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621 MOD, Remodel and add 1154 sq ft to , Studies & ReportsKEITH W. EHLERT Consulting Engineering Geologist January 10, 2000 Project No. 4572-99 Mr. Jack Shoemaker 16 Palomino Lane Rolling Hills Estates, CA 90274 SUBJECT: ADDENDUM - REPORT OF ENGINEERING GEOLOGIC AND SOILS ENGINEERING INVESTIGATION Proposed Residential Improvements # 9 Maverick Lane Rolling Hills, CA REFERENCE: REPORT OF GEOLOGIC AND SOILS ENGINEERING INVESTIGATION, Distressed Garage, #9 Maverick Lane, Rolling Hills, CA (Project No. 4398-99), dated April 14, 1999. ADDENDUM - REPORT OF GEOLOGIC AND SOILS ENGINEERING INVESTIGATION, Distressed Garage, #9 Maverick Lane, Rolling Hills, CA (Project No. 4398-99R1), dated April 26, 1999. RESPONSE TO COUNTY OF LOS ANGELES GEOLOGIC AND SOILS ENGINEERING REVIEW SHEETS, #9 Maverick Lane, Rolling Hills, CA (Project No. 4398-99R.1), dated August 31,1999. Pursuant to your request, the accompanying report has been prepared for the purpose of providing geologic and soils engineering information pertaining to the proposed site improvements. Based on information obtained during this investigation, it is our opinion the site is geotechnically suitable for the proposed construction. If you have any questions regarding the information presented in this report, please contact our office. Respectfully subm*#t` 'nc »EE'' Keith W. Ehlert Stephen W. Ng J C.E.G. 1242 GE 637 opsOFESS/ptiq Q��N WA/--��4, rr, No. 637 27520 Hawthorne Blvd., #220 • Rolling Hills Estates, CA 90274 (310) 544-7686 • Fax (310) 544-9332 P.N. 4572-99 TABLE OF CONTENTS Page INTRODUCTION 1 PURPOSE AND PROPOSED IMPROVEMENTS 1 SCOPE OF WORK 1 REFERENCES 2 SITE DESCRIPTION 3 FIGURE 1 4 GEOLOGY 5 FIGURE 2 6 CONCLUSIONS 8 COMPLIANCE WITH COUNTY CODE 111 10 RECOMMENDATIONS 11 FOUNDATION DESIGN 11 SETBACK 11 ALLOWABLE BEARING CAPACITY 12 SKIN FRICTIONAL RESISTANCE 12 SETTLEMENT 13 LATERAL DESIGN 13 DOWNHILL CREEP 14 EARTH PRESSURE ON RETAINING WALLS 15 BACKDRAIN AND WATERPROOFING 15 WALL BACKFILL 16 CONCRETE SLABS 17 EXPLORATORY BACKFILL EXCAVATIONS 18 GRADING SPECIFICATIONS 19 SLOPE SURFACE STABILITY 20 EXCAVATION 21 CONSTRUCTION SITE MAINTENANCE 22 REGULATORY AGENCY REVIEW 23 PLAN REVIEW AND CONSULTATION 23 RECOMMENDED INSPECTIONS 24 COMMENTS 25 APPENDIX I APPENDIX II APPENDIX III APPENDIX IV Test Trench Logs Laboratory Testing Slope Stability Analysis Slope Surface Stability Analysis 1 P.N. 4572-99 Page 1 INTRODUCTION PURPOSED AND PROPOSED IMPROVEMENTS ' The purpose of this investigation was to obtain information on the subsurface geologic and geotechnical conditions with regard to construction of additions to the existing ' house and to provide recommendations pertaining to foundation design, grading, temporary excavations, drainage control and other relevant parameters for the design ' and construction of the proposed improvements. No significant amount of grading is planned for the proposed construction. Construction plans have not been prepared and await the conclusions and ' recommendations of this report. Specific construction plans shall be reviewed by this facility, when available, so as to determine the need for further geologic and soils engineering study and possible revised recommendations pertinent to the proposed ' development. Further geologic and soils engineering study may include additional field exploration, laboratory testing and engineering analysis. SCOPE OF WORK ' The scope of work performed for this investigation included the following items: ' I. Gathering and reviewing of published and unpublished reports and maps pertaining to the geologic and soils engineering conditions on the site and in the surrounding area. ' . Review of aerial photographs of the site area. I. Detailed mapping and evaluation of features observed in the site area. ' . Subsurface exploration consisting of twelve backhoe trenches. ' . Detailed logging of features observed in the trenches. ' P.N. 4572-99 Page 2 I • Collection of representative samples of materials exposed in the test trenches. • Laboratory testing of the collected samples. ' • Soils engineering interpretation of laboratory test results. • Soils engineering analyses. • Preparation of this report with maps and other graphics to present the findings and 9 recommendations. 