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Home My WebLink AboutCT 81-10; Carlsbad Research Center Phase II & III; Supplemental Preliminary Geotechnical Investigation; 1982-07-26SUPPLEMENTAL PRELIMINARY GEOTECHNICAL INVESTIGATION CARLSBAD RESEARCH CENTER PHASES II AND III PREPARED FOR CARLSBAD RESEARCH CENTER 7330 ENGINEER ROAD SAN DIEGO, CALIFORNIA 92111 PREPARED BY SAN DIEGO SOILS ENGINEERING. INC. mi MERCURY STREET SAN DIEGO. CALIFORNIA 92111 JULY 26, 1982 JOB NO: SD1162-00 LOG NO: SD2-2ii75 . '^^ 6 TABLE OF CONTENTS Page I. IWTROPUCTIOM . 1 II. SITE OEl/ELOPMENT 1 III. SCOPE OF SERVICES 2 II/. SITE PESCRIPTIOW . 3 I/. FIELO INl/ESTIGATIOW . 5 l/I, LABORATORY TESTIWG 6 l/II. GEOLOGV 7 A. Regional Geology 7 B. Geologic Units 7 1. Santiago Peak Volcanics (map symbol-Jsp). 7 2. Point Loma Formation (map symbol-Kpl) . . 8 3. Santiago Formation (map symbol-Tsa) ... 9 4. Alluvium (map symbol-Qal) ........ 9 5. Fill 9 C. Structural Geology. 10 D. Ground Water 10 Vlll. SEISMICITY 11 A. Regional Seismicity ....... 11 B. Earthquake Effects 11 1. Earthquake Accelerations 11 2. Settlement of Soils 12 3. Liquefaction 12 4. Lurching and Shallow Ground Rupture ... 12 IX. ENGINEERING CONSIDERATIONS 13 A. General Description of Soils/Bedrock 13 1. Santiago Peak Volcanics 13 2. Point Loma Formation. 13 3. Topsoil 14 4. Alluvium - .• 15 B. Remedial Grading. . 15 1. Unsuitable Soils 15 2. Fill Keys 15 3. Stabilization Fills 16 4. Transition Lots 16 TABLE OF CONTENTS (continued) Page C. Expansive Soils 17 D. Slopes . 18 E. Ground Water 18 CONCLUSIONS ANV RECOMMENDATIONS. . 19 A. General 19 B. Grading and Earthwork 19 1. Clearing and Grubbing 19 2. Site Preparation. . 19 a. Treatment of Surface Soils 19 b. Existing Fill Soils 20 c. Treatment of Alluvium 20 d. Scarification and Processing of Surface Soils 20 3. Bedrock/Soil Characteristics 20 4. Overexcavation of Transition Lots .... 21 5. compaction and Method of Filling 22 6. Selective Grading 22 7. Import Fill Material 24 8. Shrinkage, Bulking and Subsidence .... 24 9. Rippability 25 10. Rock Disposal 25 C. Slopes 26 1. Fill Slopes 26 2. Cut Slopes 27 a. Santiago Peak Volcanics 27 b. Point Loma Formation 27 3. Fill-Over-Cut Slopes 28 4. Stabilization/Buttress Fills 29 5. Construction Slopes 29 6. Natural Slopes 29 D. Restriction on Future Construction 30 E. Surface and Subsurface Drainage 30 TABLE OF CONTENTS (continued) Page F. Foundations and Slabs 31 1. Expansive Soils . i 31 2. Footing Setbacks . 32 3. Soil Bearing Pressure 32 4. Lateral Load Resistance . 33 G. Retaining Walls . 33 .H. Type of Cement for Construction 34 I. Pavements 34 J. Utility Trench Backfill 35 K. Grading Plan Review 35 L. Geotechnical Observation 36 X. LIMITATIONS OF INl/ESTIGATION . .......... 37 SAN DIEGO SOILS ENGINEERING, INC. SOIL ENGINEERING & ENGINEERING GEOLOGY July 26, 1982 Carlsbad Research Center 7330 Engineer Road San Diego, California 92111 Job No: SD1162-00 Log No: SD2-2475 Attention; SUBJECT: Gentlemen: Mr. Michael J. Dunigan SUPPLEMENTAL PRELIMINARY GEOTECHNICAL INVESTIGATION Carlsbad Research Center, Phases II and III Carlsbad, California In accordance with your request, we have performed a Supple- mental Preliminary Geotechnical Investigation of Carlsbad Research Center, Phases II and III. Our report, transmitted herein, presents our findings, conclusions and recommendations for the proposed development. Accompanying the report are the various tables, figures and plates which summarize the results of our investigation and the conclusions and recommendations. Our preliminary findings have been discussed with a repre- sentative of your firm, the design civil engineer. Rick Engineering, and other project consultants. This opportunity to be of service is sincerely appreciated. If you have any questions concerning this report, please contact this office. Very truly yours, SAN DIEGO SOILS ENGINEERING, INC. GFS;tcm ' SUBSIDIARY OF IRVINE CONSULTING GROUP, INC. 6455 NANCY RIDGE DRIVE* SUITE 200 * SAN DIEGO, CA 92121 • (619)587-0250 SUPPLEMENTAL PRELIMINARY GEOTECHNICAL INVESTIGATION CARLSBAD RESEARCH CENTER, PHASE II AND III CARLSBAD, CALIFORNIA I. INTRODUCTION This report presents the results of our Supplemental Pre- liminary Geotechnical Investigation of Phases II and III of Carlsbad Research Center, located in Carlsbad, Calif- ornia. Our investigation was performed to provide geo- technical data to aid in overall site planning and develop- ment. We were provided with 80 scale and 100 scale Grading Plans prepared by Rick Engineering Company. The 80 scale grading plans were utilized as the base map for the attached Geo- technical Map, Plate No. 1. Our investigation was directed toward development as shown on the grading plan. II. SITE DEl/ELOPMENT The proposed development consists of commercial, light industrial and open space areas. Building pads will be developed by conventional cut and fill grading techniques. The locations of the proposed lots, streets and open space areas are shown on the attached Geotechnical Map, Plate No. 1. Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log NO: SD2-2475 Page Two III. SCOPE OF SERVICES The scope of services provided during the preparation of this Supplemental Preliminary Geotechnical Investigation included: A. Review of previous geologic, soils engineering and seismological reports and maps pertinent to the pro- ject area (See Appendix A); B. Analysis of stereographic aerial photographs to eval- uate the topography and geologic structure of the area (See Appendix A); C. Geologic mapping of existing exposures and outcrops; D. Subsurface exploration, including six bucket auger borings to a maximum depth of 51 feet and 38 backhoe test pits excavated to a maximum depth of 14 feet; E. Seismic traverses to evaluate rippability conditions; F. Logging and sampling of exploratory excavations to evaluate the geologic structure and to obtain ring and bulk samples for laboratory testing; G. Laboratory testing of samples representative of those obtained during the field investigation; H. Geologic and soils engineering analyses of field and laboratory data which provide the basis for our con- clusions and recommendations; I. Preparation of this report and accompanying maps, cross sections and other graphics presenting our findings, conclusions and recommendations. Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No: SD2-2475 Page Three IV. SITE DESCRIPTION Phases II and III of Carlsbad Research Center consist of an irregularly shaped parcel located in Carlsbad, Califor- nia. The location and topography are shown on the attached Location Map, Figure 1. The site is bounded on the east by the recently developed Carlsbad Research Center, Phase I and on the south by McClellan-Palomar Airport. Undeveloped areas are present north and west of the site. Topographically, the site consists of a relatively low. relief area with steeply descending slopes located near the western and northern boundaries. Natural slopes with- in the project very from nearly flat to 1.5:1 (horizontal to vertical) or steeper on the canyon sidewalls within the northern portion of the property. Maximum relief for the site is'about 155 feet with elevations ranging from approximately 170 to 325 feet above mean sea level. Drainage on-site is divided by an east-west trending ridge- line. Drainage south of the ridgeline is to the west along generally broad drainage courses. North of the ridgeline, drainage is to the north along steeply descending Letter- box Canyon and its tributaries. Access to the site is along unimproved roads from the existing Carlsbad Research Center Phase I, from El Camino Real to the north and from Palomar Airport Road to the southwest. Portions of the site have been modified by clay mining operation. Open pit excavations and associated spoil piles are present on the east-west trending ridgeline. Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No; SD2-2475 Page Four Several concrete truckloading/hopper structures associated with the mining operation are also present. Two low height earth embankments are present along the southern drainage course within the western portion of the property. Other man-made features on the site consist of unimproved roads, buried pipelines along existing ease- ments and minor amount of end-dumped debris and trash. Minor amounts of fill associated with existing access roads are located across the site. At the time of our investigation, a heavy growth of tall grasses and weeds covered most of the site. Some high brush was present in the northern drainage courses. Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No: SD2-2475 Page Five FIELD INl/ESTIGATION The field investigation performed during the course of this investigation consisted of geologic reconnaissance, mapping and subsurface investigation consisting of six drilled bucket auger borings, thirty-eight backhoe test pits and five seismic traverses. The field investigation was conducted under the direct supervision of our Engineering Geologist. A truck-mounted bucket auger drill rig was used to drill six 24-inch diameter borings to a maximum depth of 51 feet. The borings were sampled, downhole logged and back-filled, with samples returned to the laboratory for testing. Logs of the borings are presented in Appendix B. • • A tractor-mounted backhoe was used to excavate thirty- eight test pits to a maximum depth of 14 feet. The test pits were logged and backfilled. Logs of the trenches are presented in Appendix B. Five seismic traverses were performed utilizing a dual channel enhancement seismograph. A summary of the infor- mation obtained is presented in Appendix B. Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No: SD2-2475 Page Six l/I. LABORATORY TESTING Samples representative of the earth materials encountered during our field investigation were returned to the labor- atory for testing. The testing program consisted of moisture-density determinations, direct shear testing of ring and remolded samples, maximum density-optimum moisture determinations, Atterberg Limits, particle size analysis, consolidation tests, expansion tests and sulfate tests. Results and descriptions of the laboratory tests performed are included in Appendix C. Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No; SD2-2475 Page Seven l/II . GEOLOGY A. Regional Geology The subject site is located in the Peninsular Ranges • Geomorphic Province of California near the western margin of the Southern California Batholith. At the edge of the batholith, the topography changes from the typically rugged landforms developed over the granitic rocks to the flatter, more subdued landforms underlain by sedimentary bedrock associated with the coastal plain. The site is underlain by Jurassic metavolcanics and Cretaceous and Eocene sedimentary rocks. Alluvial sediments are present in the canyon bottoms. A brief description of the geologic units observed within the site follows. The distribution of the geologic units is shown on the attached Geotechnical Map, Plate 1. B. Geologic Units 1. Santiago Peak Volcanics (map symbol-Jsp) The Jurassic Age Santiago Peak Volcanics underlie the western portion of the site. The Santiago Peak Volcanics are mildly metamorphosed volcanic, or metavolcanic rocks- Regionally the Santiago Peak Volcanics vary from basalt to rhyolite but on-site they are predominantly andesite. The Santiago Peak Volcanics are moderately to highly jointed. The joint spacings are variable Carlsbad Research Center job No: SD1162-00 July 26, 1982 Log No; SD2-2475 Page Eight and the joints are generally clay-filled. The Santiago Peak Volcanics are weathered to con- siderable depth in Phase II and are, apparently, not as resistant there as in Phase III. Excavation in the Santiago Peak Volcanics will be difficult. The highly weathered material within about five feet of the existing ground surface can generally be excavated with conventional heavy earth-moving equipment. Below that depth heavy ripping and blasting should be anticipated. Heavy ripping or even blasting will generally produce oversize materials which can be considered additional cost items because of difficulty in handling. 2. Point Loma Formation (map symbol-Kpl) The Cretaceous Age Point Loma Formation consists of a marine interbedded fossiliferous siltstone and claystone with locally cemented sandstone lenses. The point Loma Formation observed on- site is generally flat lying with local dips of up to five degrees. The unweathered bedrock is stiff to very stiff, but weathering readily loosens the material. Point Loma Formation materials underlie most of the site. In certain areas of the site,the Point Loma Formation has been altered by weathering to form an ancient residual surface called a paleosol. The paleosol is identified on the map by the symbol Kpl(a). This paleosol was mined during the early 2 0th Century to obtain clay for brick production. Carlsbad Research Center July 26, 1982 Job No: SD1162-00 Log No: SD2-2475 Page Nine Excavation in the Point Loma Formation can be accomplished with conventional heavy duty earth- moving equipment. Heavy ripping may be required in some of the very stiff materials at depth. The soils produced are reusable as fill material and are moderately to highly expansive. • '-^ 3. Santiago Formation (map symbol-Tsa) The Eocene Age Santiago Formation underlies a very small portion of the site, near the southwest property boundary. The Santiago Formation, as observed, is a massive to thick-bedded silty to clayey sandstone. Because of its limited areal extent, the Santiago Formation will not signif- icantly affect the proposed grading. « 4. Alluvium (map symbol-Qal) Alluvium is present in the west trending drainage courses and the north trending tributaries of Letterbox Canyon to the north. The alluvium con- sists of dry and porous to soft and moist silty clay and sandy clay. Alluvium was observed to a maximum depth of about nine feet and was, on the average, about five feet deep. As observed, the alluvium was deepest at the center of the drainage courses with shallower depths observed along the margins. 5. Fill Fill is present on-site as the result of a prior mining operation. Tailing mounds from the earlier open pit clay mining operation are present on the northern portion of the site. Minor fills related to dirt roads, retention basins (dams) and random end-dumping are also present on-site. Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No: SD2-2475 Page Ten C. Structural Geology The predominant structural features within this portion of the Peninsular Ranges Geomorphic Province are assoc- iated with pre-Tertiary folding along north-south axes. The post-Cretaceous sequences have been folded and tilted generally to the west. Discontinuous northeast trending faulting is associated with the post-Cretaceous folding. Faulting has been mapped in adjacent and on-site areas. Faulting, as mapped by others, is indicated on the attached Geo- technical Map, Plate No. 1. It should be noted that the mapped faults are inactive and pose no significant constraints on the proposed development. The closest active fault is the Elsinore Fault located 22 miles to the northeast. D. Ground Water Ground water was encountered in alluvial areas near the alluvium/bedrock contact. This is a locally perched condition and does not reflect the regional ground water condition. No standing or flowing surface water was observed on-site at the time of this investigation. Ground water conditions will, of course, fluctuate with seasonal rainfall conditions. Carlsbad Research Center July 26/ 1982 Job No: SD1162-00 Log No; SD2-2475 Page Eleven I'm.SEISMICITY Regional Seismicity The site can be considered a seismically active area, as can all of southern California. There are, however, no active faults on or adjacent to the site. Seismic risk is considered low, as compared to other areas of southern California, due to the distance from active faults. Seismic hazards within the site can be attributed to ground shaking resulting from events on distant active faults. Listed on Table I are the active faults which can significantly affect the site. Figure 2 shows the geographic relationship of the site to these faults. B. Earthquake Effects 1- Earthquake Accelerations We have analyzed the possible earthquake accel- erations at the site and, in our opinion, for the intended use, the most significant event is a .7.0 Magnitude earthquake located on the Elsinore Fault Zone. The accelerations produced at the site by such an event would exceed those events which might occur on other known active faults. A Magnitude 7.0 earthquake on the Elsinore Fault Zone could produce a peak ground acceleration of 0.22g at the subject site with the duration of Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No: SD2-2475 Page Twelve strong shaking exceeding 30 seconds. Design of structures should be completed in compliance with the requirements of the governing juris- dictions and standard practices of the Structural Engineers Association of California. 2. Settlement of Soils The earth materials underlying the site consist primarily of firm sedimentary and metavolcanic bedrock which is generally not subject to seis-' mically induced settlement. Topsoil and areas of uncompacted fill will be compacted during grading. 3. Liquefaction The bedrock materials underlying the site have a very low to non-existent potential for lique- faction. 4. Lurching and Shallow Ground Rupture Breaking of the ground because of active faulting is not likely to occur on the site,due to the absence of active faults. Ground cracking due to shaking from distant events is not considered a significant hazard, although it is a possibility at any site. TABLE I SEISMICITY FOR MAJOR FAULTS FAULT DISTANCE FROM SITE MAXIMUM PROBABLE. EARTHQUAKE ESTIMATED PEAK BEDROCK, ACCELERATION' Elsinore Newport-Inglewood San Jacinto San Andreas 22 Miles NE 40 Miles NW 45 Miles NE 66 Miles NE 7.0 6.5 7.5 8.0 0.22 0.06 0.11 0.09 1. Seismic Safety Study, City of San Diego (1974 and Bonilla 1970) 2. Schnabel and Seed (1973) Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No: SD2-2475 Page Thirteen IX. ENGINEERING CONSIDERATIONS General Description of Soils/Bedrock The Logs of Borings in Appendix B indicates that mate- rials at the subject site consist of Santiago Peak Volcanics and Point Loma Formation bedrock overlain with clayey topsoil or alluvium. Santiago Formation sedimentary materials are so limited on-site that they will have no significant effect on the proposed grading. Fill derived from the Point Loma Formation bedrock will be the predominant material encountered during grading. Brief discussions of the significant engineering char- acteristics of the various material types are presented below: 1. Santiago Peak Volcanics Portions of Santiago Peak Volcanics underlying the site consist of hard, non-rippable rock. Excavation and/or blasting of such material may result in over-size boulders requiring special removal and burial procedures. As a minor benefit of rock hardness, however, steeper slopes may be constructed. 