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Home My WebLink AboutCT 81-46; AIRPORT BUSINESS CENTER CT 81-46 Unit 1, Lot Nos, 7, 8, 11 and 15; GEOTECHNICAL INVESTIGATION; 1996-05-08'\, GEOTECHNICAL INVESTIGATION CARLSBAD TRACT NO. 81-46 UNIT 1, LOT NOS. 7, 8, 11, AND 15 CARLSBAD, CALIFORNIA PREPARED FOR NEWPORT NATIONAL CORPORATION CARLSBAD, CALIFORNIA MAY 1996 r;i rn@ lU W ~~ I ~f JJ. 3 o 19111 IU ) l tARLSBAD \ MUNICI WATER IJISIB.tC[ I.~.- \ \ Project No. 05724-12-01 May 8, 1996 Newport National Corporation 5050 Avenida Encinas, Suite 350 Carlsbad, California 92008 Attention: Mr. Scott Merry Subject: CARLSBAD TRACT NO. 81-46 UNIT 1, LOT NOS. 7, 8, 11, AND 15 CARLSBAD, CALIFORNIA GEOTECHNICAL INVESTIGATION Gentlemen: In accordance with your authorization and our proposal dated April 10, 1996, we have performed a geotechnical investigation for the subject project. The accompanying report presents the findings of our study and our conclusions and recommendations pertaining to project development. Based on the results of our study, it is our opinion that the proposed facilities can be constructed as planned, provided the recommendations of this report are followed. If there are any questions regarding this report, or if we may be of further service, please do not hesitate to contact the undersigned at your convenience. Very truly yours, RE 22527 AS:DFL:dmc (4/del) Addressee Ali Sadr CEG 1778 TABLE OF CONTENTS PURPOSE AND SCOPE ................................................................. : ...................... 1 SITE AND PROJECT DESCRIPTIONS ........................................................... : ......... 2 SOIL AND GEOLOGIC CONDITIONS, ..................................................................... 3 Fill (Qat) ......................................................................................................... 3 Delmar Formation (Td) ................................................................ -....................... 4 GROUNDWATER ............................................................................................... 4 GEOLOGIC HAZARDS ........................................................................................ 5 Faulting and Seismicity ....................................................................................... 5 Liquefaction ..................................................................................................... 6 CONCLUSIONS AND RECOMMENDATIONS .......................................................... 7 General. .......................................................................................................... 7 Seismic Setting ................................................................................................. 9 Soils and Excavation Characteristics ....................................................................... 9 Grading ........................................................................................................ 10 Heel Drains ................................................................................................... 12 Foundations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Concrete Slabs-On-Grade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Slope Stability ............................................................ : ................................... 15 Retaining Walls and Lateral Loads . . . . . . . . . . . . . . . . . . . . .. . . . . . . .. . . . . . . . . . .. . . . . .. .. . . . . . . . . . . . . . . . . . . . . . . 16 Site Drainage ................................................................................................. 17 Foundation and Grading Plan Review ................................................................... 18 LIMITATIONS AND UNIFORMITY OF CONDITIONS MAPS AND ILLUSTRATIONS Figure 1, Vicinity Map Figure 2, Geologic Map (Site Plan) Figure 3, Wall/Column Footing Dimension Detail Figure 4, Typical Stability Fill Detail Figure 5, Retaining Wall Drain Detail APPENDIX A FIELD INVESTIGATION Figures A-1 -A-3, Logs of Borings Figures A-4 -A-14, Logs of Trenches APPENDIX B LABORATORY ANALYSIS Table B-I, Summary of Laboratory Maximum Dry Density and Optimum Moisture Content Test Results Table B-II, Summary of Direct Shear Test Results Table B-III, Summary of Expansion Index Test Results APPENDIX C RECOMMENDED GRADING SPECIFICATIONS ' I ' Project No. 05724-12-01 May 8, 1996 PURPOSE AND SCOPE GEOTECHNJCAL INVESTIGATION This report, presents the results of a geotechnical investigation for the subject project located within Carlsbad Airport Center in Carlsbad, California. The purpose of our investigation was to evaluate the surface and subsurface soil and geologic conditions and, based on the conditions encountered, to provide recommendations pertaining to the geotechnical aspects of site development. The scope of the field investigation consisted of a site reconnaissance and the excavation of two large-diameter exploratory borings and 11 exploratory trenches. A review of a portion of the as-graded geotechnical report prepared by Moore & Taber, dated February 25, 1987, was also performed. Laboratory tests were performed on selected soils samples obtained at various depths in the trenches to evaluate various physical properties. Details of the field investigation and laboratory tests are presented in Appendices A and B, respectively. The recommendations presented herein are based on analysis of the data obtained from the borings and trenches, laboratory tests, and our experience with similar soil and geologic conditions. The data presented in the referenced as-graded geotechnical report was considered as supplemental information where appropriate in arriving at the recommendations. - l - l I I Project No. 05724-12-01 May 8, 1996 SITE AND PROJECT DESCRIPTIONS 'I, The site is located just north of the Palomer Airport Road at the intersection of Palomar Oak Way within Airport Center of Carlsbad, California (Vicinity Map, Figure 1). The subject lots were sheet-graded as a part of mass grading of Carlsbad Airport Center in the mid 1980's. Testing and observation services were performed by Moore & Taber and reported on February 25, 1987. It is our understanding that two-or ·three-story commercial structures with associated parking and driveways are planned for the property. Grading plans for the proposed development are not available for our use; however, it is anticipated that earth work within Lots 7 and 8 will involve cuts up to 10 feet; Lot 11 will receive fill to a depth of approximately 20 feet, while Lot 15 will essentially remain at the same elevation. A review of the referenced as-graded geotechnical report indicates that during the mass grading operation, due to the presence of adverse geologic conditions, buttress fills were constructed within Lots 7, 8, and 11. The effect of future grading on the existing buttresses is discussed hereinafter. The Geologic Map, Figure 2, presents approximate locations of the borings and trenches. The descriptions contained herein are based upon our site reconnaissance and a review of the previously referenced project plans and reports. If project details vary significantly from those - 2 - {' ,, Project No. 05724-12-01 May 8, 1996 outlined herein, Geocon Incorporated 'should be notified for review and possible revision of recommendations presented herein prior to final design submittal. It is anticipated that when the entire design team has been selected, this report may require modification to address specific issues. SOIL AND GEOLOGIC CONDITIONS The site is underlain by compacted fill soils and the Delmar . Formation. The approximate geologic contacts are shown on the Geologic Map, Figure 2, and are based upon the referenced reports and plans and the field exploration performed for this investigation. Fill <Oaf) Fill soils of variable thickness were encountered in the majority of Lot 11 and eastern portion of Lot 8. In addition, buttress fills were constructed during the mass grading operation along most of the south-facing cut slopes. In general, these materials consist of light greenish gray to light grayish brown, silty to clayey sand to green, sandy clay. Fill soils encountered in the exploratory excavation were generally moderately dense with relatively uniform moisture content, except the near-surface materials which are disturbed by roots and/or weather. The fill soils are considered suitable for receiving additional fill or structures. -3 - Project No. 05724-12-01 May 8, 1996 Delmar Formation (Td) The Eocene-aged Delmar Formation is present in the cut areas and underneath the fill soils. The Delmar Formation as encountered in the exploratory excavation consists primarily of interbedded sandstone, claystone, and, less commonly, siltstone. The sandstone beds are generally massive to thinly bedded, slightly cemented. Cementation, however, can vary from well-cemented drill- resistant concretionary beds of approximately 1 to 2 feet thick to slightly cemented, nearly cohesionless sand. The claystones are generally thinly bedded, fractured to relatively massive, and well cemented. Bedding plane shear zones are common within the claystones. The claystones and siltstones are typically characterized as having "medium" to "high" expansion potential. Cut slopes exposing alternative sandstone and claystone bedding may present surficial instability and seepage, and require mitigation by construction of stability fill. GROUNDWATER The Delmar Formation which underlies the majority of the site has permeability characteristics and/or bedding that could be susceptible to water seepage under certain conditions. A slight seepage was encountered at the depth of 33 feet in Boring No. 1 and the depth of 13 feet in Trench No. I, and at IO and 12 feet in Trench No. 2 Groundwater conditions, either potential or actual, will be mitigated by installation of subdrains, heel drains, and drainage panels constructed to flow to allow suitable outlets. - 4 - Project No. 05724-12-01 May 8, 1996 GEOLOGIC HAZARDS Faulting and Seismicity It is our opinion, based on our field investigation and review of aerial photographs and published geologic maps (Weber, 1963 and 1982), the site is not located on any active or potentially active fault trace as defined by the California Division of Mines and Geology. The Rose Canyon and Elsinore Fault Zones, the closest active faults, lie approximately 10 and 22 miles to the west and northeast, respectively. As shown on Table I, a Maximum Probable Earthquake of Magnitude 6.5 occurring on the Rose Canyon fault could result in a peak site acceleration of approximately 0.20 g. Other active faults listed on Table I are more distant from the site and, hence, ground shaking from earthquakes on those faults will be less intensive. It is our opinion that the site could be subjected to moderate to severe ground shaking in the event of a major earthquake along any of the above-mentioned faults; however, the seismic risk at the site is not considered significantly greater than the surrounding area. - 5 - I• Project No. 05724-12-01 May 8, 1996 • · DETERMINISTIC SITE PARAMETERS FOR SELECTED FAULTS Rose Canyon IO 7.0 Offshore Zone of Deformation 13 7.5 Elsinore 22 7.5 Coronado Banlcs Fault Zone 23 6.15 San Diego Trough 33 6.5 Newport-Inglewood 44 7.5 Casa Loma-Clark (San Jacinto) 45 7.5 Coyote Creek (San Jacinto) 47 7.5 Gin. Helen-Lytle Cr-Clairemont 49 7.5 Liquefaction ·;f;Peak:Site'i't ·: Ma.xiinunl" > · .. ·· Peak Site iccelei:ation,oo p~~tf·(Mig) " ~Acceleration {g) ,. },,,,,,. ':~-·',""" . . : "·· , ·. ",, . __ ;..,., . . ,,~ •'" ' " .. 