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HomeMy WebLinkAboutCT 83-19; Calavera Hills Village Q & T; Soils Report; 1986-08-01SUPPLEMENTAL GEOTECHNICAL INVESTIGATION - VILLAGES Q and T CALAVERA HILLS SUBDIVISION CARLSBAD, CALIFORNIA Prepared For Vernon Savings and Loan c/o Charles W. Christensen & Associates 444 West "C" Street Suite 400 San Diego, California 92101 - - - - ENGINEERING DEPT. LIBRARY City of Carlsbad 2075 Las Palmas Drive Carisbad, CA92009-4859 August 5, 1986 Project No. 460.1.1 - ,- .- - - r SOIL AND FaJNDATlON ENGINtERlNG,GtOLOG~ 9006 TIERRA GRANDE SUITE 107 SAN DIEGO CALIFORNIA P2120 (MP) 095-3150 August 1, 1986 Project No. 460.1.1 Vernon Savings and Loan c/o Charles W. Christensen & Associates 444 West "C" Street Suite 400 San Diego, California 92101 Attention: Mr. Robert D. Burns ,Subject: SUPPLEMENTAL GEOTECHNICAI INVESTIGATION VILLAGES Q AND T CALAVERA HILLS SUBDIVISION CARLSBAD, CALIFORNIA Gentlemen: This report presents the results of our Supplemental Geo- technical Investigation at the subject site. Our in- vestigation consisted of additional field exploration, review of the existing documents, and the preparation of this report. As part of this investigation, we have reviewed the following documents pertinent to the site. 1. "Preliminary Geotechnical Investigation, Cala- vera Hills Subdivision, Carlsbad, California," by Southern California Soil and Testing, Inc., dated January 6, 1983. 2. "Supplemental Geotechnical Investigation, Calavera Hills Subdivision, Carlsbad, Califor- nia," by Southern California Soil and Testing, Inc., dated July 29, 1983. 3. "Buttress Recommendations, Proposed Cut Slope, Calavera Hills Village I, Carlsbad, California," by Southern California Soil and Testing, Inc., dated November 3, 1983. ORANGE COUNTY OFFICE . 23232 PERALIA DRIVE . SUITE 202 . LAGUNA HILLS . CALIFORNIA P2053 . (7W 8554686 Vernon Savings and Loan August 1, 1986 Project No. 460.1.1 Page 2 - .- - ..- - - - - - - - - - .- 4. 5. 6. 7. 8. "Geotechnical Investigation, Village Q, Calavera Hills Subdivision, Carlsbad, California," by Southern California Soil and Testing, Inc., dated January 10, 1984. "Rippability Study, Rock Area I, Villages Q, K and L, Lake Calavera Hills Subdivision, Carls- bad, California," by Southern California Soil and Testing, Inc., dated February 6, 1984. "Summary of Geotechnical Investigation, Lake Calavera Hills, Villages E-l, E-2, H, K, L-2, L-3, Q, R, S, T, U, and W-X, Carlsbad, Califor- nia," by Southern California Soil and Testing, Inc., dated August 6, 1984. "Tentative Map of: Calavera Hills - Village T," by Charles W. Christensen & Associates, printed March 17, 1986. "Tentative Map of: Calavera Hills - Village IQ'," by Charles W. Christensen & Associates, printed November 30, 1983. We have also: 1. Conducted a geological reconnaissance of the site. 2. Examined stereographic pairs of aerial photo- graphs which cover the site. The photographs were prepared by Photo GeoDetic Corporation and are dated March 20, 1986. 3. Drilled three borings with a truck-mounted bucket auger rig. The locations of the borings are shown on the enclosed Geologic Map, Plate 2. Logs of the borings are attached in Appendix A. SITE DESCRIPTION The subject site consists of two of eleven proposed villages which will be located in the northeastern part of the City of Carlsbad adjacent to the City of Oceanside. The subject - - WE~GEOEC tHi‘-l IKX .- .- .- - .- - - - - - .- Vernon Savings and Loan August 1, 1986 Project No. 460.1.1 Page 3 Villages Q and T will be situated on the west and east sides, respectively, of College Boulevard which will ultimately be extended in a southerly direction from its present intersec- tion with Lake Boulevard. Village Q is composed of 51 acres and is situated on the flanks of a rounded hill. The hill rises some 200 feet from the eastern boundary of the village and its slopes are in- clined at gradients ranging from nearly flat to as steep as l-1/2 horizontal to 1 vertical. The slopes are primarily covered with a moderately dense to dense growth of chaparral '\ through which are scattered isolated barren rock outcrops. Village T is comprised of 137 acres situated on gently rolling terrain. The ground surface drains toward the north, south, and east and slope gradients range from nearly flat to inclin- ations on the order of 7 horizontal to 1 vertical. The western part of the site supports a mixed growth of chapparal and grass. The eastern part is primarily covered with high grass. PROPOSED DEVELOPMENT Village Q will consist of 202 residential lots, seven recrea- tional lots, and two open space areas. Level lots and street grades will be created by grading the site. Cut and fill slopes will be inclined at a gradient of 2 horizontal to 1 vertical. Maximum heights of cut and fill slopes will be on the order of 50 feet. Village T will be comprised of 466 residential lots, six recreation areas, two open space areas, and one school site. Slopes will be inclined at a ratio of 2 horizontal to 1 vertical. Maximum heights of cut and fill slopes will be on the order of 25 and 50 feet, respectively. SEISMICITY A. Regional Seismicity The site can be considered a seismically active area, as can all of southern California. There are, however, no known active faults on or adjacent to the site. OUWJ/GEOEC:HNCA! - - - - - - - - - - - - - .- Vernon Savings and Loan August 1, 1986 Project No. 460.1-l Page 4 Seismic hazards within the site can be attributed to groundshaking resulting from events on distant, active faults. Listed on the following Table 1 are the active and potentially-active faults in the area which can significantly affect the site. TABLE 1 SEISMICITY FOR MAJOR FAULTS Fault Rose Canyon' Elsinore San Jacinto Newport-Inglewood San Andreas San Clemente Coronado Banks La Nacion3 Approximate Distance From Site 8 Miles 22 Miles 45 Miles 45 Miles 65 Miles 59 Miles 26 Miles 33 Miles Maximum Probable Earthquake' 6.0 7.0 7.5 6.5 8.0 7.3 6.5 6.0 Estimated Peak Bedroc Acceleration 3 0.23g 0.21g 0.17g 0.05g O.lOg 0.06g 0.2og 0.07g 1. Seismic Safety Study City of San Diego (1974) & Bonnila (1970) 2. Seed and Idriss (1983) 3. Potentially Active .- - OWN/G:OECHMX - - -_ - - - - .- - Vernon Savings and Loan August 1, 1986 Project No. 460.1.1 Page 5 B. Earthquake Effects a. b. C. d. e. Liquefaction and Seismically Induced Settlement of Soils The soils underlying the site consist primarily of firm bedrock materials which are not subject to liquefication and seismically-induced settle- ment. Existing fill and alluvium will be removed or stabilized by the intended grading. Lurching and Shallow Ground Rupture Breaking of the ground because of active fault- ing is not a problem on the site due to the absence of active faulting. Cracking, related to shaking from distant events, is not consid- ered a significant hazard, although it is a possibility at any site. Tsunamis and Seiches The site is not subject to inundation by tsuna- mis or seiches because of its elevation above sea level and the absence of lakes or ponds. Landslidinq Areas within the site are not considered subject to seismically-induced landsliding. Earthquake Accelerations Accelerations related to major events are listed in Table 1. In our opinion, for the intended use, the most significant event is a 7.0 magni- tude event on the Elsinore Fault. - - - ~~- - - ~- - .,- - Vernon Savings and Loan August 1, 1986 Project No. 460.1.1 Page 6 Design of structures should comply with the requirements of the governing jurisdictions, building codes, and standard practices of the Association of Structural Engineers of Califor- nia. GEOLOGY 1. General The approximate surficial distribution of soil and bedrock units is shown on the enclosed Geologic Map, Plates 1 and 2. The geology shown is derived from our review of referenced documents and our field reconnaissance. 