2. Point Loma Formation The Point Loma Formation bedrock underlying the site typically consists of siltstone. Typical grain size curves for the siltstone are presented in Figures C-l through C-3, Appendix C and the results indicate that the siltstone is composed principally of silt (65-75%) with clay particles TABLE 2 Typical Index and Engineering Properties of Siltstone Index Properties Natural Total Unit Weight (pcf) 125-5 Natural Dry Density (pcf) 105 - 5 Water Content (%) 20 i 3 Unified Soil Classification CL Engineering Properties Remolded Shear Strength (drained)* Cohesion (psf) 400 Friction Angle (degrees) 24 Expansion Potential High •^Applicable to normal stress range (1000-4000 psf) . Carlsbad Research Center July 26, 1982 Job No; SD1162-00 Log No; SD2-2475 Page Fourteen (15-25%). Remolded siltstone typically has a high expansion potential. Index and engineering properties of the siltstone are summarized in Table 2. The engineering characteristics of this material will result in flatter slopes, special foundation and slab recommendations and heavy pavement sections. It is expected that Point Loma Formation bedrock may be excavated utilizing conventional equipment. The fill material derived from excavation should be generally blocky requiring considerable effort to break the material down into a uniform com- pacted fill. During grading of the first phase of the Carlsbad Research Center project, a Cat-825 steel-wheel compactor or a D8 dozer and 5x5 sheeps- foot, in combination with rubber tire earth-moving equipment, worked reasonably well in breaking down the blocky material and creating a relatively uniform compacted fill condition. Topsoil Overlying the bedrock is typically a two to five foot thick layer of clayey topsoil. The topsoil is generally loose or soft in the upper two (-) feet and becomes firmer with depth. Grain size curves for this soil are presented in Figures C-4 and C-6, Appendix C and the results indicated that the topsoil is composed principally of clay (50-60%) and silt (30-40%). The topsoil is class- ified as a clay of high plasticity (CH), with low shear strength and a very high expansion Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No; SD2-2475 Page Fifteen potential. Topsoil material is considered an undesirable bearing material due to its engineering properties. Recommendations for remedial grading of the topsoil will be provided. 4. Alluvium At some locations, alluvium overlies the bedrock materials. The alluvium, which is somewhat similar to the topsoil, is also considered an undesirable material requiring remedial grading. B. Remedial Grading 1. Unsuitable Soils Due to unfavorable engineering characteristics, topsoil and alluvium will have overexcavation recommended, along with selective replacement as compacted fill. In the drainage areas, alluvium materials were encountered during our field exploration and are approximately delineated on the accompanying plan. The depths of the alluvium are indicated in the excavation logs. Moist to saturated conditions were encountered within the alluvium soils and may be expected during grading. Moisture conditioning of wet alluvium and/or dry topsoil may require special equipment and can be expected to slow production in the early stages of grading. 2. Fill Keys Numerous fill slopes are planned in conjunction with proposed grading. In order to provide support Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No; SD2-2475 Page Sixteen for succeeding lifts of compacted fill, fill slopes should be keyed into firm bedrock materials, Keying consists of overexcavation of surficial deposits and bedrock materials in order to provide recommended embedment and key widths. Stablization Fills Stabilization fills are typically recommended to enhance the stability of locally adverse geologic conditions. Stabilization consists of overex- cavating the slope face and replacement with a uniform compacted fill. Stabilization recommenda- tions can be expected for cuts within the Point Loma Formation. Transition Lots Inconsideration of anticipated cut/filled grading techniques, it is possible that future buildings would stradle cut-fill transitions created as a result of grading. Such transitions are con- sidered generally undesirable because non- uniform bearing conditions result from different materials being exposed at grade. To mitigate the potential adverse affects of cut-fill transitions, overexcavation of the cut portion and replacement as compacted fill are generally recommended. Depth of overexcavation is generally referenced from the bottom of the proposed found- ation and is limited laterally to specified dis- tances outside building lines and/or exterior foundations. In light of the fact that building Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No: SD2-2475 Page Seventeen locations and foundation conditions will not likely be known prior to grading, it is considered a reasonable alternative to elect not to proceed with remedial grading of cut/fill transitions until such time as individual site development plans are available. At that time, specific over- excavation recommendations can be developed. As an alternative to not overexcavating, however, a conservative depth of overexcavation could be assumed and the entire pad overexcavated. For this option, graded conditions would require review at such time as individual sites are developed. It has been our experience for industrial developments, that this second alternative has not been cost effective. Expansive Soils Results of expansion tests suggests that fill derived from the on-site materials will be highly expansive. Expansive soils can cause heaving/cracking of concrete walks, driveways, floor slabs, etc. On some projects, the potential adverse effects of expansive soils can be mitigated by selective grading. On this project, due to the predominance of expansive soils, selective grad- ing will not be recommended. The potential adverse effects of the expansive soils on foundations and slabs can be mitigated by special construction techniques (e.g. deeper foundations and heavy reinforcement). Using special construction techniques in pavement areas (e.g. chemical treatment of subgrade) are not generally cost effective and therefore, no recommendations for Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No; SD2-2475 Page Eighteen special treatment will be provided. Under these circumstances, potential for heaving cracks developing will exist. The treatment of heaving cracks is con- sidered normal maintenance consisting of sealing and • sanding on an as-needed basis. D. Slopes Slope stability analyses were performed for the pro- posed cut and fill slopes. Results of slope stability analyses (Appendix D) indicate that 2:1 (horizontal to vertical) slopes would posses an acceptable factor of safety against gross instability. However, 2:1 (horizontal:vertical) slopes comprised of the predom- inant on-site materials would not posses an acceptable factor of safety against surficial instability. Options to improve the surficial stability include laying the slope back to a flatter slope ratio (i.e. 2.5:1) or facing the outer portion of slopes (i.e. 12 feet) with select materials. The suitability of individual sources of proposed select material would require evaluation. Suitable sources are expected to be comprised of pre- dominantly granular with minor fractions of silt and clay. Most D.G. and sandstone derived silty and clayey sands would be appropriate. E. Ground Water Locally very moist or wet conditions were encountered during site exploration as described in the Logs of Borings. Ground water, whether natural or that which may develop as a result of grading, drainage patterns or irrigation, is often considered a major factor in undermining slopes in addition to being a nuisance where local seeps occur. To control ground water sub- I drain systems will be recommended. Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No: SD2-2475 Page Nineteen X. CONCLUSIONS AND RECOMMENDATIONS A. General Based on the results of our Supplemental Preliminary Geotechnical Investigation, we conclude that the pro- posed development of Carlsbad Research Center Phase II and III is feasible from geotechnical aspects, provided the following conclusions and recommendations are incorporated into the project plans, specifications and construction practice. B. Grading and Earthwork 1. Clearing and Grubbing Prior to grading, the site should be cleared of surface obstructions and stripped of brush and vegetation. Vegetation from the clearing oper- ation should be removed from the site. Obstructions extending below finish grade should be removed and replaced with compacted fill. 2. Site Preparation a. Treatment of Surface Soils Test excavations indicate that three to four feet of surficial soils are present on-site. The upper portions of the surface soils are generally dry and porous. It is recommended that the upper two feet of surface soils be overexcavated in areas to receive fill. Actual depths of removal may vary as recommended by the Geotechnical Consultant at the tirae of grading. Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No: SD2-2475 Page Twenty b. Existing Fill Soils It is recommended that all areas of uncon- trolled fill be overexcavated in areas to receive fill. c. Treatment of Alluvium It is recommended that loose, porous, or saturated alluvium be removed to firm ground prior to fill placement. For budgeting purposes, it should be assumed that all alluvium will be removed to bedrock. "The antici- pated areas of alluvial removals are shown on the attached Figure No. 3. d. Scarification and Processing of Surface Soils Following overexcavation of unsuitable mate- rials, areas to receive fill and/or other improvements should be scarified to a depth of 6 to 8 inches, brought to near optimum moisture conditions and compacted to at least ninety percent relative compaction. 3. Bedrock/Soil Characteristics Predominate material types on-site consist of siltstone and claystones of the Point Loma Formation as well as topsoil and alluvium derived from the same, Generally these material types are readily exca- vated with conventional earth-moving equipment, becoming firm to hard at depth increasing the I Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No: SD2-2475 Page Twenty-One difficulty of excavation as described in Section B-9, Rippability. Materials derived from the excavation will consist of silt and clay blends with considerable amounts of blocky siltstone and clay- stone fragments which require moderate to consider- able compaction effort to be broken down into a uniform compacted-fill soil. Moisture conditions in the near surface soils ' - are anticipated to vary from dry to wet. Moisture conditions vary in the surface soils depending on the actual location of the materials on-site and seasonal moisture variations. If the project is graded in late summer or fall prior to the next rainy season, we would anticipate topsoil materials to be relatively dry and alluvial materials to be moist to very moist. These materials will require moisture conditioning in conjunction with place- ment as compacted fill. Bedrock materials at depth, however, are anticipated to be at or above optimum moisture condition, requiring only limited moisture. < conditioning during placement as compacted fill. X Overexcavation of Transition Lots Because the subject lots are large industrial and commercial lots with building locations as yet undetermined, no overexcavation of transition lots is required. Overexcavation to eliminate the cut-fill transition may be a future recommendation v/hen building location and foundation design are known. Carlsbad Research Center job No: SD1162-00 July 26, 1982 Log No: SD2-2475 Page Twenty-Two 5. Compaction and Method of Filling Fill placed at the site should be compacted to a minimum relative compaction of 90 percent, based on ASTM Laboratory Test Designation D 1557-70, Fill should be compacted by mechanical means in uniform lifts of 6 to 8 inches in thickness. Fills constructed on natural slopes steeper than 5:1 (horizontal:vertical) should be keyed and benched into bedrock or competent natural ground. Compaction of slopes should be achieved by over- building the slopes laterally and then cutting back to the compacted core at design line and grade. Although overbuilding and cutting back is the preferred method, fill slopes may be back rolled at intervals not greater than four feet as the fill is placed, followed by final compaction of the entire slopes. Feathering of fill over the tops of slopes should not be permitted. Fills should also be placed and all grading per- formed in accordance with the City of Carlsbad's Grading Ordinance and the requirements of the Uniform Building Code. 6. Selective Grading As an alternative to laying-back slopes to a ratio of 2.5:1, slope faces may be constructed with select materials to a ratio of 2:1. Select materials should consist of generally well-graded granular materials with minor silt and clay frac- tions. Select materials should be nonexpansive. Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No: SD2-2475 Page Twenty-Three Suitablity of proposed select material sources should be determined upon evaluation of the engineering properties of the materials. Though limited amounts of select materials may be avail- able in the southern portion of the site, it is anticipated that the substantial amount of select material will be imported. A source of suitable select material has been identified on the pro- ject to the south. The material consists of a silty fine sand generated from the sandstone formation. In facing slopes with select material, it is recommended that a width of not less than 10 feet be maintained. Unless the minimum width is increased to provide working area for conventional slope compaction equipment, it is recommended that the slopes be overfilled and cut-backed to the compacted inner core. If the source of silty fine sand materials to the south is utilized for facing of slopes, overfilling and cutting-back is strongly recommended. From discussions with the Project Civil Engineer, it is our understanding that some slopes will be laid back to 2.5:1 in lieu of utilizing select material. A few slopes in more favorable material types in the southern portion of the project are not anticipated to be affected by the selective grading recommendations. Also, the selective grading recommendations should not be considered applicable to slopes of ten feet in height or less. Carlsbad Research Center job No: SD1162-00 July 26, 1982 Log No: SD2-2475 Page Twenty-Four Slopes presently anticipated to be affected by the selective grading recommendations have been indicated on the accompanying Figure 3. Due to the undesirable engineering properties of topsoil and alluvial soils, placement on the interior of fill masses is recommended in lieu of placement near slope faces. 7. Import Fill Material Presently it is anticipated that import fill materials will be required for selective grading operations. The type of material considered most desirable for import is a nonexpansive well- graded granular material with minor silt and clay fractions. The Geotechnical Consultant should be contacted for evaluation of individual import sources well in advance of planned import oper- ations. 8. Shrinkage, Bulking and Subsidence Volumetric shrinkage for the topsoil is estimated to be from 15 to 20 percent. Shrinkage in the alluvium is estimated to be from 10 to 15 percent. Bulking in the Point Loma Formation materials is .x lo 4o 1^ f^r Lffc \Wrf<wfl Xr- U^if ix'r expected to be from 5 to 10 percent. Bulking in the Santiage.Peak Volcanics is estimated to be lO +5 15 Let v/a«<)//U./'i*r iVr (Jh.*f 3^.4^ from 15 to 20 percent. Because alluvium and porous topsoil are being removed, subsidence due to equipment will be negligible. Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No: SD2-2475 Page Twenty-Five Due to the fact that shrinkage and subsidence can vary with many factors, it is recommended that the above values only be used for preliminary planning purposes. To provide for unforeseen variations in actual quantities a "balance area" should be designated by the Project Civil Engineer. 9. Rippability Field exploration indicates that some proposed cut areas are underlain, at varying depths, by non- rippable materials. The anticipated limits of nonrippable surface are indicated on the attached Rippability Map, Figure 3. "Nonrippable" is used to describe hard rock which is not economically excavated with conventional heavy-grading equipment. The rock may actually be rippable, but at an unacceptable production rate. Commonly accepted construction procedures in nonrippable materials include blasting and exceptionally heavy-duty grading equipment such as Catepillar D-10 or FIAT-ALLIS HD31 bulldozers. Nonrippable material at pad grade and at street subgrade will pose significant construction diffi- culty during later foundation and utility excavation, Consideration should be given to overexcavation in these areas to facilitate later construction. 