2.6 6.5 0.20 0.27 6.5 0.16 0.15 6.15 0.10 0.10 6.0 0.06 0.05 6.0 0.04 0.06 6.5 0.04 0.06 7.0 0.05 0.06 7.0 0.04 0.05 7.0 0.04 Soil liquefaction is generally limited to granular soils located below groundwater which are in a relatively loose, unconsolidated condition at the time of a large earthquake event. It is our opinion that, due to the high density and cemented nature of the formational soils occurring on the site, and lack of near surface groundwater there is no significant risk of seismically induced liquefaction within the project limits. - 6 - t. 1 .. Project No. 05724-12-01 May 8, 1996 CONCLUSIONS AND RECOMMENDA'1'IONS General 1. No soil or geologic conditions were observed during the course of the investigation or noted in review _of the referenced documents which, in our opinion, would preclude the development of the property as presently planned, provided the recommendations of this study are followed. 2. The site is currently sheet-graded and is underlain by shallow fill soils and formational materials of the Delmar Formation. These materials are generally considered suitable for receiving additional fill or settlement-sensitive structures. Laboratory tests have determined that the existing near-surface soils and soils that will be exposed in the cut areas are moderately to highly expansive. Thus remedial and select grading and/or special foundation considerations are recommended herein. 3. Buttress fill slopes have been constructed on the north margins of Lots 7 and 8, on the southern margins and within the short fill slopes within Lots 7 and 8 as well as within the southern edge of Lot 11 adjacent to Palomar Airport Road. Planned grading, as we understand it, will result in lowering the grades with Lot 7 and 8 and elevating the pad grade within Lot 11 by as much as 20 feet. Based on the conditions observed during our site investigation, the impact of the future grading on the existing buttresses was re-evaluated as discussed below. - 7 - Project No. 05724-12-01 May 8, 1996 4. Adverse bedding conditions were not observed within the formational soils underlying the ,, buttress located north of Lots 7 and 8. Therefore, reconstruction of buttress fill slopes .. is not required. However, due to the characteristics of the formational materials, including interbedding of sandstone and claystones, it is recommended that drained stability fill be constructed· below the existing buttress to reduce potential surficial instability. 5. Adverse bedding conditions were not encountered within the formational soils behind the existing buttress south of Lot 11. Therefore, it is not anticipated that the planned placement of additional fill will require special consideration during site development. 6. It is anticipated that with the 30-foot radius maintained as a setback for grading around the existing San Diego Gas and Electric (SDG&E) power pole, located at the northwest corner of Lot 8, the pole stability should not be an issue. However, the cut slope around the pole will require construction of a stability fill similar to the adjacent areas. 7. No significant grading is anticipated for Lot 15. However, the pad is underlain by expansive soils which may require remediation as recommended herein. Construction of a retaining wall at the lower portion of the cut slope along Palomar Oaks Way, would not require special construction during construction. - 8 - I' Project No. 05724-12-01 May 8, 1996 Seismic Setting 8. The project is located within seismic Zone 4. Details regarding seismicity and faulting were previously discussed. 9. A site coefficient, "S" factor (Table No. 16A-J, Uniform Building Code), equal to 1.0 should be used in design of the foundation system. Soils and Excavation Characteristics 10. Based on our field observation and laboratory test results, the prevailing soil conditions are anticipated to vary from "very low" expansive, silty sands derived from the sandstones of the Delmar Formation to "medium" to "high" expansive material derived from clayey portions of the Delmar Formation. The expansive character of the soils is defined in accordance with the Uniform Building Code (UBC) Table 18A-l-B. 11. Excavation of the fill soils should be possible with light to moderate effort with conventional heavy-duty grading equipment. Moderate to heavy effort should be anticipated for excavations in the formational soils. Excavation of the highly cemented concretionary zones within the Delmar Formation will generally be difficult, may require heavy ripping and will probably result in the generation of oversized material (greater than 12-inch). It should also be anticipated that after site grading is complete, future excavations in cut areas that expose the Delmar Formation are likely to encounter oversize material and require special excavation equipment. -9 - Project No. 05724-12-01 May 8, 1996 Grading 'lo 12. All anticipated grading for site development should be performed in accordance with the Recommended Grading Specifications contained in Appendix C, and in accordance with pertinent ordinances of the City of Carlsbad. Where recommendations of Appendix C conflict with this section of the report, the recommendations of this section shall take precedence. All earthwork should be observed by, and all compacted fill tested by, representatives of Geocon Incorporated. 13. Prior to commencing grading, a preconstruction conference should be held at the site with the Owner or Developer, Grading Contractor, Civil Engineer, and Geotechnical Engineer in attendance. Special soil and oversize material handling and/or the grading plans can be discussed at that time. 14. Site preparation should begin with removal of all deleterious matter and vegetation in areas to be graded. The depth of removal should be such that material to be used in fills is free of organic matter. Material generated during stripping operations should be exported from the site to an approved location. 15. The site should then be brought to final subgrade elevations with structural fill compacted in layers. In general, native soils are suitable for reuse as fill if free from vegetation, debris and other deleterious matter. Layers of fill should be no thicker than will allow for adequate bonding and compaction. In areas proposed for improvements, all fill (including backfill -10 - Project No. 05724-12-01 May 8, 1996 and scarified ground surfaces) shoµld be compacted to at least 90 percent of maximum dry density at or slightly above optimum moisture content, as determined in accordance with ASTM Test Procedure D1557-91. 16. Grading operations on the site should be scheduled so as to place the oversized rocks, cemented material and : "high" expansive soils in the deeper fills. All fill slopes should be constructed with granular materials having a "low" expansion potential. 17. The upper 12 inches of the sheet-graded areas subject to receiving fill or improvements should be processed by cross-ripping, moisture conditioning, and recompacting. ~ 18. It is anticipated that highly expansive claystone will be exposed within the proposed cut portion of Lots 7 and 8. It is recommended that highly expansive, clayey soils be undercut .. to a minimum depth of 5 feet ~nd replaced with granular soils with "medium" to "low" expansion potential. -.._;;;___ _____ _ 19. Surficial subgrade soils exposed for an extended period subsequent to grading tend to lose proper moisture content. Prior to construction of site improvements, particularly concrete flatwork, sub grade soils should be moisture conditioned and recompacted as necessary. 20. It is assume that, except for the highly expansive soils discussed above, the regrading of the site result in soils having a "medium" expansive characteristics. Laboratory tests should be performed during grading to verify this condition. -11 - 1• Project No. 05724-12-01 May 8, 1996 21. To reduce the potential for differential settlement, it is recommended that the cut portion of cut-fill transition lots be undercut at least 5 feet and replaced with properly compacted fill Heel Drains 22. It is our understanding that heel drains from the existing buttress fills are connected to the permanent drain system. Heel drains installed for the proposed stability fills should also be connected to the storm drain system. Foundations 23. The following preliminary foundation recommendations are based on presence of "medium" expansive soils within the upper 5 feet of building pads. It should be noted that the foundation recommendations will be provided upon completion of the grading operations and based on the actual subgrade soils. 