2. Soil and Bedrock Units 0 Artificial Fill (af) A small earthfill dam approximately 12 feet high is located in the north-central part of the site at the boundary of Villages Q and T. Aerial photographic evidence indicates that the ma- terials for the dam were derived from a small borrow pit located upslope from the left abut- ment. The estimated maximum thickness of the fill is 15 feet. 0 Younger Alluvium (Qya) Deposits of younger alluvium occur in the channels of the drainage courses in the northern parts of Village T. The alluvial soils consist primarily of brown, loose, moist, silty and clayey sands. The maximum thickness of the alluvial soils is on the order of 15 feet. 0 Older Alluvium (Qyo) A deposit of older alluvium is located in the east central part of Village T. The alluvium is 10 or more feet thick and predominately consists of brown, medium dense sand, silt, and clay. .- - MN/GEOl::CH WAI . . - ..- - - ..- - Vernon Savings and Loan August 1, 1986 Project No. 460.1-l Page 7 0 Tertiary Paleosol (Tp) Two areas underlain by a paleosol (ancient residual soil) of Tertiary age have been mapped within the bounds of Village T. A 2 feet thick layer of paleosol was encountered at a depth of 12.5 feet in our Boring 3. Reference 6 in- dicates that the thickness of the paleosol probably varies from a few feet to a few tens of feet. The paleosol materials are mottled gray, green-brown, moist, medium dense, clayey sand. 0 Santiago Formation (Es) The northeastern part of Village T is underlain by sedimentary rock of the Santiago Formation of Eocene age. In that area, the deposit is primarily composed of brown, moist, dense, silty, fine to medium-grained sandstone. 0 Iqneous Rocks (Kgr and Jmv) All of Village Q and the remainder of Village T are directly or shallowly underlain by meta- volcanic rocks of Jurassic age (Jmv) which were complexly intruded in Cretaceous time by grani- tic magma (Xgr). As illustrated on Plate 1, the resultant rock masses consist of mixtures of the two rock types in highly varying percentages by volume. The metavolcanic rocks are generally gray, very hard, very dense, and fine-grained. The intru- sive rocks are primarily composed of dark gray or brown, hard to very hard, very dense, medium to coarse-grained quartz diorite (tonalite) and granodiorite. 3. Geologic Structure Our Borings 1 and 2 indicate that the Santiago Formation (Es) in the northeastern part of Village T is predominately indistinctly and massivelv bedded. However, there are some beds which dip at angles of 5 to 10 degrees to the - - - - -- - - - - - .- - - Vernon Savings and Loan August 1, 1986 Project No. 460.1-l Page 8 northeast and southeast. The attitudes of these beds are generally favorable with respect to the stability of proposed cut slopes in that area. Nevertheless, during grading the cut slopes should be inspected by an engineering geologist to determine if adverse geologic structure exists and special treatment for stability is required. The igneous rock units (Kgr-Jmv) are broken by well developed sets of closely to moderately- spaced, very high angle joints and fractures which strike northwesterly and northeasterly. 4. Groundwater No groundwater was encountered in previous or our borings. CONCLUSIONS AND RECOMMENDATIONS A. General The proposed construction is feasible from a geo- technical engineering standpoint. The grading and foundation plans should take into account the appropriate soils engineering features of the site. The major constraint at the site is the presence of hard bedrock which will require blasting. B. SITE GRADING 1. All grading should be performed in accordance with the attached "Guidelines for Grading Projects" (Appendix B). Where the recommenda- tions of this section conflict with Appendix B, the recommendations of this section take preced- ence. All earthwork should be observed and all fills tested for proper compaction by this office. 2. Site Clearing The site should be cleared of existing vegeta- tion. Vegetation from the clearing operation OWN/G:OTT:HI‘JlC/?l - - .- - - .- - - - - .- - - - - .- Vernon Savings and Loan August 1, 1986 Project No. 460.1.1 Page 9 should be removed from the site. Holes result- ing from the removal of any buried obstructions, which extend below finished site grades, should be backfilled with compacted fill. 3. Treatment of Unsuitable Surficial Soils A review of referenced reports indicates that the majority of the site is covered by a thin layer of compressible and expansive topsoil extending to an average depth of 2 feet. In areas underlain by granitic rock, the topsoil is underlain by compressible subsoils with an average thickness of 1.5 feet. Loose to medium dense alluvium exists in relatively minor sections of the property and extends to a maximum estimated depth of 10 to 15 feet. Fill related to a small earth dam was also observed. Due to the compressible potential of the above described soils, we recommend that these soils be removed to competent bedrock. We recommend that the final depth of removal be evaluated by this office at the time of grading. Prior to placing fill, the exposed subgrade soils should be scarified to a depth of 6 inches, brought to near-optimum moisture condi- tions and compacted to at least 90 percent relative compaction. 4. Transition Between Cut and Fill For any non-uniform bearing condition created by grading, we recommend that the cut portion be overexcavated to a minimum depth of 3 feet beneath the bottom of the deepest footing. The lateral extent of overexcavation should be at least 5 feet beyond the building line. 5. Selective Gradinq To avoid expansive soils exposed at finished grade, non-expansive soils (U.B.C. Expansion .- - - - - - - - - Vernon Savings and Loan August 1, 1986 Project No. 460.1.1 Page 10 Index less than 20) within the upper 3 feet of finished grade should be used. If used in fill, expansive soils should not be placed within 3 feet of finish grade. Bedrock materials consisting of silty sandstone of the Santiago Formation will provide an excellent source of select materials for use elsewhere at the site. In order to facilitate future trenching for footings, we recommend that cut areas underlain by bedrock be undercut to a minimum depth of 12 inches below the bottom of the footings. This zone should be replaced with properly compacted, non-expansive soils. Consideration should also be given to deeper undercutting of select areas of future utility line construction. 6. Compaction and Method of Filling All fills, with the exception of "rock" fills, placed at the site should be compacted to a minimum relative compaction of 90 percent, based on ASTM Laboratory Test Designation D 1557-78. Fill should be compacted by mechanical means in uniform lifts of 6 to 8 inches in thickness. Grading operations on the site should be sche- duled so as to dispose of the rock and expansive soils in the deeper canyon fills, and to "cap" the building pads, paving areas, and fill slopes with non-expansive materials. "Rock " fills should be compacted in accordance with the "Guidelines for Grading Projects," Paragraph 5.3 of Appendix B. To document rock fill placement and settlement of rock fills once in place, it is recommended that the following program be used: 0 Rock fill placement should be documented with both photographs and video camera. Still photographs - - - - - - - .- - -, _- - - - - - - - Vernon Savings and Loan August 1, 1986 Project No. 460.1.1 Page 11 should be used throughout the entire grading process to document alluvial clean out, subdrain installation, as well as during various stages of fill placement. The video camera should be used at various stages during rock fill placement exclu- sively and will document typical rock fill placement procedures (Owen Geotechnical has this equipment available). Areas of rock fills will also be documented on the as-graded geologic map submitted with the final grading report. 