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784, Repair landslide area, Studies & ReportsDist. Office 12.02 Sheet 1 of 1 Tract / Parcel Map Parent Tract Site Address Geologist Soils Engineer 'unty of Los Angeles Department of Public Works DISTRIBUTION GEOTECHNICAL AND MATERIALS ENGINEERING DIVISION 1 Dist. Office GEOLOGIC REVIEW SHEET _ Geologist 900 So. Fremont Ave., Alhambra, CA 91803 1 Soils Engineer TEL. (626) 458-4925 1 GMED File 28147 2900 Palos Verdes Dr. Hamilton & Associates Lot(s) 4 Location City of Rolling Hills APN 7569-001-034 Developer/Owner Carley Engineer/Arch. Bolton Engineering Review of: ROUGH GRADING AND FINAL GEOTECHNICAL REPORTS Geologic Report(s) Dated Soils Engineering Report(s) Dated 8/11/11 Geology and Soils Engineering Report(s) Dated References: Grading P.C. No. 1005060001 For: Slope Repair Building P.C. No. Action: Based on the above referenced reports, rough grading is recommended for approval from a geologic standpoint for the issuance of building permits, with conditions below: Remarks: The Soils Engineering review dated 10/24/11 is attached. Prepared by Charles Nestle Reviewed by Date 10/24/11 Please complete a Customer Service Survey at htto://dow.Iacountv.aov/ao/amedsurvev, P:\Gmepub\Geology Revlew\Forms\Form07.doc 8/30/07 • COUNTY OF LOS ANGELES DEPARTMENT OF PUBLIC WORKS GEOTECHNICAL AND MATERIALS ENGINEERING DIVISION SOILS ENGINEERING REVIEW SHEET Address: 900 S. Fremont Ave., Alhambra, CA 91803 District Office 12.02 Telephone: (626) 458-4925 Job Number B359001 / A304 Fax: (626) 458-4913 Sheet 1 of 1 DISTRIBUTION: Slope Repair Drainage _ Grading Location 2900 Palos Verdes Drive North, Rolling Hills _ Geo/Soils Central File Developer/Owner Carley _ District Engineer Engineer/Architect - Bolton Engineering Corp. _ Geologist Soils Engineer Coastline Geotechnical Consultants, Inc. Soils Engineer Geologist ------ Engineer/Architect Rough Grading (Grading Plan Check No. 1005060001) Review of: Soils Engineering Report Dated 8/11/11 Previous Review Sheet Dated 10/13/10 ACTION: Rough Grading is recommended for approval. Reviewed by Yos Please complete a Customer Service Survey at http://dpw.latrounty.gov/g NOTICE: Public safety, relative to geotechnical subsurface exploration, shall be Angeles County Code, Chapter 11.48, and the State of California, Title 8, Construction P:\Yosh\2900 Palos Verdes Dr N, Rolling Hills, FGR-A Date 10/24/11 ce with current codes for excavations, inclusive of the Los • Dist. Office 12.02 Sheet 1 of 1 County of Los Angeles Department of Public Works DISTRIBUTION GEOTECHNICAL AND MATERIALS ENGINEERING DIVISION 1 Dist. Office GEOLOGIC REVIEW SHEET _ Geologist 900 So. Fremont Ave., Alhambra, CA 91803 1 Soils Engineer TEL. (626) 458-4925 1 GMED File LDD - Grading Tract 1 Parcel Map 28147 Lot(s) 4 Parent Tract Location City of Rolling Hills Site Address 2900 Palos Verdes Dr. APN 7569-001-034 Geologist — Developer/Owner Carley Soils Engineer Coastline Geotechnical Consultants Engineer/Arch. Bolton Engineering Grading P.C. No. 1005060001 Soils Engineering Report(s) Dated 4/15/10 Additional Reports Reviewed For: Slope Repair Action: Plan is not recommended for approval for reasons below. Remarks/Conditions: 1. The Soils Engineering review dated 5/26/10 is attached. 2. EffectiveAugust 1, 2006, all geotechnical reports submitted for review must include an electronic copy of the report on a CD in Adobe Portable Document Format (PDF). The electronic version shall include an electronically generated representation of the licensee's seal, signature, and date of sealing or signing. This project cannot be approved until this requirement has been met. The submittal in response to this review must include a CD containing an electronic version of the original report and the supplemental report in response to this review. Prepared by Charles Nestle Reviewed by Date 5/26/10 Please complete a Customer Service Survey at htto://dow.lacountv.aov/ao/omedsurvev P:1Gmepub\Geology Review1Fom,s\Form06.doc 2/13/08 Address: Telephone: Fax: Review No. 1 Slope Repair COUNTY OF LOS ANGELES DEPARTMENT OF PUBLIC WORKS GEOTECHNICAL AND MATERIALS ENGINEERING DIVISION SOILS ENGINEERING REVIEW SHEET 900 S. Fremont Ave., Alhambra, CA 91803 (626) 458-4925 (626) 458-4913 Location Developer/Owner Engineer/Architect Soils Engineer Geologist 2900 Palos Verdes Drive North, Rolling Hills Carley Bolton Engineering Corp. Coastline Geotechnical Consultants, Inc. Grading Plan Check No. 1005060001 Review of: Grading Plan Dated By Processing Center 5/6/10 Soil Engineering Report Dated 4/15/10 ACTION: Grading plan is not recommended for approval. REMARKS: District Office Job Number Sheet 1 of 2 12.02 B359001 / A304 DISTRIBUTION: 1 Drainage 1 Grading 1 Geo/Soils Central File District Engineer 1 Geologist 1 Soils Engineer 1 Engineer/Architect 1. Provide additional detail, clarification and description of the failure conditions, failure mode, and soil materials surrounding the slope failure. For example the soils report indicates that fill, natural soil (clay), and Terrace Deposits (silty clay) were discovered in subsurface explorations. Verify and address whether natural occurring silty clay materials may have contributed to the failure and whether the proposed fill slope will mitigate this material. Clarify whether there is adverse bedding condition that may affect the proposed fill slope. Also provide the estimated pre -failure conditions which caused the slope failure. Address and identify any drainage natural or man-made that may have contributed to the failure. Provide additional information and recommendations as necessary. 