24. Foundations for the two-to three-story structures should consist of continuous strip footings and/or isolated spread footings. Continuous footings should be at least 12 inches wide and extend at least 30 inches below lowest adjacent pad grade. Isolated spread footings should have a minimum width of 3 feet and extend at least 36 inches below lowest adjacent pad grade. Continuous footing steel reinforcement should consist of at least four No. 5 reinforcing bars placed horizontally in the footings, two near the top and two near the -12 - ~==;:;;;;illilliliiiiiiii ____ .......... ~ ..... -. ··-~ -- I• Project No. 05724-12-01 May 8, 1996 bottom. Steel reinforcement for •.the spread footings should be designed by the project structural engineer. 25. The minimum reinforcement recommended above is for soil characteristics only (Expansion Index of 90 or less) and is not intended to replace reinforcement required for structural considerations. 26. The recommended allowable bearing capacity for foundations designed as recommended above is 3,000 psf. This allowable soil bearing pressure may be increased by an additional 500 psf for each additional foot of depth and 300 psf for each additional foot of width, to a maximum allowable bearing capacity of 5,000 psf. The values presented above are for dead plus live loads and may be increased by one-third when considering transient loads due to wind or seismic forces. 27. If the foundations are constructed as recommended above, differential and total settlements of less than ½ inch and 1 inch, respectively, are estimated. 28. Foundation excavations should be observed by a representative of Geocon Incorporated -prior to the placement of reinforcing steel 9.r piacem~nt of concrete to verify that the exposed soil conditions are consistent with those anticipated. If unanticipated soil conditions are encountered, foundation modifications may be required. For a detail of footing dimensions see Figure 3. -13 - Project No. 05724-12-01 May 8, 1996 29. Footings located within 7 feet of the top of slopes are not recommended. However, footings that must be located within this zone should be extended in depth such that the outer bottom edge of the footing is at least 7 feet or horizontally from the face of the slope. Concrete Slabs-On-Grade 30. Concrete slabs-on-grade should have a minimum thickness of 5 inches, be underlain by 4 inches of clean sand and reinforced with No. 3 steel reinforcing bars spaced 18 inches on center placed at the slab midpoint. If floors are subjected to large point loads or heavy forklift loads, slab thickness and reinforcement should be designed by the project structural engineer. Where moisture sensitive floor coverings, or storage areas for moisture sensitive materials are planned, the slabs should be underlain by a visqueen moisture barrier placed at the midpoint of the sand blanket. 31. The above minimum reinforcement recommendations for footings and concrete slabs-on- grade are based upon anticipated soil characteristics only and are not intended to be in lieu of structural considerations. Additional steel reinforcement should be designed by the project structural engineer. 32. All exterior concrete flatwork with dimensions exceeding 8 feet, underlain by expansive soils, should be reinforced with 6x6-10/10 welded wire mesh to reduce the potential for cracking. In addition, all concrete flatwork should be provided with crack control joints at a maximum spacing of 12 feet. -14 - Project No. 05724-12-01 May 8, 1996 33. All subgrade soils should be at proper moisture content prior to concrete placement. Where drying has occurred, reconditioning of surficial soils will be required. 34. The recommendations presented herein are intended to reduce the potential for cracking of slabs and foundations due to expansive soils, differential settlement of deep fills or fills of varying thickness. However, even with the incorporation of the recommendations presented herein, foundations, stucco walls, and slabs-on-grade may still exhibit some cracking and/or movement. The occurrence of concrete shrinkage cracks are independent of the supporting soil characteristics. Their occurrence may be reduced and/or controlled by limiting the slump of the concrete, the use of control joints and proper concrete placement and curing. Control joints within slabs should be spaced at intervals as recommended by the American Concrete Institute to reduce shrinkage cracking. Slope Stability 35. The proposed cut slopes around the perimeter of the subject lots are considered stable against deep-seated failure. However, due to the variable nature of the Delmar Formation, it is recommended that stability fill slopes be constructed to provide suitable surficial slope stability for long-term performance. A typical stability fill configuration. is shown on Figure 4. -15 - I I I I I I I I I I l I Project No. 05724-12-01 May 8, 1996 Retaining Walls and Lateral Loads 36. 37. 38. 39. Active earth pressures against walls will depend upon the slope of backfill and the degree of wall restraint. Unrestrained walls with a level backfill surface should be designed to resist an active pressure equivalent to that generated by a fluid weighing 35 pcf. For rigid, absolutely restrained walls, an additional uniform pressure of 7H psf (where H equals the wall height in feet) should be added to the above active pressures. These values assume a drained backfill condition with no hydrostatic pressure behind the wall. The above recommendations assume level, properly drained granular backfill with no surcharge loading on the wall. For 2 to 1 sloping backfill, an active earth pressure equivalent to that exerted by a fluid weighing 45 pcf should be assumed. All retaining walls should be provided with a drainage system adequate to prevent the buildup of hydrostatic forces and should be waterproofed as required by the project architect or design engineer. Figure 5 presents a recommended retaining wall drainage detail. The above recommendations assume a properly compacted granular backfill material with no hydrostatic forces or imposed surcharges. If conditions different than those described are anticipated, or if special drainage details are desired, Geocon Incorporated should be contacted for additional recommendations. Lateral loads may be resisted by a passive pressure equivalent to that generated by a fluid weighing 250 pcf and 350 pcf for foundations in properly compacted fill and natural -16 - ,. Project No. 05724-12-01 May 8, 1996 formational soils, respectively. The upper 12 inches of soil not protected by pavement or ' floor slabs should not be included in the design for lateral pressure. A coefficient of friction of 0.35 may be used to calculate the resistance to sliding along the concrete/ soil interface. Site Drainage 40. Adequate drainage is imperative to reduce the potential for differential soil movement, erosion and subsurface seepage. Under no circumstances should water be allowed to pond adjacent to footings. The site should be graded and maintained such that surface drainage is directed away from the structure and the top of sl?pes into swales or other controlled drainage devices. Roof and pavement drainage should be directed into conduits which carry runoff away from the proposed structure. Discharge of roof drains and surface drainage structures on to surrounding subgrade soils should be prohibited. 41. Landscaping planters immediately adjacent to paved areas are not recommended due to the potential for surface or irrigation water to infiltrate the pavement's subgrade and base course. It is suggested that either subdrains, which collect excess irrigation water and transmit it to drainage structures, or impervious, above-grade planter boxes be used. In addition, where landscaping is planned adjacent to the pavement, it is recom- mended that consideration be give to providing a cutoff wall along the edge of the pavement that extends at least 6 inches below the base material. -17 - I I f o Project No. 05724-12-01 May 8, 1996 Foundation and Grading Plan Review '\ 42. Geocon Incorporated should review the grading plans and foundation plans prior to final design submittal to determine if additional analysis and/or recommendations are required. -18 - Project No. 05724-12-01 May 8, 1996 LIMITATIONS AND UNIFORMITY OF CONDITIONS 1. The recommendations of this report pertain only to the site investigated and are based upon the assumption that the soil conditions do not deviate from those disclosed in the investigation. If any variations or undesirable conditions are encountered during construction, or if the proposed construction will differ from that anticipated herein, Geocon Incorporated should be notified so that supplemental recommendations can be given. The evaluation or identification of the potential presence of hazardous or corrosive materials was not part of the scope of services provided by Geocon Incorporated. 2. This report is issued with the understanding that it is the responsibility of the owner, or of his representative, to ensure that the information and recommendations contained herein are brought to the attention of the architect and engineer for the project and incorporated into the plans, and the necessary steps are taken to see that the contractor and subcontractors carry out such recommendations in the field. 3. The findings of this report are valid as of the present date. However, changes in the conditions of a property can occur with the passage of time, whether they be due to natural processes or the works of man on this or adjaceqt properties. In addition, changes in applicable or appropriate standards may occur, whether they result from legislation or the broadening of knowledge. Accordingly, the findings of this report may be invalidated wholly or partially by changes outside our control. Therefore, this report is subject to review and should not be relied upon after a period of three years. ' I I ... - ---✓ ' I I I I; 18 I'; I J -f --.... ' \< \~ <".l 'rsr4, '<!-l'r ' ',i, I "' ' I ;g13 ,;~[ft'-'-1'1:.::-::: r------- 1~ '§ \ ~~rr er 'i" ---\ ---~--:h~~ --- S\IEtTBIII CIR f\)11 SOURCE: 1996 THOMAS BROTHERS MAP SAN DIEGO COUNTY, CALIFORNIA REPRODUCED WITH PERMISSION GRANTED BY THOMAS BROTHERS MAPS, THIS M.\P IS COPYRIGHTED BY THOW.S BROS, M.