0 After the fills are graded to finish grade elevations in the area under- lain by "rock" fills, we recommend that settlement monuments be in- stalled for settlement evaluation. The monuments would be located to extend through the deepest section of fill along the axis of the canyon clean out. After installation, readings of the monuments should be taken by a qualified surveyer on a weekly basis for a period of ap- proximately three months. After three months, the monitoring program should be evaluated and the need for further monitoring determined. Specific locations and details for the settlement monument should be given by this office at the com- pletion of grading. A remote bench mark should be established well outside the zone of influence of the fill, probably in a bedrock cut area. Settlement monitoring data should be made available to this office for evaluation on an on- going, regular basis. - - - _. - - Vernon Savings and Loan August 1, 1986 Project No. 460.1.1 Page 12 Fills should also be placed and all grading performed in accordance with the City of Carls- bad Grading Ordinance, the requirements of the Uniform Building Code, and the attached "Guide- lines for Grading Projects," Appendix B. 7. Import Fill Material Any soils imported to the site for use as fill or subgrade materials should be predominately granular and approved by this office prior to importing. Laboratory testing required for approval of import sources may require 24 to 48 hours. This office should be notified of import locations a minimum of two (2) days prior to its proposed use. 8. Shrinkage and Buildinq Shrinkage and bulking factors due to removal and recompaction of on-site materials are summarized below: Expected Soil Type Volume Change Hard bedrock ZO-30% (Kgr-Jmv) Bulking Soft bedrock O-10% (Es) Bulking Alluvium and Topsoil lo-15% (Qya, QYO, TP) Shrinkage It should be emphasised that the above values are rough estimates based on available geotech- nical information and our past experience with similar materials. Amounts of volume change are highly dependent on a number of factors such as geologic structure of bedrock units, blasting techniques, size of rock fragments, compactive efforts, etc. Therefore, provisions should be made for variations in earthwork quantities. - - CMEN/G:OECHMX Vernon Savings and Loan August 1, 1986 Project No. 460.1.1 Page 13 - --. - - - .- - - .~- - - .- - 9. 10. Rippability and Blasting Rippability studies performed for the referenced reports indicate the following: 0 The San Diego Formation (Es) and Tertiary Paleosol (Tp) deposits are rippable with convention grading equipment. 0 Granitic rock (Kgr) is anticipated to be rippable to depths of approx- imately 10 feet to several tens of feet. 0 Metavolcanic rock (Jmv) may be rippable to depths of approximately 4 to 11 feet. Deep cuts will require blasting. Blasting operations can cause damage to adjacent structures (such as residences, water tank, public improvements, etc) . Effects of blasting on adjacent structures should be evaluated by the contractor or his subcontractor prior to commencing blasting operations. The contractor or his subcontractor should be solely liable for any blasting related damage to adjacent pro- perties. We recommend, whenever possible, a program consisting of damage survey and photo- graphic documentation prior to the blasting. Rock Disposal It is anticipated that considerable amounts of shot-rock will be generated during grading operations. In addition, isolated boulders may also be encountered during grading. Where rocks or similar irreducible materials of greater than 12 inches but less than 4 feet of maximum dimension are generated during grading. Special handling in accordance with details in Appendix B is recommended. Rocks greater than 4 feet should be broken down or disposed off-site. - - - - - .-~ - - .- - - - - .- .- - - - Vernon Savings and Loan August 1, 1986 Project No. 460.1.1 Page 14 Rocks up to 4 feet maximum dimension should be placed below the upper 10 feet of any fill and should not be closer than 15 feet to any slope- face. The contractor should be aware that incorporating rock in compacted fill will significantly reduce the rate of fill placement and may require the use of special equipment. 11. Temporary Excavation and Slopes Temporary excavation of slopes in the existing surficial soils and bedrock may be made near- vertical for cuts of less than 5 feet. For deeper cuts, temporary excavation slopes should be made no steeper than 1:l (horizontal to vertical) to a maximum depth of 20 feet in surficial soils and 60 feet in bedrock. These recommended slope ratios do not preclude local raveling and sloughing. Cut surfaces should be kept moist to retard raveling and sloughing. Water should not be allowed to flow over the top of the excavation in an uncon- trolled manner. Stockpiled materials and equip- ment should be kept back a minimum of 15 feet from the top of the cut. Workmen should be protected from falling rocks, sloughing and raveling of the cut. We recommend that all cut slopes be observed by this office during excavation so that appropri- ate recommendations may be provided. C. 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-erosive devices (i.e. paved swales and storm drains). OWMGXFCHMX - - -~ - -- - - - - - - .- - - - - Vernon Savings and Loan August 1, 1986 Project No. 460.1.1 Page 15 Subdrains should be placed under all fills located in drainage courses at identified or potential seepage areas. Their specific locations will be evaluated in the field during grading. General subdrain locations should 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 B, "Guidelines for Grading Projects." Subdrain pipe may be coated metal, P.V.C., or approved equivalent (crushing strength of 1,000 p.s.i. or greater). Drainage devices will be recommended behind sta- bilization fills, if any, to minimise the buildup of hydrostatic and/or seepage forces. The details and recommended locations of these backdrains are presented in Appendix B, "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. D. SLOPE STABILITY 1. Fill Slopes It is our understanding that 2:l (horizontal to vertical) fill slopes to a height of approx- imately 50 feet are anticipated for the subject site. A review of Reference 4 indicates that said slopes will be ~constructed with native material which will predominately consist of natural silty sands. The analysis provided in Reference 4 indicates that the proposed fill slopes will have a safety factor in excess of the generally excepted minimum engineering criteria of 1.5. - - - - - - - - .- - - - Vernon Savings and Loan August 1, 1986 Project No. 460.1.1 Page 16 Fill slopes should be constructed in accordance with the conclusions and recommendations out- lined herein and the guidelines for grading projects which accompany this report as Appendix B. To enhance the surface stability of the slopes, the following recommendations should be consid- ered. a. In the event that cohesionless soils are encountered exclusively in some areas, selective grading should be accomplished and more cohesive soils with binder used on the slope surfaces. However, soils with a high expansion potential should not be utilized for the construction of fill slopes. b. Slopes should be planted as soon as feasible after grading. Sloughing, drilling, and slumping of surficial soils may be anticipated if slopes are left unplanted for a long period of time, especially during rainy seasons. Erosion control and drainage devices should be installed in compliance with the requirements of the City of Carlsbad. 