2. Provide specific recommendation for the soil materials that will be utilized for the proposed fill slope. Provide criteria of import soils, and percentages that will be mixed with the highly expansive on -site soils. The on -site soils appear to have high expansion potential based on the presented Expansion Index of 97, soil description, and the consolidation test. Address the effect of utilizing the on -site expansive soils for the construction of the proposed fill slope considering the existing natural swale and drainage. 3. Provide static, seismic, and temporary slope stability analyses that substantiate the proposed fill slope will mitigate the slope failure. Also, provide a geotechnical cross section, for each section analyzed, showing the critical failure plane used in the analyses. Indicate the various shear strength parameters used in the analyses, in the appropriate segments of each failure plane. Show locations of the cross sections used in slope stability analyses on the geotechnical map. Recommend mitigation if factors of safety are below County minimum standards. 4. Residual shear strength parameters must be used in static and surficial slope stability analyses. If remolded samples are utilized to represent fill materials, the percent relative compaction must be indicated. 5. Clarify the term "Based on 80% Peak Strength" on the submitted shear test results. Address in relation to residual shear parameters. 6. Verify the depth of suitable soils for the support of the propose keyway of the fill slope. 7. Verify whether geo-fabric will be utilized in the proposed fill slope. Provide geo-fabric recommendations, as necessary. If geo- fabric will be utilized recommendations must be show on the grading plans. 8. Provide a revised "111 Statement". The "111 Statement" must be definitive regarding future settlement. Qualifiers such as the word "abnormal" are not adequate. COUNTY OF LOS ANGELES DEPARTMENT OF PUBLIC WORKS GEOTECHNICAL AND MATERIALS ENGINEERING DIVISION SOILS ENGINEERING REVIEW SHEET Grading Plan Check No. 1005060001 Sheet 2 of 2 REMARKS (cont.): 9. Show the following on the grading plans: a. Existing topography for the areas shown on the grading plans. Include topography of natural drainage course, building pads etc.. b. Revise Vicinity Map to show location of the subject site. c. Recommendations and details of geo-fabric. Include vertical spacing, length, tensile strength, etc. as necessary. d. Location of "Restricted Use Area(s)". Per Count y policy, all areas of geo-grid and the 10 feet beyond the length of geo- grid must be placed in Restricted Use Area, as necessary. e. Recommendations of import soil characteristics, and soil mixture. f. All standard notes regarding fill compaction and density testing requirements. g. All recommended mitigation measures. 10. Submit two sets of grading plans to the Soils Section for verification of compliance with County codes and policies. 11. Requirements of the Geology Section are attached. 12. clude a copy of this review sheet with your response. NOTES) TO THE PLAN CHECKER/BUILDING AND SAFETY ENGINEER: ON -SITE SOILS HAVE HIGH EXPANSION POTENTIAL. wOFE3840, : c3 I. No. E75rj G e ` i Reviewed by /.iiwi. /. Date 5/26/10 Yosh'r'• r`` '� `7j / Please complete a Customer Service Survey at http:/�i(iw.lacoun NOTICE: Public safety, relative to geotechnical subsurface exploration, s _ 'r accordance with current codes for excavations, inclusive of the Los Angeles County Code, Chapter 11.48, and the State of California, Title ction Safety Orders. P:1Yosh12900 Palos Verdes Dr N, City of Rolling Hills, GP -NA 1 (Slope Repair) COASTLINE GEOTECHNICAL CONSULTANTS, INC. CONSULTING GEOTECHNICAL ENGINEERS 1446 W. 178TH ST. (310) 217-1504 GARDENA, CA 90248 FAX (310) 217-1909 1 1 1 I 1 1 1 1 1 1 1 GEOTECHNICAL ENGINEERING INVESTIGATION REPORT PROPOSED SLOPE RESTORATION 2900 PALOS VERDES DRIVE NORTH ROLLING HILLS, CALIFORNIA PREPARED FOR MR. and MRS. CARLEY APRIL 15, 2010 PROJECT NO. 2837C-020 COASTLINE GEOTECHNICAL CONSULTANTS, INC. L'11 I r Sal 1'YD g3 YIN(1 - 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 COASTLINE GEOTECHNICAL CONSULTANTS, INC. AI April 15, 2010 ------- _ - - - _ = CONSULTING GEOTECHNICAL ENGINEERS 1446 W. 178TH STREET GARDENA, CALIFORNIA 