\PS, IT IS UNLAWFUL TO COPY OR REPRODUCE ALL OR ANY PART THEREOF, WHETHER FOR PERSONAL use OR RESALE, WITHOUT PERMISSKlN GEOCON INCORPORATED GEOTECHNlCAL ENGINEERS AND ENGINEERING GEOLOGISTS 6?60 FLANDERS DRIVE -SAN DIEGO, CALIFORNIA 92121-2974 PHONE 619 558-6900 -FAX 619 558-6159 AS /RSS I I DSK / 00000 1VICMAP DATE \ I I I \ \ ,, ,, , I I I ------x / ·-. J --, _,,.-.,,,,. ............... ,,,,..,,,,..,,,,. ' I I I I \ .,,,.,,.,;.,,,. / _,, NO SCALE N VICINITY MAP CARLSBAD TRACT 81 -46 LOT NO'S 7, 8, 11 & 15 CARLSBAD, CALIFORNIA llOO --- I 05 -08 -19961 PROJECT NO, 05724 -12 -01 I FIG. I ,.:i \ -1@ \ T~\ Qaf (1 100' 200' APPROX. SCALE GEOCON INCORPORATED GFOTF.C.HNIC.AL FN<11NFF.RS ANO F.N<11NFF.RINCl ClFOI.OCllSTS 6960 FLANDERS ORlVE • SAN DIEGO, CALIFORNIA 92111-2974 PHONE 619 558-6900 • FA.."\ 619 558-6159 AS/RSS OSK/ GOOOO DATE .. i LEGEND Qaf ... FILL Td ... DELMAR FORMATION ------..__, ... APPROX. GEOLOGIC CONTACT B-l~ ... APPROX. LOCATION OF BORING T-~ ... APPROX. LOCATION OF TRENCH t:::\{{! ... BUTTRESS FILL SITE PLAN CARLSBAD TRACT 81 -46 LOT NO'S 7, 8, 11 & 15 CARLSBAD, CALIFORNIA 05 -08 -19961 PROJECT NO. 05724 -12. 01 I FIG. 2 : I WALL FOOTING CONCRETE SLAB PAD GRADE VISOUEEN FOOTING* ~, WIDTH COLUMN FOOTING CONCRETE SLAB FOOTING WIDTH * * ...... SEE REPORT FOR FOUNDATION WIDTH AND DEPTH RECOMMENDATION NO SCALE WALL/ COLUMN FOOTING DIMENSION DETAIL GEOCON INCORPORATED GEOTECHNICAL ENGrNEERS AND ENGrNEERING GEOLOGISTS 6960 FLANDERS DRIVE. Si\NDIECiO, Ci\LIFORNI.'\ 92121-2974 PHONE 619 558-6900 • FAX 619 558-6159 AS/RSS I I DSK/GTYPI 5724AS2 CARLSBAD TRACT 81 -46 LOT NO'S 7, 8, 11 & 15 CARLSBAD, CALIFORNIA DATE 05 -08 -1996 I PROJECT NO. 05724 -12 - 0 I I FIG 3 1.5' MIN. EXISTING GROUND SURFACE FINISHED SLOPE NOTE 1 rNOTE 2 FINISHED LOT GRADE NOTE 4 DETAIL NOTES: NOTE 5 -5%MIN. SEE DETAIL 1... ... EXCAVATE BACKCUT AT 1:1 INCLINATION i 2 ...... BASE OF STABILITY FILL TO BE 3 FEET INTO DENSE, FORMATIONAL SOILS SLOPING A MINIMUM 5% INTO SLOPE UNDISTURBED FORMATIONAL SOIL NO SCALE 3 ..... BUTRESS FILL TO BE COMPOSED OF PROPERLY COMPACTED GRANULAR SOIL WITH MINIMUM SHEAR STRENGTH OF ♦= 25°, C' 250 psi' 4 ...... WHERE SEEPAGE IS ENCOUNTERED IN BACKCUT, CHIMNEY DRAINS TO BE APPROVED PREFABRICATED CHIMNEY DRAIN PANELS (MIRADRAIN, TENSAR, OR EQUIVALENl) SPACED APPROXIMATELY 30 FEET CENTER TO CENTER OR 12-lNCH BY 24-lNCH SLOTS FILLED WITH FILTER MATERIAL (SEE NOTES). DRAINS WILL BE REQUIRED WHERE AREAS OF SEEPAGE ARE ENCOUNTERED. 5 ..... FILTER MATERIAL TO BE 1-lNCH, OPEN-GRADED CRUSHED ROCK ENCLOSED IN APPROVED FILTER FABRIC 6 ...... COLLECTOR PIPE TO BE 4-INCH MINIMUM DIAMETER, PERFORATED, THICK-WALLED PVC SOR 21 OR EQUIVALENT, AND SLOPED TO DRAIN AT 1 PERCENT MINIMUM TO APPROVED ounET. CHIMNEY DRAINS MAY BE REQUIRED IF AREAS OF ACTIVE SEEPAGE ARE ENCOUNTERED. TYPICAL STABILITY FILL DETAIL GEOCON CARLSBAD TRACT 81 -46 LOT NO'S 7, 8, 11 & 15 CARLSBAD, CALIFORNIA INCORPORATED GEOTECHNICAL ENGINEERS AND ENGINEERJNG GEOLOGISTS 6960 FLANDERS DRIVE • SAN DJEC10, C/\LJFORNI:\ 92121-297-i PHONE 619 558-6900 • FA.'< 619 558-6159 AS/ RSS I I DSK /G0000 DATE 05. 08. 19961 PROJECT NO. 05724. 12. 0 I I FIG 4 ' . GROUND SURFACE PROPERLY COMPACTED BACKFILL ~ CONCRETE BROWIJITCH ~ PROPOSED RETAINING WALL---+-- 213 H PROPOSED GRADE ~ NOTE: t------i 0° ·.~·/: _-( :/: .. 1,;_' __ APPROVED FILTER FABRIC · .o ·o O · o/ 1------f ..... o .. ( ;o.·.··<?-·.·_.. --r-- t------f ~ .o.· +·'--'·>-+· --1----OPEN GRADED 1"MAX. AGGREGATE -;;·.-o .. I ... o .. o·. -.. o ... ··'?· ·.-.. , \Q•_,·._ •._o·H _ _._ 5' MAX. 1" ~--4" DIA. PERFORATED PVC PIPE MIN. 1/2% FALL TO APPROVED OUTLET IF DESIRED, WALL DRAINAGE PANELS SUCH AS MIRA DRAIN OR EQUIVALENT MAY BE USED IN LIEU OF EXTENDING GRAVEL TO TWO THIRDS OF THE WALL HEIGHT NO SCALE RETAINING WALL DRAIN DETAIL GEOCON CARLSBAD TRACT 81 -.46 LOT NO'S 7, 8, 11 & 15 CARLSBAD, CALIFORNIA INCORPORATED GEOTECI-INICAL ENGINEERS AND ENGINEERING GEOLOGISTS 6960 FLANDERS DRIVE -S/\N DIECiO, C/\LIFORNI,\ 9:? 121-297-1 PHONE 619 558-6900 -FAX 619 558-6159 AS /RSS I I DSK/GTYPI 5724AS1 DATE OS -08 - I 996 I PROJECT NO. 05724 -12 - 0 I I FIG. 5 Project No. 05724-12-01 May 8, 1996 APPENDIX A FIELD INVESTIGATION The field investigation was performed on April 17 and 19, 1996, and consisted of a site reconnaissance by an engineering geologist from our firm, the excavation of 2 large-diameter borings and 11 exploratory trenches to depths ranging from 3 to 42 feet below existing ground elevation. The approximate locations of our exploratory borings and trenches are shown on Figure 1. As drilling and trenching proceeded, the soils encountered were continuously observed, visually classified and logged. Logs of the borings and trenches are presented on Figures and A-1 through A-14. The logs depict the various soil types encountered and indicate the depths at which samples were obtained. The exploratory borings were excavated by an E-120 truck-mounted bucket drill rig equipped with 30-inch-diameter bucket auger. The relatively undisturbed samples were obtained by driving a 3- inch O.D. split-tube samples into the undisturbed soil mass with blows from the drill rig Kelly bar falling 12 inches. The exploratory trenches were performed by means of a hydraulic backhoe mounted on a rubber-tire Case 590 backhoe equipped with a 24-inch bucket. pROJECT I NO 05724-12-0 I a:: BORING B 1 >-w Zw" >-,... (.!) I-Ou• ~,... w;:,.: 0 <I: SOIL Hzl-a::..., DEPTH ...J :I en • SAMPLE 0 Cl I-<I:u.. zu.. . =>1- IN :c z CLASS ELEV. (MSL.) 177 DA TE COMPLETED 4/19/96 <I:1-'-LIJ • t-z NO. a:: (/)CJ) FEET I-::::) (USCS) t-H::J: 0~ (/)w H 0 Hi- ...J a:: WcnO >-Q. Oz EQUIPMENT E-120 Zw...l (.!) W a::10 a::'"' ::Co Q. "" C u MA TE RIAL DESCRIPTION ... 0 :1. 1.-,. -rt·, SM FILL ... ... Medium dense moist, light grayish brown, Silty, fine -2 -;/·//. , to medium SAND with little clay • -------------------------------------' /· .. Becomes medium dense, very moist, dark grayish --·/ -{// SC brown, very Clayey, fine SAND -4 -/// - --//. -// 6 -v-// ... .-1-1-l ... -:i--t ., SM DELMAR FORMATION -Dense, moist, light tan to yellowish brown, Silty, very ... 8 -.-1.1--i-' fine SANDSTONE, laminated, yellow and orange r --l.1 ., CL ~--~aj~~& _____________________________ : ... _"j t. ,. Hard, moist, gray, thinly laminated with light yellow ... 10 -staining, random orientation ~ -• 1 i -i -Bedding N75, 8SW at 9 feet -·1-1·l -Wet lenses at 9.5 feet r I J ... 12 -"t 1 -, 1 -Becomes purplish brown laminated, heavy orange 1 ~ --:·1 t-1· ll -_ssaJ~i~g_ ~t_l_O_f~~t_ - - - - - - - - - - - - - - - - - - - - --~ ~ SM Dense, moist, light gray, Silty, fine to medium SAND -14 -.-1-·l laminated - li ·1 -Bedding Nl0W, 6SW at 11 feet, orange yellow and ... -- _.1 t. ,-dark purple with gypsum veinlets from 11 to 11.5 feet -16 --Becomes very light gray, massive from 15 feet -.. t .; -Becomes laminated with gypsum veins and dark I ' r --', __ l~_r9~~ ~~d_ qr~~g_e_aJ ]~ fe_e1 ________________ ,' - Hard, moist, grayish brown, thinly bedded . -18 -- CL CLA YSTONE, gypsum, yellow staining, irregular --deposional and contact at 16.5 feet - 20 -- ' --,,, -Carbon rich layer at 21 feet, near horizontal ·t,·r ' r :: :j::,: ~------------------------------------' -22 -Very dense, moist, light grayish brown, Silty, fine to -d:f-t: medium SANDSTONE, cross bedded --=t-:=t· - -24 -:rkf. -: :t: ~= :t SM --- -26 -==t *=t· -=\=~\---==t*=t: - -28 -: :t: i: :t. --Becomes wet, medium to coarse white and light --\=j\: yellow -... '.r J. 'l Figure A-1 Log of Boring 8 1, page 1 of 2 CRT81 , SAMPLE SYMBOLS O ... SAMPLING UNSUCCESSFUL !!§ ••• DISTURBED OR BAG SAMPLE I] ... STANDARD PENETRATION TEST ■ ... DRIVE SAMPLE (UNDISTURBED) ~ ... CHUNK SAMPLE J ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. \ . PROJECT NO. DEPTH SAMPLE IN NO. FEET -30 ... - -32 - -- -34 - -- -36 - ... 38 - - -40 - Figure A-2 05724-12-01 >-(!) 0 .J 0 :I: I-H .J •• r. ,. ·t •• r ••••• :•t··kr: •• • 1· .r. 0::: LI.J I-(C :3: C z ::> 0 0::: (.I) •:r:◄:•t·· • r •• -• ::t•:~::r: SZ •• • 1· .r. -==- SOIL CLASS (USCS) BORING B 1 ELEV. (MSL..,_) -'1 __ 7 __ 7 __ EQUIPMENT ______ __;;--"------- zUJ" >-,-.. Ou • 1-,-.. LI.J:,.: Hzl-H. a::'-' I-<Cu. cnu. ... i::1-DA TE COMPLETED 4/19/96 <C,-' z. a:: en U> LI.Ju u,Z 1-H:3: c. HLI.J LI.Ju,O >-0. 0 .... E-120 ZLI.J.J :cZ ~o:::e 0::: '-' 0 C u MATERIAL DESCRIPTION -Slight seepage .... -Bedding N30E, I SSE 1: :c :~: :► · ......-~------------------------------------------1-----------1 ~ CL Very hard, well cemented, black to very dark gray, h':•.__1-.,,.. 1_.,_l-+--+---+, ___ rich in carbon and &Y.PSum __________________ -1--------------1 •1 __ 1. 1 SM Very dense, moist, light yellow to orange, Silty, fine - 1 to medium SANDSTONE - ._·l -tt. 1· -Becomes very dense, moist, dark gray, massive, . ·l-_.1_ moderately cemented, Silty, fine to medium J SANDSTONE l 1 ., SM :·1 r 1- _-1. ·l . I· 1 ·1 BORING TERMINATED AT 42 FEET Log of Boring 8 1, page 2 of 2 .... .... .... .... CRT81 SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL ~ ..• DISTURBED OR BAG SAMPLE IJ ... STANDARD PENETRATION TEST ■ ... DRIVE SAMPLE (UNDISTURBED) ~ ••• CHUNK SAMPLE ~ ••• WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHO~N HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. PROJECT NO 05724-12-01 -0:: BORING B 2 >-UJ Zw""' >-..... (.!) I-......... UJ~ 0 <I: Ou• DEPTH _J 3 SOIL Hzl-H. 0:: '-' SAMPLE 0 0 I-<Cu. <nu.--=>1-IN :c z CLASS ELEV. (MSL.) 179 DA TE COMPLETED 4Lt9L96 <Ci-' z. 1-z NO. I-::::, (USCS) o:: cn<n Wu <nw FEET H 0 1-H:I c. H1-_J 0:: Wu,O >-Q. Oz EQUIPMENT E-120 ZwJ (.!) Wo::al o::'"" :Co Q. '-' 0 u 0 ¥A TERIAL DESCRIPTION '-ru;r: --~;Pp; FILL ... Medium dense, moist, medium grayish brown, Silty to -2 -rvtr Clayey, fine to medium SAND -SM-SC I --%-~ - I: 4 -(tf;r -FA --.1/1· 6 -)/iX: ,~ ··r·'··t •. ·l·•:• DELMAR FORMATION -=·t· ·=( .... ... SM Dense, moist, light gray, laminated, Silty, very fine . . "~·· .. .... 8 -:•r· ·r SANDSTONE, orange and yellow staining along -. . l· . 1--=t ·=r: bedding planes -.· 'f • . ·r ··f ... -10 -: . •· j•: ' -Becomes medium gray with gypsum lenses -r · r : ... : ' [ -.. ~· . ' -··r· ·T . . . ' 12 -=rj==( -Concretion layer 4 to 5 inches thick carbon rich with .... .· . f. .... -r = t gypsum crystals -near horizontal -, .... • •• j•" . . .. 