2. Cut Slopes Cut slopes to a maximum height of approximately 50 feet are planned at the site. The analysis provided in Reference 4 indicates that cut slopes graded in bedrock materials to a height of 50 feet with a slope ratios of 2:l (hori- zontal to vertical) or flatter should exhibit gross stability greater than the generally accepted minimum engineering criteria of 1.5 (subject to favorable geologic conditions). All slopes should be protected from erosion by appropriate planting and drainage devices. - - - - - - Vernon Savings and Loan August 1, 1986 Project No. 460.1.1 Page 17 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 (with appropriate drainage) should be constructed at the cut/fill contact. A typical fill-over-cut detail is presented in Appendix B. 4. Stabilisation Fills Stabilization fills are not expected at this time. We recommend that final evaluation of the need for stabilization be evaluated by the geotechnical consultant at the time of grading. E. PRELIMINARY FOUNDATION AND SLAB RECOMMENDATIONS 1. General The following recommendations are provided based on the assumption that building lots will be capped with a minimum of 3 feet of non-expansive soils. These preliminary recommendations should be confirmed by additional expansion testing on lot-by-lot basis at the completion of rough grading. The footing configurations and reinforcement recommendations herein do not preclude more restrictive criteria by the governing agencies due to bearing or structural considerations. A structural engineer should evaluate foundation configurations and reinforcement requirements for structural loadings, shrinkage, and tempera- ture stresses. 2. Foundations The recommended type of foundation is spread footings, either square or continuous. No footings should straddle a cut/fill interface. .- - .- .- - .- - - - - - - - Vernon Savings and Loan August 1, 1986 Project No. 460.1.1 Page 18 All footings for a given building should be founded either entirely in bedrock or entirely in compacted fill. a. Columns Columns may be supported on spread footings founded a minimum of 12 inches for one-story and 18 inches for two-story buildings below lowest adjacent finish subgrade. Rein- forcement should be based on struc- tural loading. b. Walls Exterior and interior footings should be continuous and founded at least 12 inches below lowest adjacent finish subgrade for one- story buildings and 18 inches below lowest adjacent finish subgrade for two-story buildings. Reinforcement in exterior and interior footings should consist of a minimum of two No. 4 reinforcing bars, placed one at the top and one at the bottom of the footing. Four No. 4 reinforcing bars placed two at the top and two at the bottom are recommended for foundations in areas underlain by structural rock fill. 3. Slabs Slabs should be at least 4 inches actual thick- ness reinforced with 6x6/10-10 welded wire mesh located at mid-height supported on concrete chairs. Living area slabs should be provided with 2 inches of clean sand followed by a 6-mil "visqueen" (or equivalent) moisture barrier. The moisture barrier should be sealed at all splices and overlain by at least 1 inch of clean sand. Areas to receive concrete should be thoroughly moistened prior to placing concrete. - .- - - - Vernon Savings and Loan August 1, 1986 Project No. 460.1.1 Page 19 4. Allowable Bearing Pressure for Footinqs Footings may be designed for an allowable dead plus live load bearing pressure of 2,500 pounds per square foot with a one-third increase for short-term wind or seismic loads. Footings should have a minimum width of 12 inches and, where located adjacent to utility trenches, and should extend below a 1 to 1 plane projected upward from the inside bottom corner of the trench. 5. Lateral Load Resistance Lateral loads against buildings may be resisted by friction between the bottom of footings and the supporting soils. An allowable friction coefficient of 0.40 is recommended. Alter- nately, an allowable lateral bearing pressure equal to an equivalent fluid weight of 300 pounds per cubic foot to a maximum of 3,000 pounds per cubic foot acting against the foot- ings may be used, provided the footings are poured tight against undisturbed soils. If it is desired to combine both frictional and passive resistance in design, an allowable friction coefficient of 0.30 should be used. 6. Footing Setback If footings are proposed adjacent to slopes, we recommend that the footings be deepened to provide a minimum horizontal distance of 7 feet from the outer edge of footings to the adjacent slope face. Footings planned under the influence of this recommendation should be given specific review by the geotechnical consultant prior to con- struction. - - - - - - .- - - - - .- - - - - - Vernon Savings and Loan August 1, 1986 Project No. 460.1.1 Page 20 7. Retaining Walls Restrained and cantilevered be designed in accordance design criteria. retaining walls may with the following Soil Pressure, Equivalent Fluid Pressure (P.C.F.) Restrained Cantilevered Backfill Level Sloping Level Sloping Soil Type Backfill 2:l Backfill 2:l Select Granular 45 55 35 45 Soils Walls subject to uniform surcharge loads should be designed for an additional uniform lateral pressure equal to one-third the anticipated surcharge pres- sure in the case of cantilevered walls, and one-half the anticipated surcharge in the case of restrained walls. Walls design should also consider surcharge from any adjoining structures located within a zone defined by extension of an imaginary 1:l lineup from the level of the wall footing. Additional design parameters may be requested. Retaining wall footings should be founded at a minimum depth of 18 inches below lowest adjacent grade. Recommendations for footing setback are provided in the previous section. Footings should be reinforced as recommended by the structural engineer. OWN/GEOlX HNCA - - -- - - ,.- - - - - Vernon Savings and Loan August 1, 1986 Project No. 460.1.1 Page 21 Flooding or jetting of backfill should not be permitted. Backfill placed behind the walls should be compacted to a minimum relative compaction of 90 percent as determined by ASTM Test Method 1557-78. It should be noted that the use of heavy compaction equipment in close proximity to retaining structures can result in excess wall movement. In this regard, the contractor should take appropriate precautions during the backfill placement. In case of subsurface building walls, considerations should be given to moisture proofing. Appropriate backdrainage should be designed by the project Civil Engineer and reviewed by this office. Minimum backdrainage should consist of a 4 inch perforated pipe surrounded by at least 3 cubic feet per lineal foot of filter rock wrapped in geofabric. F. SETTLEMENT If an entire building is founded in bedrock, overall differential settlements are expected to be neglig- ible. However, for buildings placed in areas of considerable differences in fill thickness, some differential settlements should be anticipated. Final grading plans and structure locations should be reviewed to evaluate if differential settlements are a potential constraint on construction. We recommend that building locations be reviewed and evaluations made by the architect, project civil and structural engineer to take potential deep fill settlements into account for specific structures. - .- - - - .