommendations given in this report. Final foundations and grading plans may be reviewed by the project geotechnical consultant for conformance with the requirements of the geotechnical investigation report outlined herein. More specific recommendations may also 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. The amount of shrinkage and related cracks that occur in the concrete slab-on- grades, flatworks and driveways depends on many factors, the most important of which is the amount of water in a concrete mix. The purpose of the slab 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 considered: * Use the stiffest mix that can be handled and consolidated satisfactorily. * Use the largest maximum size of aggregate that is practical, (for example, concrete made with 3/8-inch maximum size aggregate usually requires about 40 lbs more (nearly 5 gal.) water per cubic yard than concrete with 1-inch aggregate). * 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 provided. VINJE & MIDDLETON ENGINEERINc, INC. 2450 Vineyard Avenue, Escondido, California 92029-1229 • Phone (760) 743-1214 • Fax (760) 739.0343 cEOTECHNICAL INVESTIGATIONS QRADINQ SUPERVISION PERC TESTING . ENVIRONMENTAL INCSTIQATI. PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 23 EL CAMINO REAL, CARLSBAD, CALIFORNIA OCTOBER 17, 2003 12. A preconstruction meeting between representatives of this office, the property owner or planner, the grading contractor I builder, and the city inspector is recommended in order to discuss grading/construction details associated with site development. VIII. LIMITATIONS The conclusions and recommendations provided herein have been based on available data obtained from the review of pertinent reports and plans, subsurface exploratory 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 may vary in characteristics between excavations. Of '-ecessity we must assume a certain degree of continuity between exploratory 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. 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 impossible to 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 ½..inch wide in 20 feet may develop as a result of normal concrete shrinkage (according to the American Concrete Institute). VINJE & MIDDLETON ENGINEERING, INC. 2450 Vineyard Avenue, Escondido, California 92029-1229 • Phone (760) 743.1214 • Fax (760) 739.0343 ,Xmr,('8T,f'JV GRADING SUPERVISION PERC TESTINQ ENVIRONMENTAL INVESTIGATION PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 24 EL CAMINO REAL, CARLSBAD, CALIFORNIA OCTOBER 17, 2003 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. 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. Once again, should any questions arise concerning this report, please do not hesitate to contact this office. Reference to our Job #03-390-P will help to expedite our response to your inquiries. We appreciate this opportunity to be of service to you. VINJE & MIDDLETON ENGINEERING, INC. C S Dennis Middleton , \ E CERTHRED NGINEERiNG) CE G #980 Op CA'/ Li ehdi S. Shariat No. 46174 #46174 (Ru Exp.i2-i.o 7' Steven J. MelzerC/ C) r wo.em i RG#6953 ( Distribution: Addressee (2) c Vista Engineering, Inc., Attn: Mr. Kir, fax) VINJE & MIDDLETON ENQINEERINç, INC. 2450 Vineyard Avenue, Escondido, California 92029.1229 • Phone (760) 743-1214 • Fax (760) 739-0343 cEOTECI-INICAL INVESTIGATIONS GRADING SUPERVISION PCRC TESTING ENVIRONMENTAL INVESTIGATION I 