90248-3202 E-mail: coastlinegeo@sbcglobal.net Project No. 2837C-020 Mr. and Mrs. Jamie Carley 2900 Palos Verdes Drive North Rolling Hills, CA 90274 Project Reference: Geotechnical Engineering Investigation Proposed Slope Restoration 2900 Palos Verdes Drive North Rolling Hills, California Dear Mr. and Mrs. Carley: Tel. (310) 217-1504 Fax (310) 217-1909 Submitted herewith is a report of a geotechnical engineering investigation for the referenced project. This investigation was made for the purpose of obtaining information on the subsurface soils on which to base recommendations for a suitable method of slope repair, which was damaged by recent heavy rains. Location of the site, relative to general topography, streets and landmarks, is shown on the attached Vicinity Map, Plate 1. As outlined in the proposal of February 10, 2010, our work consisted of geotechnical observations, subsurface exploration and sampling, field and laboratory testing, calculations and analyses, and the preparation of this report. PROPOSED CONSTRUCTION It is understood that the proposed project will consist of the restoration of the failed, descending slope directly below the end of the residence driveway. Project No. 2837C-020 2 Carley/Rolling Hills DESCRIPTION OF SITE The subject site is an irregularly shaped parcel, situated on the south side of Palos Verdes Drive North, in the City of Rolling Hills. The access to the property is via a paved driveway serving several residences. From the building pad, the property descends at an average angle of 30 degrees to a natural drainage ravine adjacent to the westerly property line. During the recent rain storms, a surficial landslide occurred in the existing westerly descending slope. The area involved in the slope failure extends from directly below the end of the residence driveway toward the north, measuring approximately 70 feet long, with an average of 37 feet wide, and 1 to 5 feet deep. Partially blockage of the drainage ravine by the slump debris was observed during the field investigation. The property is occupied by a one story single family residence with an attached garage and swimming pool. Maximum topographic relief in the property is estimated to be 30 feet. The lot was developed by conventional cut and fill grading techniques to create level pads and driveways. FIELD INVESTIGATION Three test pits were excavated by means of hand equipment to depths ranging from 5.5 to 11.5 feet at the locations shown on Plate 2. The approximate locations of the test pits were determined by tape measurement from existing structures and property boundaries. Approximate elevations of the test pits were determined by interpolation between contours on a Partial Topographic Survey Plan, prepared by Bolton Engineering Corporation, dated April 5, 2010. The locations should be considered accurate only to the degree implied by the method used. A continuous record of the soils encountered during the excavating was made by our field representative, and is presented on Plates 3 through 5, Summary of Test Pits. The lines designating the interface between materials on the Summary of Test Pits represent approximate boundaries. The actual transition between materials was gradual. Undisturbed and bulk samples were secured at frequent intervals from the test pits for laboratory testing. Project No. 2837C-020 3 Carley/Rolling Hills SUBSURFACE CONDITIONS The study area of the site is mantled by a minor to moderate amount of fill consisting of mottled brown, moderately compact, silty clay with roots and scattered rock fragments. Below the fill is natural soil composed of medium brown to dark and blackish brown, firm, silty clay with occasional rock fragments. Underneath the fill and natural soils, to the final depth explored, is tan, firm to stiff, silty clay Terrace deposits. Creep, which is a nearly imperceptible movement of surficial soils downslope caused by the forces of gravity, was observed on the property. It is believed this movement extends to a depth of 5 feet below the surface. Groundwater and Drainage Groundwater was not encountered and none is anticipated within depths pertinent to the proposed construction. Fluctuations in the level of groundwater may occur due to variations in rainfall, temperature and other factors not evident at the time of the measurements reported herein. Fluctuations may also occur across the site. Surface drainage is comprised of sheet flow run-off of incidental rainfall derived primarily within the parcel boundaries, and runoff water within the ravine at the base of the slide. LABORATORY TESTS Laboratory testing was programmed following a review of the field investigation and after considering the probable foundation designs to be evaluated. Laboratory testing included the determination of density, moisture content and shearing resistance of the materials, as well as consolidation, compaction and expansion characteristics. The results of the tests