1 Procedures and findings of field exploration and laboratory testing are presented in Appendices I and II. Procedures and results of stability analyses of the subject slopes are presented in Appendices Ill and IV. REFERENCES The items utilized during this review included: • Geology and Paleontology of the Palos Verdes Hills, California, by W.P. Woodring, IM.N. Bramlette, and W.S.W. Kew, U.S.G.S. Professional paper 207, 1946. • Geology of the Palos Verdes Hills, Los Angeles County, California, CDMG Map Sheet 1 27, by George B. Cleveland, 1980. I• Geologic Map of the Palos Verdes Peninsula, by Thomas W. Dibblee, May 1999. I I I I I I I I I I I I I I I I I I P.N. 4572-99 Page 3 SITE DESCRIPTION The site is situated at the northerly end of Maverick Lane in the City of Rolling Hills, Los Angeles County, California. Figure 1 shows the approximate geographic location of the site. The Geologic Map (Plate 1) and Geologic Cross -Sections (Plates 2 and 3) are adapted from our previous work at the site. Plates 4 and 5 are additional Geologic Cross - Sections drawn through the site area. The site is improved with a single-family residence. The existing house and appurtenances are located on a relatively level pad. Slopes descend from the northerly and easterly margins of the pad. The easterly -facing slope descends to a lower pad that contains a corral. Information obtained during this investigation indicates that the site was developed by placing fill on a natural northeasterly descending slope. • A AN, CONI; • \IIS r a; DES `I I I t sr0E tM i• No . s tE) Q2__, '; TN BEND _ L I I ttt3 ��, �.._ ;_ J (,HESi.RFlE[D a2 1`ro�u. f. • • REATA % RD ,_ LN 4.p �' N R RDK'. DS (TE _ .0 V-* 'Of EBACK RD P,D pDDIERgCK PPt TR •( ..SDP •1• 0.D / s'ttcrCP,5SS 'tnRNDR tk •�iCr IWC�• 1 g0."CO O� G/ ,nnw,R 4. F \ "M •J . (,oRG„, NO ' 7B v` q 'c x/ 4,o,S n yC x1 ' O ,q 90 y0 R GH•"i f r'rCBRAND ', PN?D RO RD 9:" 0.SSTSNI T R' , r PACKSADDLE, p 1 M.t.�p�'a'i i •4:. "oua o-�{r . sot 17'-‘C/19(1' Wei Sr DRVE o¢ py 7700 J'500 CCfJ df• 7M� 45ri ANT P'P'&IADERI`�( '4fc Gry'/ b, DE1UNA 4300 LESS �t• �o- ,,! LINEA x a44 �,+42 J, Cl�� DR , r 750D^ NR IR r. 4R 'fOn DR H x DR ni£f `P\ DR S >5s� QR ��F9 QP �C rn rt Es PALOS l I , irQ' s` oq\ a9 4' 43„�t'CaIfr PAto 9 7lE max` � ,�9 1 I � QWi %- GAHADO RDES SEE D J6 CO F( 1111ua15 EN 2 WE TER 3 443(40RT 444 4 FOREWARN Ex R (SITE) Avf• i ;b[Ekr.til DP �t P 1,------.� , VE,90 X (\ � / ed. Op LOCATION MAP IP.N.4572-99 I • 9N1 4:: - 4P L1W FE[ICAHD '-55x5a VDO f CLF OR v, 01�.- itoD op ` f !=� �' iwvAc ..._.. ;ems `.[to I ` e rt \ Im YIf aJR H5a fi UDS`IT4 s' VIEE?(+E Nx Page 4 SUMMERLAI, 4)37. SI 4O0N s(nnyto•_o-s T+x+• ,v ES17, Figure 1 P.N. 4572-99 Page 5 GEOLOGY Information obtained from the referenced reports and maps, from previous experience at ' the site and from the exploratory excavations indicates that the subject site is underlain by shale and volcanic bedrock of the Miocene Monterey Formation locally mantled by natural soil and fill materials. Logs of the test trenches are included in Appendix I of this report. ' Plate 1 is a Geologic Map that shows the geologic data obtained from the test trenches excavated during this investigation and from test pits excavated during our previous investigation at the site. Plates 2, 3, 4, and 5 are Geologic Cross -Sections drawn through the site area. Figure 2 is a Regional Geologic Map that was included in our previous work ' at the site. Fill soils observed in the test trenches generally consist of mottled light to dark -colored silty clay. The fill soils generally appear dry to slightly moist and soft to stiff. ' Natural soil observed in the test trenches generally consists of dark -colored silty clay. The soil generally appears slightly moist and stiff, and appears to be in gradational contact with the underlying bedrock. Bedrock observed in the test trenches generally consists of yellow to orange brown siltstone that in some locations appears to be intruded with orange brown volcanic rocks. ' The siltstone and volcanic rocks are hard and tight. Bedding planes within the bedrock are poorly to well defined and generally appear to be dipping southeasterly, consistent with ' bedding orientations that we have observed at the southerly adjacent lot (#7 Maverick Lane). • Vx.s.•••• 4. Li rn a s LANDSLIDE MAPPED BY CLEVELAND / s/ A PORTION OF CLEVELAND'S GEOLOGIC MAP, 1976 SCALE 1" = 200' 1 P.N. 4572-99 I • ' Page 6 r: . •••, - • / • .••• • , • ••.\ • • • • e'r S's V.