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 CLAYS AND PLASTIC SILTS STRENGTH BLOWS/FOOT VERY SOFT 0-'/4 0-2 SOFT Y4-'/2 2-4 FIRM '/2-1 4-8 STIFF 1-2 8-16 VERY STIFF 2-4 16-32 HARD OVER 4 OVER 32 Ll E PRIMARY DIVISIONS GROUP I SECONDARY DIVISIONS SYMBOL GRAVELS CLEAN GW Well graded gravels, gravel-sand mixtures, little or no fines. GRAVELS CC a UJ a I— cj MORE THAN HALF OF COARSE (LESS THAN GP Poorly graded gravels or gravel-sand mixtures, little or no fines. O < 5% FINES) GM Silty gravels, gravel-sand-silt mixtures, non-plastic fines. Cl) d FRACTION IS GRAVEL LL 2 Uj uj Oz!: LARGER THAN WITH < Cl) NO. 4 SIEVE FINES GC Clayey gravels, gravel-sand-clay mixtures, plastic fines. cr < I— LU SANDS CLEAN SW Well graded sands, gravelly sands, little or no fines. SANDS W Z U.I Cl) C/) <C MORE THAN HALF (LESS THAN SF Poorly graded sands or gravelly sands, little or no fines. OF COARSE 5% FINES) < I—< O u-j -J FRACTION IS SANDS SM Silty sands, sand-silt mixtures, non-plastic fines. o SMALLER THAN WITH Sc Clayey sands, sand-clay mixtures, plastic fines. 0 NO. 4 SIEVE FINES u-I ML Inorganic silts and very fine sands, rock flour, silty or clayey fine N SILTS AND CLAYS sands or clayey silts with slight plasticity. ________ CL Inorganic clays of low to medium plasticity, gravelly clays, sandy U) 0 O ui co uJ < > LIQUID LIMIT IS co . 2 u-i LESSTHAN5O% clays, silty clays, lean clays. OL Organic silts and organic silty clays of low plasticity. O IC) Lu z MH Inorganic silts, micaceous or diatomaceous fine sandy or silty =__jc\J < F— CO SILTS AND CLAYS soils, elastic silts. u-I M wz GREATER THAN 50% I— 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 SILTS AND CLAYS COBBLES BOULDERS I FINE I MEDIUM I COARSE FINE COARSE RELATIVE DENSITY CONSISTENCY I I 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 V Sand Cone Test Bulk Sample 246 = Standard Penetration Test (SPT) (ASTM D-1586) with blow counts per 6 inches U Chunk Sample D Driven Rings 246 = California Sampler with blow counts per 6 inches VINJE & MIDDLETON ENGINEERING, INC. 2450 Vineyard Ave., #102 Escondido, CA 92029-1229 KEY TO EXPLORATORY BORING LOGS Unified Soil Classification System (ASTM D-2487) PROJECT NO. I flA. KEY F1 >( EXPLANATION - Test, Trench 275j I Approximate Limits of X Existing Pad Fill Geologic Cross-Section /Gh'OUND v.rc /5 /1 - T58' x J•T/T 1 - EDGE UPPER LEVEL FAPSCEL B 14,887 S.F. CROSS 276 BSMT Pfl 267± MAX. RC T=U306± x EDGE BASEMENT GARAGE— I ir vi / it I 276.1 I L III I1 PREiAR.BY: .. VPS1TA ENG1NERNG. INC-" 939 '1ST 'IL' GE DRIVE VIST,\CA 9084-606. I.TELL (6b)91-2271I 1JN122-'O3(G) 276.7 \ \DENjSE TREES 257.2 1 % \ \\\\ RLrMINRY SrNd AND \V.\\ \RADI\JGSTUD/Y \A.P.N 167-080-36 H/ >( \ \\ \\\ \ \\ \ \ LOT 9, MAP 538t 449.0 : \ \ \, \ ., EL CAMINO REAL, CARLSBAD I\ ) JOB #03-390_P \\ \\ 2J4/ SCALE 1"=20' EXST6ACP/WIJER-flW4 N \\\,; ii I' \ I L) 1)/I/I / \\ \\\Ei E 7 1 / \ / 'H ..' I C14! /r1-rWL,L / ii eln ,/ RO\ / 4 I MA R0O PEAk 286±FILL ! icnl EStTJ - / D Ct i / 4 i 26J 3 ------------ X 277J \ "N V U P1 ATP 9 / \ \ \ GEOLOGIC CROSS-SECTION JOB #03-390-P 3001 280] 260 — — — — — — — - PROPOSED 3-STORY DWELLING I I I II I II I I I II P EXISTING GRADE I _ 4- — — - PROPOSED GRADE I I PROPOSED I \ I 3-STORY DWELLING •• . /2\ 300 280 260 F TIIL • •. • - I- YTIII1O • -I -------.? a -. - - p_ •, -____________________ a • a a .