are plotted or tabulated on the Summary of Test Pits, Plates 3 through 5, Direct Shear Test Results on Plates 6 through 8, and Consolidation Tests on Plates 9 and 10. A compaction test was performed on the silty clay. The sample was taken from Test Pit No. 1at 1 to 3 feet. The test, performed in accordance with ASTM D- 1557-09, indicated a maximum dry density of 93.5 pounds per cubic foot at an optimum moisture content of 25 percent. Project No. 2837C-020 4 Carley/Rolling Hills An expansion test was performed on the finest -grained soil found at the ground floor level. The sample was obtained from Test Pit No. 1, at a depth of ito 3 feet, and is classified as silty clay. The purpose of this test was to evaluate the potential for volume change and pressure increases with changes in moisture content. The test, performed in accordance with the ASTM D-4829-08a, indicated an Expansion Index of 97. The material would be classified as having a high potential for expansion. Details of the sampling and test procedures are given in Appendix A. DISCUSSION AND GENERAL COMMENTS, Based on the findings summarized in this report, and provided the recommendations of this report are followed, and the designs, grading and construction are properly and adequately executed, it is our finding that construction within the building site will not be subject to geotechnical hazards from landslides, slippage, or abnormal settlement. Further, it is our finding that the proposed building and anticipated site grading will not adversely effect the stability of the site, or adjacent properties, with the same provisos listed above. "Settlement" in the report is defined as structural movement in excess of 1-inch in a horizontal distance of 30 feet. It is our opinion that the slope failure occurred in saturated soil materials. The saturation likely was the results of extensive seasonal rainfall. The poor drainage of the site, made it possible for water infiltration into the slope during the recent rains. From a geotechnical engineering standpoint, remedial slope repair is feasible. The slope repair proposed herein will not adversely impact the property at the subject site, nor properties on the adjacent site. To reduce the possibility of the same problem occurring in the future, it is recommended that landslide debris and any loose soil be removed and the slope restored with an engineered fill to the original gradient. Fill shall be placed in accordance with recommendations given herein. All new remedial fill shall be keyed and benched into the existing competent soil material. Although, it is not ideal for a fill slope, we expect that the slump debris material will be utilized in the new compacted fill. Any vegetation should Project No. 2837C-020 5 Carley/Rolling Hills be removed from the earth material prior to being used for fill. The on -site soil is considered to be highly expansive. A more suitable fill material would be a low to moderate expansive blend of granular and fine soils. This may be achieved by importing a certain amount of soils for the slope repair. A key, at least 10 feet wide at the toe of the failed area, and a minimum of 24 inches into competent Terrace deposits or natural soil on the downslope site, is recommended. The fill then should be benched into the competent soil material as grading proceeds, as shown on Plate 11. The repair should be extended laterally to be at least 5 feet beyond the limits of the failure area and tied into firm soil material. To improve drainage of the fill slope, a pipe backdrain should be installed at the heel of the keyway and in midslope along the entire length of the backcut of the failure area. The backdrain pipe should be a minimum 4-inch diameter scheduled 40 PVC perforated drain pipe, with the perforations facing down, and enveloped with 3 cubic feet of clean 3/4-inch crushed rock. Backdrain should have two outlets consisting of non -perforated pipe. The pipe should be placed with a minimum two percent gradient out of slope, for positive drainage. The outlet pipes should be directed to the bottom of the natural drainage ravine. To improve the stability of the repair area, a suitable geogrid fabric or equivalent reinforcement should be installed during compaction of the fill. The supplier of the reinforcement should provide design calculations and specifications regarding the length, spacing and size of fabric required to be used by the civil engineers designing the repair. Surface drainage shall be controlled. Drainage control devices upslope from the failure area should be checked carefully. It is recommended that a qualified contractor and/or engineer evaluate site drainage devices with regards to adequate capacity and whether they are functioning properly. In no case shall drainage be allowed to discharge onto the repaired slope. Nor shall water be allowed to pond on the slope or cross over the top of slopes in a concentrated and uncontrolled