\ • • A, ) )1( FIGURE 2 P.N. 4572-99 Page 7 A relatively small inactive surficial slump was observed in the trenches on a portion of the slope below the site. We have indicated the approximate location of the slump on Plate 1. Trench 10 was excavated in the slump. A relatively thick deposit of dark clayey soil was observed to be lying on top of bedrock. A brown slide surface that contains slickensides is present at the contact with bedrock. It appears that the slump involved the natural soil only. The bedrock below the clay appears to be tight and in -place. Bedding planes observed in the bedrock below the slump are well bedded with southeasterly orientations consistent with bedding plane orientations observed outside of the apparent slump. The slump has not adversely affected the gross stability of the slope. No features were observed during this investigation which indicates the site has recently undergone or is undergoing any major gross instabilities. It is important to recognize the potential for damage from earthquakes is a risk common to all of Southern California. Although we are not aware of any active faults that trend through the site, the site could be subjected to severe and destructive ground shaking from earthquakes that may occur on one of several active faults that are located in Southern California. P.N. 4572-99 Page 8 CONCLUSIONS GENERAL CONCLUSIONS The proposed project is considered feasible from a geologic and soils engineering standpoint provided that the recommendations given below are followed. In addition, the recommendations of the project structural engineer should be followed. The local department of building and safety should be contacted and the project properly permitted and inspected during construction. The following should be noted: 1. The existing fill soils, natural soil and any disturbed or weathered bedrock, are subject to downhill creep and local soil movement (i.e., settlement). These materials should not be used to support any structure and their potential for downhill creep should be considered in the design of retaining walls and foundations. 2. The underlying firm bedrock is suitable for structural support. The proposed improvements, including any proposed retaining walls, shall be supported by foundations embedded in firm bedrock. Any existing foundation to be used to support the proposed additions shall be extended into firm bedrock. The project structural engineer should determine the integrity of the existing foundations and their adequacy to be tied to the new foundations. 3. Any portion of the existing structures notsupported in firm bedrock could be subject to movement resulting in distress. 4. Differential settlement between the portions of the house supported by foundations embedded in firm bedrock and any portions not supported in firm bedrock may occur. This can result in cosmetic cracking requiring maintenance. 5. Due to the depths of the firm bedrock and the recommended setback from the face of the descending slopes, deep foundations, such as cast -in -place caissons or piles, may be required in some areas. 6. The project structural engineer should determine the types of foundations. P.N. 4572-99 Page 9 7. Some of the on -site soils have a medium to high potential for expansion. These materials could swell significantly in the presence of moisture and shrink when dried. Foundations and slabs supported on these soils should be designed for expansive soil conditions. 8. The existing fill soils and natural soil have potential for caving in steep cuts. Temporary excavations may need to be supported or trimmed back. Foundation excavations may need to be formed. 9. Cantilevered retaining walls will deflect and settle. Settlement of the backfill behind the walls is anticipated and should be allowed for in the design and construction of any structure, such as slabs and utilities, placed behind the walls. 10. It has been our experience that moisture or water intrusion through retaining walls is a relatively common problem in the Palos Verdes area. Common causes of the problem include poor construction techniques and using improper waterproofing materials. 11. Slabs supported by the existing fill soils, natural soil or disturbed or weathered bedrock could be subject to movements and cracking. Supporting the slabs on firm bedrock or compacted fill placed on firm bedrock may reduce distress to the slabs. Alternatively the slabs may be structurally supported by foundations embedded in firm bedrock. 12. Cracking of reinforced concrete is a common process. Reinforcement and crack control joints are intended to minimize this risk. In addition, irregularities of new slabs are common. A completed slab is generally not perfectly level and not free of some type of cracking. If this condition is not tolerable, the slabs should be structurally supported by foundations embedded in firm bedrock. 