14 -·t .. f .... . . . -Gypsum veins and thin clay layer N50W, 5SW ::t:~::( --. . .. -t 16 -::t:j\ .· . f · . -·r =r . . .. -::t:j:~f · .... r: I 8 -... ~·. ,. __ -Concretion lenses 4 to 8 inches thick, heavy_staining ,· ½ -CL Hard, moist, olive to yellowish brown, Sandy -..... ' CLA YSTONE, laminated . --20 -------------------------------------' I Well cemented, very dark, gray SANDSTONE -I I Extremely difficult drilling -Refusal BORING TERMINATED AT 20 FEET l ) ' t I I figure A-3 Log of Boring B 2, page 1 of 1 cRT81 ·----------------------------------------------, I SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL ~ .•• DISTURBED OR BAG SAMPLE IJ ... STANDARD PENETRATION TEST ■ ... DRIVE SAMPLE (UNDISTURBED) ~ .•• CHUNK SAMPLE :!'. .•. WATER TABLE OR SEEPAGE ,--------------------------------~-----------..1 -NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. I PROJECT NO. I I DEPTH SAMPLE I IN NO. FEET t -0 t ~ - ... 2 - I-- I -4 - ~ - I~ 6 - -- 05724-12-01 a:: >-UJ (.!) I-0 <C ...J :I SOIL 0 0 ::I: z CLASS I-:::::, H 0 (USCS) ...J a:: (.!) ;,/1/: [(: .; [{// ~// /.f; /// V ,· / -SC TRENCH T 1 ELEV. (MSL.) 211 DA TE COMPLETED 4Ll 7 !..96 EQUIPMENT CASE590EXTENDAHOE. MATERIAL DESCRIPTION FILL Slightly dense, moist, yellow, Clayey medium SAND - - -1. l .-,. ½ -~---=S __ Mc........+ ... DELMAR FORMATION ,- \ Dense, moist, yellow and white mottled, Silty , ,... ~ CL v·✓.;; ~//> SC , medium SAND 1 ----------------------------------' Stiff, moist, olive with rust, CLAY laminated I to 2 inch, N55E, 5S -Waxy clay gypsum layers red-brown with tan ... '" -_tellQ~ - - - --- - - - - - - - - - - - - - - - - --- - - -, ,. Very dense, moist, olive with yellow and brown layers, Clayey medium SAND, cross stratified, some clay lenses, trace carbon - Zw" >-,... Ou• 1-,... IJJ~ Hzl-~ . ·-a::'-' 1-<CLL zLL :::,I-<ti-' IJJ • t-z a::(/)(/) 0~ (/)IJJ 1-H:J: Hi-IJJ (/)0 >-a.. Oz Zw...J ~a::e a::'-' :Co 0 u I_ t/j 8 -"·/ .-1.'-l -+---+-----+ ____ -Contact N27E, 14N _____________________ +----i---+---i r~ - ~ 10 - r-- li ·1 :·l f 1· _-]. -l li ·1 :· j r 1· SM Very dense, moist olive green, Silty medium SAND, cross bedded - - - 12 -.-1-,-l !-½ l-'---C-+--'--+---+--------------------------------------f-----4----4---~ --¥'. CL Hard, very moist, purplish brown, thinly bedded, light yellow and medium brown CLAY, rich in iron oxide, occasional gypsum 0 -14 -½ ..,..c.~------+... -Bedding near horizontal to N80E, 5SW • +--~1----+-----1 CL \ __ -Moderate seepage from_l3 feet ____________ ,' -. / Stiff, moist, olive brown, and black, Sandy CLAY, laminated 1 TO 2 mm TRENCH TERMINATED AT 15 FEET Figure A-4, Log of Trench T 1 CRT81 SAMPLE SYMBOLS □ ... SAMPLING UNSUCCESSFUL Ill!) ••• DISTURBED OR BAG SAMPLE I] ... STANDARD PENETRATION TEST ■ ... DRIVE SAMPLE (UNDISTURBED) liiJ ... CHUNK SAMPLE ~ •.• UATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHO\JN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT UARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. · PROJECT NO 057''4-J ?-O I --I a:: TRENCH T 2 >-w zw ...... >-"' l!) I-Ou• I-"' w~ 0 <r SOIL Hzl-~-a::'-' DEPTH ..J :I I-a:U. SAMPLE 0 0 CLASS DA TE COMPLETED 4/17/96 <r1-' zU. :::, I- I IN NO. :c z ELEV. (MSL.) 214 a:: CJ)(/) w· 1-z I-:::, (USCS) 1-H::I o': U)IJJ FEET H 0 Wu,O >-Q. H,_ ..J a:: EQUIPMENT CASES90EXTENDAHOE Zw..J Oz (!) ~a::e a::'-' E:o C u I . MATERIAL DESCRIPTION ... 0 ~✓-1/-SC FILL , ... .,-y/. Dense, moist, light olive, Clayey, medium SAND -•~/.}-T2-1 DELMAR FORMATION 116.3 9.7 ... 2 -t{// Dense, moist, light olive green with rust, Clayey .... l7/:/ SC medium SAND, gypsum and indistinct layering at , ... ·-/· top grading into massive bed .... -/.)) 1/// 4 V. ,·/ --------------------------------------, ... -~ -Sharp contact undulatory red brown, very stiff, .... ... -moist, olive brown with rust Sandy CLAY, , ... ~ CL gypsum, laminated I to 2 mm 6 -.... ,--.... I ... . -___ -Sharp near_horizontal contact ______________ -~~ 8 -Hard, moist, black, CLAY, waxy, thinly laminated .... T2-2 CL ,--~ .... ¥'. -Slight seepage ~ .... 10 -.... , ... -~ -Concretion at 9.5, 11 and 13 feet .... r5l . ,-12 -~ -Slight seepage at 12 feet - -Refusal at 13 feet ,_ / " I TRENCH AT 13 FEET I : I figure A-5, Log of Trench T 2 CRT81 SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL I] ... STANDARD PENETRATION TEST ■ ... DRIVE SAMPLE (UNDISTURBED) I I I ~ .•• DISTURBED OR BAG SAMPLE liJ ... CHUNK SAMPLE ]!'. ••• WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. I . ' . piZOJECif NO. 05724-12-01 I a: TRENCH T 3 >-UJ zw,... >-,... (.') I-Ou • 1-,... UJ~ 0 <C DEPTH ..J :I SOIL Hzl-H. a:'-' SAMPLE 0 0 1-<ClL (l)lL =>1- I IN ::i:: z CLASS ELEV. (MSL.) 219 DA TE COMPLETED 4L11L96 <C1-' ffi •·· . 1-z NO. I-::> o:: en en 0~ enUJ FEET H 0 (USCS) I-H :I H1- ..J a: WenO >-0. Oz EQUIPMENT CASE 590 EXTENDAHOE Zw..J (.') ~a:S a:'V :co 0 u I MATERIAL DESCRIPTION 0 T3-l T3-2 FILL I Firm, moist, olive, Sandy CLAY, massive 106.0 14.8 2 CL I -Chunks of laminated claystone I 4 -Pieces of wood at 5 and 8 feet I 6 I 8 I 10 I I 12 -Thin layer of medium dense, very moist, very dark brown, Clayey SAND -Contact clean and benched I CL DELMAR FORMATION 14 Hard, moist, brown laminated, yellow and rust, CLA YSTONE laminated 1 to 2 mm gypsum veinlets I TRENCH TERMINATED AT 15 FEET I l lFigure A-6, Log of Trench T 3 CRT81 SAMPLE SYMBOLS O ... SAMPLING UNSUCCESSFUL IJ ... STANDARD PENETRATION TEST ■ ... DRIVE SAMPLE (UNDISTURBED) I -fl§ ..• DISTURBED OR BAG SAMPLE liiiJ .•. CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. l . ·-· .. -. ------------------. p'ROJECT NO 05724-12-01 I a:: TRENCH T 4 >-LLJ ZLLJ" >-" (!) I-Ou• I-" UJ~ 0 <J: SOIL Hzl-H. a::"' DEPTH SAMPLE ...J :::t I-<J:LI. U>u.--=>1-0 C CLASS <J:1-' z. I IN :c z ELEV. (MSL.) 198 DA TE COMPLETED 4/17/96 t-z NO. I-::::> CUSCS) a::(/)(/) Wu (/)UJ FEET 1-H:::t c. H 0 UJ (/)0 H1- ...J a:: >-a.. Oz (!) EQUIPMENT CASE 590 EXTENDAHOE . Zw...J a::"" I:o ~a::e C u I -0 ~A TERIAL DESCRIPTION ·-1. 1 --1-SM ! ::fft: ALL I --Loose, moist. tan. Silty medium SAND '- T4-l ·r ··f • DELMAR FORMATION .· . ~· .. ♦:f: =·f · Dense, moist, light green, Silty, medium -2 -. . .. -. ·r . SANDSTONE =·f. •:f. I -... ~-.. SM -Orange mottling -.:f: =·t· -. . . :f~\ 4 . : : 1: .. ' I~ EXCAVATION TERMINATED AT 4 FEET I I I I - I I I I I . IF1gure A-7, Log of Trench T 4 CRT81 SAMPLE SYMBOLS O ... SAMPLING UNSUCCESSFUL IJ ... STANDARD PENETRATION TEST ■ ... DRIVE SAMPLE (UNDISTURBED) I ~ ... DISTURBED OR BAG SAMPLE ~ .•. CHUNK SAMPLE ! ... ~ATER TABLE OR SEEPAGE I NOTE: THE LOG OF SUBSURFACE CONDITIONS SHO~N HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT ~ARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. I • ·, . PROJECT NO 05724-12-0 I 0:: TRENCH T 5 >-w Zw" >-....... (!) I-Ou• 1-,.... w~ 0 <C DEPTH J :I SOIL Hzl-H, 0:: V' SAMPLE 0 C I-<Cu. cnu.: ::JI-IN :::c z CLASS ELEV. (MSL.) 196 DA TE COMPLETED 4LJ1 L96 <C1-' z • t-z NO. I-::J (USCS) o:: en en Wu cnw FEET H 0 t-H::I c. H._ J 0:: WcnO >-~ Oz (!) EQUIPMENT CASE 590 EXTENDAHOE · ZwJ 0:: '-" :Co ~ o::!9 C u MA TE RIAL DESCRIPTION ,_ 0 :-i. 1 --1-SM ALL ·1-1 ·1 Loose, moist, li2ht tan, Siltv, medium SAND ,_ -~ .-1-1-l T5-l SM 11 ·, DELMAR FORMATION ... 2 - :·l i° !· Dense, moist, light tan with brown, Silty, medium L. SAND, indistinct laminations ,_ -.-1-l ,_ 4 :d·, ,- EXCAVATION TERMINATED AT 4 FEET - Figure A-8, Log of Trench T 5 CRT81 SAMPLE SYMBOLS □ ... SAMPLING UNSUCCESSFUL ~ .•• DISTURBED OR BAG SAMPLE IJ ... STANDARD PENETRATION TEST ■ ... DRIVE SAMPLE (UNDISTURBED) liiJ ... CHUNK SAMPLE J!'.'. ••• WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS ANO TIMES. j ; I I I I I I I -r NO 05724 12 01 E_ROJEC" - - 0:: >-UJ <..!) I-0 <C DEPTH ..J :I SOIL SAMPLE 0 0 IN :I: z CLASS NO. I-:::> FEET H 0 (USCS) ..J 0:: L'J - L 0 :-1.1l SM ·1· 1 ·1 -... I ... 2 -CL ... - "•f·1··t· ... 4 -:-.·~•: .. r · f· SM :• •(r, .· ... ~. ·f • • t · ... -:•.·1•:., • •L,• •~t. ' ~ ... 6 -CL . TRENCH T 6 ELEV. (MSL.) 162 DA TE COMPLETED 4/17/96 EQUIPMENT CASES90EXTENDAHOE MATERIAL DESCRIPTION FILL ' Loose, slightly moist, light tan, Silty, medium SAND DELMAR FORMATION Very firm, slightly moist, olive gr~en, . CLA YSTONE, highly fractured with gypsum vems on fracture surf aces -------------------------------------- Dense, slightly moist, light tan, Silty SANDSTONE -Becomes orange-brown -------------------------------------- Stiff, slightly moist, olive green, CLA YSTONE EXCAVATION TERMINATED AT 6.5 FEET Figure A-9, Log of Trench T 6 z 1.1.1"' >-,... 1-,... UJ~ Ou• Hzl-H. ·o::v I-<Cu. U>u. =>1-<Ci-' z. 1-z 0:: (/) (/) Wu U>w 1-H:::I o. H.,_ IJJ (/)0 ,-a.•. Oz Zw..J o::v :Co UJo:;ID Q. 'J 0 u - - .... .... ... CRT81 SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL ~ • • • DISTURBED OR BAG SAMPLE (] ..• STANDARD PENETRATION TEST ■ ... DRIVE SAMPLE (UNDISTURBED) iiJ ... CHUNK SAMPLE .Y ••• WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION ANO AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. I I I . , PROJECT NO 05724-12-0 I a:: >-LLJ (!) I- 0 <I: DEPTH ..J ::J: SOIL SAMPLE 0 0 CLASS IN NO. :::c z I-::> (USCS) FEET H 0 ..J 0:: (!) .... 0 Jl-l ·1· i ·1 SM .... -. ... .... SM . . . . • .•. .... 2 -~ CL I .... -CH 4 .... -.... . . . . . . . . .... -. . . . . ... .· .· ... •, ••••• •.•1 •• •• •• ♦·1 SM 6 ······••1 .... -•• •• •• •• 1 .... . . . . TRENCH T 7 Zw'"' >-'"' Ou• ::;,.... LLJ~ Hzl-(/) . a::'"' 1-<I:U. z~ =>1-<I:1-"-ELEV. (MSL.) 166 DA TE COMPLETED 4LJ1L96 0:: (/)(/) w• 1-z 0~ <l>w 1-H::J: HI-LLJ (/)0 >-a.. Oz EQUIPMENT CASE 590 EXTENDAHOE Zw..J ~o::~ 0:: '-' :Co 0 u MATERIAL DESCRIPTION FILL Loose, moist, tan and light brown, Silty medium SAND . i I DELMAR FORMATION I ~ I Very dense, moist, orange, Silty, medium to coarse , I ' 1 SANDSTONE indurated ' r '-----------~-----------------------·' L... 1 Stiff, moist, olive, Sandy CLA YSTONE ' ~----------------------------------' Stiff, moist, olive brown, CLA YSTONE, shiny L... partings highly fractured -------------------------------------- Very dense, slightly moist, Silty, medium L... SANDSTONE L... EXCAVATION TERMINATED AT 6.5 FEET - . (· Figure A-10, Log of Trench T 7 CRT81 IJ ... STANDARD PENETRATION TEST ■ ... DRIVE SAMPLE (UNDISTURBED) SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL 1----------~---· _· _0_1 s_T_uR_B_Eo_o_R _B_AG_sA_M_P_LE __ ~_-._._c_H_uN_K_s_A_M_PL_E _____ ..!!