manner. Following repair operations, the resulting exposed soil surface should be planted with lightweight, deep-rooted, low maintenance and low water use vegetation based on recommendations of a landscape architect and the City of Rolling Hills planting requirement. Project No. 2837C-020 6 Carley/Rolling Hills CONCLUSIONS AND RECOMMENDATIONS ' Liquefaction Potential Liquefaction is a process by which soil below the water table temporarily loses strength and behaves as a viscous liquid rather than a solid. The types of soil most susceptible to liquefaction are clay -free deposits of sands and silts. Liquefaction is caused by seismic waves, primarily shear waves passing through ' saturated, granular layers distorting the granular structure and causing loosely packed groups of particles to collapse. These collapses increase the pore water pressure between the grains, if drainage cannot occur. If the pore water pressure rises to a level approaching the weight of the overlying soil, the granular layer temporarily behaves as a viscous liquid rather than a solid, and liquefaction has occurred. ' The State of California, Division of Mines and Geology, has prepared an "Official Seismic Hazard" map, Torrance Quadrangle, dated March 25, 1999, which ' indicates the site is not in an area that may contain liquefiable materials. Seismicity I s Verdes Fault Zones,per Sheet The site is located 2.6 km from the Pao M-33, Maps of Known Active Fault Near -Source Zones, California Division of Mines and Geology, February 1998. In accordance with the implementation of the 2007 CBC by most regulatory agencies, attached on Plate Z are the Seismic Design ' Parameters. Temporary Excavation Slopes Temporary excavation sloes in the existing surface soil may be made vertical P Y P for cuts of less than five feet. For deeper cuts, temporary excavation slopes ' shall be made no steeper than 1:1 (horizontal to vertical). In areas where soils with little or no binder are encountered, shoring or flatter excavation slopes ' shall be made. Your attention is directed to the fact that while caving was not encountered in ' the test excavations, it is possible that a trench or excavation could react in an altogether different manner. Project No. 2837C-020 Carley/Rolling Hills All excavations shall be made in accordance with the regulations of the State of California, Division of Industrial Safety. These recommended temporary excavation slopes do not preclude local raveling and sloughing. Drainage Site drainage should be dispersed by non -erosive devices in accordance with the grading regulations of controlling agencies to preclude concentrated run-off and erosion over the site. In no case shall water be allowed to pond or drain down the slope in a concentrated and uncontrolled manner. Slabs -on -Grade Based on expansion tests, these soils are considered highly expansive. In order to mitigate the potential effects of expansion, it is recommended that slabs -on - grade should be a minimum of five inches thick and reinforced with No. 4 bars, 12 inches on -center each way. It is further recommended that the subgrade soils be moistened to a depth of 24 inches prior to placing of the membrane and pouring of floor slabs. The moisture content should be at least three percent greater than the optimum moisture content. A moisture barrier beneath the slabs -on -grade, preferably consisting of at least four inches of sand, with a waterproof vapor barrier, such as a plastic membrane of at least ten mils in thickness, covered with two inches of clean sand, is recommended in areas where soil moisture would be detrimental. Grading The following general specifications are recommended: 1. Areas to be graded or paved shall be grubbed and stripped of all vegetation, slide debris and other deleterious material. 2. In all cases where the ground slope is steeper than 5 (horizontal) to 1 (vertical), the existing ground shall be benched, as the fill thereon is brought up in layers. That existing ground which slopes flatter than 5 to 1 may also require benching, if the geotechnical engineer considers such to be necessary. 3. The exposed surface shall be compacted to at least 90 percent. All new fill shall be brought to near optimum moisture content, placed in layers not exceeding six inches thick and compacted to at least 90 percent. Project No. 2837C-020 8 Carley/Rolling Hills 4. The existing subgrade soils within the paved areas shall be compacted prior to construction of paving to secure uniform support and to minimize differential settlement. It is recommended the degree of compaction within the upper 12 inches be at least 90 percent. 5. All other fills and backfills shall be compacted to at least 90 percent. 6 The compaction characteristics of all fill soils shall be determined by ASTM D-1557-09. The field density and degree of compaction shall be determined by ASTM D-1556, or by other acceptable ASTM standard methods which are acceptable to the governing public agency. 