13. Unless structurally designed to resist expansive soil influences, concrete walkways, steps and other appurtenances could experience some distress (i.e., cracking and movement). Walkways and other appurtenances located on or near slopes could be subject to very noticeable creep influences. 14. As is the case with most hillside properties, surficial slope failures (slumps, erosion, mudflows) could occur on steeper slopes. The risk of such failures may be reduced by maintaining proper planting and drainage control. 15. Excavation may be difficult due to the hardness of some of the bedrock. Large blocks of rock may be generated from the excavations. 1 P.N. 4572-99 Page 10 ' 16. There are certain hazards connected with owning a hillside property in Southern California. Property damage may result from flooding, debris flows, slope erosion, brush fires and earthquakes of major magnitude. It is important to recognize that considerable damage could occur to the proposed development from earthquakes. Damaging earthquakes could be generated on any of several faults in Southern California (i.e., Palos Verdes, San Andreas, Newport -Inglewood, etc.). Such a risk is ' common to most areas in Southern California. COMPLIANCE WITH COUNTY CODE 111 The County of Los Angeles requires that a 111 Statement be provided. It is understood that the county will not approve the site for development unless such a statement is provided. As such, the following statement is provided: ' It is this consultant's opinion the proposed construction (additions to the existing house) will be safe from hazards of landslide, settlement, and slippage. It is also this consultant's opinion the proposed site improvements will not adversely affect adjoining properties. Obtaining these goals will require adherence to good construction practices and following the recommendations in our report. P.N. 4572-99 Page 11 RECOMMENDATIONS FOUNDATION DESIGN The proposed improvements, including any retaining walls, shall be supported by foundations embedded in firm bedrock. The project structural engineer should determine the type of foundations. All foundations shall be continuous or tied with grade beams. At a minimum, two #4 bars shall be placed near the top and two #4 bars near the bottom of all continuous footings. Spread footings shall be embedded at least 18 inches into firm bedrock, measured from the lowest adjacent finished grade of the firm bedrock. Caissons shall be embedded at least 3 feet into firm bedrock. Friction piles shall be embedded at least 10 feet into firm bedrock. Continuous footings shall be at least 12 inches wide. Square footings shall be at least 24 inches wide. Caissons shall be at least 24 inches in diameter. Friction piles shall be at least 18 inches in diameter. Setback As required by the regulatory agency, all foundations shall be set back a minimum horizontal distance from the surface of the adjacent descending slope equal to 1/3 of the height of the slope. The minimum setback shall be 5 feet horizontally from the firm bedrock surface. P.N. 4572-99 Page 12 Allowable Bearing Capacity For preliminary design purposes, the allowable bearing value for foundations placed as recommended may be calculated from the following. The allowable bearing value should not exceed 4,000 pounds per square foot for the firm bedrock. Firm bedrock Continuous Footings: q = 800 + 800d + 400b Square Footings: q = 900 + 800d + 300b Caissons: q = 900 + 800d + 200b where: q = allowable soil bearing value, in pounds per square foot. d = depth of foundation into firm bedrock, in feet. b = smallest width of footing, or diameter of caisson, in feet. The recommended values are for dead load plus frequently applied live load and may be increased by one-third when considering total loads including short durations of wind or seismic forces. Skin Frictional Resistance The preliminary design purposes, the allowable load capacities of each pile placed as recommended may be assumed as follows: Depth of Allowable Load Capacity Embedment In of each Pile Firm Bedrock 18-inch Diameter 24-inch Diameter 30-inch Diameter 10 feet 20 kips 26 kips 32 kips 15 feet 32 kips 42 kips 52 kips 20 feet 46 kips 62 kips 78 kips 25 feet 64 kips 86 kips 108 kips 1 ' P.N. 4572-99 Page 13 Intermediate values may be interpolated. The point of fixity may be assumed to be 3 ' feet into firm bedrock. The above recommended values are for dead load plus frequently applied live load and may be increased by one-third when considering total loads including short duration of wind or seismic forces. ' Settlement Total and differential settlements of the proposed foundations, embedded in firm bedrock ' as recommended, are anticipated