10. Rock Disposal Grading in the nonrippable materials will produce rock fragments larger than normally allowed as fill material. Where practical, it is recoimnended Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No: SD2-2475 Page Twenty-Six that a non-structural, rock disposal area be identified. Possible areas for consideration include canyon areas currently outside the limits of planned grading. Larger rocks may also be incorporated into the lower portions of compacted fills, provided the placement and compaction are performed under the observation and testing of the Geotechnical Consultant. The recommended Rock Disposal Methods are presented in Appendix E ,, Standard Guidelines for Grading Projects. The contractor should be aware that incorporating rock in compacted fill will significantly reduce the rate of fill placement and may require bringing in special rock handling equipment. C. Slopes 1. Fill Slopes Fill slopes are proposed on-site to a height of on the order of 100 feet. One hundred-foot fill slopes at a ratio of 2:1 (horizontal:vertical) should possess gross stability in excess of the generally accepted minimum engineering criteria. Fill slopes in excess of ten feet in height should be laid-back to a ratio of 2.5:1 or flatter or should be constructed at 2:1 and provided v/ith at least ten feet of select material on the slope face to enhance surficial stability. Fill slopes should be constructed in accordance with the conclusions and recommendations outlined herein and the guidelines for grading projects Carlsbad Research Center July 26, 1982 Job No: SD1162-00 Log No: SD2-2475 Page Twenty-Seven which accompany this report as Appendix E. For 2:1 fill slopes of ten feet in height or less, construction should proceed in accordance with the guidelines for over-filling and cutting back to the compacted inner core. Cut Slopes a. Santiago Peak Volcanics The orientations of proposed cut slopes in the Santiago Peak Volcanics are generally favorable with respect to the geologic struc- ture. Final determination of the need for slope stabilizations will be made in the field during grading. Continuous geologic obser- vation of cuts in progress is essential. Cut slopes in this material made at slope ratios of 2:1 (horizontal:vertical) or flatter are anticipated to be surficially and grossly stable to the proposed heights. While cut slopes in the Santiago Peak Vol- vanics pose no significant geotechnical constraints, the exposed rock slopes may pose aesthetic and/or landscaping problems. Con- sideration should be given to overexcavation if exposed rock slopes are considered a sign- ificant problem. b. Point Loma Formation The orientations of proposed cut slopes in the Point Loma Formation are generally favorable Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No: SD2-2475 Page Twenty-Eight with respect to geologic structure and the daylighting of bedding planes. Some slopes may expose locally the very gently undulating bedding in daylighted fashion. Final deter- mination of the need for slope stabilization will be made in the field during grading. Continuous geologic observation of the cuts in progress is essential. Cut slopes in this material made at slope ratios of 2:1 (horizontal:vertical) or flatter are antic- ipated to be grossly stable to the proposed heights. Weathering characteristics of the Point Loma Formation materials will necessitate special treatment to mitigate surficial stability concerns on cut slopes. The Point Loma For- mation materials weather or slake rapidily, generally loosing integrity when exposed in excavations. The rapid deterioration of- the cut slope face will necessitate miti- gation measures identical to those previously recommended for fill slopes made of Point Loma Formation materials, e.g., blanket stabilization fills or reduced slope ratios. 3. Fill-Over-Cut Slopes Where fill-over-cut slopes are proposed, it is recommended that the cut portion be completed prior to fill placement. An equipment width minimum key should be constructed at the cut/fill Carlsbad•Research Center job No: SD1162-00 July 26, 1982 Log No: SD2-2475 Page Twenty-Nine contact. A typical fill-over-cut detail is pre- sented in the Standard Guidelines for Grading Projects which accompany this report as Appendix E. • 4. Stabilization/Buttress Fills Blanket stabilization fills are recommended for cut and fill slopes over 10 feet in height con- structed of Point Loma Formation materials, where laying-back the slopes to 2.5:1 is not adopted. Buttress fills are not anticipated at this time, however, final determination of the need for stabilization and buttress fills will be made in the field during grading. 5. Construction Slopes Construction slopes in the Santiago Peak Volcanics are recommended at slope ratios of 1.5:1 (horizon- tal : vertical) to a maximum height of 50 feet. Above that height, construction slopes should be cut at 2:1 (horizontal:vertical). Construction slopes in the Point Loma Formation are recommended at slope ratios of 1.5:1 to heights up to 30 feet. Above that height, construction slopes are recom- mended at slope ratios of 2:1 (horizontal:vertical) These recommended ratios can be steepened if the possibility of construction sliding is acceptable.. 6. Natural Slopes The proposed grading virtually eliminates natural slopes in Phase II. Natural slopes will remain Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No: SD2-2475 Page Thirty in the southwest corner of Phase III. These natural slopes v/ill continue to be subject to erosion and occasional minor surficial instabil- ity. The potential for erosion and surficial instability should not significantly impact the project nor should the project significantly impact the potential for such instability. D. Restriction on Future Construction No significant geotechnical restrictions, such as restricted use areas, are anticipated on future con- struction if grading is performed in accordance with the recommendations presented herein. These recom- mendations will not, however, preclude setbacks from buried utilities, easements, etc. Site specific geotechnical investigations are recom- mended prior to construction on the graded pads. Specific foundation recommendations should be made based upon evaluation of building types and structural loading conditions. E. Surface and Subsurface Drainage Surface runoff into downslope natural areas and graded areas should be minimized. Where possible, drainage should be directed to suitable disposal areas via non-erodible devices (eg. paved swales and storm drains). Subdrains should be placed under all fills placed in drainage courses and at identified or potential seepage areas. Their specific locations will be determined in Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No: SD2-2475 Page Thirty-One the field during grading. General subdrain locations will be indicated on the approved grading plan. The subdrain installation should be reviewed by the Engineering Geologist prior to fill placement. Typical subdrain details are presented in Appendix "E, Standard Guidelines for Grading Projects. Subdrain pipe may be coated metal, P.V.C., or approved equiv- alent (crush strength of 1000 pounds/foot or greater). Drainage devices will be recommended behind buttresses and/or stabilization fills to minimize the build-up of hydrostatic and/or seepage forces. The details and recommended locations of these back drains are presented in Appendix E, Standard Guidelines for Grading Projects. Depending on slope height, more than one tier of drains may be required. Drains may also be recommended at contacts between permeable and non- permeable formations. F. Foundations and Slabs 1. Expansive Soils The on-site soils and materials generated from the predominate bedrock formation on-site will possess ' high expansion potential. Though minor amounts of more favorable materials exist, it is not con- sidered practical to selectively grade to mitigate potential adverse affects of expansive soils. The existence of expansive soils near grade will dic- tate special foundation and slab configuration and reinforcement recommendations. Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No: SD2-2475 Page Thirty-Two 2. Footing Setbacks Special footing setbacks are presently not anticipated to be a factor in the development of the project. If footings are proposed adjacent to slope areas, we recommend that the footings be deep and to provide a minimum horizontal distance of 10 feet from the outer edge of footings to the adjacent slope face. Footings planned under the influence of this recommendation should be provided specific review by the Geotechnical Consultant prior to construction. 3. Soil Bearing Pressure Soil bearing compacity will vary on a lot by lot basis, in consideration of site geotecnnical con- ditions and proposed developments. Foundation bearing compacity recommendations should be developed subsequent to site specific geotechnical evaluations as individual lots are proposed for development. In general, bearing capacity is expected to be moderate to high in bedrock areas. In compacted fill areas consisting of the predominate silty and clayey materials bearing capacity is expected to be low to moderate. Where future buildings are proposed in transition areas, overexcavation of cut-portions or deepened footings could be_ recom- mended to create relatively uniform bearing con- ditions. Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No: SD2-2475 Page Thirty-Three 4. . Lateral Load Resistance Development of recommendations for lateral load resistance can be best performed subsequent to site specific evaluations. These site specific evaluations can be performed as development plans for individual sites are made available. G. Retaining Walls The development of geotechnical design critera for retaining walls can be best developed following review of the proposed wall configurations and review of the site specific geotechnical conditions. Over most of the site, however, the following critera may be utilized for preliminary design purposes. Where fr'ee-standing walls are proposed to retain granular backfill, equivalent fluid weight for static active lateral earth loadings of 45, 70 and 90 pounds per cubic foot may be utilized for walls re- taining level, 2.5:1 and 2:1 backfill conditions respectively. Appropriate allowances should be made for anticipated surcharge conditions, unless walls are also designed to resist seepage and/or hydrostatic forces. Walls should be provided with designed drain- age systems. It should be noted that the use of heavy compaction equipment in close proximity to retaining walls can result in excess wall movement (strains greater than those normally associated with the development of active conditions) and/or soil pressures exceeding Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No: SD2-2475 Page Thirty-Four design values. In this regard, care should be taken during back-filling operations. H. Type of Cement for Construction • Evaluation of soluable sulfate content of samples considered representative of the predominate material types on site suggest that Type V concrete is not a requirement for use in construction. Type I or II cement should be utilized. Cement type recommendations should be verified following site specific investi- gations on individual lots. I. Pavements Due to generally poor subgrade characteristics of the predominant soil types, generally heavy pavement sections can be anticipated. For traffic index values of 7.0, 8.0 and 8.5 which are expected for the street areas, the following preliminary pavement sections can be utilized for planning purposes. Traffic Index 7.0 8.0 8.5 R-Value 7.0 7.0 7.0 Pavement Thickness 4" 4" 5" Aggregate Base 15" 18" 19" Total Thickness 19" 22" 24" From review of the above sections, it is apparent that street areas during rough grading should be kept about two feet low to accomodate the pavement sections. Pavement recommendations should be reviewed as final grades are achieved. Carlsbad Research Center Job No: SD1162-00 July 26/ 1982 Log No: SD2-2475 Page Thirty-Five If practical, selective grading in street areas may be considered for the purpose of reducing pavement section requirements. If it is considered practical to place about one-foot of good granular material in • street subgrade areas, the required aggregate base material section could be reduced substantially. J. Utility Trench Backfill Utility trench backfill should, unless otherwise recommended, be compacted by meachanical means. Unless otherwise recommended, the degree of compaction should be a minimum of 90% of the laboratory maximum density. As an alternative, granular material (Sand Equivalent greater than 30) may be thoroughly jetted in-place. Jetting .should only be considered to apply to trenches no greater than two feet in width and four feet in depth. Following jetting operations, trench backfill should be thoroughly mechanically compacted and/or wheel rolled from the surface. K. Grading Plan Review When final grading plans for the proposed development are completed, the plans should be reviewed by the Geotechnical Consultant to determine compliance with the recommendations presented herein. Substantial changes from the present plan may necessitate additional investigation and analyses. Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No: SD2-2475 Page Thirty-Six L. Geotechnical Observation Continuous observation by the Geotechnical Consultant is essential during grading to confirm conditions anticipated by the preliminary investigation, to adjust designs to actual field conditions and to determine that grading proceeds in general accordance with the recommendations contained herein. Carlsbad Research Center Job No: SD1162-00 July 26, 1982 Log No: SD2-2475 Page Thirty-Seven X., LIMITATIONS OF INl/ESTIGATION Our investigation was performed using the degree of care and skill ordinarily exercised, under similar circum- stances, by reputable Soils Engineers and Geologists practicing in this or similar localities. No other warranty, express or implied, is made as to the conclusions and professional advice included in this report. The samples taken and used for testing and the observations made are believed representative of the entire area. How- ever, soil and geologic conditions can vary significantly between borings, test pits and surface outcrops. , As in most major grading projects, conditions revealed by excavation may be at variance with preliminary findings. If this occurs, the changed conditions must be evaluated by the Geotechnical Consultant and designs adjusted or alternate designs recommended. Very truly yours, SAN DIEGO SOILS ENGINEERING, INC. .CE. 26098 Stephen W. Jensen, C.E.G. 1074 Chief Engineer Manager, Geologic Services GWA:SWJ:tcm -p.-,'v:' APPENDIX A REFERENCES 1. "Eocene and Related Geology of a Portion of the San Luis Rey and Encinitas Quadrangles, San Diego County," December 1972: University of California, Revierside, Masters Thesis prepared by K. L. Wilson; 2. Mines and Mineral Resources of San Diego County, 1963: California Division of Mines and Geology, County Report 3; 3. Crustal Strain and Fault Movement Investigation, January ,1964: California Department of Water Resources Bulletin No. 116-2; 4. "Accelerations in Rocks for Earthquakes in the Western United Stages," Bulletin of the Seismological Society of America, Vol. 63, No. 2, Schnabel and Seed, April 1973; 5. Fault Hazard Zones in California, Revised January 1977: California Division of Mines and Geology, Special Publi- cation 42; 6. "Fault Map of California," 1975: California Division of Mines and Geology, Geologic Data Map No. 1; 7. "Repeatable High Ground Accelerations from Earthquakes," California Geology, California Division of Mines and Geology, Ploessel and Slosson, September 1974; 8. Clay Mineralogy and Slope Stability, Special Report 133, California Division of Mines and Geology, 1977; 9. Seismicity of the Southern California Region 1932-1972, 1973: California Institute of Technology, Seismological Laboratory; 10. "Preliminary Soil and Geologic Investigation, Carlsbad Research Center, Carlsbad,California" April 1981, Woodward- • Clyde Consultants; 11. "Additional Studies, Carlsbad Research Center, Carlsbad, California" August 1981, Woodward-Clyde Consultants; 12. "Addendum to Additional Studies, Carlbad Research Center, Carlsbad, California" September 1981, Woodward-Clyde Consultants; 13.. "Aerial Photographs," USDA Flight AXN-8M, 1953, Photo /•.r,: Nos. 71-73, 99-101. ' APPENDIX B SUBSURFACE EXPLORATION l$\ ..." The subsurface exploration consisted of 6 borings to a maximum depth of 51 feet and 38 test pits excavated to a maximum depth of 14 feet. The borings were drilled with a truck-mounted bucket auger drill rig and the pits were excavated with a tractor moxonted backhoe. The subsurface exploration was conducted under the direction of the Engineering Geologist. The borings and pits were logged, sampled and backfilled. Samples of the materials encountered were returned to the laboratory for testing. Logs of our borings are presented as Figures B-2 through B-8. The logs of test pits are presented as Figures B-9 through B-46. The locations of the borings and pits included in this appendix are shown on the attached Geotechnical Map, Plate No. 1. California Sampler blow counts were obtained by driving a 2.625 inch, inside diameter sampler, with a hammer dropping through a 12 inch free fall. A 1600 pound hammer was used at depths less than 25 feet and an 800 pound hammer was used at depths greater than 25 feet. Unless otherwise shown, the blows per foot recorded on the Boring Logs represent the nvimber of blows used to drive the sampler 12 inches. Samples shown on the Boring Logs as "UNDISTURBED SAMPLES" were obtained with the California Sampler. Seismic Traverses Seismic traverses were made to determine rock hardness in pro- posed cut areas. Velocities of shock waves were measured along these traverses to determine the rippability characteristics of the bedrock underlying the property. A summary of the seismic data utilized during evaluation of the site is included as . Table B-l."^ . A. Equipment The equipment utilized during the seismic survey phase of this investigation was a signal enhancement seismograph, manufactured by Bison Instruments, Inc. The energy source employed was a sledge hammer, with an impulse spacing of 10 feet. The traverses were each 200 feet long. B. General Seismic Parameters In general, seismic velocity is closely related to rock hardness. Soil and loose.surface material generally have a seismic velocity of about 1000 feet per second. Velocities of 1000 to 2500 feet per second are characteristic of soft sediments and easily ripped weathered bedrock. Velocities of 3000 to 5500 feet per second are typical of firm materials that require moderate to heavy ripping. Blasting is commonly required to excavate bedded materials that have a velocity 6500 feet per second or faster, while massive volcanic materials with velocities greater than 5500 feet per second generally require blasting. TABLE B-1 ' Depth Velocity Traverse No. (Feet) (Feet per Second) 1 .. 