~---._wA_T_E_R _T_AB_L_E_o_R_s_E_E_PA_G_E _ __...1 NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS ANO TIMES. I I pROJECt NO 05724-12-01 ,-0::: TRENCH T 8 >-IJJ ZUJ"" >-,-.. (!) I-Ou • I-,.._ IJJ~ 0 <I: SOIL Hzl-H. o::'"' DEPTH _J :I (l)LL SAMPLE 0 C I-<I: LL =>1-CLASS <r:1-' z. I IN NO. :I: z ELEV. (MSL.) 163 DA TE COMPLETED 4l}1{.96 0:::(/)(/) U.Ju t-z I-=> (USCS) (/)IJJ FEET H 0 1-H::? c. HI- _J 0::: UJ(/)0 >-a.. Oz (!) EQUIPMENT CASE 590 EXTENDAHOE ZwJ 0:::'"' E:o ~o::e C u L ~A TERIAL DESCRIPTION 0 TS-I ~ ·-1. ~--1-SM ~ FILL -Loose, moist, oranee tan. Silty, medium SAND ... r • -✓ CL DELMAR FORMATION ~=:i:?. " . SC , \ __ 5_tlf[, _IJ!ojs_!,_ q_ILv~ _g~e~12._~e_diu_Il!. ~~PX S:!-i\ y ___ ,'i ... 2 -~ 1 Dense, moist, orange and olive, mottled Clayey , I~ CL I SANDSTONE I t __________________________________ , Stiff, moist, brown with yellow stringers, CLAY, highly fractured. shiny oarting surfaces I EXCAVATION TERMINATED AT 3 FEET I I I I - ~ ~ ~ (; 1! . (-Figure A-11, Log of Trench T 8 cRTs1 l SAMPLE SYMBOLS □ ... SAMPLING UNSUCCESSFUL I] ... STANDARD PENETRATION TEST ■ ... DRIVE SAMPLE (UNDISTURBED) l ~ ... DISTURBED OR BAG SAMPLE iii::] .•. CHUNK SAMPLE ! ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SH~N HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. l I .. PROJECT NO 05724-12-01 ~ I I~ I~ ~ 1~ I I I I I I t [ l l DEPTH IN FEET 0 - 2 - 0: >-UJ (.!) I-0 <C SOIL SAMPLE ...J :I 0 C CLASS NO. ::c z I-::J (USCS) H 0 ...J 0: (!) v✓.} i-/~/> l{:1-/. SC y/. •✓:// ~ CL TRENCH T 9 ZUJI"'\ >-I"'\ Ou• 1-1"'\ UJX Hzl-H. 0:: V' I-<Cu. (/)u. :JI-<Ci-' z. ELEV. (MSL.) 180 DA TE COMPLETED 4/17/96 0:(/)(/) UJu .. t;z 1-H:::I c. HUJ UJ(/)0 >-0.. ot- EQUIPMENT CASE590EXTENDAHOE ZUJ...J :cZ ~o:e o:'-" 0 C u M.A TERIAL DESCRIPTION FILL Slightly dense, moist, olive brown, Clayey SAND ... ... DELMAR FORMATION Very stiff, moist, brown, CLA YSTONE, highly fractured EXCAVATION TERMINATED AT 3 FEET . [ Figure A-12, Log of Trench T 9 cRre, -SAMPLE SYMBOLS O ... SAMPLING UNSUCCESSFUL I] ... STANDARD PENETRATION TEST ■ ... DRIVE SAMPLE (UNDISTURBED) l ~ ... DISTURBED OR BAG SAMPLE ~ •.• CHUNK SAMPLE ~ .•• WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOYN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION ANO AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. I I I I I I I I I . PROJECT NO. 05724-12-0 I ~ >-UJ (!) .... 0 <I: DEPTH ...J ::J: SOIL SAMPLE 0 C IN ::i::: z CLASS NO. I-::::, FEET H 0 CUSCS) ...J ~ (!) -0 y.•~~ ~1~ SC , .· ... -- -2 -CL -- -4 TRENCH T 10 ELEV. (MSL.) 206 DA TE COMPLETED 407 L96 EQUIPMENT CASE 590 EXTENDAHOE - MATERIAL DESCRIPTION DELMAR FORMATION . Dense, slightly moist, olive, Clayey SANDSTONE, i I 1_ _ _1~1!1!_0~t~Q,_}!_ighJt fr_?~t~r_e9,_g_yp~u_ll!, ~a_y~r~ _____ ,' Hard, slightly moist, black, CLA YSTONE EXCAVATION TERMINATED AT 4 FEET . I Figure A-13, Log of Trench T 10 Zw" >-" Ou • .... " UJ~ Hzl-H. ~'-' I-<CLL (J)LL'· ::::,._ <C._' z. 1-z ~ (J)(J) Wu (J)UJ 1-H::J: 0 • H1-UJcnO >-Q. Oz Zw...J ~'-' :Co UJ~CO Q. ..,, 0 u - - CRT81 SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL I] ... STANDARD PENETRATION TEST ■ ... DRIVE SAMPLE (UNDISTURBED) I ~ ... DISTURBED OR BAG SAMPLE i:I ... CHUNK SAMPLE Ji'. ••• WATER TABLE OR SEEPAGE I - NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOIJN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. I PROJECT NO 05724-12-01 i Q:: TRENCH T 11 >-UJ ZUJ"' >-" (!) I-1-,... UJX 0 <C Ou• SOIL Hzl-H • Q:: '-' DEPTH ...J :::i: cnu. •. SAMPLE 0 0 I-<Cu. =>1-IN :x: z CLASS ELEV. (MSL.) 217 DA TE COMPLETED 4LJ7 L96 <C1-' z. t-z NO. I-:::, (USCS) Cl::u,U> Ulu cnUJ FEET H 0 t-H::J: o. H1-...J Q:: Ulu,O >-a. Oz (!) EQUIPMENT CASE590EXTENDAHOE ZUJ...J Q:: '-' :co UJ Q::cc a. '-' 0 u MATERIAL DESCRIPTION -0 LY.·~~ ~1/.~, SC DELMAR FORMATION :,:(.:' •; ... -. ~:, Dense, moist, yellow tan, Clayey SANDSTONE, 1 ... ~ ~·"' lY-'.;i-/2 SC ... ... __ mm peat laminations ___________________ , ,. 2 •.,1.• • ... ... __ {?~n~e_, _f1!.0_!S_!,_(!_a£~ Qr_9:_\'!_l,_ ~l~le.Y _Sf.~~S.!9!-1~-_,,. '--l,y.• •A·:~ li'1/.~ Dense, moist, tan with yellow mottling, Clayey ... -:r.J~ SANDSTONE ... ;f.; ~ ~%:-SC '-4 -»;f.:• ... ~:1 rff --• • ••• t ... ~:, l;f.~ ~» . ~ 6 -;t:· ... »····· . ':, ,_ -lif:i~ --------------------------------------~ 8 CL Very stiff, slightly moist, light olive, ... -CLA YSTONE, laminated 1 to 2 mm ... ,_ -... ... 10 EXCAVATION TERMINATED AT 10 FEET - I I I I l . Figure A-14, Log of Trench T 11 CRT81 I SAMPLE SYMBOLS □ ... SAMPLING UNSUCCESSFUL (] •.. STANDARD PENETRATION TEST ■ ... DRIVE SAMPLE (UNDISTURBED) ! ~ . • • DISTURBED OR BAG SAMPLE ~ .•• CHUNK SAMPLE :'I'. •.. WATER TABLE OR SEEPAGE •NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. ~ I I I I I I I .· APPENDIX . -. . . . •. -• . ·-. . . . . . ,. ,, . . . . ' '.. ,. . . . : . '·, : .-. . . ·.. . . . . -· ' .. -.. I .. . ' Project No. 05724-12-01 May 8, 1996 APPENDIXB LABORATORY TESTING Laboratory tests were performed in accordance with generally accepted test methods of the American Society for Testing and Materials (ASTM) or other suggested procedures. Selected relatively undisturbed drive samples were tested for their in-place dry density, moisture content. The maximum dry density and optimum moisture content of selected disturbed bulk samples were determined in accordance with ASTM D1557-91. Portions of the bulk samples were remolded into rings and subjected to direct shear and Expansion Index tests. The results of the laboratory tests are included in tabular form herewith. I I I I I I I I I I I I I I I I Project No. 05724-12-01 May 8, 1996 TABLEB-1 SUMMARY OF LABORATORY MAXIMUM DRY DENSITY AND OPTIMUM MOISTURE CONTENT TEST RESULTS ASTM D1557-91 Optimum Sample Maximum Dry Description Moisture Content No. Density (pct) (% Dry Wt.) T2-2 Dark gray, Silty CLAY 112.8 16.2 T3-1 Grayish brown, Clayey, fine to medium SAND 113.6 15.1 T5-1 Light tan, Silty, fine to medium SAND 120.0 11.8 - Project No. 05724-12-01 May 8, 1996 TABLEB-Il SUMMARY OF DENSITY AND DIRECT SHEAR TEST RESULTS Dry Moisture Unit Angle of Sample No. Density Content Cohesion Shear Resistance (pct) (%) (pst) (degrees) T3-1 102.6 14.7 545 24 T5-1 108.4 11.1 580 28 Samples remolded to approximately 90 percent maximum dry density at near optimum moisture content. I I I I ! Project No. 05724-12-01 May 8, 1996 TABLEB-ID . SUMMARY OF LABORATORY EXPANSION INDEX TEST RESULTS Moisture Content Sample No. Before After Dry Density Expansion Index Test Test (pct) (%) (%) T2-2 12.4 35.2 100.4 128 T3-1 12.4 31.4 102.2 99 T5-1 8.9 22.0 113.0 16 . . . . . . _·.-\ ' - -.· ._. - ·.: ;~. , : ~.: .-.: . . . ,' ...... _·, APPENDIX __ . --.... _. -- APPENDIXC RECOMMENDED GRADING SPECIFICATIONS FOR CARLSBAD TRACT NO. 81-46 UNIT 1, LOT NOS. 7, 8, 11, AND 15 CARLSBAD, CALIFORNIA Project No. 05724-12-01 .. RECOMMENDED GRADING SPECIFICATIONS 1 GENERAL 1.1 These Recommended Gradirlg Specifications shall be used in conjunction with the Geotechnical Report for the project prepared by Geocon Incorporated. The recom- mendations contained in the text of the Geotechnical Report are a part of the earthwork and grading specifications and shall supersede the provisions contained hereinafter in the case of conflict. 1.2 Prior to the commencement of grading, a geotechnical consultant (Consultant) shall be employed for the purpose of observing earthwork procedures and testing the fills for substantial conformance with the recommendations of the Geotechnical Report and these specifications. It will be necessary that the Consultant provide adequate testing and observation services so that he may determine that, in his opinion, the work was performed in substantial conformance with these specifications. It shall be the responsibility of the Contractor to assist the Consultant and keep him apprised of work schedules and changes so that personnel may be scheduled accordingly. 1.3 It shall be the sole responsibility of the Contractor to provide adequate equipment and methods to accomplish the work in accordance with applicable grading codes or agency ordinances, these specifications and the approved grading plans. If, in the opinion of the Consultant, unsatisfactory conditions such as questionable soil materials, poor moisture condition, inadequate compaction, adverse weather, and so forth, result in a quality of work not in conformance with these specifications, the Consultant will be empowered to reject the work and recommend to the Owner that construction be stopped until the unacceptable conditions are corrected. 2 DEFINITIONS 2.1 Owner shall refer to the owner of the property or the entity on whose behalf the grading work is being performed and who has contracted with the Contractor to have grading performed. 2.2 Contractor shall refer to the Contractor performing the site grading work. 2.3 Civil Engineer or Engineer of Work shall refer to the California licensed Civil Engineer or consulting firm responsible for preparation of the grading plans, surveying and verifying as-graded topography. 2.4 Consultant shall refer to the soil engineering and engineering geology consulting firm retained to provide geotechnical services for the project. 2.5 Soil Engineer shall refer to a California licensed Civil Engineer retained by the Owner, who is experienced in the practice of geotechnical engineering. The Soil Engineer shall be responsible for having qualified representatives on-site to observe and test the Contractor's work for conformance with these specifications. 2.6 Engineering Geologist shall refer to a California licensed Engineering Geologist retained by the Owner to provide geologic observations and recommendations during the site grading. - 2. 7 Geotechnical Report shall refer to a soil report (including all addendurns) which may include-a geologic reconnaissance or geologic investigation that was prepared specifically for the development of the project for which these Recommended Grading Specifications are intended to apply. 