to be within tolerable limits. Total settlement of each foundation subject to no more than the allowable pressure is expected to be no more than 1/2 inch, accompanied by differential settlement on the order of 1/4 inch. ' Differential settlement is expected to occur between the new foundations and the existing foundations, resulting to some distress. Periodic cosmetic repairs may be necessary. ' Lateral Design beresisted bypassive earth pressure and friction. Lateral loads may Allowable Maximum Coefficient Lateral Lateral of Bearing Bearing Friction Firm Bedrock 400 psf/ft. 4,000 psf 0.40 P.N. 4572-99 Page 14 The allowable bearing values may be used provided there is positive contact between bearing surface and the firm bedrock. Lateral bearings for foundations placed adjacent to a descending slope should be neglected above the level where the horizontal setback to the firm bedrock surface is less than 5 feet. If the frictional and lateral bearing resistances are combined, the lateral bearing resistance should be reduced by one-third. The above values may be increased by one-third for short durations of seismic and wind forces. DOWNHILL CREEP The near -surface soils are susceptible to downhill creep, which must be presumed and allowed for in the design. Caissons and friction piles, as well as grade beams and wall footings parallel to the contours of the adjacent descending slope, when placed within 20 feet horizontally of the slope surface, shall be designed for pressures due to downhill creep. The creep force may be assumed as 1,000 pounds per linear foot acting upon each caisson or pile for its portions within 20 feet of the slope surface. Grade beams and wall footings subject to the downhill creep shall be designed for earth pressures presented below in the section discussing earth pressures on retaining walls. P.N. 4572-99 Page 15 RETAINING WALLS Earth Pressure on Retaining Walls The earth pressure on cantilevered walls retaining the on -site materials, or grade beams and wall footings subject to the downhill creep, may be assumed equal to that exerted by a fluid having a density not less than that shown in the following table: Backfill Slope (Horiz. to Vert.) Equivalent Fluid Pressure Level 45 pcf 2 to 1 65 11/2 to 1 85 Walls restrained from movements at the top, such as basement walls, shall be designed for earth pressure equal to 150% of the above -recommended value. Walls designed for the recommended earth pressure need not be designed for additional creep forces. The recommended earth pressure shall be increased in the event of surcharge loads affecting the walls. Backdrain and Waterproofing An adequate backdrain system shall be incorporated in the design of the retaining walls. One of such backdrain system may consist of 4-inch diameter perforated pipes, placed with perforations facing down and surrounded by crushed rocks. The backdrain should be P.N. 4572-99 Page 16 wrapped with suitable geofabrics to minimize the potential for clogging. Water collected in the pipes shall be dispersed by gravity flow in a controlled manner . We recommend that the retaining walls be suitably waterproofed to minimize the potential for damages due to moisture intrusion, seepage and leakage. Conventional waterproofing materials, such as asphalt emulsion, have often proved ineffective. Certain precautions can be taken to reduce the possibility of future seepage problems. Superplasticized and water -retardant concrete may be used to make pouring easier and reduce shrinkage and cracking. Wall Backfill If the retaining walls are not constructed directly against the face of the temporary excavation, the space between the walls and the cut faces should be backfilled with gravels. The gravel backfill should be placed in lifts of no more than 12 inches in thickness and should be compacted with vibratory equipment. In areas where sloped temporary cuts are made that require placement of larger quantities of backfill, the fill materials should consist of approved granular soils. The new fill soils shall be compacted to a minimum of 90% relative compaction in accordance with recommendations on grading presented in the section on Grading Specifications. Revised specifications may be required after review of the detailed construction drawings. Some settlement of the backfill is anticipated and should be allowed for in the design and placement of slabs and utilities. P.N. 4572-99 Page 17 CONCRETE SLABS Concrete slabs should be supported on firm bedrock or compacted fill placed on the firm bedrock. The existing fill soils and natural soil, as well as