- . .. . • - . •- • a a . -- . • •• _240 220 SCALE: 1 "= 20 PLATE 3 - 240 220 Li I Date: 9-23-03 Logged by: SJM DEPTH (It) SAMPLE T-1 USCS SYMBOL FIELD MOISTURE (%) FIELD DRY DENSITY (pcf) RELATIVE COMPACTION (%) DESCRIPTION FILL: ______ - Silty fine to medium sand. Pale brown color. Dry. Loose. SM j 9.3 111.6 89.0 _- ST-1 - - \ i\ \ TOPSOIL: Silty fine to medium sand. Trace of clay. Dark brown color. Moist. Loose to medium dense. ST-2 SM/SC 13.2 109.5 87.3 -- \ Sandy clay to clayey sand. Tan to blue-grey color. Rust 10.8 109.1 88.4 - - 10 colored staining. Moist to very moist. Firm to stiff. A few scattered cobbles. ST-2 CL/SC FORMATIONAL ROCK: - - Clayey to silty sandstone. Fine to coarse grained. Tan - - color. Moist. Weathered friable. Weakly cemented at SC/GC -15 - upper contact. Becomes somewhat blocky and locally - - cemented at 6'. Locally cobbles and gravels. Poorly - - sorted. Clay content decreases at depth. ST-3 - - End Test Trench at 8'. (No caving. No groundwater.) -20- Date: 9-23-03 Logged by: SJM I EPTH (It) T-2 SAMPLE DESCRIPTION USCS SYMBOL FIELD MOISTURE (%) FIELD DRY DENSITY (pcf) RELATIVE COMPACTION (%) I -- TOPSOIL: - 1 - Silty fine to medium sand. Pale brown color. Porous to - - highly porous. Dry. Loose. Scattered cobbles and gravel. SM I - 2 - - - Roots up to 6' in diameter from nearby eucalyptus trees. ST-1 1.6 104.0 - .3 Clayey sand. Medium to coarse grained. Red-brown - -color. Moist. Loose to medium dense. Porous. Scattered SC - - cobbles. Clay content decrease at depth. ST-2 -5- FORMATIONAL ROCK: I -- - 6 - Cobble conglomerate. ± 25% cobbles 6" minus. Silty to - - - 7 - clayey sand matrix. Fine to medium grained. Red-brown DU color. Weakly cemented. Moist. Difficult to excavate. GC 8.8 105.2 83.9 -8 -U] ST-4 7.2 114.0 90.9 9— ________________________________________ II - - - —10 End Test Trench at 10'. (No caving. No groundwater.) I - & MIDDLETON ENGINEERING, INC TEST TRENCH LOGS :VINJE I 2450 Vineyard Avenue, Suite 102 Escondido, California 92029-1229 EL CAMINO REAL, CARLSBAD I - ice 760-743-1214 Fax 760-739-0343 PROJECT NO. 03-390-P PLATE 4 L nd Cone Test • Bulk Sample 0 Chunk Sample 0 Driven Rings I I I I I i I mdo I Date: 9-23-03 Logged by: SJM I DEPTH (ft) SAMPLE T-3 USCS SYMBOL FIELD MOISTURE (°I) FIELD DRY DENSITY (pcf) RELATIVE COMPACTION (%) DESCRIPTION j FILL: —1 — Silty fine to medium sand. Scattered cobbles. Pale brown SM - - color. Dry. Medium dense. No evidence of benching. : ST-1 i TOPSOIL: Sandy clay to clayey sand. Red-brown color. Moist. CL/SC I - - Blocky. FORMATIONALROCK: - 5 - Silty sandstone. Medium to coarse grained. Trace of clay. S P/SC - 6 - Off-white color. Blocky. Cemented. Massive. Poorly - - sorted. ST-3 -7- - - End Test Trench at 3W. (No caving. No groundwater.) Date: 9-23-03 Loggedby:SJM DEPTH (ft) SAMPLE 1-4 USCS SYMBOL FIELD MOISTURE (%) FIELD DRY DENSITY (pcf) RELATIVE COMPACTION (%) DESCRIPTION - - FILL: sand / cobble mix. Red-brown color. Up to 50% GP - I -Silty cobbles by volume. Dry. Medium dense. -2- • .ST-5 - 3 - TOPSOIL: Silty fine sand. Pale brown color. Porous. Dry. Loose. SM - 4 - Some rootlets. Locally gravelly. ST-1 - 5 - Sandy clay to clayey sand. Red-brown color. Moist. CL/SC Blocky. Stiff. - 6 - ST-2 10.2 126.6 100+ - 7 - FORMATIONALROCK: - - Siltstone. Pale grey color. Locally sandy. Blocky. — 8— Indurated. - - SP — 9 - Grades to sandstone at 7. Fine to coarse grained. Off- - - white color. Blocky. Cemented. Poorly sorted. Some rust _10 - colored staining. No apparent structures. ST-3 End Test