- - - - - - - - - - - - Vernon Savings and Loan August 1, 1986 Project No. 460.1.1 Page 22 H. I. J. K. L. TRENCH BACKFILL Utility trench backfill consisting of the on-site material type should be placed by mechanical compac- tion to a minimum of 90 percent of the laboratory maximum density. SURFACE DRAINAGE Pad drainage should be designed to collect and direct surface waters away from proposed structures to approved drainage facilities. Drainage patterns approved at the time of fine grading should be maintained throughout the life of proposed struc- tures. GRADING PLAN REVIEW When final grading plans for the proposed develop- ment are completed, they should be reviewed by the geotechnical consultant to evaluate compliance with the recommendations presented herein. Review of grading plans may necessitate additional investiga- tion and analysis. FOUNDATION OBSERVATION All foundation excavations should be observed by the soils engineer prior to the placement of forms, reinforcement, or concrete. GEOTECBNICAL OBSERVATION Continuous observation by the geotechnical consul- tant is essential during grading to confirm condi- tions anticipated by the preliminary investigation, to adjust designs to actual field conditions and to determine that grading proceeds in general accord- ance with the recommendations contained herein. - - .~~. .- .- - .- - .- - - - .- Vernon Savings and Loan August 1, 1986 Project No. 460.1.1 Page 23 LIMITATIONS OF INVESTIGATION Our investigation was performed using the degree of care and skill ordinarily exercised, under similar circumstances, by reputable soils engineers and geologists practicing in this or similar localities. No other warranty, expressed 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 site conditions; however, soil and geologic conditions can vary significantly between 'borings and surface outcrops. As in most major projects, conditions revealed by excavation may be at variance with preliminary findings. If this occurs, the changed conditions must be evaluated by the project soils engineer and geologist and designs adjusted as required or alternate designs recommended. This report is issued with the understanding that it is the responsibility of the owner, or of his representative, to ensure that the information and recommendations contained herein are brought to the attention of the architect and engineer for the project and incorporated into the plans, and the necessary steps are taken to see that the contractor and subcontractors carry out such recommendations in the field. This firm does not practice or consult in the field of safety engineering. We do not direct the contractors operations, and we cannot be responsible for other than our own personnel on the site; therefore, the safety of others is the responsibil- ity of the contractor. The contractor should notify the owner if he considers any of the recommended actions presented herein to be unsafe. The findings of this report are valid as of the present date, however, changes in the conditions of a property can occur with the passage of time, whether they are due to natural processes or the works of man on this or adjacent properties. In addition, changes in applicable or appropriate standards may occur, whether they result from legislation or the broad- ening of knowledge. - - -. - .- - - - - - - - - - - - - - Vernon Savings and Loan August 1, 1986 Project No. 460.1.1 Page 24 Accordingly, the findings of this report may be invalidated wholly or partially by changes outside our control. There- fore, this report is subject to review and should be updated after a period of three years. This opportunity to be of service is appreciated. If you have any questions, please call. Very truly yours, OWEN GEOTECHNICAL --ml. -r: s&c TARA S. SIKH, RCE 35454 Senior Project Engineer -THOMAS C. GRAY, CEG 281 Senior Project Geologist l:ssb/bsz TSS/TCG/MRO Attachments Copies: (6 ) Addressee - - APPENDIX A APPENDIX A _- - - - - - - - .- - - - - SUBSURFACE EXPLORATION The subsurface exploration consisted of borings drilled to a maximum depth of 50 feet. Logs of borings are presented herein as Figures A-l through A-4. California sampler resistance blow counts were obtained by driving a 2.5 inch I.D. sampler with 140 pound hammer dropping through a 30 inch free fall. The blows per foot recorded on the boring logs represent the number of blows that were required to drive the last 12 inches. Boring log notations for the California sampler are indicated below: H California Sampler - .-. - _. - - - - - - - - - .- )RILLING COMPANY: MORRISON RIG: BUCKET-AUGER DATE: 6-16-86 IORlNl E F : Y z % 0 - o- 5- lo- 15- 20- 25 - 30 - )IAMETER: 3 IN. - z z 5% 0s i --- )RIVE ws n- g$ 6$ IO 0 --- SHl = 0 9-r : : :: J" j2 0 - SC -- 5” 3,548 LBS. DROP: 12 IN. ELEVATION: 291’ f SOIL DESCRIPTION BORING NO. 1 BEDROCK Gmtiago Formation,: Rust brown. clayey, fine ta medium sandetone, damp, medium dense Gradational contact an, silty, fine to medium sandstone, damp, dense, massively bed& @ 7.0 ft. Grades into light gray ccdor @ 15.0 to 16.0 ft. Highly cemented BORING LOG RILLING COMPANY: MORRISON RIG: BUCKET-AUGER DATE: 6-16-86 3RIN( - f if Y I k z o- 5- IO- 15- 20- m- 30 - IRIVE V - ZHl = SP - SP 3,543 LBS. DROP. 12 IN. ELEVATION: 305’ f SOIL DESCRIPTION BORING NO. 2 TOPSOIL: Light brown, fine to medium sand, dry, loose to medium dense BEDROCK Isantiago Oomtion, : Tan, silty, fine to medium sandsto damp. dense, massive bedding @ 3.0 ft. Bedding on rust co1ored 1aminatic.n Naw, 10'N @ 4.0 ft. Bedding on 1,4 in. gray clay seam N4ow. lO*N @ 5.0 ft. Grades into light gray color '/ @ 8.0 to 9.0 ft. Becomes slightly silty EORING LOG - - - - - - - - - - - - - - - - RILLING COMPANY: MOFzISON RIG: BUCKET-AUGER DATE: 6-16-86 --- --- --- I >RIVE - .-__ --- --- --- _- ML - SP .- ML & 3,548 LBS. DROP: 12 IN. ELEVATION: 305’ t SOIL DESCRIPTION BORING NO. 2 (continued) Irregular contact Green-gray with mottled rust brown, Siltstone, damp, dense N50E. 59 Light gray. fine to medium sandstone, damp, dense Green-gray Siltstone, damp. dense Gradational contact Tan-gray, silty sandstone, damp, dense Tofal Depth: 50.0 ft. NO water NO caving BORING LOG - - - - - - - - - - - - - - - - - - - ,RILLING COMPANY: MORRISON RIG: BUCKET-AUGER DATE: 5-16-86 IORINI E iti g z FL 0 - o- 5- 15- ZO- 25 - 30 - --_ push push --, 2 EuSh I IN. - k $5 OS i --- )RIVE 1 - wz 5; c,E 55 =8 _--- --- 3H’ = I 17 : : :: J” j2 I - SM 3,548 LE. DROP: 12 IN. ELEVATION: 244’ t SOIL DESCRIPTION BORING NO. 3 ALLrJvI”l4: Dark gray-brown, Silty sand, damp, loose to medium de”6 Tan, fine to medium sand, damp, loo5e to medium dense GTay-brown, clayey sand, moist, medium dense PALso3oL: Mottled gray, green-brown, c1ayey. film to medium Sandy moi6t. medium dense META "OLCANIC BEDROCK: Gray, ardesite, very dense TOtal Depth: 15.0 ft. NO water NO caving . . BORING LOG APPENDIX B APPENDIX B GUIDELINES FOR GRADING PROJECTS - _- - .-, 1.0 General 1.1 The work of the Contractor covered by this guideline consists of furnishing all plant, labor and equipment and performing all operations required to remove deleterious and undesirable materials from areas of grading, to properly prepare areas to receive fill, and to excavate fill to the lines and grades shown on the plans or as directed in the field by the Engineer of Work. '1.2 It is the intent of these guidelines to set forth re- quirements concerning removal of deleterious and un- desirable materials, preparation of areas to receive fill, quality of materials used for fill, moisture content and compaction requirements for fill and such other requirements as necessary to grade the site in accordance with the plans and specifications. 1.3 The Contractor shall perform the work in strict ac- cordance with these guidelines and he shall be respons- ible for the quality of the finished product notwith- standing the fact that the grading work may be observed and tests made by the Soil Engineer. 