3 MATERIALS 3 .1 Materials for compacted fill shall consist of any soil excavated from the cut areas or imported to the site that, in the opinion of the Consultant, is suitable for use in construction of fills. In general, fill materials can be classified as soil fills, soil-rock fills or rock fills, as defined below. 3.1.1 Soil fills are defined as fills containing no rocks or hard lumps greater than 12 inches in maximum dimension and containing at least 40 percent by weight of material smaller than 3/4 inch in size. 3.1.2 Soil-rock fills are defined as fills containing no rocks or hard lumps larger than 4 feet in maximum dimension and containing a sufficient matrix of soil fill to allow for proper compaction of soil fill around the rock fragments or hard lumps as specified in Paragraph ~.2. Oversize rock is defined as material greater than 12 inches. 3.1.3 Rock fills are defined as fills containing no rocks or hard lumps larger than 3 feet in maximum dimension and containing little or no fines. Fines are defined as material smaller than 3/4 inch in maximum dimension. The quantity of fines shall be less than approximately 20 percent of the rock fill quantity. 3.2 Material of a perishable, spongy, or otherwise unsuitable nature as determined by the Consultant shall not be used in fills. 3.3 Materials used for fill, either imported or on-site, shall not contain hazardous materials as defined by the California Code of Regulations, Title 22, Division 4, Chapter 30, Articles 9 and 10; 40CFR; and any other applicable local, state or federal laws. The Consultant shall not be responsible for the identification or analysis of the potential presence of hazardous materials. However, if observations, odors or soil discoloration cause Consultant to suspect the presence of hazardous materials, the Consultant may request from the Owner the termination of grading operations within the affected area. Prior to resuming grading operations, the Owner shall provide a written report to the Consultant indicating that the suspected materials are not hazardous as defined by applic~ble laws and regulations. 3 .4 The otiter 15 feet of soil-rock fill slopes, measured horizontally, should be composed of properly compacted soil fill materials approved by the Consultant. Rock fill may extend to the slope face, provided that the slope is not steeper than 2: 1 (horizontal:vertical) and a soil layer no thicker than 12 inches is track-walked onto the face for landscaping purposes. This procedure may be utilized, provided it is acceptable to the governing agency, Owner and Consultant. 3.5 Representative samples of soil materials to be used for fill shall be tested in the laboratory by the Consultant to determine the maximum density, optimum moisture content, and, where appropriate, shear strength, expansion, and gradation characteristics of the soil. 3.6 During grading, soil or groundwater conditions other than those identified in the Geotechnical Report may be encountered by the Contractor. The Consultant shall be notified immediately to evaluate the significance of the unanticipated condition. 4 CLEARING AND PREPARJNG AREAS TO BE FILLED 4.1 Areas to be excavated and filled shall be cleared and grubbed. Clearing shall consist of complete removal above the ground s~rface of trees, stumps, brush, vegetation, man-made structures and similar debris. Grubbing shall consist of removal of stumps, roots, buried logs and other unsuitable material and shall be performed in areas to be graded. Roots and other projections exceeding 1-1/2 inches in diameter shall be removed to a depth of 3 feet below the surface of the ground. Borrow areas shall be grubbed to the extent necessary to provide suitable fill materials. 4.2 Any asphalt pavement material removed during clearing operations should be properly disposed at an approved off-site facility. Concrete fragments which are free of reinforcing steel may be placed in fills, provided they are placed in accordance with Section 6.2 or 6.3 of this document. 4.3 After clearing and grubbing of organic matter or other unsuitable material, loose or porous soils shall be removed to the depth recommended in the Geotechnical Report. The depth of removal and compaction shall be observed and. approved by a representative of the Consultant. The exposed surface shall then be plowed or scarified to a minimum depth of 6 inch~ and until the surface is -free from uneven features that would tend to prevent uniform compaction by the equipment to be used. -4.4 Where the slope ratio of the original ground is steeper than 6: 1 (horizontal:vertical), or where recommended by the Consultant, the original ground should be benched in accordance with the following illustration. NOTES: TYPICAL BENCIDNG DETAIL HO SC.:.L!' (1) Key width "B" should be a minimum of 10 feet wide, or sufficiently wide to permit complete coverage with the compaction equipment used. The base of the key should be graded horizontal, or inclined slightly into the natural slope. (2) The outside of the bottom key should be below the topsoil or unsuitable surficial material and at least 2 feet into dense formational material. Where hard rock is exposed in the bottom of the key, the depth and configuration of the key may be modified as approved by the Consultant. 4.5 After areas to receive fill have been cleared, plowed or scarified, the surface should be disced or bladed by the Contractor until it is uniform and free from large clods. The area should then be moisture conditioned to achieve the proper moisture content, and compacted as recommended in Section 6.0 of these specifications. 5 COMPACTION EQUIPMENT 5 .1 Compaction of soil or soil-rock fill shall be accomplished ·by sheepsfoot or segmented- steel wheeled rollers, vibratory rollers, multiple-wheel pneumatic-tired rollers, or other types of acceptable compaction equipment. Equipment shall be of such a design that it will be capable of compacting the soil or soil-rock fill to the specified relative compaction at the specified moisture content. 5.2 Compaction of rock fills shall be performed in accordance with Section 6.3. 6 PLACING, SPREADING Al'TD COMPACTION OF FILL MATERIAL 6.1 Soil fill, as defined in Paragraph 3.1.1, shall be placed by the Contractor in accordance with the following recommendations: 6.1.1 Soil fill shall be placed by the Contractor in layers that, when compacted, should generally not exceed 8 inches. Each layer shall be spread evenly and shall be thoroughly mixed during spreading to obtain uniformity of material and moisture in each layer. The entire fill shall be constructed as a unit in nearly level lifts. Rock materials greater than 12 inches in maximum dimension shall be placed in accordance with Section 6.2 or 6.3 of these specifications. 6.1.2 In general, the soil fill shall be compacted at a moisture content at or above the optimum moisture content as determined by ASTM D1557-91. 6.1.3 When the moisture content of soil fill is below that specified by the Consultant, water shall be added by the Contractor until the moisture content is in the range specified. 6.1.4 When the moisture content of the soil fill is above the range specified by the Consultant or too wet to achieve proper compaction, the soil fill shall be aerated by the Contractor by blading/mixing, or other satisfactory methods until the moisture content is within the range specified. 6.1.5 After each layer has been placed, mixed, and spread evenly, it shall be thoroughly compacted by the Contractor to a relative compaction of at least 90 percent. Relative compaction is defined as the ratio (expressed in percent) of the in-place dry density of the compacted fill to the maximum laboratory dry density as determined in accordance with ASTM D1557-91. Compaction shall be continuous over the entire area, and compaction equipment shall make sufficient passes so that the specified minimum density has been achieved throughout the entire fill. 6.1.6 Soils having an Expansion Index of greater than 50 may be used in fills if placed at least 3 feet below finish pad grade and should be compacted at a moisture content generally 2 to 4 percent greater than the optimum moisture content for the material. · 6.1. 7 Properly compacted soil fill shall extend to the design surface of fill slopes. To achieve proper compaction, it is recommended that fill slopes be over-built by at least 3 feet and then cut to the design grade. This procedure is considered preferable to track-walking of slopes, as described in the following paragraph. 6.1.8 As an alternative to over-building of slopes, slope faces may be back-rolled with a heavy-duty loaded sheepsfoot or vibratory roller at maximum 4-foot fill height intervals. Upon completion, slopes should then be track-walked with a D-8 dozer or similar equipment, such that a dozer track covers all slope surfaces at least twice. 6.2 Soil-rock fill, as defined in Paragraph 3.1.2, shall be placed by the Contractor in accordance with the following recommendations: 6 .2 .1 Rocks larger than 12 inches but less than 4 feet in maximum dimension may be incorporated into the compacted soil fill, but shall be limited to the area measured 15 feet minimum horizontally from the slope face and 5 feet below finish grade or 3 feet below the deepest utility, whichever is deeper. 6.2.2 Rocks or rock fragments up to 4 feet in maximum dimension may either be individually placed or placed in windrows. Under certain conditions, rocks or rock fragments up to 10 feet in maximum dimension may be placed using similar methods. The acceptability of placing rock materials greater than 4 feet in maximum dimension shall be evaluated during grading, as specific cases arise and shall be approved by the Consultant prior to placement. 6.2.3 For individual placement, sufficient space shall be provided between rocks to allow for passage of compaction equipment. 6.2.4 For windrow placement, the rocks_ should be placed in trenches excavated in properly compacted soil fill. Trenches should be approximately 5 feet wide and 4 feet deep in maximum dimension. The voids around and beneath rocks should be filled with approved granular soil having a Sand Equivalent of 30 or greater and should be compacted by flooding. Windrows may also be placed utilizing an "open-face" method in lieu of the trench procedure, however, this method should first be approved by the Consultant. 