0-5 1,600 5-20 5,800 20+ • 14,000 2 0-7 1,500 7-50 4,000 3 0-5 1,000 5-30 2,900 4 0-5 1,000 5-20 4,500 20+ 10,000 5 0-5 4,000 • 5+ 6,000 PRIMARY DIVISIONS GROUP SYMBOL SECONDARY DIVISIONS COARSE GRAINED SOILS MORE THAN HALF OF MATERIAL IS LARGER THAN NO. 200 SIEVE SIZE GRAVELS MORE THAN HALF OF COARSE FRACTION IS LARGER THAN NO. 4 SIEVE CLEAN GRAVELS GW Well graded gravels gravel-sand rrut'.uie:. Iillie or no fines. COARSE GRAINED SOILS MORE THAN HALF OF MATERIAL IS LARGER THAN NO. 200 SIEVE SIZE GRAVELS MORE THAN HALF OF COARSE FRACTION IS LARGER THAN NO. 4 SIEVE (LESS THAN 5% FINES) GP Poorly graded gravels or gravel-sand midures little or no fines. COARSE GRAINED SOILS MORE THAN HALF OF MATERIAL IS LARGER THAN NO. 200 SIEVE SIZE GRAVELS MORE THAN HALF OF COARSE FRACTION IS LARGER THAN NO. 4 SIEVE GRAVEL WITH FINES GM Silty gravels, gravel-sand-sill mixtures, non-plastic lines COARSE GRAINED SOILS MORE THAN HALF OF MATERIAL IS LARGER THAN NO. 200 SIEVE SIZE GRAVELS MORE THAN HALF OF COARSE FRACTION IS LARGER THAN NO. 4 SIEVE GRAVEL WITH FINES GO Clayey gravels, gravel-sand-clay mixtures, plastic lines. COARSE GRAINED SOILS MORE THAN HALF OF MATERIAL IS LARGER THAN NO. 200 SIEVE SIZE SANOS MORE THAN HALF OF COARSE FRACTION IS SMALLER THAN NO. 4 SIEVE CLEAN SANDS (LESS THAN 5% FINES) SW Well graded sands, gravelly sands little or rxj fines. COARSE GRAINED SOILS MORE THAN HALF OF MATERIAL IS LARGER THAN NO. 200 SIEVE SIZE SANOS MORE THAN HALF OF COARSE FRACTION IS SMALLER THAN NO. 4 SIEVE CLEAN SANDS (LESS THAN 5% FINES) SP Poorly graded sands or gravelly sands, little or rH> (ires COARSE GRAINED SOILS MORE THAN HALF OF MATERIAL IS LARGER THAN NO. 200 SIEVE SIZE SANOS MORE THAN HALF OF COARSE FRACTION IS SMALLER THAN NO. 4 SIEVE SANDS WITH FINES SM Silty sands, sand-silt mixtures, non-plastic lines. COARSE GRAINED SOILS MORE THAN HALF OF MATERIAL IS LARGER THAN NO. 200 SIEVE SIZE SANOS MORE THAN HALF OF COARSE FRACTION IS SMALLER THAN NO. 4 SIEVE SANDS WITH FINES SC Clayey sands, sand-clay mixtures, plastic fines. FINE GRAINED SOILS MORE THAN HALF OF MATERIAL IS SMALLER THAN NO. 200 SIEVE SIZE SILTS AND CLAYS LlOUlO LIMIT IS LESS THAN 50% ML Inorganic silts and very (ine sands rock flour si'ty or Clayey fine sands or clayey silts with shqht plasticity. FINE GRAINED SOILS MORE THAN HALF OF MATERIAL IS SMALLER THAN NO. 200 SIEVE SIZE SILTS AND CLAYS LlOUlO LIMIT IS LESS THAN 50% CL Inorganic Clays of low to medium plasticity, gravelly clays, sandy clays, silty clays, lean clays. FINE GRAINED SOILS MORE THAN HALF OF MATERIAL IS SMALLER THAN NO. 200 SIEVE SIZE SILTS AND CLAYS LlOUlO LIMIT IS LESS THAN 50% OL Organic silts and organic silty clays of low plasticity. FINE GRAINED SOILS MORE THAN HALF OF MATERIAL IS SMALLER THAN NO. 200 SIEVE SIZE SILTS AND CLAYS LIQUID LIMIT IS GREATER THAN 50% MH Inorganic sills micaceous nt diatomaceous fine sandy or silly soils, elastic silts FINE GRAINED SOILS MORE THAN HALF OF MATERIAL IS SMALLER THAN NO. 200 SIEVE SIZE SILTS AND CLAYS LIQUID LIMIT IS GREATER THAN 50% CH Inorganic clays of high plasticity, fat clays. FINE GRAINED SOILS MORE THAN HALF OF MATERIAL IS SMALLER THAN NO. 200 SIEVE SIZE SILTS AND CLAYS LIQUID LIMIT IS GREATER THAN 50% OH Organic clays of medium to high plasticity, organic silts. HIGHLY ORGANIC SOILS Pt Peat and other highly organic soils. 200 DEFINITION OF TERMS U.S. STANDARD SERIES SIEVE 40 10 CLEAR SQUARE SIEVE OPENINGS 3/4" 3". 12" SILTS AND CLAYS SAND FINE MEDIUM COARSE GRAVEL FINE COARSE COBBLES BOULDERS GRAIN SIZES SANDS.GRAVELS AND NON-PLASTIC SILTS BLOWS/FOOT* VERY LOOSE 0-4 LOOSE 4-10 MEDIUM DENSE io -30 DENSE 30-50 VERY DENSE tVER 50 CLAYS AND PLASTIC SILTS STRENGTH* BLOWS/FOOT* VERY SOFT 0 - 1/4 0-2 SOFT 1/4 - 1/2 2-4 FIRM 1/2 - 1 4-8 STIFF 1 - 2 8-16 VERY STIFF 2-4 16-32 HARD OVER 4 OVER 32 RELATIVE DENSITY CONSISTENCY Number o( blows o( 140 pound hammer (ailing 30 inches to drive a 2 inch O D (1-3/8 inch I D.) split spooi> (ASTM 0-1586). ^Unconfined compressive strength in tons/sq. ft. as determined by laboratory testing or approximated by the standard penetration test (ASTM D-1586). pwcket penetrometer, torvane. or visual observation. KEY TO EXPLORATORY BORING LOGS Unified Soil Classification System (ASTM D-2487) '""^ SD1162-00 DATE: July, 1982 FIGURE: B-1 SAN OIFQO SOUS ENGINEERING. INC. DATE OBSERVED:. 4-9-82 METHOD OF PRH i itin- 24 Bucket Auger LOQQED BY: KS .GROUND ELEVATION: 310 ,+ LOCATiQM- See Map P Ul lU u. a. Ul o o «9 CO < *-O O u. « O o Ul Sui 30. £< oo» z 3 Ul -J a. 2 < C9 2^ SO u Qo. ^Z IS BORING NO L DESCRIPTION SOIL TEST CH TOPSOIL; Brown CLAY, wet, soft, with organics S - lo-ll 18 20 22 101 106 104 BEDROCK: POINT LOMA FORMATION; Green grey clayey SILTSTONE, moist, stiff to very stiff. Very fractured and weathered to 5*. Occasionally jointed, orange staining in joints @8' massive, very few joints @13' and 14' minor cemented zones 15- 22 10? ao-@21' cemented lens, 6" thick, horizontal Dark green grey SILTSTONE, moist, very stiff, massive. 28-14 SS 17 112 SIEVE ANALYSIS HYDROMETER 90- Total Depth 30' No Water No Caving 96- 40- JOB NO.: SD1162-00 LOG OF BORING FIGURE: B-2 SAN OIEQO SOILS ENQINEERINiH. INd DATE naftPPypp- 4-9-82 METHOD OF nnii i mn- 24 RnrT<:p>(- Angp^i- LOQQED BY: KS GROUND ELEVATI0N:_J15' - LOCATION: M!=>P Ul a Ul 30. 2< o« z 3 SO o St* Qo. ^Z St BORING NO L DESCRIPTION SOIL TEST CH TOPSOIL; Brown CLAY, wet, soft. with organics S - BEDROCK; POINT LOMA FORMATION; 10- 4/ 5" SS 21 104 15 20- 25- 80- 96- 40- 23 22 S 19 light green grey clayey SILTSTONE moist, stiff to very stiff, with orange staining. Weathered and fractured to 5', jointed below 5' @ 6.5' dark brown carbonaceous bed, 1" thick, horizontal @ 10.5' cemented layer, 3" thick, horizontal @ 15.5' cemented layer, 2" thick @ 17-20' vertical joint, iron stained material • (§ 21' joint N10°W, 90° @ 23' gypsum seam, .5" thick, horizontal (§ 27-28' minor cemented layers 107 |@ 30' cemented layer, 4" thick, horizontal ~BTacTt-grey clayey SILTSTONE," :noist, very stiff with hard layers, massive CONSOLIDATION MAXIMUM DENSITY DIRECT SHEAR (Remolded) SIEVE ANALYSIS HYDROMETER ATTERBERG LIMITS EXPANSION TEST SULFATE TEST 102 DIRECT SHEAR (Ring Samples) JOB NO_-SD1162-00 LOG OF BORING FIGURE: B-3 SAN DIEQO SOILS ENQINEERINQ. INC. DATE OBSERVED: 4-9-82 METHOD OF npii IIMQ- 24" Bucket Auger LOGGED BY:. KS .GROUND ELEVATION: 315'± iQCATioM- See Map P Ul Ul 0. Ul Q 40-SS o Ul Oui OC-I 3a «^ QO) z 3 ui£ h so o Oo. *"Z it BORING NO. DESCRIPTION SOIL TEST 20 18 105 46- Black-grey clayey SILTSTONE, moist, very stiff with hard layers, massive 60-25 17 107 CONSOLIDATION ^XIMUM DENSITY SIEVE ANALYSIS HYDROMETER \TTERBERG LIMITS EXPANSION TEST SULFATE TEST DIRECT SHEAR (Ring Samples) Total Depth 51' No Water No Caving 66- 60 65 70- 76- 80- JOB NO.:sDll62-00 LOG OF BORING FIGURE: B-4 SAN DIEGO SOILS ENGINEERING. INC. DATE QBftgPVPP- 4-1 METHOD OF Pam IMO- Rnr-Vpt Angpr LOQQED BY: KS QROUND ELEVATION:_2a£l^_ LOCATION: See Map Ul Ik o. Ul O •0 z O u 0} CO O O h. CO O o Ul (Dili cr_j ?l 2< o« z 3 UJ < CO SO u OQ. is sg BORING NO. DESCRIPTION BOH. TEST TOPSOIL; Red brown CLAY, moist, firm CH SS 19 100 SIEVE ANALYSIS HYDROMETER S 17 106 BEDROCK: POINT LOMA FORMATION; Green grey clayey SILTSTONE, moist, stiff to very stiff, with orange staining. Weathered and fractured to 6' 10- 15-5/ 6" S 15 112 20- 25- @16' cemented layer, 6" thick, horizontal @18.5' cemented layer, 10" thick horizontal @22' gypsum seam, .5" thick, horizontal @24' cemented layer, 6" thick, horizontal @28' cemented layer, 7" thick, horizontal 90-18 S 14 99 Black grey clayey SILTSTONE, moist, very stiff with hard layers, massive 96- Total Depth 36' No Water No Caving 40- JOBNO.: SD1162-0C LOG OF BORING FIGURE: B-5 SAN DIEQO SOILS ENQINEERINQ. INC DATE OBSgRygp- 6-9-82 METHOD OF npii i iNO- 24" Bucket Auqer LOGGED BY; KS GROUMn ELEVATION: 256' LOCATION: _See_Ma2_ -Or o Ul CD m OCl 30. «l 0(0 Oz SO u Oo. it 5S BORING NO. DESCRIPTION SOIL TEST 6- 10- 15- 20- 26- 30 36 40- ALLUVIUM; Light to medium brown silty CLAY, moist, soft. S 19 106 S s 27 98 BEDROCK; Point Loma Formation; green-brown clayey SILTSTONE; moist, stiff. @9Js' Cemented lens. Total Depth 10" No Water No Caving JOB NO. SD1162-00 LOG OF BORING FIGURE: SAN DIEGO SOILS ENGINEERING. INC. DATE OBRgBygPr 6-9-82 LOGGED BY:__JiS_GROUND ELEVATION:_260J_j:i_ LOCATION; Sge MflR. METHOD OF DRILLING: 24" Buckfit Auger Ul CD UJ CCJ 30. «1 QCO Ill5 Is 55 SO u >-u: Oo. ""Z it Ul = o BORING NO 5_ DESCRIPTION SOIL TEST BEDROCK; Santiago Peak Vol- 6T- canics; very weathered, varied colors, white, pink, red and light green, metavolcanics, moist, medium dense to dense, texture chalky to hard:rock. 10- 16 20 26- 30 36 Total Depth 34' No Water No Caving 40- JOB NO.: SD1162-00 LOG OF BORING FIGURE: B-7 SAN DIEGO SOILS ENGINEERING, INC. DATE OBSERVED: 6-9-82 METHOD OF DRILLING: 24" Bucket Auqer LOGGED BY:. KS GROUND FiF"*TinM- 256' - LOCATION: See Map. Ul Ul a. UJ o •0- H |0 o o u. to ? O CD 3 Ul ODni I (r_j 30. \ao)\ Zi 3 00 Ul -I a < 0) Ul£ SO U Oo. it BORING NO. DESCRIPTION SOIL TEST 10- 16 20 26- 30 36 40 lOl 16 TOPSOIL; Light brown silty CLAY to clayey SILT, moist; firm. 10 123 BEDROCK: 121 Point Loma Formation grey with brown mottling SILT- STONE, moist, very stiff. Approximately horizontal lamin- ations, semi-cemented. @ 7' Predominately grey, some sand. @ 9H' Cemented zones Horizontal • ; @ 20' Less cemented, softer. @ 22' Cemented, thin layers. Horizontal @ 2235'Fossiliferous @ 26^2'Grey-brown SANDSTONE. @ 30' Cemented layer, 2" thick, horizontal joint; N26'' E, 66" NW. Total Depth 34' No Water No. Caving Maximum Density Sieve Analysis Hydrometer Atterberg Limit JOB NO.: SD1162-00 LOG OF BORING FIGURE: B-8 SAN DIEGO SOILS ENGINEERING. INC. DATE OBSERVED:. 4-28-82 METHOD OF DRiLLiNGr 24" Backhoe LOGGED BY- KS oRniiMn FI PVATION; 2 35'- LOCATION- See Map P UJ Ul u. .z O. Ul o hO- o UJ CD itj OCl 30. 51 oco z 3 tu£ Oz SO u OQ. *"Z it 5g TEST PIT NO.. DESCRIPTION SOIL TEST CH ALLUVIUM; Brown silty CLAY, moist to saturated, soft Seepage @ 0-3' BEDROCK; Point Loma Formation; Yellow - green grey SILTSTONE wet, stiff to very stiff 10- Total Depth 6' Seepage @ 0'-3 Caving @ 0'-4' IS- 20- 26- 30- 36- 40- JOB NO.: SD1162-00 LOG OF TEST PIT FIGURE: B-9 SAN DIEGO SOILS ENGINEERING. INC. DATE OBSERVED: 5-3-82 METHOD OF DRILLING: 24" Backhoe LOGGED BY:. KS .GROUND ELEVATION: 285'-LOCATION: See Map a. Ul o o UJ SUI 30. 51 QO) uj£ h coju oS SO o >-u: <t TEST PIT NO. DESCRIPTION SOIL TEST CH 6- 10- 15- 20- 26- 30- 36: 40- TOPSOIL: Brown silty CLAY, wet, soft BEDROCK: Point Loma Formation; Green grey SILTSTONE, moist, S^iff, fractured ' Total Depth 5h' No Water No Caving JOB NO.:sD1162-00 LOG OF TEST PIT FIGURE: B-10 SAN DIEQO SOILS ENGINEERING. INC. DATE OBSERVED: b-3-82 METHOD OF DRILLING: 24" Backhoe LOGGED BY: KS .GROUND ELEVATION:. 285'-LOCATION: See Map 0. Ul o ho- o o u. (0 O Q UJ CO Ml (r_i 30. 2l QO) Z 3 Ul£ is OTUI So u OQ. *"Z it t% 5S TEST PIT NO. ^ DESCRIPTION SOIL TEST CH TOPSOIL; Brown silty CLAY, moist to wet, soft 10- 15- 20- 25r 30- 35 40- BEDROCK; Point Loma Formation; Dark green grey SILTSTONE, Moist, tiff, fractured Total Depth 5' No Water No Caving JOB NO.:SD1162-00 LOG OF TEST PIT FIGURE: B-11 SAN DIEQO SOILS ENGINEERING. INC. DATE OBSERVED:. 5-3-82 METHOD OF DRILLING:. 24" Backhoe LOGGED BY: KS GROUND ELEVATION: 284 •-LOCATION: See Map Ul Ul u. X H a Ul o ho- o o u. CO $ O Q Ul CD nj OCl 30. QO) z 3 UIJ5 =5 Oz SO o Oa '"Z <t tt-Z z>u -o TEST PIT NO. DESCRIPTION SOIL TEST CH S TOPSOIL: Orange brown CLAY, moist, firm BEDROCK: Point Loma Formation; 6-Dark orange olive green SILT- STONE, moist, stiff, fractured N 10^ Total Depth 6 No Water No Caving CONSOLIDATION MAXIMUM DENSITY DIRECT SHEAR (Ring Sample) SIEVE ANALYSIS HYDROMETER ATTERBERG LIMITS EXPANSION TEST SULFATE TEST 16- 20- 26- 30- 36- 40- JOB NO. -SD1162-00 LOG OF TEST PIT FIGURE: B-12 SAN DIEGO SOILS ENGINEERING. INC. DATE OBSERVED: 5-3-82 METHOD OF DRILLING: 24" Backhoe LOGGED BY:_JiS_GROUND FtFVATioM- 248'- LOCATION- See Map til lU 0. Ul o ho- o UJ CD UJ cr_j 30. QCO z 3 uj£ h coUJ 5z so o Oo. ""Z <t TEST PIT NO. 5 DESCRIPTION SOIL TEST CH ALLUVIUM: Brown CLAY, wet. soft 5-BEDROCK: Point Loma Formation; Dark green grey SILTSTONE, moist to wet, fractured 10-Total Depth 6' No Water No Caving 16- 20- 26- 30- 36- 40- JOB NOJSD1162-00 LOG OF TEST PIT FIGURE: B-13 SAN DIEGO SOILS ENGINEERING. INC DATE OBSERVED:. 5-3-82 METHOD OF DRILLING: 24" Backhoe LOGGED BY: KS QROiiNn ELEVATION: 298'- LOCATION; See Map Ul Ul ti. a. UJ o -0- z o u iZ m CO < o o UL CO o a tu CD Ul OC _l 3a •-S 52< oto z 3 Ul -I 0. S < (0 coUJ oS so o OQ. 5S TEST PIT NO. ^ DESCRIPTION SOIL TEST CL FILL: Green grey silty Clay moist, very loose Total Depth 5' No Water No.Caving 10- 16- 20- 26- 30- 36- 40- JOB NO.:sD1162-00 LOG OF TEST PIT FIGURE: B-14 SAN DIEQO SOILS ENGINEERING. INC DATE OBSERVED: 5-3-82 METHOD OF DRiLLiNGr 24" Backhoe LOGGED BY:. KS .GROUND ELEVATION:. 288 LOCATION- See Map P UJ UJ li. a. Ul o -0- z O m CO < -I o O O u. *^ CO o o UJ CDui C J 30. oco z 3 UJ -I a S < CO 3 ffi UJ ^ h couf Oz so u OQ. <t: is 5g TEST PIT NO. DESCRIPTION SOIL TEST BEDROCK; POINT LOMA FORMATION; 6- Dark grey green SILTSTONE, moist stiff to very stiff, fractured in the top 3', jointed to 6' (33-6' joints: N56°W, 75°N; N50°W, 90°; N-S 90°, N10°W, 80°E; N60°wi 80°N; N10°E, N^N20°E, 80°W 90 10-Total Depth 6' No Water No Caving 16- 20- 26- 30- 36- 40- JCiS NO.:SD1162-00 LOG OF TEST PIT FIGURE: B-15 SAN DIEGO SOILS ENGINEERING. INC DATE OBSERVED:. 5-3-82 METHOD OF DRILLING:. 24" Backhoe LOGGED BY: KS .GROUND ELEVATION: 285'i LOCATION: See Map Ui Ul b. 0. UJ Q -0- z O o CO CO < O O u. (0 $ O o Ul CDuj OC J 30. «^ OCO UJ < (0 3 CO UJJS h CoUJ 5z SO u Oo. it is 5S TEST PIT N0._8 DESCRIPTION SOIL TEST CH ALLUVIUM: Brick red CLAY, S wet, firm SIEVE ANALYSIS 5-BEDROCK; Santiago Peak Volcanics Orange stained green "weathered metavolcanics", moist, very dense 10-Total Depth 6H' Near Refusal No Water No Caving 16- 20- 26- 30- 36- 40- JOB NOJ SD1162-00 LOG OF TEST PIT FIGURE: B-16 SAN DIEQO SOILS ENGINEERING. INC DATE OBSERVED: ^"3-82 MFTHOn DP npii i INO-24" Backhoe LOGGED BY: ^S GROUND ELEVATION: 298'- , OOATION-See Map p UJ UJ h. ^ Z H 0. UJ Q -0- < O w <0 < -I o »-O O li. *^ (0 $ O o UJ CD UJ flC_i 30. 2^ oco z 3 UJ _l o. S < CO 3 OQ Uj£ Oz so u OQ. <t: o!S TEST PIT NO. DESCRIPTION SOIL TEST CH 6-CH 10- 16- 20- ?5H 30- 36- 40- ALLUVIUM; Brown red CLAY, moist to wet, firm Brown CLAY, moist, firm, with root holes BEDROCK; Santiago Peak Volca- nics; Orange stained green y"weathered metavolcanics \^oist, very dense Total Depth Ills' Near Refusal No Water No Caving JOB NO.: SDli62-00 LOG OF TEST PIT FIGURE: B-17 SAN DIEQO SOILS ENGINEERING, INC I DATE OBSERVED: 5-3-82 METHOD OF DRILLING: 24" Backhoe LOGGED BY: KS .GROUND ELEVATION: 304'- LOCATION: See Map & UJ o -0- 6- 10- 16- 20- 26- 30- 36 40- CH o UJ CD UJ ac_i 30. oco z 3 s Ul* h (OUJ So o Oo. s:s TEST PIT NO. 10 DESCRIPTION TOPSOIL; Brown CLAY, moist to wet, firm BEDROCK; Point Loma Formation; Light green grey SILTSTONE, moist, stiff to very stiff, massive with orange staining, ' feathered to 5%' Total Depth 7' No Water No Caving SOIL TEST JOB NO.; SD1162-00 LOG OF TEST PIT FIGURE: B-18 SAN DIEQO SOILS ENGINEERING. INC DATE OBSERVED:. 5-3-82 METHOD OF DRILLING:. 24" Backhoe LOGGED BY: KS .GROUND ELEVATION: 307'± LOCATION: See Map »- UJ UJ u. 0. UJ O 6- 10- 16- 20- 25- 30- 35- 40- z O o iZ m CO < o CH O o u. CO $ O o UJ ODuj a:!j 30. oco z 3 S lU _i a. S < CO 3 a Is Oz so u VuT Oo. ^z <t ss TEST PIT NO. 11 DESCRIPTION TOPSOIL: Brown sandy CLAY, dry to moist, soft BEDROCK; Santiago Peak Volca- nics; Very light green "veathere^ metavolcanics, moist, medium dense to 6', dense 6' to 9', with orange and red staining Total Depth 9' No Water No Caving SOIL TEST JOB NO.:sDll62-00 LOG OF TEST PIT FIGURE: B-19 SAN DIEGO SOILS ENGINEERING. INC hO- DATE OBSERVED: 5-3-82 LOGGED BY: KS METHOD OF DRILLING: ,+ 24" Backhoe P UJ UJ lb 0. UJ o 6- 10- 16- 20- 26- 30- 35- 40- QROUND ELEVATION; 286'- LOCATIQNt See Map z O o iZ m V) < CH H O o u. CO $ O o UJ CD m ac_i 3a Q(0 UJ -I o. S < CO 3 OD UJs^ Is Oz so o JOB NO.: sj3j^j^g2-00 Oo. '"Z <t «^z ZUJ -o TEST PIT NO. 12 DESCRIPTION TOPSOIL; Dark brown CLAY, moist, -firm BEDROCK: Point Loma Formation; Dark green grey clayey SILTSTONE moist, stiff, massive, with orange staining, upper 2' weatheijed Total Depth 8'. No Water No Caving SOIL TEST LOG OF TEST PIT FIGURE:B-20 SAN DIEQO SOILS ENGINEERING. INC I I DATE OBSERVED: 5-3--82 MPTHnn OF DRII LiNR- 24" Backho© KS . + LOGGED BY: KS GROUND PLEVATION- " LOCATION- ^66 Map 3 DEPTH (FEET) CLASSIFICATION BLOWS/FOOT UNDISTURBED SAMPLE BULK SAMPLE 1 MOISTURE CONTENT (%) IN PLACE DRY DENSITY (PCF) TEST PIT NO. 13 DESCRIPTION ; SOIL TEST i GH '^ • / • •„• i ALLUVIUM: Brown CLAY, moist, ' soft to firm : •J »^ BEDROCK: Point Loma Formation; Grey green SILTSTONE, moist, r -J • -\^^iff, with orange staining 10-1 f If . ' : --4 Total Depth 7' No Water No Caving 16- '4 _ 1 ••" '^V. . : • l .Y.' •_'t .-. .,>. " • . .: - .. • •• .. • •. . •'•) L .* --I ' ~ ' . , ^ c _ /.••\.-: *" ^ # i 20-• i — ,r < . iJ-J, • * .... ^,_ 25-. r • 11"-- • 30-F ^ • • - •> 1 ( - 36- "., • f\: I • ••••• • • • . • .. - • •• • . 40- r'.-r .. JOB NOJSD1162 -00 LOG OF TEST PIT FIGURE: B-21 SAN DIEQO SOILS ENGINEERING. INC. 1 f \ \ j . f ( DATE OBSERVED: _ LOGGED BY- KS 5-3-82 METHOD OF DRILLING: .GROUND FI FVATION- 258'- LOCATION: 24" Backhoe See Map »-u u u. 0. UJ o 10- 16- 20- 26- 30- 36- 40- co CO < CH I-O o u. CO o Q Ul CD Ul flCj 3a 0(0 UJ -J 0. s < CO 3 CO uj£ Is cou 55 so o >-u: Oa ""Z <t tt SS JOB NO.: SD1162-00 TEST PIT NO. 14 DESCRIPTION ALLUVIUM:S , Brovm CLAY, moist, firm BEDROCK: Point Loma Formation; Green brown SILTSTONE, moist, tiff to very stiff « Total Depth 8* No Water . No Caving LOG OF TEST PIT SOIL TEST FIGURE: B-22 SAN DIEQO SOILS ENQINEERINQ. INC. DATE OBSERVED: 5-3-82 METHOD OF DRILLING: 24" Backhoe LOGGED BY:. KS .GROUND ELEVATION . 262 .+ LOCATION: See Map UJ UJ u. Z a Ul o z O u 0) CO < O O u. CO o a Ul to Ul OC_l 3a OCO z 3 UJ -I a S < (0 uj£ Is coUJ Oz so u Oa ""Z <t tt ss TEST PIT NO. 15 DESCRIPTION SOIL TEST CH 5- lOr^ 15- 20- 26- 30- 36- 40 ALLUVIUM: Brown Clay/Light brown SAND, moist to saturated, soft @ 3*2'-7' Seepage . ' BEDROCK; Point Loma Formation; ellow green SILTSTONE, moist, • .stiff • • ' Total Depth 8' . Water @ 3^5'- 7' Minor/Caving @ 3^5'; - 7' V ! JOB Np.^Dll62-00 LOG OF TEST PIT FIQURE:B-23 SAN DIEQO SOILS ENGINEERING, INC. DATE OBSERVED: 5-3-82 LOGGED BY: . KS METHOD OF DRILLING:. .GROUND ELEVATION: 270'- LOCATION:. 