1.4 Deviations from these specifications will be permitted only upon written authorisation from the Soil Engineer with concurrence of the governing agencies. A geo- technical investigation has been performed for this project. Any recommendations made in the report of soil investigation or subsequent reports or addendums concern- ing grading aspects of the project shall become an addendum to these guidelines. 2.0 Fill Materials Materials for compacted fill shall consist of any soil excavated from the cut areas or imported to the site that, in the opinion of the Soil Engineer, is suitable for use in construction of fills. In general, fill - - .- - - - - - - - - - - .- .- - - - Project No. 460.1.1 August 1, 1986 Page 2 materials can be classified as "soil" fills, "soil-rock" fills or "rock" fills. 2.1.1 2.1.2 2.1.3 "Soil" fills are defined as fills con- taining no rocks or hard lumps larger than 12 inches in maximum dimension and containing at least 40 percent by weight of material smaller than l/4 inch in size. "Soil-rock" fills are defined as fills containing no rocks or hard lumps larger than 4 feet in maximum dimension and containing a sufficient matrix of 'IsoilW fill to allow for proper compaction of "soil" fill around the rock fragments or hard lumps. "Rock" fills are defined as fills con- taining no rocks or hard lumps larger than 3 feet in maximum dimension and containing little or no fines. 2.2 2.3 2.4 2.5 Material of a perishable, spongy, or otherwise unsuitable nature as determined by the Soil Engineer shall not be used in fills. "Soil" fill placed within at least the upper 3 feet of building pad grade shall be select finish grade material that contains no rocks or hard lumps greater than 6 inches in maximum dimension and that has an Expansion Index of 20 or less when tested in accordance with UBC Standard 29-2. The outer portion of fill slopes equal to at least the height of the slope (measured horizontal to the slope- face) or 15 feet, whichever is less, should be composed of properly compacted "soil" fill materials approved by the Soil Engineer. Representative samples of materials to be used for fill shall be tested in the laboratory by the Soil Engineer in order to determine the maximum density, optimum moisture content, and, where appropriate, shear strength and expansion characteristics of the soil. - - Project No. 460.1.1 August 1, 1986 Page 3 - - - - - - - 2.6 3.0 3.1 3.2 3.3 3.4 During grading, soil types other than those analysed in the geotechnical investigation may be encountered by the Contractor. The Soil Engineer shall be consulted to determine the suitability of these soils for use as fill and for use as finish grade soils conforming to recom- mendations in the geotechnical investigation report. Clearing and Preparing Areas to be Filled Areas to be excavated and filled shall be cleared and grubbed. Clearing shall consist of complete removal above the ground surface of all trees, stumps, brush, vegetation, man-made structures and all similar debris. Grubbing shall consist of removal of all stumps, roots, buried logs and other unsuitable materials and shall be performed in all areas to be filled. All roots and other deleterious materials shall be removed from areas to be filled. Borrow areas shall be grubbed to the extent necessary to provide materials free from unsuitable matter. After clearing and grubbing of vegetable matter and objectionable material, loose or porous soils shall be removed to the depth recommended in the geotechnical investigation. The depth of removal and compaction shall be observed and approved by a representative of the Soil Engineer. The exposed surface shall then be plowed or scarified to a minimum depth of 6 inches and until the surface is free from uneven features that would tend to prevent uniform compaction by the equipment to be used. Where fills are constructed on hillsides or slopes, topsoil, slopewash, colluvium or other loose or porous soils shall be removed and the slope of the original ground on which the fill is to be placed shall be stepped or "keyed" by the Contractor as indicated on Figures B-l and B-2. The steps shall extend completely through the soil mantle and into the underlying competent formational material or, where competent formation soil is not present, into compacted ground. After the foundation for the fill has been cleared, plowed, or scarified, it shall be disced or bladed by the Contractor until it is uniformly free from large clods, brought to the proper moisture content, then compacted as recommended for fill. ~N/G:OECi’ill(;b~: I - - - - - - - - - - - - - - Project No. 460.1.1 August 1, 1986 Page 4 4.0 Compaction Equipment 4.1 Compaction shall be accomplished by sheepsfoot rollers, vibratory rollers, multiple-wheel pneumatic-tired rollers, or other types of acceptable compaction equip- ment. Equipment shall be of such a design that it will be capable of compacting the "soil" or "soil-rock" fill to the recommended density and moisture content. 4.2 Compaction of "rock" fills shall be performed in accord- ance with Paragraph 5.3. ,5.0 Placing, Spreading and Compaction of Fill Material 5.1 "Soil" fill shall be claced bv the Contractor in accord- ance with 5.1.1 the following reco&endations: "Soil" fill shall be placed by the Contractor in layers that, when com- pacted, shall not exceed 6 to 8 inches. Each layer shall be spread evenly and shall be thoroughly mixed during spread- ing to obtain uniformity of material in each layer. The entire fill shall be constructed as a unit in nearly level lifts. Rock materials greater than 12 inches in maximum dimension shall be placed in accordance with Paragraphs 5.2 or 5.3, as appropriate. In general, the "soil" fill shall be compacted at a moisture content at or slightly above the optimum moisture content as determined by ASTM D 1557-78. 5.1.2 5.1.3 5.1.4 When the moisture content of "soil" fill is below that specified by the Soil Engineer, water shall be added by the Contractor until the moisture content is in the range specified. When the moisture content of the "soil" fill is above the range specified by the Soil Engineer or too wet to achieve - - - .~_ - - .- - - -. - .._ - - ,- - Project No. 460.1.1 August 1, 1986 Page 5 proper compaction, the "soil" fill shall be aerated by the Contractor by blasting, mixing, or other satisfactory methods until the moisture content is within the range specified. 5.1.5 After each layer has been placed, mixed, and spread evenly, it shall be thoroughly compacted by the Contractor to a relative compaction that is not less than 90 percent. Relative compaction is defined as the ratio (expressed in percent) of the in-place dry density of the compacted fill to the maximum laboratory dry density as determined in accordance with ASTM D 1551-18, or other laboratory density tests that will produce equiva- lent results. Compaction shall be continuous over the entire area, and compaction equipment shall make suffi- cient passes so that the desired density has been achieved throughout the entire fill. 5.1.6 Potentially "medium" to "high" expansive soils (soils having an expansion index of greater than 50) may be used in fills below a depth of 3 feet below finish grade and shall be compacted at a mois- ture content of 2 to 4 percent greater than the optimum moisture content for the material. 5.1.7 Properly compacted "soil" fill shall extend to the design surface of fill slopes. The surface of fill slopes shall be backrolled with a heavy loaded sheeps- foot or vibratory roller at maximum 4 foot fill height intervals and upon completion they shall be track-walked with a dozer so that a track covers all slope surfaces at least twice. Feathering of fill over tops of slopes shall not permitted. - - . - -- .,- - - - - - - - - - - .- - Project No. 460.1.1 August 1, 1986 Page 6 5.1.8 As an alternative to track-walking, upon completion, the slopes may be overbuilt by at least 5 feet and then trimmed back to the design grade. 