Trench at 8. (No caving. No groundwater.) VINJE & MJDDLETON ENGINEERING, INC TEST TRENCH LOGS 2450 Vineyard Avenue, Suite 102 Escondido, California 92029-1229 Office 760-743-1214 Fax 760-739-0343 ELCAMINOREAL,CARLSBAD PROJECT NO. 03-390-P PLATE 5 V Sand ConeTest U Bulk Sample LiChunk Sample 0 DrivenRings Date: 9-23-03 Logged by: SJM I- T-5 FIELD DEPTH (ft) SAMPLE USCS SYMBOL FIELD MOISTURE DRY DENSITY (pcf) RELATIVE COMPACTION (%) DESCRIPTION FILL: Silty fine sand/cobble mix. Redbrown color. Dry. Blocky. ST-5 GP - 1 - - - 9.4 126.7 100+ -2- - - \ FORMATIONAL ROCK: - 3 - Silty sandstone. Medium to coarse grained. Locally trace SP/SC - - of clay. Off-white color. Rust colored staining. Poorly - 4 - sorted. Blocky. Cemented. ST-3 -5- - - End Test Trench at 2. (No Caving. No groundwater.) -6- -7- -8- Date: 9-23-03 Logged by: SJM PTH SAMPLE 1-6 USCS SYMBOL FIELD MOISTURE (%) FIELD DRY DENSITY (pcf) RELATIVE COMPACTION (%) DESCRIPTION - - FILL I TOPSOIL: -1-- Silty fine to medium sand. Up to 50% cobbles and GP . - - pebbles by volume. Dry. Somewhat loose. ST-5 -2- FORMATIONAL ROCK: - - 3— Silty sandstone. Fine to medium grained. Locally trace of - - clay. Off-white. Rust colored staining. Weathered friable S P/SC - 4 - near surface. Becomes somewhat blocky and moderately - - cemented at 2. No apparent structure. -5- ST-3 End Test Trench at 3. (No caving. No groundwater.) 6 - -8- -9- -10- - VINJE & MIDDLETON ENGINEERING, INC TEST TRENCH LOGS 2450 Vineyard O Suite 102 EL CAMINO REAL, CARLSBAD - PROJECT NO. 03-390-P PLATE 6 Office 760-743-1214 Fax 760-739-0343 V Sand Cone Test 0 Bulk Sample C3 Chunk Sample 0 Driven Rings 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." Earthquake Magnitude .......4.0 TO 4.9 PROJECT: Job #03-390-P 50T05.9 ............ 6.0 TO 6.9 EL CAMINO REAL, CARLSBAD ID........ Fault, PLATE: 7 Perforated drain pipe L /1 5 _ Filter Material. Crushed rock (wrapped in filter fabric) or Class 2 Permeable Material (see specifications below) Competent, approved soils or bedrock RETAINING WALL DRAIN DETAIL Typical - no scale drainage :•: Granular, non-expansve backfill. Compacted./ Waterproofing CONSTRUCTION SPECIFICATIONS: Provide granular, non-expansive backfill soil in 1:1 gradient wedge behind wall. Compact backfill to minimum 90% of laboratory standard. Provide 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. Backdrain should consist of 4" diameter PVC pipe (Schedule 40 or equivalent) with perforations down. Drain to suitable outlet at minimum 1%. Provide %" - 1W crushed gravel filter wrapped in filter fabric (Mirafi 140N or equivalent). Delete filter fabric wrap if Caltraris Class 2 permeable material is used. Compact Class 2 material to minimum 90% of laboratory standard. Seal back of wall with waterproofing in accordance with architect's specifications. Provide positive drainage to disallow ponding of water above wall. Lined drainage ditch to minimum 2% flow away from wall is recommended. * Use 11/2 cubic foot per foot with granular backfill soil and 4 cubic foot per foot if expansive backfill soil is used. VJNJE & MIDDLETON ENGINEERING, INC. PLATE 8 I I I I I I I I I ISOLATION JOINTS AND RE-ENTRANT CORNER REINFORCEMENT Typical - no scale (a) (b) ISOLATION JOINTS LE CONTRACTION JOINTS ENTRANT NER CRACK RE-ENTRANT C( R El N FO RCEMEN NO. 4 BARS PL BELOW TOP OF 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. - VINJE & MIDDLETON ENGINEERING, INC. PLATE 9