24" Backhoe See Map -0- "CH 10^ 16- 20- 25- 30- 36: 40- o UJ CD Ul a:_i 3a «^ 0(0 z 3 UJ^ Is (0{U Oz SO o >u: Oa <t tt SS l^rey green SILTSTONE, moist, Nstiff, fractured TEST PIT NO. 16 DESCRIPTION TOPSOIL; Dark brown CLAY, moist to wet, firm BEDROCK: Point Loma Formation; Total Depth 5' No Water No Caving SOIL TEST JOB NOJSD1162-00 LOG OF TEST PIT FIGURE: B-24 SAN DIEQO SOILS ENGINEERING. INC. DATE OBSERVED: 5-3-82 METHOD OF DRILLING: 24" Backhoe LOGGED BY: KS .GROUND ELEVATION: 268 .+ LOCATION- see Map P Ul UJ lb X I-0. UJ Q ho- o UJ COuj oc^ 3a •-S 2< 0(0 Ul£, Is (0}»| Oz SO u Oa ""Z <t tt SS TEST PIT NO. 17 DESCRIPTION SOIL TEST CH '5- 10- 15- 20- 26r 30- 35- 40- S ALLUVIUM; Brown sandy CLAY, moist to saturated, soft to firm ' •'• @4' - 6 ' Seepage . ^ : SIEVE ANALYSIS BEDROCK; Point Loma Formation; Green grey SILTSTONE, moist, stiff, fractured Total Depth 8' Seepage @ 4' - 6'., No Caving ., JOB NO.:sD3_i62-00 LOG OF TEST PIT FIGURE: B-25 SAN DIEGO SOILS ENGINEERING. INC. DATE OBSERVED: _ LOGGED BY: ^S 5-3-82 METHOD OF DRILLING: 24" Backhoe .GROUND ELEVATION . 268'-LOCATION: See Map P UJ UJ Ik a UJ o -0- o UJ OD UJ a:_i 3a ^1 oco Is (OjU Oz SO u Oa ^Z <t tt SS TEST PIT NO. 18 DESCRIPTION SOIL TEST CL 10- 15- 20- 28- »"' 30- 35- 40- ALLUVIUM: Light brown sandy CLAY/clayey SAND, wet to satu- rated, soft ; -^''ir!-/ @1.5.' - 5' Seepage! ' BEDROCK; Point Loma Formation; .Grey green SILTSTONE, moist, Sstiff to very stiff Total Depth 7• Seepage (§ 1%' - 5' JOB NO.:sDll62-00 LOG OF TEST PIT FIGURE: 3.26 SAN DIEGO SOILS ENQINEERINQ. INC DATE OBSERVED: 5-3-82 METHOD OF DRILLING: 24" Backhoe LOGGED BY:. KS .GROUND ELEVATION:. 274 '-LOCATION: See Map UJ L. a Ul O < o a (0 (0 < -I o o UJ CO Ul 0C_J 3a SI oco z 3 a S < CO Is Oz SO u Oa <t tt ss TEST PIT NO. 19 DESCRIPTION SOIL TEST SM 5- 10- 15- 20r 25- 30^ 35- 40- ALLUVIUM; Light brown clayey silty SAND, wet to saturated, loose @ 1' - 4• Seepage BEDROCK: Point Loma Formation; Grey green SILTSTONE, moist to Wet, stiff, fractured Total Depth 6' Seepage @ 1' - 4' Minor Caving @ 1'. - 4' JOB NO.:sDll62-00 LOG OF TEST PIT FIGURE: B-27 SAN DIEGO SOILS ENQINEERINQ. INC. DATE OBSERVED: 5-3 -82 MPTHon OP nRii MMR- 24" Backhoe 1. LOGGED BY:. KS GROUND ELEVATION: 276'- IOCATION- See Map \ O DEPTH (FEET) CLASSIFICATION BLOWS/FOOT UNDISTURBED SAMPLE BULK SAMPLE MOISTURE CONTENT (%) IN PLACE DRY DENSITY (PCF) TEST PIT NO. 20 DESCRIPTION SOIL TEST 3P ALLUVIUM: Light brown SAND, saturated loose \@ 0' - 2' Seepage 0\ 1 ^ 6- 1 \BEDR0CK: Point Loma Formatior \ Grey green SILTSTONE, wet, Nstiff, fractured ; 10- • - - ' Total Depth 3' Seepage @ 0' - 2' !, • No Caving • •, / • 1 . i^ / ^ > 1. . ..-VjA"^ t. • • . 1 15-j 20-•'•j • 26- / -.: / 30-- ' "- •. ... • ; ^ / > ( t. y 36- J' - i~, t > ... I'll. :.v-,w', • •^\'rr-„, j. , ^ * ^ 40- JOB NO.: SD1162-0 LOG OF TEST PIT 1 FIGURE: B-28 SAN DIEQO SOILS ENGINEERING, INC DATE OBSERVED: 5-3-82 METHOD OF DRILLING: 24" Backhoe LOGGED BY: KS .GROUND ELEVATION:. 283'i LOCATION:. See Map Ul Ul IJL a Ul o ho- co 0) < o O O u. —. (0 O o UJ COul o:_j 3a 2^ 0(0 Ul -i a < CO 3 CD Ul£ Is (OW Oz SO u >a Qa ""Z <t tt ss TEST PIT NO. 21 DESCRIPTION SOIL TEST CH 5- 10- 16- 20- 25- 30- 36- 40- TOPSOIL; Brown CLAY, moist, firm BEDROCK; Point Loma Formation; strange stained green SILTSTONE, Nmoist, stiff, fractured, with Xcemented zones Total Depth 4' No. Water . No Caving JOB NO. SD1162-00 LOG OF TEST PIT FIGURE: B-29 SAN DIEQO SOILS ENQINEERINQ. INC DATE OBSERVED: 6-2-82 METHOD OF DRILLING:. Backhoe LOGGED BY: KS .GROUND ELEVATION: 2Q0-LOCATiON; See Map Ul Ul k. a Ul o -0- z. O m (0 < O o u. (0 $ O _i a o Ul 03 m OC_l 3a 2< 0(0 Z': 3 Ul a S < CO 3 CD Ul£ Is coj^ Oz so o >u: Oa ""Z it tt SS TEST PIT NO. 22 DESCRIPTION SOIL TEST 6r- 10- 15- 20- 26- 30- 35- 40- TOPSOIL: Red brown CLAY, dry to moist, firm, with organics V BEDROCK; Point Loma Formation; olive,green grey clayey SILT- STONE, moist, stiff, fractured Total Depth 4.5' No water - No caving JOB NO.:sDll62-00 LOG OF TEST PIT FIGURE: B-30 SAN DIEGO SOILS ENQINEERINQ. INC. DATE OBSERVED: 6-2-82 METHOD OF DRILLING:. Backhoe LOGGED BY: KS .GROUND ELEVATION:. 282i LOCATIQM- See Map X »-a Ul o hO- z O p < o a CO (0 < o Ul Olui OC_j 3a 2< 0(0 z 3 Ul£ Is WUJ Oz so u Oa •"^ it tt SS TEST PIT NO. 23 DESCRIPTION SOIL TEST 6- 10- 15- 20- 25- 30- 35- 40- TOPSOIL: Brown CLAY, dry to moist, firm, with organics BEDROCK; POint Loma Formation; olive green grey clayey SILT- STONE, moist, stiff, with orange [Staining , ~ Total Depth 5.5' JOB NO.: SD1162-00 LOG OF TEST PIT FIGURE: B-31 SAN DIEGO SOILS ENGINEERING. INC. DATE OBSERVED: 6-2-82 METHOD OF DRILLING: Backhoe LOGGED BY- KS GROUND Ft PVATiON: 286- LOCATION: See Map o Ul OD UJ 0C_| 3a ^1 oco Ul£ Is COUf Oz SO o Oa *"Z it tt SS TEST PIT NO._ii DESCRIPTION SOIL TEST 5:^ 10- 15- 20- 26r- 30- 35- 40 TOPSOIL; Brown CLAY, dry to moist,'firm, with organics and voids ' \ BEDROCK: Point Loma Formation; olive green grey SILSTONE, moist, stiff Total Depth 5.5' No Water No Caving JOB NO.: SD1162-00 LOG OF TEST PIT FIGURE: B-32 SAN DIEGO SOILS ENGINEERING, INC. DATE OBSERVED: 4-29-82 METHOD OF DRILLING- 24" Backhoe LOGGED BY: .GROUND ELEVATION: LOCATION: See Map P Ul Ul u. a Ul o -0- z O u « CO < -J o o o u. (0 o o Ul CD Ul CJ 3a 2^ oco z 3 Ul a S < (0 3 CD ui£ Is so o Oa *"Z it tt SS TEST PIT NO. 25 DESCRIPTION SOIL TEST 10- 15- 20- 25- 30- 35- 40 JOB NO.. SD1162-00 FILL; Light to medium brown SAND, moist, loose. TOPSOIL: Dark brown CLAY, moist, firm, with organics. BEDROCK: Point Loma Formation; White-green SILTSTONE, moist, hard-cemented. 8"^10" jointed blocks.~ Total Depth 7%' Refusal No Water No Caving' , ' LOG OF TEST PIT FIGURE: B-33 SAN DIEGO SOILS ENGINEERING. INC DATE OBSERVED: 4-29-82 METHOD OF DRILLING: 24" Backhoe LOGGED BYr KS .GROUND ELEVATION:. LOCATION: See Map P Ul Ul z a Ul o -0- O O u. CO O o Ul CD m 3a o<o Ul -I a S < CO ui£ Is (OUJ So u Qa ^Z it tt SS TEST PIT NO. 26 DESCRIPTION SOIL TEST 10- 16- 20- 26r- 30rr 35: 40- TOPSOIL: Dark brown CLAY, dry to moist, firm. BEDROCK; Point Loma Formation; Dark green-grey SILTSTONE, \moist, stiff, fractured to 3' @ 4' cemented layer: 4" Thick •N16?W,•4^W, \ Olive-grey clayey SILTSTONE, moist, very stiff. Total Depth 6' No Water No Caving JOB NO.: sniif^;^-nn LOG OF TEST PIT FIGURE: B-34 SAN DIEGO SOILS ENGINEERING, INC DATE OBSERVED: 4-29-82 METHOD OF DRII MMft- 24" Backhoe LOGGED BY: KS .GROUND ELEVATION:. LOCATION- See Map Ul Ul L. z 1-a Ul o CO (0 < O O u. (0 o o Ul CDu) 0C_| 3a QCO Ul -1 a S < CO 3 CD UlS Is «UJ Oz so u >u: 5" Qa ^Z it tt SS TEST PIT NO 27 DESCRIPTION SOIL TEST 5- 10- 15- 20- 26- 30- 35 40- TOPSOIL: Brown CLAY, dry, firm organics. Upper 2 feet is . , natural exposure. . , PALEOSOL: Blue-green and purple stained silty CLAY, dry to ynoist, fractured. BEDROCK: Point Loma Formation; Olive green-grey SILSTONE, ,moist, very stiff, with some Vpurple staining. ' . Total Depth 10' No Water No Caving JOB NO.:gj^3_^g2_QQ LOG OF TEST PIT FIGURE: B-35 SAN DIEGO SOILS ENGINEERING. INC. DATE OBSERVED:. 4-29-82 METHOD OF DRILLING: 24" Backhoe LOGGED BY: KS .GROUND ELEVATION:. LOCATION: See Map »-Ul Ul b. a Ul o ho- z o u CO CO < o o u. CO O o Ul CD Ul a:_i 3a 2< oco z. 3 Ul a S < CO ui£ Is mUl Oz so o Oa ""Z it tt SS TEST PIT NO. 28 DESCRIPTION SOIL TEST 10- 15- 20- 26- 30- 36: 40 TOPSOIL; Red brown silty CLAY, dry to moist, firm. PALEOSOL: Green-purple-red mottled silty CLAY, moist, very stiff. • -vv . S Total depth 9' No Water No Caving JOB NO.: SD1162-00 LOG OF TEST PIT FIGURE: B-36 SAN DIEGO SOILS ENGINEERING. INC. DATE OBSERVED: 4-29--82 METHOD OF DRILLING: 24" Backhoe LOGGED BY: KS .GROUND ELEVATION: I nr.ATION: See Map EET) ATION •OCT 1 UNDISTURBED SAMPLE j WPLE uj£ DRY [PCF) TEST PIT NO. 29 LL. I 1- a UJ o -0-CLASSIFIC BLOWS/F 1 UNDISTURBED SAMPLE j BULK SAI MOISTU CONTEN1 IN PLACE DENSITY I DESCRIPTION SOIL TEST TOPSOIL: Brown CLAY, moist, firm. •6- -BEDROCK: Point Loma Formation; Green-grey clayey SILTSTONE, moist, stiff, fractured, caliche \in upper 3 feet fractures. BEDROCK: Point Loma Formation; Green-grey clayey SILTSTONE, moist, stiff, fractured, caliche \in upper 3 feet fractures. 10H Total Depth 6' ^ .. No Water No Caving' 15- 20-• > -••tfji.. 25r- y •.>•"•'"• . " • " , ' • • • 30-<•'• / • •• 35T TV-. . . J f ,1-' ' ' ' ' ' • '• 40- -% . • • . ••• . ' ' • . '• ' • ' JOB NO.: SD1162-00| LOG OF TEST PIT jFIGURE: B-37 SAN DIEGO SOILS ENGINEERING. INC DATE OBSERVED:. 4-29-82 METHOD OF DRILLING:. 24" Backhoe LOGGED BY:. KS .GROUND ELEVATION:. LOCATION; See Map p UJ lU a UJ o -0- z O u CO CO' < o o UL CO o o UJ CDuj OC_l 3a 2^ oco z 3 UJ _l a S < CO 3 O uj£ Is COjU so u Oa *"Z <t tt SS TEST PIT NO. 30 DESCRIPTION SOIL TEST 6- 10- 16- 20- 26- 30- 36- 40- s TOPSOIL: Light brown silty SAND, Dry to moist, loose. BEDROCK; Santiago Peak Volcanics Green Metavolcanic, weathered, ^ard with fractures. ' Total Depth 6'; Near Refusal• No Water No Caving JOB NO.: SD1162-00 LOG OF TEST PIT FIGURE: B-38 SAN DIEGO SOILS ENGINEERING. INC DATE OBSERVED:. 4-29-82 METHOD OF DRILLING: 24" Backhoe LOGGED BY:. KS .GROUND ELEVATION: LOCATION:. See Map Ul UJ u. a UJ o -0- z. o o.. a (0 < _i u O o UL 0) O o UJ (Qui CC_J 3a 2i oco z 3 Ul|S Is «U1 2^ so u Qa •"I it tt SS TEST PIT NO. 31 DESCRIPTION SOIL TEST 6- 10- 16- 20- 26- 30- 35 40 TOPSOIL: Brown SAND, dry, loose BEDROCK: Santiago Peak Volcanic Brown-green Metavolcanic, very hard, fractured. Total Depth 3' Refusal No Water No Caving ' , JOB NO.: SD1162-00 LOG OF TEST PIT FIGURE: B-3 9 SAN DIEGO SOILS ENQINEERINQ. INC. DATE OBSERVED: 6-24-82 METHOD OF DRILLING: 24" Backhoe. LOGGED BY: JFK GROUND Fi PVATION- 240' - LOCATION:__See_Map_ TO- o Ul £ui 0C_| 3a QCO z 3 Ul £ Is Oz SO u Oa ^Z it tt SS TEST PIT NO. 32 DESCRIPTION SOIL TEST ^5- 10- 16 20- 25 30- 35- 40- TOPSOIL: Light brown silty CLAY moist, soft to firm, ^u^^ r 2 • loose with roots. BEDROCK; Point Loma Formation; grey and reddish-brown clayey SILSTONE, moist, firm to stiff, weathered to 8'. @,8' Red cobble layer @:, 10' Bedding N 45'^ .^E,, 20° NW. Total Depth 13' , No Water , ii.:=7 No Caving, JOB NO.: SD1162-00 LOG OF TEST PIT FIGURE: B-4 0 SAN DIEGO SOILS ENGINEERING. INC. i f DATE OBSERVED: 6-24-82 METHOD OF DRILLING:. 24" Backhoe LOGGED BY:_JFK_GROUND Fi FVATION- 244' - LOCATION:__See_Ma£ -0« 6- 10- 15- 20r 25: 30- 36 40- o UJ CDUJ OCZJ 3a 51 oco z 3 ui£ is 5z so Oa '"Z <t tt SS TEST PIT N0._^ DESCRIPTION TOPSOIL; Reddish-brown silty CLAY, moist, soft to firm. BEDROCK: Point Loma Formation; mottled grey reddish light brown SILTSTONE, stiff to very stiff, weathered in upper 4', poorly to well bedded. @ 6' Bedding: N4° E, lO'W @ 11' Bedding: N30° E, 7° NW Total Depth 14' No Water No Caving SOIL TEST JOB NO.:so-|_3_52_00 LOG OF TEST PIT FIGURE: B-41 SAN DIEGO SOILS ENGINEERING. INC. DATE OBSERVED: 6-24-82 METHOD OF DRILLING:. 24" Backhoe LOGGED BY: JFJL—GROUND Fl FVATION- 216' - LOOATION- See Map -0- 6^ 10- 16- 20- 26- 30- 35- 40- o Ul CD Ul 3a 2l oco ui£ Is ^Ul 2z so u >u: Oa ^Z it tt SS ALLUVIUM/COLLUVIUM; Dark brown TEST PIT NO. 34 DESCRIPTION silty CLAY, moist, soft to firm. BEDROCK; Point Loma Formation; mottled red and grey SILTSTONE, slightly moist, stiff, abundant caliche. (3 6' Bedding: N30° W, 15<'NE Total Depth 10'. No Water No Caving • SOIL TEST JOB NO. SD1162-00 LOG OF TEST PIT FIGURE: B-42 SAN DIEGO SOILS ENGINEERING. INC. A DATE OBSERVED: 6-24-82 MFTHnn DF DRILLING: 24" Backhoe LOGGED BY:. JFK GROUND ELEVATION: 2 38' - LOCATION: -See Map 9 DEPTH (FEET) CLASSIFICATION BLOWS/FOOT UNDISTURBED SAMPLE BULK SAMPLE MOISTURE CONTENT (%) IN PLACE DRY DENSITY (PCF) TEST PIT NO. 35 DESCRIPTION SOIL TEST •V :• . BEDROCK: Santiago Peak Vol- canics; red-brown clayey SILT, dry, stiff to hard, weathered to 4 •. .',6-^-•i • 1 -. ' ' • Total Depth , 4' ?• No -Water , ; r''*.; No Caving 10- " •If'.".. 15- - • - 20- ;j>_. • \^ " / > •V.' • 26- . . • • -.u- ••. 30- 35- ...... .. ir • ; ' • ' • 'V • "." , 40- JOB NO. SD1162-00 LOG OF TEST PIT FIGURE: B-4 3 SAN DIEGO SOILS ENGINEERING. INC. DATE OBSERVED: 6-24-82 METHOD OF DRILLING: 24" Backhoe LOGGED BY:. JFK GROUND ELEVATION: 258' - i or.ATION- See Map 3 DEPTH (FEET) CLASSIFICATION BLOWS/FOOT UNDISTURBED SAMPLE BULK SAMPLE MOISTURE CONTENT (%) IN PLACE DRY DENSITY (PCF) TEST PIT NO. 36 DESCRIPTION SOIL TEST BEDROCK: Santiago Peak Vol- canics; yellow-brown metavolcan- ics, hard. 6- •••Total Depth' V.<Crl:ri\ /Refusal at-'3'•••;•/ '-.H^;'• /'• . .No Water • -•. No Caving • v;, . -:: :... • ••• . v.' 10- • J. - > 15--• : •:-:'-\ ' ''^^At.;. ?-^/"/^^5-,;' /•••• 20- • - 26-• ,.t..'>"' 30- ^ r-i : •* / ."'^ f 36- 40-. . - • . • ' / ,_ '-A' - JOB NO„- - f . • , • . SD1162-00| LOG OF TEST PIT [FIGURE: B-44 SAN DIEGO SOILS ENGINEERING. INC [p^Tr nnqFnvFP^ 6-24-82 METHOD OF DRILLING: 24" Backhoe LOGGED BY - JFK GROUND ELEVATION:_212_;_j_ LOCATION: See Map UJ UJ b. Z O u Z S: a Ul Q u. (0 (0 < o o u. (0 o O UJ 3a < *-S (0 2< 5d QCO Ii Z 3 3 I a UJS Oz SO u Oa tt SS TEST PIT NO. 37 DESCRIPTION SOIL TEST BEDROCK: Santiago Peak Vol- canics; mottled green, red and brown metavolcanics, moderately hard, weathered to 8' . . ,, . 10-Total Depth 8' No Water /ii No Caving, '' 16- 20- 25- ' 130- . I 36- 40- JOB NO.:sDii62-00 LOG OF TEST PIT I FIGURE: B-4 5 SAN DIEGO SOILS ENQINEERINQ. INC. I DATE OBSERVED: 2 4 - 8 2 METHOD OF DRILLING: 24" Backhoe. LOGGED BY: JFK GROUND ELEVATION: 254' - LOCATION:—S^a-JlaB- UJ Ul a. UJ o UJ £ui a:_j 3a >-S 2< oco Uj£ H' Z CO|U Oz so u >-u: Qa <t tt SS TEST PIT NO. 38 DESCRIPTION SOIL TEST •5- 10 15 20- ^ . |26 I'SO' '35 40- TOPSOIL: Reddish-brown silty CLAY, moist, soft. BEDROCK: Point Loma Formation; mottled grey SILTSTONE, stiff, weathered in upper 5' . ;. ' Total Depth 10' No Water No Caving - JOB NOJ SD1162-00 LOG OF TEST PIT FIGURE: B-46 SAN DIEQO SOILS ENGINEERING. INC. APPENDIX C LABORATORY TESTING A. Index Tests Moisture content and dry density determinations were made for most ring samples. Results of moisture-density de- . V terminations are shown on tHe Logs of Borings, included in Appendix B of this,report. . Results of Hydrometer Tests and Sieve Analyses performed in accordance with ASTM: D 422-72, on portions of representative , samples are presented in Figures C-l through C-9. Results of Atterberg Limits, consisting of both liquid limit and plastic limit analyses are plotted on the Plas- •ticity Chart in Figure C-10. Atterberg Limits were performed in accordance with ASTM: D 423-72. The test results are also recorded on the grain size curves. B. . .Consolidation Tests • Consolidation tests were performed on remolded siltstone i. . (Figures C-11 and C-12) , and topsoil (Figure C-13) . Water was added to the apparatus at the load indicated on the consolidation curves. The consolidation test results are presented on Figures,C-11 through C-13. C. ' Direct Shear Tests ' > Direct shear strength tests were performed on remolded and selected ring samples. -Test results for remolded silt- stone, topsoil, intact siltstone, and remolded sandstone (proposed import source) are presented in Figures C-14, C-15, C-16 and C-17 respectively. All samples were inundated . . and allowed to come to equilibrium prior to shearing with . , , the exception of the topsoil. For the topsoil, approximate unconsolidated-undrained (^f=0 analysis) direct shear tests \ were performed. • • . / D. Expansion ; . , Expansion tests were performed on representative samples of the on-site soils remolded and tested under a surcharge , . of 144 pounds per square foot in accordance with the Uni- , form Building Code Standard No.'29-2. The test results are summarized on Table 1, Figure 0-18.' E. Maximum Density/Optimum Moisture Content The maximum dry density/optimum moisture content rela- tionship was determined for typical samples of the on-site soils. The laboratory standard used was ASTM: D 1557-78. The test results are summarized on Table.2, Figure C-18. Sulfate Tests. Sulfate test results are summarized in Table 3, Figure C-19 c O o D CTl N) I O o CO o m o O CO O F CO m z o z m m 3 z p z o > 33 H O r-m w N m > z > r- -< CO CO c in n I - GRAVEL SAND . SILT CLAY - GRAVEL COARSE MEDIUM FINE . SILT CLAY SIEVE SIZES-U.S. STANDARD m o m z H •o > CO (0 z o 10.0 1.0 0.1 PARTICLE SIZE-MILLIMETERS 01 /4" 1/ 2" IA 20 4 0 1( 0 2 DO - i -s IE VE \ . .. \ -HYDRO ET E: >' 100 90 80 70 •0 60 2 3 O m z 60 > CO CO 40 z O 30 20 10 0 .001 BORING NO. DEPTH (FEET) SYMBOL LIQUID LIMIT PLASTICITY INDEX CLASSIFICATION V 2S o A CL •»•-- "... ,- !-r'' 'f-i^ O a z o I o o > H O r-m w N m > z > r-•< w 03 •n 5 c 3 m GRAVEL SAND ;-• / /^r'-S'LT . -v^// ''••'// CLAY GRAVEL COARSE MEDIUM FINE ;-• / /^r'-S'LT . -v^// ''••'// CLAY ^SIEVE SIZES-U.S. STANDARD 100 90 80 70 m 60 3 O m z > CO CO 60 40 30 20 10 10.0 1.0 0.1 PARTICLE SIZE-MILLIMETERS .01 n I - ii,-*— ^\ -HY DROMET: : f « J 1 • f f 100 90 80 70 •0 60 2 3 o m z 60 •* •o •> CO CO 40 z O 30 20 10 .001 BORING NO. DEPTH (FEET) SYMBOL LIQUID LIMIT PLASTICITY INDEX CLASSIFICATION 2 10 OA 38 23 CL O CD Z p D I o o > JD H O r-m CO N m > z > r- < CO D c 3 m n I GRAVEL ' SAND .; •/r'^V-r?^3iLT . -CLAY GRAVEL COARSE 1 MEDIUM FINE SIEVE SIZES-U.S. STANDARD 100 90 80 70 m 60 3 O m z > 2 z o 50 40 30 20 10 1 » 1 rr r [2^ .V • ^ t ' J - ' Yr , — 10.0 1.0 0.1 PARTICLE SIZE-MILLIMETERS .01 100 90 80 70 •0 60 nj 3 O m z 60 > CO CO 40 z a 30 20 10 0 .001 BORING NO. DEPTH (FEET) SYMBOL LIQUID LIMIT PLASTICITY INDEX CLASSIFICATION 2 40 OA 46 30 CL o B Z O D cn o o > JO H O 1- m CO N m > z > r- < CO CO •n O c 3 rn ORAVEL SAND 8ILT CLAY ORAVEL COARSE MEDIUM FINE 8ILT CLAY SIEVE SIZES-U.S. STANDARD 100 90 80 70 m 60 3 o m > CO (0 60 40 30 20 10 10.0 —i CEl :3 ^' h e -HYDRO A ET 100 90 80 70 60 m 3 O m z 60 •0 > CO CO 40 Z O 30 20 10 1.0 0.1 PARTICLE SIZE-MILLIMETERS .01 .001 O I BORING NO. DEPTH (FEET) SYMBOL LIQUID LIMIT PLASTICITY INDEX CLASSIFICATION 3 3 Q A --CH o a O I. o cn I o o •D > JD H O 1— m w N m > < CO 03 o c 3 m n I GRAVEL SAND SILT CLAY GRAVEL COARSE MEDIUM FINE SILT 3/4" 1/2' 100 00 80 70 •0 m 60 3' O m z 60 "0 > CO CO z 40 O 30 20 10 10 20 SIEVE SIZES-U.S. STANDARD 40 100 200 SI 4^. 