5.2 "Soil-rock" fill shall be placed by the Contractor in accordance with the following recommendations: 5.2.1 Rocks larger than 12 inches but less than 4 feet in maximum dimension may be incorporated into the compacted "soil" fill, but shall be limited to an area measuring 15 feet minimum horizontally from the slope face and 10 feet below finish grade or 3 feet below the deepest utility, whichever is deeper. 5.2.2 Rocks or rock fragments up to 4 feet in maximum dimension may be individually placed or placed in windrows. 5.2.3 For individual placement, sufficient space shall be provided between rocks to allow for passage of compaction equip- ment. 5.2.4 For windrow placement, rocks must be placed in trenches excavated in well compacted "soil" fill. Trenches shall be 5 feet wide and 4 feet deep in maximum dimension. The voids around and beneath rocks must be filled with approved granular soil having a Sand Equivalent of 30 or greater and must be compacted by flooding. 5.2.5 All windrows must be parallel to each other and may be placed either parallel to or perpendicular to the face of the slope depending on the site geometry. Rock disposal details are provided in Figure B-5. - - - - - .- - Project No. 460.1.1 August 1, 1986 Page 7 5.2.6 All rock placement, fill placement and flooding of approved granular soil in windrows must be continuously observed by the Soil Engineer or his representative. 5.3 "Rock" fills shall be placed by the Contractor in accord- ance with the following recommendations: 5.3.1 The "rock" fill shall be placed on a sloping surface (minimum slope of 1 percent). The surface shall slope toward suitable drainage outlet facilities. The "rock" fills shall be drained during construction so that a hydrostatic pressure buildup does not develop. The drains shall be permanently connected to controlled drainage facilities to control post-construction infiltration of water. 5.3.2 "Rock" fills shall be placed in lifts not exceeding 3 feet. Placement shall be by rock trucks traversing previously placed lifts and dumping at the edge of the currently placed lift. Spreading of the "rock" fill shall be by dozer to facil- itate "seating" of the rock. The "rock" fill shall be watered heavily during placement. Watering shall consist of water trucks traversing in front of the current rock lift face and spraying water continuously during rock placement. Compaction equipment with compactive effort comparable to or greater than the dynamic effort of a 20 ton steel vibra- tory roller shall be utilised. The number of passes to be made will be determined as described in Paragraph 5.3.3 5.3.3 Plate load bearing tests, in accordance with ASTM D1196-64, will be performed in both the compacted "soil" fill and in the "rock" fill to aid in determining the number of passes of the compaction - - OWZN/G:OEC Hl;\ilC:,~.~ Project No. 460.1.1 August 1, 1986 Page 8 - .- - - - - - - - - - - - - - equipment to be performed. A minimum of three plate load bearing tests shall be performed in the properly compacted "soil" fill (minimum relative compaction of 90 percent). Plate load bearing tests shall then be performed on areas of "rock" fill having two passes, four passes and six passes of the compaction equipment, respectively. The number of passes required for the "rock" fill shall be determined by comparing the results of the plate bearing tests for the "soil" fill and the "rock" fill. The required number of passes of the compaction equipment will be performed as necessary until the plate bearing deflections are equal to 'or less than required. 5.3.4 A representative of the Soil Engineer shall be present during rock fill opera- tions to verify that the minimum number of "passes" have been obtained, that water is being properly applied and that specified procedures are being followed. At least two plate load bearing tests shall be performed per day in the "rock" fill. The actual number of plate load bearing tests will be determined by the Soil Engineer during grading with at least one test being performed for each approximately 5,000 cubic yards of "rock" fill placed. 5.3.5 Test pits shall be excavated by the Contractor so that the Soil Engineer can state that, in his opinion, sufficient water is present and that voids between large rocks are properly filled with smaller rock material. In-place density testing will not be required in the "rock" fills. 5.3.6 To reduce the potential for "piping" of fines into the "rock" fill from overlying "soil" fill material, a 2 foot layer of graded filter material shall be placed OW$N/GEOF - ,- ,- - ,- Project No. 460.1.1 August 1, 1986 Page 9 above and below the "rock" fill. The gradation of the graded filter material will be de termined at the time the "rock" fill is being excavated. Materials typical of the "rock" fill shall be submitted to the Soil Engineer in a timely manner to design the graded filter. 5 3 7 All "rock" fill placement shall be con- . . tinuously observed during placement by representatives of the Soil Engineer. 6.0 Observation and Testing 6.1 The Soil Engineer shall be the Owners representative to observe and make tests during fill foundation preparation and filling and compaction operations. In general, no more than 2 feet of "soil" or "soil-rock" fill in vertical elevation shall be placed without at least one field density tests being made within that interval; In addition, a minimum of one field density test shall be made for every 1,000 cubic yards of "soil" or "soil-rock" fill placed and compacted. 6.2 The Soil Engineer shall make random field density tests of the compacted "soil" or "soil-rock" fill to provide a basis for expressing an opinion as to whether the fill material is compacted as recommended. The basis for his opinion that the fill material has been compacted to at least the minimum relative compaction specified shall be that no tests in compacted or recompacted fill areas indicate a relative compaction of less than that spec- ified. Density tests shall be made in the compacted materials below any disturbed surface. When these tests indicate that the density of any layer of fill or portion thereof is below that specified, the particular layer or areas represented by the test shall be reworked until the specified density has been achieved. 6.3 The Soil Engineer shall verify that the minimum number of "passes" have been obtained per the criteria discussed in Section 5.3.3. The Soil Engineer shall make random - - OWSN/GEOl:C t MX ,~~~ - .,-. - - .- - - - - - - ,- .- - Project No. 460.1.1 August 1, 1986 Page 10 observation pits and plate load bearing tests of the placed "rock" fills. The observation pits will be excavated to provide a basis for expressing an opinion as to whether the "rock" fill is properly seated and suf- ficient moisture has been applied to the material. Plate load bearing tests will also be performed randomly on the surface of the previously placed lift. Plate bearing tests will be performed to provide a basis for expressing an opinion as to whether the "rock" fill is adequately seated. The maximum deflection in the "rock" fill determined in Section 5.3.3 shall be less than the maximum deflection of the properly compacted "soil" fill. When any of the above criteria indicate that a layer of "rock" fill or any portions thereof is below that speci- fied, the particular layer or area represented by the criteria shall be reworked until the "rock" fill has been adequately seated and sufficient moisture applied. 6.4 Testing shall conform to the following standards as appropriate: 6.4.1 "Soil" and Soil-Rock" Fills: 0 Field Density Test, ASTM D1556-82, "Density of Soil In-Place by the Sand Cone Method. 0 Field Density Test, Nuclear Method, ASTM D2922-81, "Density of Soil and Soil- Aggregate In-Place by Nuclear Methods (Shallow Depth) ." 