7. Imported fill shall consist of clean, cohesive soil (clays and silts), free of vegetation and other debris, and shall be placed in layers not exceed six inches at near optimum moisture content. No rocks over three inches in greatest dimension shall be used. No soil shall be imported to the site without prior approval by the geotechnical engineer. The surface soils found on the project would be suitable for use in compacted fills, provided the deleterious material (mainly organics) are removed. 8. No jetting or water tamping of fill soils shall be permitted. 9. Cares shall be exercised during rough grading so that areas involved will drain properly. Water shall be prevented from running over slopes by temporary berms. 10. At all times, the contractor shall have a responsible field superintendent on the project, in full charge of the work, with authority to make decisions. He shall cooperate fully with the geotechnical engineer in carrying out the work. 11. No fill shall be placed, spread or rolled during unfavorable weather. When the work is interrupted by rain, operations shall not be resumed until field tests by the geotechnical engineer indicate that conditions will permit satisfactory results. Inspection As a necessary requisite to the use of this report, the following shall be observed by the geotechnical engineer: 1. Inspection of all grading operations Project No. 2837C-020 9 Carley/Rolling Hills 2. Inspection of all surface and subsurface drainage systems. 3. Inspection of premoistening of subgrade soils and placement of sand cushion and vapor barrier beneath the slab. The consultant should be notified at least two days in advance of the start of construction. A joint meeting between the contractor and geotechnical consultant is recommended prior to the start of construction to discuss specific procedures and scheduling. REMARKS The conclusions and recommendations contained herein are based upon findings and observations made at the three test pit locations. While no great variations in soil conditions are anticipated, if conditions are encountered during construction which appear to differ from those disclosed by the test excavations, this office should be notified, so as to consider the need for modifications. No responsibility for construction compliance with the design concepts, specifications or recommendations is assumed unless on -site construction review is performed during the course of construction which pertains to the specific recommendations contained herein. Footings should be located below a line measured at a 45 degree angle from the bottom of any utility trench, unless reviewed and approved by the geotechnical engineer. This report is subject to review by controlling public agencies having jurisdiction. This report has been compiled for the exclusive use of Mr. and Mrs. James Carley and their authorized representatives. It shall not be transferred to, or used by a third party, to another project, or applied to any other project on this site, other than as described herein, without consent and/or review by this facility. Should the project be delayed beyond the period of one years after the date of this report, the site and report shall be reviewed to consider possible changed conditions. Project No. 2837C-020 10 Carley/Rolling Hills Samples obtained in this investigation will deteriorate with time and will be unsuitable for further laboratory testing within three months from the date of this report. Unless otherwise advised, the samples will be discarded at that time. This investigation was made in accordance with generally accepted engineering procedures and included such field and laboratory tests considered necessary in the circumstances. In the opinion of the undersigned, the accompanying report has been substantiated by mathematical data in conformity with generally accepted engineering principles and presents fairly the information requested. No other warranty, expressed or implied, is made as to the professional advice included in this report. Respectfully submitted, COASTLINE GEOTECHNICAL CONSULTANTS, INC. 144///;A Amir Khalaj LOQ C.iJMJ- Richard A. Martin, RGE 563 RAM/AK/jm (5) Addressee APPENDIX A EXPLORATION AND TESTING FIELD EXPLORATION WAS ACCOMPLISHED USING A TRUCK -MOUNTED BUCKET AUGER OF SIXTEEN TO TWENTY-FOUR INCHES IN DIAMETER, ORAN EIGHT INCH, HOLLOW STEM AUGER, OR A BACKHOE WITH AN EIGHTEEN TO THIRTY INCH BUCKET, AND/OR A HAND DIGGING CREW USING POWER SHOVELS, AND/OR HAND AUGERS. THE METHOD(S) EMPLOYED IS COVERED IN THE FIELD INVESTIGATION SECTION OF THIS REPORT, THE EARTH MATERIALS ENCOUNTERED WERE CONTINUOUSLY LOGGED BY OUR FIELD REPRESENTATIVE AND VISUALLY CLASSIFIED IN ACCORDANCE WITH THE UNIFIED SOIL CLASSIFICATION SYSTEM. UNDISTURBED SAMPLES OF THE SOIL AND/OR ROCK WERE SECURED AT INTERVALS FROM THE EXCAVATIONS BY DRIVING A THIN -WALLED, STEEL SAMPLING TUBE INTO THE GROUND AHEAD OF THE