10.0 1.0 0.1 PARTICLE SIZE-MILLIMETERS .01 100 90 80 10 0 .001 BORING NO. DEPTH (FEET) SYMBOL LIQUID LIMIT PLASTICITY INDEX CLASSIFICATION 6 6 A 40 28 CL O ta z O (A-D cn NJ I o o •D > JD H O I—, m CO N m > z > r--< CO CO o c X m n I cn GRAVEL SAND SILT CLAY GRAVEL COARSE 1 MEDIUM 1 FINE SILT 3/4" 1/2" 100 1/4" 4 10 90 80 70 -a cn 60 3 O m z > CO tn z a 50 40 30 20 10 20 SIEVE SIZES-U.S. STANDARD 40 100 200 10.0 1.0 0.1 PARTICLE SIZE-MILLIMETERS .01 r—7-A J IE VI ^: •HYDROI 1 ?I • v s k > 100 90 80 70 60 2 3 o 60 > CO CO 40 30 20 10 .001 BORING NO. DEPTH (FEET) SYMBOL LIQUID LIMIT PLASTICITY INDEX CLASSIFICATION T-4 1 O A 53 39 CH <_ O CB z o cn a M cn I o o T3 > JD H O r-m CO N m > z. > I- -< CO CO o c 3 m n I GRAVEL SAND 8ILT CLAY 1 GRAVEL COARSE 1 MEDIUM FINE 8ILT 3/4" 1/2" 100 1/4- 4 90 80 70 •n m 60 3 O m z -* 60 > CO CO z 40 O 30 20 10 SIEVE SIZES-U.S. STANDARD 40 100 200 10.0 1.0 0.1 PARTICLE SIZE-MILLIMETERS .01 100 90 80 30 20 10 0 .001 BORING NO. DEPTH (FEET) SYMBOL LIQUID LIMIT PLASTICITY INDEX CLASSIFICATION T-8 2 O A --CH ORAVEL BAND SILT CLAY ORAVEL COARSE 1 MEDIUM FINE SILT 3/4" 1/2" 100 V4" 4 1P 20 SIEVE SIZES-U.S. STANDARD 40 100 200 100 90 80 70 60 nj 3 O m z 60 . > CO CO 40 Z 0 00 80 70 60 60 40 30 20 10 7 m 3 o m z H -0 > CO CO ~z o •HYDRPMP ?I:R 20 10 O .001 10.0 1.0 0.1 PARTICLE SIZE-MILLIMETERS .01 BORINQ NO. DEPTH (FEET) SYMBOL LIQUID LIMIT PLASTICITY INDEX CLASSIFICATION T-17 2 o A --CL cn O tn NJ I o o "0 > JD H O r-m CO N m > CO CO o c 3 m n 1 VD ORAVEL BAND SILT CLAY ORAVEL COARSE 1 MEDIUM 1 FINE SILT SIEVE 8fZE8-U.8. STANDARD m .3 O m z 00 80 70 80 50 CB OB z o 40 30 20 10 • 1 —7 fl 1 1 \ \ I, / V \ 1 \ \ \ •I A i 100 80 80 70 •0 60 m 3 O m 60 > CO CO 40 30 20 10 K).0 1.0 0.1 PARTICLE 8IZE-MiLLIMETER8 .01 .0O1 BORINQ NO. DEPTH (FEET) SYMBOL LIQUID LIMIT PLASTICITY INDEX CLASSIFICATION --A --REMOLDED SILTY SANDSTONE (SM) PROPOSED IMPORT SOURCE PLASTICITY CHART X m a z o p CO < 80 50 40 30 20 X) > 4 0 CH CL A O d 7 MH or-• OH CL-ML_ ML ML or OL 1 10 20 30 40 50 80 LIQUID LIMIT (%) 70 80 90 100 SYMBOL BORINQ NO-- SAMPLE DEPTH A (feet) NATURAL WATER ICONTENT] % LIQUID LIMIT PLAS- TICITY INDEX % . PASSING NO.: 200 SIEVE % LIQUIDITY INDEX % UNIFIED SOIL CUSSIF-ICATION SYMBOL O 10 21 38 23 78 26 CL A 40 18 46 30 92 CL V 10 40 28 63 CL T-4 53 39 92 CH Job No:. SD1162-00 Date: July, 1982 Figure: C-10 SAN DIEGO SOILS ENGINEERING. INC. o o o o o o o o W CO * IO o o o o o o M o o o CO o o o o o o o o o o o o o o o o o o o o o o o o IO o o o o o o CM CO IO o NORMAL LOAD (PSF) JOB NO.: SD1162-00 LOAD CONSOLIDATION TEST FIGURE: C-11 SAN DIEQO SOILS ENGINEERING. INC z O CO z <. & X 111 < o IJ O CO z o o 3 3-0 2.0 1.0 1.0 2.0 3.0 4.0 Z o 5.0 6.0 7.0 8.0 8.0 10.0 BORING NO. DEPTH (FEET) 40 SYMBOL £1 EXPLANATION FIELD MOISTURE SAMPLE SATURATED REBOUND HR. o o CM O o CO o o o o * IO o o o o o o CM o o o CO o o o o o o * IO o o o o o o o o o o o o o o o o o o o o CM CO IO o o o o o NORMAL LOAD (PSF) JOB NO.: SD1162-00 LOAD CONSOLIDATION TEST FIGURE: C-12 SAN DIEGO SOILS ENGINEERING. INC. Z.: O W Z'' X III 4.0 1^ Z o o IJ o CO z o o 3.0 2.0 1.0 1.0 2.0 3.0 5.0 6.0 7.0 8.0 9.0 10.0 BORING NO. S T-4 DEPTH (FEET) 1 ^ SYMBOL O EXPLANATION ^>^AfrE^ o o CM o o o O: O O O. « IO o o o o o o CM FIELD MOISTURE SAMPLE SATURATED REBOUND o o o CO NORMAL LOAD (PSF) o o o o o o o o o o o o o o o o o o o . o o o o o lO o o o o o o CM CO IO o JOB NO.: SD1162-00 LOAD CONSOLIDATION TEST FIGURE: C-13 SAN DIEGO SOILS ENGINEERING. INC 3000 1000 2000 Normal Stress (psf) 3000 4000 JOB NO.: SD1162-00 . July, 1982 : 3000 BORINQ DEPTH COHESION. ANGLE OF SAMPLE DESCRIPTION 3000 NO. (FEET) CPSF) FRICTION.® i .-• T-d'*^ • 2_ 700 4 REMOLDED TOPSOIL 2000 (0 to tn 0) u +j cn u tts <u • w 1000 nj ft ^ • ... • ^Z '' • h 'S '" i • • fl'"-. .. .-- .. . .. ••-•^^ •• .. •. ^ i-S"-.... • . • .. - . • - • •-. • • NOTE: )2f=o ANALYSIS -• 1000 2000 Normal Stress (psf) 3000 4000 JOB NO.: SD1162-00 July, 1982 FIGURiE: ^ , _ C-15 SAN DIEGO SOILS ENGINEERING. INC. , 3000 2000 •4-1 ta 04 tn tn ; 0) - w 1000 «J •• • BORINQ NO. DEPTH (FEET) COHESION. (PSF) ANGLE OF FRICTION.® SAMPLE DESCRIPTION BORINQ NO. DEPTH (FEET) COHESION. (PSF) ANGLE OF FRICTION.® INTACT SILTSTONE • ' • . .f • .; 20 400 27 INTACT SILTSTONE • ' • . .f • .; -. i'-V,^;- " ••""TH; r.*.. - . .f • .; I. •/;••*:"•'•• • . .- . ( ) • "' /- • ... y-'-'-'. 1000 2000 Normal Stress (psf) 3000 4000 JOB NO.: SD1162-00 July, 1982 FIGURE: SAN DIEGO SOILS ENGINEERING. INC. 3000 2000 tn OJ w to 0) w 10^0 m Q) CU BORINQ NO. DEPTH (FEET) COHESION. (PSF) ANGLE OF FRICTION.* SAMPLE DESCRIPTION REMOLDED SILTY" STANDSTONE(£ ... •rur.. .•'•-'^^•^^ 200 32 PROPOSED IMPORT £ SOURCE ... •rur.. .•'•-'^^•^^ • -.' ,: A. . . . ji- ... •rur.. .•'•-'^^•^^ -" • f • >^ . — ' ... "-^e. / • fi • • Normal Stress (psf) JOB NO.: SD1162-00 DATE: July. 1982 FIGURE: C-17 SAN DIEGO SOILS ENGINEERING. INC TABLE 1 - RESULTS OF EXPANSION TESTS (U.B.C. Standard 29-2) h '9 Test Location Expansion Index Potential Expansion B-2 at 10' 83 Medium - High B-:2 at 40' 63 Medium T-4 at 1' 142 Very High /^|/;f/; • /^/- ; /?//U?.^'^ :'.'.'^ff.': ... • . .. -. • ' . - • • ,, " - . • . TABLE 2 : "•' ft-.• , ' . MAXIMUM DENSITY/OPTIMUM MOISTURE TESTS (A.S.T.M. Test Procedure D 1557-78) Test Location Maximum Dry Density (pcf) Optimum Moisture Content (%) B-2 at 10' 108 17 B-2 at 40' 21 B-6 at 6' T-4 at 1' : /• • :109 V 14' / job;No: SD1162-00 Date: July, 1982 Figure; C-18 .... i tr TABLE 3 RESULTS OF SULFATE TESTS Test Location % Soluble Sulfate B-2 at 10' 0.0160 B-2 at 40' 0.0189 T-4 at 1' 0.0152 / J- V 7^ 14 • T, . Job No: SD1162-00 Date: July,. 1982 . Figure: C-19 APPENDIX D STABILITY ANALYSIS •11. .Appendix D summarizes results of stability.analysis, Gross stability computations for compacted slopes were performed using Janbu's stability charts with the shear strength parameters for remolded siltstone presented in Figure C-13. Gross stability .analysis are presented in Figures D-1 and D-2. ;. Surficial stability analysis were performed assuming an infinite - slope with seepage parallel to the slope face. To determine the shear strength for surficial stability analysis, drained Direct V Shear tests were performed on remolded siltstone samples at low normal loads (75-150 psf) and the samples were permitted to swell . "jprior to shearing. . Shearing of samples provided at a strain rate of on the order of 0.005 inches per minute. The surficial stability analysis for three feet of seepage is presented in Figure D-3 and ;; the factor of safety versus depth of seepage is presented in Figure D-4. . • ' / 10 15 20 25 * 30 SLOPE x (DEGREES) 35 40 A5 SLOPE DATA;'' Slope Height (H) Slope Ratio («x) 50 feet Friction Angle (0) 24 degrees 26 degrees Cohesion (C) 400 Unit Weight (Jf) 120 _psf pcf FACTOR OF SAFETY (F.S.); ^ yjijifl^ = 6.7 Nr = 27 from chart F. S. • = Nr C 1.80 GROSS STABILITY ANALYSIS (JANBU'S CHART) JOB NO.: DATE: FIGURE: • SD1162-00 July, 1982 D-1 SAN DIEGO SOILS ENGINEERING INC. SLOPE « (DEGREES) SLOPE DATA; Slope Height (H) Slope Ratio (<»<) 100 feet Friction Angle (0) 24 22 degrees Cohesion (C) 400 Unit Weight (J) 120 _degrees psf pcf • FACTOR OF SAFETY-(F.S.); y Htan0:J 13.4 49 from chart F.S. = N, If H 1.63 GROSS STABILITY ANALYSIS (JANBU'S CHART) JOB NO.: SD1162-00 DATE: July, 1982 FIGURE: D-2 SAN DIEGO SOILS ENGINEERING. INC. 50 100 NORMAL STRESS SURFICAL STABILITY DATA: . Slope Ratio («»0 22 120 Total Unit Weight ()^t) Bouyant Unit Weight 57.6 150 (N) psf _degrees pcf 200 250 'Depth of Seepage Flow (D) FACTOR OF SAFETY (F.S.) 3.0 _pcf feet N = >^ D COS = 149 S = 158 from above chart F.S. = COS c>f sxn oC " . •. - J' 1.27 SURFICAL STABILITY ANALYSIS JOB NO.: DATE: FIGURE: SD1162-00 July, 1982 D-3 SAN DIEGO SOILS ENGINEERING. INC. I 1 I I I I I I I I 2.5 • >^ E-i W CO b O PiJ O E-i O < 2.0 1.5 1.0 0.5 ^: -..2 ., , -^3 . DEPTH OF SEEPAGE (feet) SURFICIAL STABILITY DATA: Slope Ratio ^) 21.8 Total Unit Weight ( Yr ) Soil Type REMOLDED SILTSTONE 120 degrees pcf FACTOR OF SAFETY (F.S.): 2.30 F.S. :=' FiS. = F.S.", = F.S. = 1.60 1.27 1.13 (D (D ,1 foot) 2 feet) 3 feet) 4 feet) SURFICIAL STABILITY ANALYSIS: SUMI4ARY JOB NO.: SD1162-00 DATE: July, 1982 FIGURE: D-4 1 t ' r ^'X'i'.'- APPENDIX E . • . , / STANDARD GUIDELINES FOR GRADING PROJECTS 'J-- ' Sc/'^;.^ : TABLE OF CONTENTS /. . , ' ' ' '•:'-•••[:''. ' . Page 1. ' GENERAL . .• y •/.•.Vo:'//.;:. .. j. ^ . : .. ' .: 1 2. DEFINITION OF TERMS ... . ./.• . . / . . . . . . . 1 ' \ / 3. ' OBLIGATIONS. OF PARTIES. . ........ . . 5 \' , 4; -SITE PREPARATION ^ 5 5. \ SITE PROTECTION '^/. - .X v;^ ^/'^^ V; . .. 6 6, EXCAVATIONS-- . . V :.' .. v. ' .V:.-. / ; ./.. , .;: '„' . . \- 8 . ! -6.1 UNSUITABLE MATERIALS. 8 ' ^ '6-2 cuT.vSLOPEs..;i/:;^^ r~ ' 6.3 PAD;AREAS-..: /,...,... . .'...'9. .7. COMPACTED FILL. . . . ... . . . .• . . . ., . . 9 7.1 PLACEMENT : . \ iQ ' . 7.^2 ' MOISTURE . . 11 7. 3 " X FILL MATERIAL \ . ... .12 7.4 FILL SLOPES .' 7. 7^^^^^ 7.5 OFF-SITE FILL \ . i. .16 - /8. ' DRAINAGE.. / . .16 ^ - \ 9. ' STAKING .; . ./ . . . . • . . ... . . / . 17 10. ^SLOPE MAINTENANCE ... . . /. . . . . ./. ,.. . . . . .17 ' " ; 10.1 A LANDSCAPE PLANTS . . . . . / . . . i. . . . 17 , ''I ^' - ' <• 10.2 IRRIGATION. ....... . . . . 17 ' ' ' ,10.3 MAINTENANCE . . ....... . . .18 ///^ , '10-4 REPAIRS .; . . .18 11. TRENCH BACKFILL . . . ........ ..... . . 19 ' 12.^ STATUS vOF- GRADING . . . .. . . . .20 ^"^'t/h'^'l «, * " . ' ./'.•.• STANDARD GUIDELINES FOR GRADING PROJECTS . 1. GENERAL 1.1 1.2 1.3 1;4 1.5 The guidelines contained herein and the standard details attached hereto represent this firm's stan- dard recommendations for grading and other associated operations on construction projects. These guide- lines should be considered a portion of the project specifications. All plates attached hereto shall be considered as part of these guidelines. The Contractor should not vary from these guidelines without prior recommendation by the Geotechnical Con- sultant and the approval of the Client or his auth- orized representative. Recommendation by the Geo- technical Consultant and/or Client should not be considered to preclude requirements for approval by the controlling agency prior to the execution of any changes. These Standard Grading Guidelines and Standard De- tails may be modified and/or superseded by recommen- dations contained in the text of the preliminary geotechnical report and/or subsequent reports. If disputes arise out of the interpretation of these grading guidelines or standard details, the Geotech- nical Consultant shall provide the governing inter- pretation. DEFINITIONS OF TERMS 2.1 ALLUVIUM - unconsolidated detrital deposits resulting from flow of water, including sediments deposited in river beds, canyons, flood plains, lakes, fans at the foot of slopes and estuaries. 2.2 AS-GRADED (AS-BUILT) - the surface and subsurface con- ditions at completion of grading. 2.3 BACKCUT - a temporary construction slope at the rear of"earth retaining structures such as buttresses, shear keys, stabilization fills Or retaining walls. 2.4 BACKDRAIN - generally a pipe and gravel or similar drainage system placed behind earth retaining struc- tures such as buttresses, stabilization fills and retaining walls. Page Two 2.5 BEDROCK - a more or less solid, relatively undis- turbed rock in place either at the surface or be- neath superficial deposits of soil. 2.6 BENCH - a relatively level step and near vertical rise excavated into sloping ground on which fill is to be placed. 2.7 BORROW (Import) - any fill material hauled to the project site from off-site areas. 2.8 BUTTRESS FILL - a fill mass, the configuration of which is designed by engineering calculations to retain slope conditions containing adverse geologic features. A buttress is generally specified by min- imum key width and depth and by maximum backcut angle. A buttress normally contains a backdrainage system. 2.9 CIVIL ENGINEER - the Registered Civil Engineer or consulting firm responsible for preparation of the grading plans, surveying and verifying as-graded topographic conditions. ,2.10 CLIENT - the Developer or his authorized representa- tive who is chiefly in charge of the project. He shall have the responsibility of reviewing the find- ings and recommendations made by the Geotechnical Consultant and shall authorize the Contractor and/or other consultants to perform work and/or provide services. 2.11 COLLUVIUM - generally loose deposits usually found near the base of slopes and brought there chiefly by gravity through slow continuous downhill creep (also see Slope Wash). 2.12 COMPACTION - is the densification of a fill by mech- anical means. 2.13 CONTRACTOR - a person or company under contract or otherwise retained by the Client to perform demoli- tion, grading and other site improvements. 2.14 DEBRIS - all products of clearing, grubbing, demoli- tion, contaminated soil material unsuitable for reuse as compacted fill and/or any other material so desig- nated by the Geotechnical Consultant. 2.15 ENGINEERING GEOLOGIST - a Geologist holding a valid certificate of registration in the specialty of Engineering Geology. , Page Three 2.16 ENGINEERED FILL - a fill of which the Geotechnical Consultant or his representative, during grading, has made sufficient tests to enable him to conclude that the fill has been placed in substantial com- pliance with the recommendations of the Geotechnical Consultant and the governing agency requirements. '2.17 EROSION - the wearing away of the ground surface as a result of the movement of wind, water and/or ice. 2.18 EXCAVATION - the mechanical removal of earth materials. 2.19 . EXISTING GRADE - the ground surface configuration prior to grading. 2.20 FILL - any deposits of soil, rock, soil-rock blends or other similar materials placed by man. 2.21 FINISH GRADE - the ground surface configuration at which time the surface elevations conform to the approved plan. 2.22 GEOFABRIC - any engineering textile utilized in geo- technical applications including subgrade stabiliza- tion and filtering. 2.23 GEOLOGIST - a representative of the Geotechnical Con- sultant educated and trained in the field of geology. .2.24 GEOTECHIillCAL CONSULTANT - the Geotechnical Engineering and Engineering Geology consulting firm retained to provide technical services for the project. For the purpose of these specifications, observations by the Geotechnical Consultant include observations by the Soil Engineer, Geotechnical Engineer, Engineering Geologist and those performed by persons employed by and responsible to the Geotechnical Consultants. 2.25 GEOTECHNICAL ENGINEER - a licensed Civil Engineer who applies scientific methods, engineering principles and professional experience to the acquisition, interpre- tation and use of knowledge of materials of the earth's crust for the evaluation of engineering problems. Geo- technical Engineering encompasses many of the engi- neering aspects of soil mechanics, rock mechanics, geology, geophysics, hydrology and related sciences. 2.26 GRADING - any operation consisting of excavation, ' fill ing or combinations thereof and associated opera- tions. 2.27 LANDSLIDE DEBRIS - material, generally porous and of low density, produced from instability of natural or man-made slopes. 2.28 MAXIMUM DENSITY - standard laboratory test for maximum dry unit weight. Unless otherwise specified, the I maximum dry unit weight shall be detennined in accor- dance with ASTM Method of Test D 1557-78. Page Four 2.29 OPTIMUM MOISTURE - test moisture content at the maximum density. 2.30 RELATIVE COMPACTION - the degree of compaction (expressed as a percentage) of dry unit weight of a material as compared to the maximum dry unit weight of the material. 2.31. ROUGH GRADE - the ground surface configuration at which time the'.surface elevations approximately conform to the approved plan. ' 2.32 SITE - the particular parcel of land where grading is being performed. 2.33 SHEAR KEY - similar to buttress, however, it is gen- erally constructed by excavating a slot within a natural slope in order to stabilize the upper por- tion of the slope without grading encroaching into ; the lower portion, of the slope. 2.34 SLOPE - is an inclined ground surface the steepness of which is generally specified as a ratio of hori- zontal: vertical (e.g.,2:l). 2.35 SLOPE WASH - soil and/or rock material that has been transported down a slope by mass wasting assisted by runoff water not confined by channels (also see Colluvium). 2.36 SOIL - naturally occurring deposits of sand, silt, clay, etc. or combinations thereof. 2.37 SOIL ENGINEER - licensed Civil Engineer experienced in soil mechanics (also see Geotechnical Engineer). 2.38 STABILIZATION FILL - a fill mass, the configuration of which is typically related to slope height and is specified by the standards of practice for enhancing the stability of locally adverse conditions. A sta- bilization fill is normally specified by minimum key width and depth and by maximum backcut angle. A stabilization fill may or may not have a backdrainage system specified. ' - 2.39 , SUBDRAIN - generally a pipe and gravel or similar drainage system placed beneath a fill in the align- ment of canyons or former drainage channels. 2.40 SLOUGH - loose, noncompacted fill material generated during grading operations. 2.. 41 TAILINGS - nonengineered fill which accumulates on or adjacent to equipment haul-roads. 2.42 TERRACE - relatively level step constructed in the face of a graded slope surface for drainage control and maintenance purposes. Page Five 2.43 TOPSOIL - the presumably fertile upper zone of soil which is usually darker in color and loose. 2.4 4 WINDROW - a string of large rock buried within en- gineered fill in accordance with guidelines set forth by the Geotechnical Consultant. 3. . OBLIGATIONS OF PARTIES 7^ 3.1 The Geotechnical Consultant should provide observa- / , tion and testing services and should make evalua- • tions in order to advise the Client on geotechnical matters. The Geotechnical Consultant should report ../r his findings and recommendations to the Client or his authorized representative. ,3.2 The Client should be chiefly responsible for all aspects of the project. He or his authorized rep- resentative has the responsibility of reviewing the findings and retommendations of the Geotechnical Consultant. He shall authorize or cause to have authorized the Contractor and/or other consultants to perform work and/or provide services. During grading the Client or his authorized representative should remain on-site or should remain reasonably accessible to all concerned parties in order to make decisions necessary to maintain the flow of the project. I 3.3 The Contractor should be responsible for the safety of the project and satisfactory completion of all grading and other associated operations on construc- tion projects, including, but not limited to, earth work in accordance with the project plans, specifi- cations and controlling agency requirements. During .V grading^ the Contractor or his authorized represen- tative should remain on-site. Overnight and on days off, the Contractor should remain accessible. 