0 Laboratory Compaction Test, ASTM D 1557- 70, "Moisture-Density Relations of Soils and Soil-Aggregate Mixtures Using 10 Pound Hammer and 18 Inch Drop." 0 Expansion Index Test, Uniform Building Code Standard 29-2 "Expansion Index Test." 6.4.2 "Rock" Fills 0 Fi eld Plate Load Bea Dl 196-64 (Reapproved .ring Test, ASTM 1977). Standard - - - - .- - - Project NO. 460.1.1 August 1, 1986 Page 11 Method for Non-representative Static Plate Load Tests of Soils and Flexible Pavement Components, For Use in Evalua- tion and Design of Airport and Highway Pavements." 7.0 Protection of Work 7.1 During construction, the Contractor shall properly grade all excavated surfaces to provide positive drainage and present ponding of water. He shall control surface water to avoid damage to adjoining properties or to finished work on the site. The Contractor shall take remedial measures to prevent erosion of freshly graded areas and until such time as permanent drainage and erosion control features have been installed. 7.2 After completion of grading and when the Soil Engineer has finished his observation of the work, no further excavation or filling shall be done except under the observation of the Soil Engineer. 8.0 Certifications and Final Reports 8.1 Upon completion of the work, Contractor is to furnish Owner a certification by the Civil Engineer stating that the lots are graded to within O.l+ foot vertically of elevations shown on the grading plan and that all tops and toes of slopes are within 0.5 foot horizontally of the positions shown on the grading plans. After in- stallation of the subdrain, the project civil engineer should survey its location and prepare "as-built" plans of the subdrain location. The project civil engineer should verify the proper outlet for the subdrains and the contractor should ensure that the drain system is free of obstructions. 8.2 Owner is also to furnish a final as-graded soils and geologic report satisfactory to the appropriate governing agencies and signed by a duly licensed Civil Engineer qualified in soil engineering and by a Certified Engi- neering Geologist, indicating that the work was done in substantial conformance with the recommendations or approved changes to the recommendations as authorised under Paragraph 1.4 of these guidelines. - - - - - - Project No. 460.1.1 August 1, 1986 Page 12 9.0 9.1 9.2 9.3 Streets, Storm Drains, Sewers and Lots in Rock Areas All streets in "rock" areas shall be undercut to sufficient depth to allow utility lines to be installed. Trenches shall be backfilled with material as described in Paragraph 2.1.1 of these guidelines and to the City of Carlsbad requirements. The lots in the rock areas shall be undercut 12 inches below the bottom of the footing and material as described in Paragraph 2.1.1 is to be placed on the lots. Storm drains in rock areas are to be backfilled with material as described in Paragraph 2.1.1 of these guide- lines and to the City of Carlsbad requirements. All spoil from the storm drain trenches is to be hauled and placed in the fill area at Contractor's expense as specified in Paragraph 5.0 of these guidelines. - - - - - - - ,- - - - - - - - - - - - ~- CALAVERA HlLL,S YARIABLE FILL SLOPE HEIQHT TOE OF FILL SLOPE TOF OF a, rlPF NATURAL SLOPE PROJECTED I:, MINIMUM .-- -. ---.- SHOWN ON GRADING PLAN f-75’ MINIMUM,-4 BASE KEY WIDTH MINIMUM DOWNSLOPE KEY DEPTH NOTE: WHERE NATURAL SLOPE GRADIENT IS Sr, OR LESS. BENCHING IS NOT NECESSARY. HOWEVER. FILL IS NOT TO BE PLACED ON COMPRESSIELE OR UNSUITABLE MATERIAL. I TYPlCAL BENCH WIDTH FILL SLOPE ABOVE NATURAL GROUND DETAIL UUEW,kEOFCHNICAL /PKIJECI NO. 480.1.1 I FIGURE NO, 8-l I I I I I I I I I I I I I I I I 1 I CALAVERA HILLS /---CUT/FILL CONTACT SHOWN ON ‘AS-BUILT’ / I- CUT/FILL CONTACT SHOWN ON GRADING PLAN ‘NOTE: CUT SLOPE PORTION SHALL BE MADE PRIOR TO PLACEMENT OF FILL FILL SLOPE’ABOVE CUT SLOPE DETAIL CYWJt$kOECHNICAL f I PmJfCTh%T 460.1.1 I FIGURf NO. B-2 - - - - - - - - - - - - - CALAVERA HILLS f SURFACE OF FIRM EARTH MATERIAL TYPICAL \ -+, COMPACTED FILL INCLINE TOWARD DRAIN SEE DETAIL BELOW DETAIL ----- ---- - MINIMUM 4’ DIAMETER APPROVED PERFORATED PIPE (PERFORATIONS MINIMUM 9 FT3PER LINEAR FOOT OF APPROVED FILTER MATERIAL 8. FILTER MATERIAL BEDDING FILTER MATERIAL TO MEET FOLLOWING SPECIFICATION OR APPROVED EOUAL: SIEVE SIZE PERCENTAGE 1’ 314’ 318’ NO.4 NO.30 NO.50 NO-POD 100 80-100 40-100 26-40 S-16 o-7 o-3 APPROVED PIPE TO BE SCHEDULE 40 POLY-VINYL-CHLORIDE (P.V.C.) OR APPROVED EOUAL. MINIMUM CRUSH STRENGTH 10.00 ~61 PIPE DIAMETER TO MEET THE FOLLOWING CRITERIA. SUBJECT TO FIELD REVIEW BASED ON ACTUAL GEOTECHNICAL CONDITIONS ENCOUNTERED DURING GRADING LENGTH OF RUN PIPE DIAMETER UPPER 600’ NEXT 1000’ ,150O’ 4’ 6’ 8’ TYPICAL CANYON SUBDRAIN DETAIL UWS?&kO732HNlCAL /PR~IE~IN~, 460.1.1 I FIGURE NO, 8-3 - - - - - .~- - - - - -- - - - - - - ~- - CALAVERA HILLS CANYON SUBDRAIN DETAILS /-- SURFACE OF FIRM EARTH -----____- MATERIAL TY;,C AL ~ENCH?~;$~;; UNSUITABLE .L 0 JJ L INCLINE TOWARD DRAIN SEE DETAIL BELOW DETAIL 0’ MIN. OVERLAP --- /MIN. 9 FT3 F(ER LINEAL FOOT OF APPROVED DRAlN MATERIAL SUPAC 5-P FABRIC OR APPROVED EOUAL 6’. MIN. OVERLAP ,-3UPAC 5-P FABRIC OR APPROVED EQUAL ADD 4’.tMIN.) DIAMETER APPROVED PERFORATED PIPE WHEN GRADIENT IS LESS THAN 2% MIN. 8 FT3 PER LINEAL FOOT OF APPROVED DRAIN MATERIAL DRAIN MATERIAL TO MEET FOLLOWING SPECIFICATION OR APPROVED EOUAL: APPROVED PIPE TYPES: PER’CENTAGE PASS,NG 7. SCHEDULE 40 POLY-VINYL- SIEVE SIZE CHLORIDE OR 7 7IZ’ ~88 - 100 2. CARLON VYLON ‘2’ PVC-SDR35 1’ 6 - 40 3/4’ 0 - ,‘I 3/8’ .o - NO. 200 o-3 GEOFABRIC SUBDRAIN M$EOlECHNlCAL /P~PCUEC, NO, 460.1.1 I FIGURE NO, B-4 r - - - - - - - ~- - - - ,- .- - - CALAVERA HILLS BIJILDINQ FINISHED BAADE CLEAR AREA FOR FOUNDATIONS. UTILITIES. AND SWIMMIND POOLS SLOPE FACE STREET f I_ 5’ OR BELOW DEPTH OF DEEPEST UTILITY TRENCH (WHICHEVER GREATER) TYPICAL WINDROW DETAIL (EDGE VIEW) GRANULAR SOIL FLOODED TO FILL VOIDS \ \ HORIZONTALLY PLACED COMPACTION FILL / / / PROFILE VIEW ROCK DISPOSAL DETAIL UUGN,kO7ZCHNICAL /P~XCTNO. 460.1.1 I FIGURE NO. B-S - - - - - - - - - - - - - -- - \ A COMPACTED FILL / Al I SUPAC 8-P FABRIC OR I -2% MlNlMUM GRADIE~NT APPROVED EOUAL A 4’ MlNlM”M APPROVED PERFORATED PIPE 4’ MINIMUM DIAMETER (PERFORATIONS DOWN) SOLID OUTLET PIPE MlNlMUM 2% GRADIENT SPACED PER SOIL TO OUTLET ENGINEER REOUIREHENTS TYPICAL BENCli INCLINED BENCHING TOWARD DR,“’ FINISH SURFACE SLOPE MtNlMUM 3 FT3 PER LINEAL FOOT OPEN GRADED AQGREGATE* TAPE AND SEAL AT CONTACT DETAIL A-A r TEMPORARY FILL LEVEL , / 1 COMPACTED MINIMUM BACKFILL 12’ COVER MINIMUM 4’ DIAMETER APPROVED SOLID OUTLET PIPE *NOTE: AGGREGATE TO MEET FOLLOWING SPECIFICATIONS OR APPROVED EOUAL: SIEVE SIZE PERCENTAGE PASSING 1 112’ 100 1’ S-40 314’ o-17 318’ o-7 NO. 200 o-3 BACKDRAIN DRAIN (GEOFABRIC) Wl+It&EOECHNICAL /P,~JECI NO. 460.1.1 I NGURE NO, B-6 - - - - - - - - - - - - - - - -- FINISH SURFACE SLOPE FINISH SURFACE SLOPE 3 FT3 MlNlMUM PER LINEAL FOOT 3 FT3 MlNlMUM PER LINEAL FOOT APPROVED FILTER ROCK* APPROVED FILTER ROCK* COMPACTED FILL COMPACTED FILL 4’ MINIMUM DIAMETER SOL,D OUTLET PIPE SPACED PER SOIL ENGINEER REOUIRE- MENTS DURING GRADING 4. MINIMUM APPROVED PERFORATED PIPE** (PERFORATIONS DOWN) MINIMUM 2X GRADIENT TO OUTLET BENCH INCLINED TOWARD DRAIN TYPICAL BENCHING DETAIL A-A TEMPORARY FILL LEVEL COMPACTED BACKFILL 4. MINIMUM DIAMETER APPROVED SOLID OUTLET PIPE 12’ MINIMUM COVER 12’ MINIMUM **APPROVED PIPE TYPE: SCHEDULE 40 POLYVINYL CHLORIDE (p.V.C.) OR APPROVED EOUAL. ,.,lNlM”M CRUSH STRENGTH 1000 PSI. *FILTER ROCK TO MEET FOLLOWINQ SPECIFlCATlONS OR APPROVED EOUAL: SIEVE PERCENTAGE PASSING 1. 100 314’ *o-100 310’ 40-100 NO.4 25-40 NO.30 5-15 NO.50 o-7 NO.200 o-3 TYPICAL BACKDRAIN DETAIL ~,kOFCHNICAL /PGO.IECTNO. 460.1.1 I NGLJRE NO. B-7