6.2.5 Windrows should generally be parallel to each other and may be placed either parallel to or perpendicular to the face of the slope depending on the site geometry. The minimum horizontal spacing for windrows shall be 12 feet center-to-center with a 5-foot stagger or offset from lower courses to next overlying course. The minimum vertical spacing between windrow courses shall be 2 feet from the top of a lower windrow to the bottom of the next higher windrow. 6.2.6 All rock placement, fill placement and flooding of approved granular soil in the windrows must be continuously observed by the Consultant or his representative. 6.3 Rock fills, as defined in Section 3.1.3, shall be placed by the Contractor in accordance with the following recommendations: 6.3.1 The base of the rock fill shall be placed on a sloping surface (minimum slope of 2 percent, maximum slope of 5 percent). The surface shall slope toward suitable subdrainage outlet facilities. The rock fills shall be provided with subdrains during construction so that a hydrostatic pressure buildup does not develop. The subdrains shall be permanently connected to controlled drainage facilities to control post-construction infiltration of water. 6.3.2 Rock fills shall be placed in lifts not exceeding 3 feet. Placement shall be by rock trucks traversing previously placed lifts and dumping at the edge of the currently placed lift. Spreading of the rock fill shall be by dozer to facilitate seating of the rock. The rock fill shall be watered heavily during placement. Watering shall consist of water trucks traversing in front of the current rock lift face and spraying water continuously during rock placement. Compaction equipment with compactive energy comparable to or greater than that of a 20-ton steel vibratory roller or other compaction equipment providing suitable energy to achieve the required compaction or deflection as recommended in Paragraph 6.3.3 shall be utilized. The number of passes to be made will be determined as described in Paragraph 6.3.3. Once a rock fill lift has been covered with soil fill, no additional rock fill lifts will be permitted over the soil fill. 6.3.3 Plate bearing tests, in accordance with ASTM D1196-64, may be performed in both the compacted soil fill and in the rock fill to aid in determining the number of passes of the compaction equipment to be performed. If performed, a minimum of three plate bearing tests shall be performed in the properly compacted soil fill (minimum relative compaction of 90 percent). Plate bearing tests shall then be performed on areas of rock fill having two passes, four passes and six passes of the compaction. equipment, respectively. The number of passes required for the rock fill shall be determined by comparing the results of the plate bearing tests for the soil fill and the rock fill and by evaluating the deflection variation with number of passes. The required number of passes of the compaction equipment will be performed as necessary until the plate bearing deflections are equal to or less than that determined for the properly compacted soil fill. In no case will the required number of passes be less than two. 6.3.4 A representative of the Consultant shall be present during rock fill operations to verify that the minimum number of "passes" have been obtained, that water is being properly applied and that specified procedures are being followed. The actual number of plate bearing tests will be determined by the Consultant during grading. In general, at least one test should be performed for each approximately 5,000 to 10,000 cubic yards of rock fill placed. 7 6.3.5 Test pits shall be excavated by the Contractor so that the Consultant can state that, in his opinion, sufficient water is present and that voids between large rocks are properly filled with smaller rock material. In-place density testing will not be required in the rock fills. 6.3.6 To reduce the potential for "piping" of fines into the rock fill from overlying soil fill material, a 2-foot layer of graded filter material shall be placed above the uppermost lift of rock fill. The need to place graded filter material below the rock should be detennined by the Consultant prior to commencing grading. The gradation of the graded filter material will be detennined at the time the rock fill is being excavated. Materials typical of the rock fill should be submitted to the Consultant in a timely manner, to allow design of the graded · filter prior to the commencement of rock fill placement. 6.3.7 All rock fill placement shall be continuously observed during placement by representatives of the Consultant. OBSERVATION AND TESTING 7 .1 Tne Consultant shall be the Owners representative to observe and perform tests during clearing, grubbing, filling and compaction operations. In general, no more than 2 feet in vertical elevation of soil or soil-rock fill shall be placed without at least one field density test being performed within that interval. In addition, a minimum of one field density test shall be ·performed for every 2,000 cubic yards of soil or soil-rock fill placed and compacted. 7 .2 The Consultant shall perform random field density tests of the compacted soil or soil-rock fill to provide a basis for expressing an opinion as to whether the fill material is compacted as specified. Density tests shall be performed in the compacted materials below any disturbed surface. When these tests indicate that the density of any layer of fill or portion thereof is below that specified, the particular layer or areas represented by the test shall be reworked until the specified density has been achieved. 7 .3 During placement of rock fill, the Consul~t shall verify that the minimum number of passes have been obtained per the criteria discussed in Section 6.3.3. The Consultant shall request the excavation of observation pits and may perform plate bearing tests on the placed rock fills. The observation pits will be excavated to provide a basis for expressing an opinion as to whether the rock fill is properly seated and sufficient moisture has been applied to the material. If performed, plate bearing tests will be performed randomly on the surface of the most-recently placed lift. Plate bearing tests will be performed to provide a basis for expressing an opinion as to whether the rock fill is adequately seated. The maximum deflection in the rock fill determined in Section 6.3 .3 shall be less than the maximum deflection of the properly compacted soil fill. When any of the above criteria indicate that a layer of rock fill or any portion thereof is below that specified, the affected layer or area shall be reworked until the rock fill has been adequately seated and sufficient moisture applied. I I I I I I I I I .. I I I 8 7.4 A settlement monitoring program designed by the Consultant may be conducted in areas of rock fill placement. The specific design of the monitoring program shall be as recommended in the Conclusions and Recommendations section of the project Geotechnical Repon or in the final report of testing and observation services performed during grading. 7 .5 The Consultant shall observe the placement of subdrains, to verify that the drainage devices have been placed and constructed in substantial conformance with project specifications. 7.6 Testing procedures shall conform to the following Standards as appropriate: 7.6.1 Soil and Soil-Rock Fills: 7.6.1.1 Field Density Test, ASTM D1556-82, Density of Soil In-Place By the Sand-Cone Method. 7.6.1.2 Field Density Test, Nuclear Method, ASTM D2922-81, Density of Soil and Soil-Aggregate In-Place by Nuclear Methods (Shallow Depth). 7.6.1.3 Laboratory Compaction Test, ASTM D1557-91, Moisture-Density Relations of Soils and Soil-Aggregate Mixtures Using JO-Pound Hammer and 18-Inch Drop. 7.6.1.4 Expansion Index Test, Uniform Building Code Standard 29-2, Expansion Index Test. 7.6.2 Rock Fills: 7.6.2.1 Field Plate Bearing Test, ASTM D1196-64 (Reapproved 1977) Standard Method for Nonrepresentative Static Plate Load Tests of Soils and Flexible Pavement Components, For Use in Evaluation and Design of Airport and Highway Pavements. PROTECTION OF WORK 8.1 During construction, the Contractor shall properly grade all excavated surfaces to provide positive drainage and prevent ponding of water. Drainage of surface water shall be controlled to avoid damage to adjoining properties or to finished work on the site. The Contractor shall take remedial measures to prevent erosion of freshly graded areas until such time as permanent drainage and erosion control features have been installed. Areas subjected to erosion or sedimentation shall be properly prepared in accordance with the Specifications prior to placing additional fill or structures. 8.2 After completion of grading as observed and tested by the Consultant, no further excavation or filling shall be conducted except in conjunction with the services of the Consultant. , 9 CERTIFICATIONS AND FINAL REPORTS 9.1 Upon completion of the work, Conn-actor shall furnish Owner a certification by the Civil Engineer stating that the lots and/or building pads are graded to within 0.1 foot vertically of elevations shown on the grading plan and ~ all tops and toes of slopes are within 0.5 foot horizontally of the positions shown on the grading plans. After installation of a section of subdrain, the project Civil Engineer should survey its location and prepare an as-built plan of the subdrain location. Toe project Civil Engineer should verify the proper outlet for the subdrains and the Contractor should ensure that the drain system is free of obstructions. 9.2 The Owner is responsible for furnishing a final as-graded soil and geologic report satisfactory to the appropriate governing or accepting agencies. The as-graded report should be prepared and signed by a California licensed Civil Engineer experienced in geotechnical engineering and by a California Certified Engineering Geologist, indicating that the geotechnical aspects of the grading were performed in substantial conformance with !}le Specifications or approved changes to the Specifications. Cicoc:a, IDcorporar.ed Form, Revision date: 08/93