4. • SITE PREPARATION 4.1 The Client, prior to any site preparation or grading, should arrange and attend a meeting among the Grading Contractor, the Design Engineer, the Geotechnical Con- sultant, representatives of the appropriate governing I authorities as well as any other concerned parties. All parties should be given at least 48 hours notice. 4.2 Clearing and grubbing should consist of the removal of vegetation such as brush, grass, woods, stumps, trees, roots of trees and otherwise deleterious natural mater- ials from the areas to be graded. Clearing and grub- bing should extend to the outside of all proposed excavation and fill areas. Page Six 4.3 Demolition should include removal of buildings, structures, foundations, reservoirs, utilities (in- eluding underground pipelines, septic tanks, leach fields, seepage pits, cisterns, mining shafts, tun- nels, etc.) and other man-made surface and sub- surface improvements from the areas to be graded. Demolition of utilities should include proper cap- ping and/or rerouting pipelines at the project per- imeter ana cutoff and capping of wells in accordance with the requirements of the governing authorities and the recommendations of the Geotechnical Consul- tant at the time of demolition. 4.4 Trees, plants or man-made improvements not planned to be removed or demolished should be protected by the Contractor from damage or injury. 4.5 Debris generated during clearing, grubbing and/or demolition operations should be wasted from areas to be graded and disposed off-site. Clearing, grub- bing and demolition operations should be performed under the observation of the Geotechnical Consultant. 4.6 The Client or Contractor should obtain the required approvals from the controlling authorities for the project prior, during and/or after demolition, site preparation and removals, etc. The appropriate ap- provals should be obtained prior to proceeding with grading operations. SITE PROTECTION 5.1 Protection of the site during the period of grading should be the responsibility of the Contractor. Un- less other provisions are made in writing and agreed upon among the concerned parties, completion of a portion of the project should not be considered to preclude that portion or adjacent areas from the requirements for site protection until such time as the entire project is complete as identified by the Geotechnical Consultant, the Client and the regu- lating agencies. 5.2 The Contractor should be responsible for the stability of all temporary excavations. Recommendations by the Geotechnical Consultant pertaining to temporary exca- vations (e.g., backcuts) are made in consideration of stability of the completed project and, therefore, should not be considered to preclude the responsi- bilities of the Contractor. Recommendations by the Geotechnical Consultant should not be considered to preclude more restrictive requirements by the regu- lating agencies. Page Seven 5.3 Precautions should be taken during the performance of site clearing, excavations and grading to protect the work site from flooding, ponding or inundation by poor or improper surface drainage. Temporary provi- sions should be made during the rainy season to ade- . quately direct surface drainage away from and off the work site. Where low areas cannot be avoided, pumps should be ^f^pt on hand to continually remove water during periods of rainfall. 5.4 During periods of rainfall, plastic sheeting should be kept reasonably accessible to prevent unprotected slopes from becoming saturated. Where necessary dur- ing periods of rainfall, the Contractor should install checkdams, desilting basins, rip-rap, sand bags or other devices or methods necessary to control erosion and provide safe conditions. 5.5 During periods of rainfall, the Geotechnical Consultant should be kept informed by the Contractor as to the nature of remedial or preventative work being performed (e.g., pumping, placement of sandbags or plastic sheet- ing, other labor, dozing, etc.). 5.6 Following periods of rainfall, the Contractor should contact the Geotechnical Consultant and arrange a walk- over of the site in order to visually assess rain re- lated damage. The Geotechnical Consultant may also recommerid excavations and testing in order to aid in his assessments. At the request of the Geotechnical Consultant, the Contractor shall make excavations in order to evaluate the extent of rain related-damage. 5.7 Rain-related damage should be considered to include, but may not be limited to, erosion, silting, saturation, swelling, structural distress and other adverse condi- tions identified by the Geotechnical Consultant. Soil adversely affected should be classified as Unsuitable Materials and should be subject to overexcavation and replacement with compacted fill or other remedial grad- ing as recommended by the Geotechnical Consultant. 5.8 Relatively level areas, where saturated soils and/or erosion gullies exist to depths of greater than 1.0 foot, should be overexcavated to unaffected, compe- tent material. Where less than 1.0 foot in depth, un- suitable materials may be processed in-place to achieve near-optimum moisture conditions, then thoroughly re- compacted in accordance with the applicable specifica- tions. If the desired results are not achieved, the affected materials should be overexcavated, then re- placed in accordance with the applicable specifications. ' I.J . Page Eight 5.9 In slope areas, where saturated soil and/or erosion gullies exist to depths of greater than 1.0 foot, they should be overexcavated and replaced as compacted fill in accordance with the applicable specifications. Where affected materials exist to depths of 1.0 foot or less below proposed finished grade, remedial grad- ing by moisture conditioning in-place, followed by thorough recompaction in accordance .with the applic- able grading guidelines herein may be attempted. If the desired results are not achieved, all affected materials should be overexcavated and replaced as •compacted fill in accordance wi-th the slope repair recommendations herein. As field conditions dictate, other slope repair procedures may be recommended by the Geotechnical Consultant. 6 ., \ - EXCAVATIONS 6.1 UNSUITABLE MATERIALS •- 6.1.1 Materials which are unsuitable should be exca- vated under observation and recommendations of the Geotechnical Consultant.. Unsuitable mater- ials include, but may not be limited to, dry, loose, soft, wet, organic compressible natural soils and fractured, weathered, soft bedrock and nonengineered or otherwise deleterious fill materials. 6.1.2 Material identified by the Geotechnical Consul- tant as unsatisfactory due to it's moisture conditions should be overexcavated, watered or dried, as needed, and thoroughly blended to a uniform near optimum moisture condition (as per guidelines reference 7.2.1) prior to placement as compacted fill. 6.2 CUT SLOPES 6.2.1 Unless otherwise recommended by the Geotechnical consultant and approved by the regulating agen- cies, permanent cut slopes should not be steeper than 2:1 (horizontal:vertical). 6.2.2 If excavations for cut elopes expose loose, co- hesionless, significantly fractured or otherwise unsuitable material, overexcavation and replace- ment of the unsuitable materials with a compacted stabilization fill should be accomplished as ^ "• recommended by the Geotechnical Consultant. Unless otherwise specified by the Geotechncial consultant, stabilization fill construction should conform to the requirements of the Stan- •• • ^ dard Details. .•;.•/•••-•,;, Page Nine 6.2.3 The Geotechnical Consultant should review cut slopes during excavation. The Geotechnical Consultant should be notified by the contractor prior to beginning slope excavations. 6.2.4 If, during the course of grading, adverse or potentially adverse geotechnical conditions are ^^cppntered which were not anticipated in the preliminary report, the Geotechnical Consultant should explore, analyze and make recommenda- ' tions to treat these problems. 6.2.5 When cut slopes are made in the direction of the prevailing drainage, a non-erodible diver- sion swale (brow ditch) should be provided at •^^i-'"'*4/:'.-^/ the top-of-cut. './f*^|'77- "6.3 PAD AREAS 6.3.1 All lot pad areas, including side yard terraces, above stabilization fills or buttresses should be overexcavated to provide for a minimum of 3 feet (refer to Standard Details) of compacted fill over the entire pad area. Pad areas with both fill and cut materials exposed and pad areas containing both very shallow (less than 3 feet) and deeper fill should be overexcavated to provide for a uniform compacted fill blanket ; • with a minimum of 3 feet in thickness (refer to ' . Standard Details). Cut areas exposing signi- ficantly varying material types should also be overexcavated to provide for at least a 3-foot thick compacted fill blanket. Geotechnical conditions may require greater depth of over- excavation. The actual depth should be de- lineated by the Geotechnical Consultant during grading. 6.3.2 For pad areas created above cut or natural slopes, positive drainage should be established away from the top-of-slope. This may be accom- plished utilizing a berm and/or an appropriate , ... : pad gradient. A gradient in soil areas away from the top-of-slopes of 2 percent or greater is recommended. 7. COMPACTED FILL All fill_materials should be compacted as specified below or by other methods specifically recommended by the Geotech- nical Consultant. Unless otherwise specified, the minimum degree of compaction (relative compaction) should be 90 percent of the laboratory maximum density. - V . Page Ten /;/^;;7 7. 1 PLACEMENT 7.1.1 Prior to placement of compacted fill, the Con- tractor should request a review by the Geotech- nical Consultant of the exposed ground surface. Unless otherwise recommended, the exposed ground surface should then be scarified (six inches mini- mum) , watered or dried as needed, thoroughly blended to achieve near optimum moisture condi- tions, then thoroughly compacted to a minimum ' . of 90 percent of the maximum density. The re- . view by the Geotechnical Consultant should not ' •:'. be considered to preclude requirement of inspec- tion and approval by the governing agency. t 7.1.2 Compacted fill should be placed in thin hori- zontal lifts not exceeding eight inches in loose thickness prior to compaction. Each lift should be watered or dried as needed, thoroughly blended to achieve near optimum moisture condi- tions then thoroughly compacted by mechanical ..^ : ' methods to a minimum of 90 percent of laboratory maximum dry density. Each lift should be treated in a like manner until the desired finished grades are achieved. 7.1.3 The Contractor should have suitable and suffi- cient mechanical compaction equipment and water- ing apparatus on the job site to handle the amount of fill being placed in consideration of moisture retention properties of the mater- . -.,. ials. If necessary, excavation equipment should be "shut down" temporarily in order to permit proper compaction of fills. Earth moving equip- /, ment should only be considered a supplement and hot substituted for conventional compaction equipment. 7.1.4 When placing fill in horizontal lifts adjacent to areas sloping steeper than 5:1 (horizontal: vertical), horizontal keys and vertical benches should be excavated into the adjacent slope area. Keying and benching should be sufficient to pro- . . vide at least six-foot wide benches and a mini- / .' • • ^ inum of four feet Of vertical bench height within ' :/ the firm natural ground, firm bedrock or engi- neered compacted fill. No compacted fill should ^ ' be placed in an area subsequent to keying and 7 benching until the area has been reviewed by the Geotechnical Consultant. Material generated by the benching operation should be moved suf- ficiently away from the bench area to allow for the recommended review of the horizontal bench prior to placement of fill. Typical keying and , . • ^ ; benching details have been included within the , \ ; • , accompanying Standard Details. Page Eleven 7.1.5 Within a single fill area where grading proce- dures dictate two or more separate fills, tem- porary slopes (false slopes) may be created. V7hen placing fill adjacent to a false slope, benching should be conducted in the same man- ner as above described. At least a 3-foot vertical bench should be established within the firm core of adjacent approved compacted fill-prior to placement of additional fill. Benching should proceed in at least 3-foot vertical increments until the desired finished grades are achieved. 7.1.6 Fill should be tested for compliance with the recommended relative compaction and moisture , conditions. Field density testing should con- form to ASTM Method of Test D 1556-64, D 2922-78 *: and/or D 2937-71. Tests should be provided for / :, ' about every two vertical feet or 1,000 cubic yards of fill placed. Actual test interval may vary as field conditions dictate. Fill found not to be in conformance with the grad- ing recommendations should be removed or other- wise handled as recommended by the Geotechnical Consultant. 7.1.7 The Contractor should assist the Geotechnical Consultant and/or his representative by digging test pits for removal determinations and/or for Tv ,. : testing compacted fill. ' •• 7.1i8 As recommended by the Geotechnical Consultant, the Contractor should "shut down" or remove |. , . , grading equipment from an area being tested. 7.1.9 The Geotechnical Consultant should maintain a plan with estimated locations of field tests. Unless the client provides for actual surveying of test locations, the estimated locations by ' the Geotechnical Consultant should only be con- sidered rough estimates and should not be uti- , lized for the purpose of preparing cross sec- tions showing test locations or in any case for the purpose of after-the-fact evaluating of the sequence of fill placement. /./V/ 7.2 MOISTURE ' 7.2.1 For field testing purposes, "near optimum" mois- , " ture will vary with material type and other factors including compaction procedure. "Near • , ' optimum" may be specifically recommended in , /,, Preliminary Investigation Reports and/or may be evaluated during grading.. f. • . , Page Twelve 7.2.2 Prior to placement of additional compacted fill following an overnight or other grading delay, the exposed surface or previously com- pacted fill should be processed by scarifica- tion, watered or dried as needed, thoroughly blended to near-optimxam moisture conditions, then recompacted to a minimum of 90 percent of.laboratory maximum dry density. Where wet or other dry or other unsuitable materials exist to depths of greater than one foot, the unsuitable materials should be overexcavated. 7.2.3 Following a period of flooding, rainfall or overwatering by other means, no additional fill should be placed until damage assess- . ments have been made and remedial grading performed as described under Section 5.6 ' • herein. ; ' - ,7.3 FILL MATERIAL 7.3.1 Excavated on-site materials which are accept- able to the Geotechnical Consultant may be utilized as compacted fill, provided trash, ^ vegetation and other deleterious materials are removed prior to placement. 7.3.2 Where import materials are required for use . on-site, the Geotechnical Consultant should be notified at least 72 hours in advance of im- porting, in order to sample and test materials from proposed borrow sites. No import mater- ials should be delivered for use on-site with- ^ out prior sampling and testing by Geotechnical Consultant. 7.3.3 Where oversized rock or similar irreducible ma- terial is generated during grading, it is rec-^ ommended, where practical, to waste such mater- ial off-site or on-site in areas designated as "nonstructural rock disposal areas". Rock placed in disposal areas should be placed with sufficient fines to fill voids. The rock should be compacted in lifts to an unyielding condi- tion. The disposal area should be covered with at least three feet of compacted fill which is free of oversized material. The upper .three , feet should be placed in accordance with the guidelines for compacted fill herein. »i%/fe siis^C'-v '- ''''y I I I I Page Thirteen 7.3.4 Rocks 12 inches in maximum dimension and smal- ler may be utilized within the compacted fill, provided they are placed in such a manner that nesting of the rock is avoided. Fill should be placed and thoroughly compacted over and around all rock. The amount of rock should not exceed 40 percent by dry weight passing the 3/4-inch sieve size. The 12-inch and 4o percent recommendations herein may vary as field conditions dictate. 7.3.5 During the course of grading operations, rocks or similar irreducible materials greater than 12 inches maximum dimension (oversized material), may be generated. These rocks should not be placed within the compacted fill unless placed as recommended by the Geotechnical Consultant. 7.3.6 Where rocks or similar irreducible materials of greater than 12 inches but less than four feet of maximum dimension are generated during grading, or otherwise desired to be placed within an engineered fill, special handling in accord- ance with the accompanying Standard Details is recommended. Rocks greater than four feet should be broken down or disposed off-site. Rocks up to four feet maximum dimension should be placed below the upper 10 feet of any fill and should .fiot be closer than 20 feet to any slope face. These recommendations could vary as locations of improvements dictate. Where practical, over- sized material should not be placed below areas where structures or deep utilities are proposed. Oversized material should be placed in windrows on a clean, overexcavated or unyielding com- pacted fill or firm natural ground surface. Select native or imported granular soil (S.E. 30 or higher) should be placed and thoroughly flooded over and around all windrowed rock, such that voids are filled. Windrows of oversized material should be staggered so that successive strata of oversized material are not in the same vertical plane. 7.3.7 It may be possible to dispose of individual larger rock as field conditions dictate and as recommended by the Geotechnical Consultant at the time of placement. 