EXCAVATION WITH SUCCESSIVE DROPS OF THE DRILLING BAR OR STEEL WEIGHT, THE DRIVE ENERGY REQUIRED FOR TWELVE INCHES OF PENETRATION IN POWER AUGER EXCAVATIONS IS SHOWN ON THE SUMMARY OF BORINGS. SAMPLES OF EARTH MATERIALS WERE RETAINED IN ONE INCH HIGH, TWO AND THREE -EIGHTH INCH INSIDE DIAMETER, BRASS RINGS, WHICH WERE ENCLOSED IN A POLYETHYLENE BAG AND STORED IN WATER -TIGHT PLASTIC CANS. REPRESENTATIVE BULK SAMPLES WERE OBTAINED AND PLACED IN WATER -TIGHT POLYETHYLENE BAGS FOR TRANSPORT. THE FIELD CLASSIFICATION WAS REVIEWED IN THE LABORATORY BY VISUAL EXAMINATION AND MAY HAVE BEEN AUGMENTED BY ASTM CLASSIFICATION TESTS SUCH AS GRAIN SIZE ANALYSIS AND ATTERBERG LIMITS TESTS, UNIT DRY WEIGHT AND FIELD MOISTURE CONTENT WERE DETERMINED FOR ALL UNDISTURBED SAMPLES. SHEAR TESTS PERFORMED ON SELECTED SAMPLES WHICH WERE PLACED IN CONTACT WITH WATER FOR A MINIMUM OF TWENTY FOUR HOURS TO SIMULATE EXTREME MOISTURE CONDITIONS, EACH SAMPLE WAS VERTICALLY LOADED AT SELECTED CONFINING PRESSURES, THEN SHEARED IN THE DIRECT SHEAR MACHINE AT A CONSTANT STRAIN RATE .OF 0.005 IN/MIN. THE SHEAR STRENGTHS PRESENTED HEREIN. REPRESENT EIGHTY PERCENT OF THE PEAK STRENGTH OR RESIDUAL STRENGTH, AND THE PEAK STRENGTH IS LIMITED TO 0.20 INCH OF STRAIN. CONSOLIDATION TESTS MAY HAVE BEEN PERFORMED ON SELECTED UNDISTURBED SAMPLES CONTAINED IN AN APPARATUS DESIGNED TO ACCOMMODATE A ONE INCH HIGH SAMPLE. LOADING IS APPLIED TO THE SPECIMEN IN SEVERAL INCREMENTS OVER SELECTED TIME INTERVALS, AND THE VERTICAL DEFORMATION RECORDED. UNCONFINED COMPRESSION TESTS ARE PERFORMED ON UNDISTURBED SAMPLES HAVING A LENGTH AT LEAST TWO TIMES THE WIDTH, UNDER CONSTANT INCREASING VERTICAL LOADING. ALL OTHER LABORATORY TESTS ARE PERFORMED IN ACCORDANCE WITH ASTM OR UBC DESIGNATED PROCEDURES. SYMBOLS AND ABBREVIATIONS SOME OR ALL OF THE FOLLOWING SYMBOLS AND ABBREVIATIONS HAVE BEEN USED WITHIN THE TEXT, PLATES, AND FIGURES OF THIS REPORT: - -- LOCATION OF BORING S - DIRECT SHEAR TEST -OE-LOCATION OF PIT C - CONSOLIDATION TEST XASSUMED DATUM POINT E - EXPANSION TEST - - -PROPERTY LINE G - GRADATION TEST U - UNDISTURBED SAMPLE A - ATTERBERG LIMITS TEST B - BULK SAMPLE F - UNCONFINED COMPRESSION TEST M - MAXIMUM DENSITY - OPTIMUM MOISTURE TEST 1 r 1 . ,-P/ 1 1 1 1 1 1 1 1 1 1 1 1 1 • VICINITY SAP `��'�"�`` , /!I((�����'c: `:.ter._ �j � ��•,6 `�`> ``- 1.-'. t ��, ,� GGG111YYY . J ;\ >\•`.1.r, •i'(��� �`V 'i teri a / \� ,, n V W *,, •�.lit �\(\,I (( -�`�� 1�,�`' t ✓ ' l� ram, �G, �i �.wr►��_.,,�,l—:,...-= �`:,` ,\\ \ i �\\1�` t i •`f (.1'„"1'l'i �1L� ,`,1 t( �� r` 1„�•� ,i ) 1 •./ 1'�.. 'J,(1'�` 7, >\\ (: ;,ti _ 4 . I t �1' w\\���' ��f r"-� l: - �-�l\',• 1 }`` '...:_.--:-- ijcs? -Q(-\,- :.T7,-, I � � �,'t t ` ti! f (,,, !r Jt ,, -, 'a - �"•` '� a �'� 't n�`$i�J�`� s�}�\vie i ��%��i��l"`'I' �;�\�•��`N '• ,�...� � �•---_.:_:• � : Boa 1i�'/' ��. 7 �, `�� r„ . 1 •\. -- ems �'.� 'T ' . >, ! ^yi'" �i�` `•'�. �. -�--.. �'�{ ,�r . •%^1 _ �� i'^.7 .,.1,� �JY=�—=t�ii1/la- .�\,` :�i+ tr" Y r �' '`I' A` 11—�;_=-'�"•� ��\ �„--•gy\ %�'1 (/t i\r< :H �C_r ` \ :��Ji;� +�a i1 /y //•r/.,t -`�,���ii'�\\� � •���-`,'''� 3�'i�«{' ' �`1�,� ,`.�� %,ia.,.. p ' No 2837G-020 i M.�... - anon Engineering investigation plate Geotechnicai E Verdes Drive North 2900 Palos Rolling Hills, California nsu�tants� Inc. CoastlineGeOttClinfCat Co 1 5 99.00 CONC z-- -POWER 0/ POLE --WOOD FENCE CONC. DRIVEWAY D FENCE \\los 2B141 kSYC M.I3.7B1, PG. 42 S 75.41 ,40„ E 134.14' -Tgiaci. to. 2041 kSYC 2. 0.ve).181 42 , 27' GENE'R is\k_ 1 El_EP k.-\ ONE E ASE. - 11110.• ED SON EASE. —is 10' ....... r DRAINAGE COURSE P ARTI ALLY BLOCKED /J.: co o • • (.5A 69 30' EDISON EASE. pO\I\O —el 10' zz 1' I 1 Li z -0 • i V) ! 02_ 10.64 (Nti FL0WLIN 0.20 • 11 AREA SUBJECT TO _ ------ FLOOD HAZARD ------ 30' 111010.104 EDISON EDISON EASE. EASE. - --11100.-00111 11110.- 1 0 1 . • 30' 3. 1 ‘40. 2BA41 V-01' 3 Mee. IBA , 42 tx N A5 to 105 GARA Ci\ike•( V.01. 4 d47 IlkNG1' . 2.B 0.5. IBA , 42. • a .... :_m_......--7::._ . :....77....„...<: .7:7:::-:::-----...:,..T.Ti. . -..--L-- ... 1°. ..06Lv..£::.._ .... N--wifillic,i d .... ...... /4'),,,(5, .... . ..... : . :::r7'N.2...07...,.0.... .... ......... . : .... . .. ..:_: _.„.411110".-A . ss •t.81 Ann Carley 2900 Palos Verdes Drive North Rolling Hills, Co. 90274 SCALE: DATE: 1"=10' April 2010 Colton Engineering Corp. Civil Engineering and Surveying 25834 Narbonne Avenue Suite 201 t.onvta. Ca 90717 Pn. 310-325-5580 Fax: 314325-5581 PARTIAL TOPOGRAPHIC SURVEY Rear Yard Slide ;1 GEOTECHNICAL ENGINEERING I, NVESTI1 GATION 2900 PALOS VERDES DRIVE NORTH ROLLING HILLS, CALIFORNIA APPROVED BY: DRAWN BY REVISED COASTLINE GEOTECHNICAL CONSULTANTS PROJECT NO. 2837C-020 IDRAWING NUMBER 2 DATE: 03/12/10 cc. 22g E a)0 ., a o 0 aai 0 g UB 0 - a.) 4-1 u_ 76 36.8 y 75 33.7 84 33.7 5 80 35.1 10 15 20 SUMMARY OF TEST PIT NO. 1 Description FILL: CLAY --- silty, slightly sandy with occasional rock fragments O 0 U 0 a) N c 0 V Mottled Moderately Brown Compact NATURAL SOIL: CLAY — silty with occasional Medium Firm rock fragments Brown TERRACE DEPOSITS: CLAY --- silty — End of Test Pit at 11.5 Feet Hand Excavation: 0-8 Feet — Hand Auger: 8-11.5 Feet No Water — No Caving Light Brown Firm to Stiff Geotechnical Engineering Investigation Project No. 2837C-020 2900 Palos Verdes Drive. North Rolling Hills, California Plate 3 SUMMARY OF TEST PIT NO. 2 DATE: 03/12/10 o a) (7) -a c c•-• a) a) 0 17) Description a a_ rn cn 'EL 0 "(3 0 UBO 0 71 35.6 77 31.2 68 35.4 74 28.2 7 5 10 FILL: CLAY — silty, slightly sandy with rock Mottled Moderately fragments Brown Compact NATURAL SOIL: CLAY — silty with occasional Dark Brown Firm rock fragments TERRACE DEPOSITS: CLAY — silty with rock fragments End of Test Pit at 7.5 Feet — No Water No Caving Geotechnical Engineering Investigation 2900 Palos Verdes Drive, North Rolling Hills, California Light Orange Firm to Brown Stiff Project No. 2837C-020 Plate 4 SUMMARY OF TEST PIT NO. 3 I DATE: 03/12/10 '' o U LL L C N o n N `p° Description 0o -ui p 2 U B 0 0 SLIDE DEBRIS/Fill: CLAY — silty Mottled So .. ft Brown 68 33.2 - , NATURAL SOIL: CLAY — silty with occasional Dark Brown Firm rock fragments to Black 78 30.5 TERRACE DEPOSITS: CLAY — silty with rock Light Orange Firm to fragments Brown Stiff 79 36.3 77. 5 End of Test Pit at 5.5 Feet ' _ No Water No Caving ' Geotechnical Engineering Investigation Project No. 2837C-020 2900 Palos Verdes Drive, North Rolling Hills, California Plate 5 3 1 0 0 SHEAR TEST RESULTS Test Pit No. 1 @ 3 Feet' 1 2 3 Confining Pressure (kips/sq. ft.) Stress - Displacement Diagram 4 4 01 Kip p- 3 m 2 Kips ®3 Kips w 2 N N 2 1 -65 0-0 LLALIA in El ri EnCIp®®InL1 ®p ®®®©* V v v v 0 1 2 Horizontal Displacement (X 1/10 inch) Silty clay samples were submerged for at least 24 hours. The samples had a density of 75 lbs./cu.ft. and a moisture content of 47.1 % Cohesion = 375 psf Friction Angle = 23 degrees Based on 80% Peak Strength Geotechnical Engineering Investigation 2900 Palos Verdes Drive North Rolling Hills, Califomia Project No. 2837C-020 Plate 6 COASTLINE GEOTECHNICAL CONSULTANTS 1 4 3 4 • 2 w 0 SHEAR TEST RESULTS Test Pit No. 1 @ 7 Feet' 1 2 3 Confining Pressure (kips/sq. ft.) Stress - Displacement Diagram 4 4 Al Kip aT 3 ®2 Kips n A 3 Kips eL • , ein0©0oUU CUCaaa000 0 0 1 Horizontal Displacement (X 1/10 inch) 2 Silty clay samples were submerged for at least 24 hours. The samples had a density of 80 lbs./cu.ft. and a moisture content of 42.3 % Cohesion = 410 psf Friction Angle = 23 degrees Based on 80% Peak Strength Geotechnical Engineering Investigation Project No. 2837C-020 2900 Palos Verdes Drive North Rolling Hills, California Plate 7 COASTLINE GEOTECHNICAL CONSULTANTS SHEAR TEST RESULTS Test Pit No. 3 @ 5 Feet 3 co 0) 52. 2 N N ''^^ 0) �+ 0 0 1 2 3 Confining Pressure (kips/sq. ft.) Stress - Displacement Diagram I‘t4LAAe®©oe© �® ��--�®®®©mot, 0 1 Horizontal Displacement (X 1/10 inch) 2 4 .1 Kip E 2 Kips A 3 Kips Silty clay samples were submerged for at least 24 hours. The samples had a density of 79 lbs./cu.ft. and a moisture content of 43 % Cohesion = 450 psf Friction Angle = 22 degrees Based on 80% Peak Strength Geotechnical Engineering Investigation 2900 Palos Verdes Drive North Rolling Hills, Califomia Project No. 2837C-020 Plate 8 COASTLINE GEOTECHNICAL CONSULTANTS Consolidation (Percent) 0.1 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 - CONSOLIDATION TEST RESULTS Test Pit No. 2 @ 1 Foot Pressure (Kips Per Square Foot) 0 Test Specimen at In -Situ Moisture 0 Test Specimen Submerged Geotechnical Engineering Investigation 2900 Palos Verdes Drive North Rolling Hills, California 10 Project No. 2837C-020 Plate 9 COASTLINE GEOTECHNICAL CONSULTANTS Consolidation (Percent) 0.1 -1.00 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 - CONSOLIDATION TEST RESULTS Test Pit No. 2 @ 7 Feet Pressure (Kips Per Square Foot) I' I I I 0 Test Specimen at In -Situ Moisture 0 Test Specimen Submerged Geotechnical Engineering Investigation 2900 Palos Verdes Drive North Rolling Hills, California i 10 Project No. 2837C-020 Plate 10 COASTLINE GEOTECHNICAL CONSULTANTS Inn EMI 1111111 I 1111111 •3u1 `s;us4InsuoJ F��Shed fl 0) i 0 0 Zia M Subdrains to consist of perforated, 4-inch diameter (minimum), schedule 0' 40 pvc pipe or better, placed with perforations down and surrounded by 1114 a minimum of 3-cubic feet per linear foot of 3/4-inch diameter durable aggregate gravel. Gravel and pipe to be wrapped in geosynthetic fabric (Mirafi 140 or approved equivalent). SECTION A -A' Geogrid fabric or equivalent reinforcement as specified by manufacturer or Project Civil Engineer Approved natural materials Solid subdrain lateral 4`///$//////,�/ outlet • > /. `/ii,`//; ZZI /1 Keyway constructed with a minimum 2 feet dense natural material exposed on downhill side of excavation. Keyway bottom inclined at 2% gradient into slope Typical Fill -Slope, Keyway, Benching, and Subdrain Detail SCALE: 1" = 8' 1t B$ lL b�• 1 .i