7.3.8 Material that is considered unsuitable by the Geotechnical Consultant should not be: utilized in the compacted fill. Page Fourteen 7.3.9 During grading operations, placing and mixing the materials from the cut and/or borrow areas may result in soil mixtures which possess unique physical properties. Testing may be required of samples obtained directly from the fill areas in order to verify conformance with the specifications. Processing of these ad- ditional samples may take two or more working days. The Contractor may elect to move the operation to other areas within the project, or may continue placing compacted fill pending laboratory and field test results. Should he elect the second alternative, fill placed is ' . • done so at the Contractor's risk. 7.3.10 Any fill placed in areas not previously re- viewed and evaluated by the Geotechnical Con- sultant, and/or in other areas, without prior notification to -the Geotechnical Consultant may require removal and recompaction at the Con- tractor 's expense. Determination of overex- cavations should be made upon review of field conditions by the Geotechnical consultant. •7.4 FILL SLOPES , 7.4.1 Unless otherwise recommended by the Geotechnical Consultant and approved by the regulating agen- ts cies, permanent fill slopes should not be ( steeper than 2:1 (horizontal:vertical). 7.4.2 Except as specifically recoimnended otherwise or as otherwise provided for in these grading guidelines (Reference 7.4.3), compacted fill slopes should be overbuilt and cut back to grade, exposing the firm, compacted fill inner ' , core. The actual amount of overbuilding may ' vary as field conditions dictate. If the de- sired results are not achieved, the existing slopes should be overexcavated and reconstructed under the guidelines of the Geotechnical Consul- tant. The degree of overbuilding shall be in- creased until the desired compacted slope sur- face condition is achieved. Care should be taken by the Contractor to provide thorough mechanical compaction to the outer edge of the overbuilt slope surface. . \ /.. , 7.4_.3 Although' no construction procedure produces a ; ., . slope free from risk of future movement, over- filling and cutting back of slope to a compacted inner core is, given no other constraints, the most desirable procedure. Other constraints, , however, must often be considered. These con- i . straints may include property line situations. Page Fifteen access, the critical nature of the development and cost. Where such constraints are identi- fied, slope face compaction may be attempted by conventional construction procedures includ- ing backrolling techniques upon specific recom- mendation by the Geotechnical Consultant. A?^a_ second best alternative for slopes of 2:1 (Horizontal:vertical) or flatter, slope con- struction may be attempted as outlined herein. Fill placement should proceed in thin lifts, i.e., six to eight inch loose thickness). Each lift should be moisture conditioned and thoroughly compacted. The desired moisture condition should be maintained and/or re-established, where necessary, during the period between successive lifts. Selected lifts should be tested to ascertain that desired compaction is being achieved. Care should be taken to ex- tend compactive effort to the outer edge of the slope. Each lift should extend horizontally to the desired finished slope surface or more as needed to ultimately establish desired grades. Grade during construction should not be allowed to roll off at the edge of the slope. it may be helpful to elevate slightly the outer edge of the slope. Slough resulting from the place- ment of individual lifts should not be allowed to drift down over previous lifts. At intervals not exceeding four feet in vertical slope height or the capability of available equipment, which- ever is less, fill slopes should be thoroughly backrolled utilizing a conventional sheepsfoot- type roller. Care should be taken to maintain the desired moisture conditions and/or re- establishing same as needed prior to backrolling. Upon achieving final grade, 'the slopes should again be moisture conditioned and thoroughly backrolled. The use of a side-boom roller will probably be necessary and vibratory methods are strongly recommended. Without delay, so as to avoid (if possible) further moisture conditioning, the slopes should then be grid-rolled to achieve a relatively smooth surface and .uniformly com- pact condition. In order to monitor slope construction proce- dures, moisture and density tests will be taken at regular intervals. Failure to achieve the desired results will likely result in a recom- mendation by the Geotechnical consultant to I' . V Page Sixteen overexcavate the slope surfaces followed by reconstruction of the slopes utilizing over- filling and cutting back procedures and/or further attempt at the conventional back- rolling approach. Other recommendaitons may also be provided which would be commensurate with field conditions. 7.4,. 4 Where placement of fill above a natural slope or above a cut slope is proposed, the fill slope configuration as presented in the ac- companying Standard Details should be adopted. 7.4.5 For pad areas above fill slopes, positive drain- age should be established away from the top- of-slope. This may be accomplished utilizing a berm and pad gradients of at least 2 percent in soil areas. , 7.5 OFF-SITE FILL 5, 7.5.1 Off-site fill should be treated in the same manner as recommended in these specifications for site preparation, excavation, drains, com- paction, etc. , 7.5.2 Off-site canyon fill should be placed in prep- aration for future additional fill, as shown in the accompanying Standard Details. 7.5.3 Off-site fill subdrains temporarily terminated (up canyon) should be surveyed for future re- location and.connection. ,8. DRAINAGE ' ^ 8.1 Canyon subdrain systems specified by the Geotechnical Consultant should be installed in accordance with the Standard Details. '8.2 Typical subdrains for compacted fill buttresses, slope stabilizations,or sidehill masses, should be installed in accordance with -the specifications of the accompany- ing Standard Details. 8.3 Roof, pad and slope drainage should be directed away from slopes and areas of structures to suitable dis- posal areas via non-erodible devices (i.e.,, gutters, / downspouts, concrete swales). // 8.4 For drainage over soil areas immediately away from structures, (i-e. , within four feet) a minimum of 4 percent gradient should be maintained. Pad drainage of at / least 2 percent should be maintained over soil areas. Pad "drainage may be reduced to at least 1 percent for Page Seventeen projects where no slopes exist, either natural or man- made, of greater than 10 feet in height and where no '-l slopes are planned, either natural or man-made, steeper than 2:1 (horizontal:vertical slope ratio). 8.5 Drainage patterns established at the time of fine grad- ing should be maintained throughout the life of the project. ^Property owners should be made aware that altering arainage patterns can be detrimental to slope stability and foundation performance. 9. STAKING /: 9.1 In all fill areas,: the fill should be compacted prior ' ; -to the placement of the stakes. This particularly is important on fill slopes. Slope stakes should not be placed until the slope is thoroughly compacted (back- rolled) . If stakes must be placed prior to the com- pletion of compaction procedures, it must be recognized that they will be removed and/or demolished at such , time as compaction procedures resume. 9.2 In order to allow for remedial grading operations, : • - which could include overexcavations or slope stabili- zation, appropriate staking offsets should be provided. For finished slope and stabilization backcut areas, we recommend at least a 10-foot setback from proposed toes and tops-of-cut. t-' ' 'i '. I • . 10 ,, 3L0PE MAINTENANCE ; 10.1 LANDSCAPE PLANTS In order to enhance surficial slope stability, slope planting should be accomplished at the completion of • grading. Slope planting should consist of deep-rooting ; vegetation requiring little watering. Plants native to the southern California area and plants relative to native plants are generally desirable. Plants native to other semi-arid and arid areas may also be appro- priate. A Landscape Architect would be the best party to consult regarding actual types of plants and plant- ing configuration. . ••. . • . \. 10.2 IRRIGATION 10.2.1 Irrigation pipes should be anchored to slope faces, not placed in trenches excavated into slope faces. 10.2.2 Slope irrigation should be minimized. If auto- ' " . matic timing devices are utilized on irrigation systems, provisions should be made for inter- r rupting normal irrigation during periods of .v' rainfall. " ' : .. ' - • I I I Page Eighteen 10.2.3 Though not a requirement, consideration should be given to the installation of near-surface moisture monitoring control devices. Such de- vices can aid in the maintenance of relatively uniform and reasonably constant moisture conditions. 10.2.4 Property owners should be made aware that over- watering of slopes is detrimental to slope stability. 10.3 MAINTENANCE 10.3.1 Periodic inspections of landscaped slope areas should be planned and appropriate measures should be taken to control weeds and enhance growth of -the landscape plants. Some areas may require occasional replanting and/or 1 reseeding. . 10.3.2 Terrace drains and downdrains should be period- ically inspected and maintained free of debris. Damage to drainage improvements should be re- paired immediately. 10.3.3 Property owners should be made aware that bur- rowing animals can be detrimental to slope sta- bility, A preventative program should be esta- blished to control burrowing animals. 10.3.4 As a precautionary measure, plastic sheeting ^ should be readily available, or kept on hand, to protect all slope areas from saturation by periods of heavy or prolonged rainfall. This measure is strongly recommended, beginning with the period of time prior to landscape planting. 10.4 REPAIRS 10.4.1 If slope failures occur, the Geotechnical Con- sultant should be contacted for a field review of site conditions and development of recommen- dations for evaluation and repair. 10.4.2 If slope failures occur as a result of exposure to periods of heavy rainfall, the failure area and currently unaffected areas should be covered i with plastic sheeting to protect against addi- tional saturation. 10.4.3 In the accompanying Standard Details, appro- priate repair procedures are illustrated for superficial slope failures (i.e., occuring typi- cally within the outer one foot to three feet± of a slope face). Page Nineteen / . . 11. TRENCH BACKFILL •11.1 Utility trench backfill should, unless otherwise recommended, be compacted by mechanical means. Unless otherwise recommended, the degree of compaction should be a minimum of 90 percent of the laboratory maximum . density. 11.2 As an alternative, granular material (sand equivalent greater than 30) may be thoroughly jetted in-place. Jetting should only be considered to apply to trenches no greater than two feet in width and four feet in depth. Following jetting operations, trench backfill should be thoroughly mechanically compacted and/or wheel- rolled from the surface. 11.3 Backfill of exterior and interior trenches extending below a 1:1 projection from the outer edge of founda- tions should be mechanically compacted to a minimum of 90 percent of the laboratory maximum density. 11.4 Within slab areas, but outside the influence of foun- dations, trenches up to one foot wide and two feet deep may be backfilled with sand and consolidated by jet- ting, flooding or by mechanical means. If on-site materials are utilized, they should be wheel-rolled, tamped or otherwise compacted to a firm condition. For minor interior trenches, density testing may be deleted or spot testing may be elected if deemed necessary, based on review of backfill operations during construction. ^ 11.5 If utility contractors indicate that it is undesirable to use compaction equipment in close proximity to a buried conduit, the Contractor may elect the utiliza- tion of light weight mechanical compaction equipment and/or shading of the conduit with clean, granular , ^ material, which should be thoroughly jetted in-place . above the conduit, prior to initiating mechanical com- paction procedures. Other methods of utility trench compaction may also be appropriate, upon review by the Geotechnical Consultant at the time of construction. 11.6 In cases where clean granular materials are proposed for use in lieu of native materials or where flooding or jetting is proposed, the procedures should be con- sidered subject to review by the Geotechnical Consultant. 11.7 Clean granular backfill and/or bedding are not recom- mended in slope areas unless provisions are made for • ' ,4, a drainage system to mitigate the potential build-up of seepage forces. V,"' Page Twenty 12. STATUS OF. GRADING Prior to proceeding with any grading operation, the Geotech- nical Consultant should be notified at least two working days in advance in order to schedule the necessary observation and testing services. 12.1 Prior to apY_significant expansion or cut back in the , grading operation, the Geotechnical Consultant should be provided with adequate notice (i.e. , two days) in order to make appropriate adjustments in observation and testing services. 12.2 Following completion of grading operations and/or be- tween phases of a grading operation, the Geotechnical Consultant should be provided with at least two working days notice in advance of commencement of additional grading operations. CANYON SUBDRAIN /^oposeJ Grading Bench: \Jitt/cc/Hff:/n,ft. Dozer Trench Co/i^cf'ef fill l^emav^/ of \ unsi^ihble Drm/is qUff^ canyon w<ills Geofabric Alternative V- fiyf€ ^4**/// 4"mi^. dt4tme./erj b "mirt. Ar tum Scoff e''^/r7. re should As 5W4r/<? 4o five stm,Ja*'. sM^ cop/>*c/. ^ ;*W /"rom vpp4r ^cofif. fior runs «f SOO^/ooo ,ond ^Socff ^r- STANDARD DETAIL NO. 1 FILL OVER NATURAL SLOPE -fo <//T#//» Of f/or/4c>t ft I tffmtn. FILL OVER CUT SLOPE MM mm. ^r^tf€ /5 aef0/>f€*/^ /w"/^. ,^// kf/<^A nuty ^9 reefucec/ ii> /Zff: mm. Sr} /)o caae sA^t/fc/ -Hic A/f STANDARD DETAIL NO. 2 STABILIZATION FILL All kV/«//4 ^Up€ 2:/ or/'/0^er (t) 3fif. *f»//». dtp (z) i97tn. f/ort iPt^ ^<a/ (, ff. ftttrt. jSa£^</r0/rf s/s/0*^ //^ ^^^—^ff, 07IO, r-t<^f^/*^tndtt/ ^tcMMnf^/ Cc*)ii//fi0n/* fir f/4ff€r 0) f^<^) BUTTRESS FILL u*ff»it*t /ef/ MM. tudH \ I fnin " I p~ nttfj. cap(z) _ 8te/t/,nj p/ants ofht-r <Undt/j*^. e*heh'' \/trh£^f ^ff-min. f^/. rcducad A, case 6Aou/d ' /;// W/^ ^ /<S5^ //^^ /;// ^^^^^ rerrt<i,nin^ <?/jy i>i/tfr€i>$ /////. 73J« *n0yi?c -7» 3" kf * </f$y/,*y W/tfiV^ f:€/. 6' O,^ dep/h oA f:ei Jt^tl; (/nUss cfHer (A/lit. 'ipeciffedy P^z O^-f- //"/ STANDARD DETAIL NO. 3 BUTTRESS BACKDRAIN SYSTEM <fddt^/o/tff op^r cfram /n^y he f/'om»Jt^f -^tie/nj aid/^fi sA0uy M S/ankg/ fi//i 3ff. -—\4r / 6e€ defaih behtu Conventional Backdrain Geofrabic Altemative 7ypor S^O/^ sr ^m,/0^; V0 P • / ^ X ypw t I A f'pe ^4»^yAe. ^/n0A d*0^^Hr 40 pyc or ^tmt/0r. I - ^reKfttnh ^o0fifSt 4% ar^/^^r. 3' Cap t^^g^remm Crtd^ 4' TrcAcAti /or p'fts S^iftrm/y spaced ^tf/Vi*^//«v»s /V/- fofi/^/f/^ead So^ offset' an £^f*dg,^stde ofp'pe.. OufUt'p»/>e sU>fld Se ffnper/^Of^'a/^, ^'/vr-fAejetff^rtc cif/tr/m/t^ Mc Sacjkdr^tit p'pe m^y <9^^/l^ed /rfivfded /ea*/- Zcfee^(/,e. /o/-f *aeA We af auf-Uf-) cf perf»r9fed f'fie /s /ftfit/fded ^0 /wef »^^» ourfe^. 7-^/1/eacA <v/4r//^e ^e* fabric ^cv/d be 0/ff>n>^H»/m/y 0^9r/0ppet/ y///) Au/s ,4 ^4r*c dr ^^Aerione se^/*d sr tV/»r</ ar^ttmt/ STANDARD DETAIL NO. 4 FUTURE CANYON FILL view Along Canyon __^^ed_£'^t!^r±^^^ Current fim*-f ef ^rtfi^e^r^pf/i// i/nstft'^«$/e ' ' '^^•"^^,'fopsof' *^^^^;Vy^4- -'-^'^ur^y €^0f:suidr^^H View of Canyon Sidewall \ Cti^z/Ktred A// | ^f^**^ .£^^meer€d Aff / Snyt^e^ree//^,/// / /'^ir^_ :, •: ////////// /// /.//•/////.\w 'V /Seefriofe. STANDARD DETAIL NO. 5 TRANSITION LOT OVEREXCAVATION Cut Lot ^^^^^^^^ ^ "^^^^^ in pf4c^ <9nd /ecentpac-f/o^ Cut-Fill Lot ^r€K/i4j p/an, ^ A^ttteert^-f,//, A/,/^^, »or.^^f./^pt^,„, ^ripf^c^rec0/.p0ct'/o, /- Tcpso,/, C0//r^fu/9i,tue0^kere4f Ucfrc^ ond ^Aerw/se c/n,*^ri'^U/e. m^^er/et/s SAeuiA/Ae renf<»u</ -f'rm ffa^rtr/fra^nc/ fdenftfied je0fecAjt/c4i/ C^/lSuZ/mnf-. Z' rU i^,D,Kt,M) 0f<4pfh 'f aMtre^c0^mff00 6t coyiS*d^ra/ s^kjecf -f. rtuieu^ Sf ^e. ^^ecAs9i€al cort-iu/f^inf. Sfe€^r /ruffSi/to^i rtfytrt. afeep^r ^- Ti< /a/trg/ a^cfen^ of aiier«itca^/,OA s4ou/e/ Ae //)c/t^c T^e €»tfif-e/o^ r€c«,»n*ntndee/6y ^eo^^A»i,eaJ Cdtsu/f-ani- ecAi^VMf /irt4/ S*-*^ 0'€. 6u^^'^ 6^f:) mapder ^vaA^Pe /^^e^,Mff<^ STANDARD DETAIL NO. 6 ROCK DISPOSAL ^//itjAeaf ^r4r<d^ foft •3fi mm. ^ ^'^ff« ^ ^ OC0/*0M 5 J- 0r r^cf: vutndr*tui b* D £fi^tr/7^/ ^epar^i/foi^ Windrow Section /^// ^ur^Lt!^ ^fff^f^j ^radtftj *r^/«c////*Mf/tf.^. by w4*e/rH/,Aj): Windrow Profile dean ^r^tttflar '0^«fer/«/ -fA^roujA/y A/oeded /o Atli Vmds <9r0f/nd rock . C0f3^*^ fsd ^, '// ^>if SurA<.t. durM0 fr0d,^ f -^cfe ^A»v4d 69. p/ifce«f M-^oef^d. ^' P/^ZlfT'"*''' ifS"^^^ ^''"•^"-^ ^O^W.- /^<f^<r/./, ^n<y SAfft/A/ iPM0rfi^y4f/ CffAjpo^cP^d fr^ f4< aur/Cree. prep^r^ 4>y ^urv^y <^c^u^-.^,0j ^/y^y,^, ,p iCneTrcS. r^-£/5/^/ /^ree/, >^-r/ ^ suAje^ ^ ^,re. ^^/r,c/^v^ r^u,re^ ^Ae Jc^Mrw^y ^auMmr^/^ei, ' STANDARD DETAIL NO. 7 MINOR SLOPE REPAIR Oufdf F.p -S0rM Serin £/*pe 6t/rf<K<. /-o Ae ^eco/t^prucpe^ :$/<//9t/> c/eAr/s ^ y ^/un^p ^li¥4 ^rr^ec fir/>^se. of ^rrfi*i9ri. daHih d^hto). \/*.rfiorf ip«t<iAj d-ff r}o*n/rtiff. O^AUf <*j'H ftofl/ferAr^i/et/ z*^* "f Sofp, mfittmvfn spac/nj. F/an fir^i- l*^el of drti4^i y© ^/^f- /'2 // aito^t. Ac ^f s/opt.. ^XCa^o/e. Aey /npo f'rn^, Shi&ofCo/.f. Clos^Z />er/>7Mh/^ ntt/enaf fAfmo^fo/ fP^, mi/i. Conventional Drain //o<t.p"pe «/) 4Mdt /ni/i. S&d of rce^/*im ended perineairtitPtruri ^toftfbric: 5**p^c S-p^ Typ^r 3^1 »riimi /mr^Bos /ec -/4o. m/n. over/4fp- ^pen ^ritded 3''per4»r0f^Sdt4op]/c Cifl -//»/0rA»r0fi0rts So^ yp/4<0d doiun) jrmdedfff 4^' pip*s perforated fiprted ^ r- S^ff M4t'^imUfrt. Geofabric Alternative ' place. p>tpe 0f» ^incX do/Wf/0/^€x:/ of reco0^m0Aded O/ierffr^t^ee/ r&c>/k.. ^tn/c fif Gt/./, C/aisZ pertit^^ a^oMriir/, f6^Vff'. "^'^ ^p <^//drain p^/^s *fA n^sPremot eno^e. Drain Guard' Pipe T'Ara: //feJt "jDram <^rd 'ppe or Simi/ar p/4<ed on lf*d o^ao/Ac/" /Jurpjy/etfr reco/9t0te^ded per/neab/* iri*^pe.ria/. G/rade. df 4-/^ -ff oe/y^fptpes. STANDARD DETAIL NO. 8 LOT DRAINAGE j4a: 3 A/o/eS: •Yard draiti *fA or ^r«a/e*^ 4 ffteJt mf**'ifit0ri puc, ^*p*. or •s/'uif^t' fo •s*^i fmhfe ^/yyosa/ ^r^a..{e.y. curb /./X™.-^. STANDARD DETAIL NO. SAN DIEQO SOILS ENQINEERING. INC. EXPLANATION Anticipated areas of alluvial removal Anticipated rock cut areas Slopes subject to special recommendations CARLSBAD RESEARCH CENTER-PHASE I AND H JOB NO.: SD1162-00 JULY 1982 FIGURE: - ^ SAN DIEGO SOILS ENGINEERING. INC.