any disturbed or weathered bedrock, should be removed and recompacted. All new fill soils shall be compacted to a minimum of 90% relative compaction in accordance with Gradina Specifications section in this report. Alternatively, the slabs may be structurally supported by foundations embedded in the firm bedrock. It should be noted that slabs not structurally supported in firm bedrock may be subject to some distress and cracking. Some periodic maintenance may be required. It is recommended that floor slabs and exterior slabs placed on -grade be supported by a minimum of 6 inches of base. These slabs shall be at least 5 inches thick and be reinforced with at least No. 4 bars at 12 inches, both ways. A moisture barrier, such as 6- mil visqueen, shall be placed beneath the slabs where upward capillary of moisture is undesirable. The visqueen should be covered with one inch of sand to prevent puncture. Presoaking of 24 inches of subgrade soils is recommended. The subgrade soils shall be further tested for expansion potential during construction to determine if revised slab design would be necessary. Exterior slabs should be provided with proper crack control joints. Typical concrete shrinkage can result in cracks and gaps along the crack control joints and where the slab connects to structures. The gaps will require periodic caulking to limit infiltration of moisture. P.N. 4572-99 Page 18 Exterior slabs planned adjacent to the descending slope should be provided with a thickened edge. The thickened edge should be a minimum of 12 inches wide, 24 inches deep and reinforced with four #4 bars, two placed near the top and two placed near the bottom. The thickened edge will not eliminate the possibility of cracking or movement of the slab, but will reduce the risk. Decking which caps a retaining wall should be provided with a flexible joint to allow for the normal 1 to 2 percent deflection of the retaining wall. Decking which does not cap a retaining wall should not be tied to the wall. The space between the wall and decking will require periodic caulking to prevent moisture intrusion into the retaining wall backfill. Patio slabs, walkways, etc., are generally not given the level of treatment that floor slabs are given. It is important to recognize that patio slabs, walkways, etc., could be subjected to cracking and tilting due to local soil influences, unless they are structurally designed to resist such influences. EXPLORATORY BACKFILL EXCAVATIONS The exploratory excavations were backfilled upon completion of the field exploration using the excavated soils. Backfilling was performed to the extent possible with the equipment on hand. However, the backfill was not compacted to the requirements of "structural fill". If any improvement is to be located in close proximity to the exploratory excavations, the backfill shall be removed and recompacted. The fill soils shall be compacted to a minimum of 90% relative compaction in accordance with Grading Specifications section in this report. Alternatively, the improvement may be designed to "span" over the excavations. P.N. 4572-99 GRADING SPECIFICATIONS Page 19 Major grading is not anticipated in conjunction with the proposed additions. However, if grading is performed, the following criteria should be followed. 1. Prior to placement of compacted fill, the site shall be cleared of all vegetation, existing fill, loose topsoil, debris, and any other deleterious materials. 2. Import soils shall be tested and approved by the soils engineer prior to import. 3. Surfaces receiving fill soils shall be scarified, aerated, or moistened to moisture content acceptable to the soils engineer, then compacted to a compaction of not less than 90% of the maximum density. 4. If the moisture content of the fill soils is below the limits specified by the soils engineer, water shall be added until the moisture content is as required. 5. If the moisture content of the fill soils is above the limits specified by the soils engineer, the fill soils shall be aerated by blading or other satisfactory methods until the moisture content is as required. If drying of soils is not desired, the wet soils shall be mixed with drier materials to achieve an acceptable moisture content. 6. The fill soils shall be placed in lifts of no more than six (6) inches in thickness and compacted until field density tests indicate that a compaction of not less than 90% of the maximum density as determined by ASTM D 1557-98 has been obtained. 7. Field density tests shall be made in accordance with ASTM D 1556-97. Field density tests shall be made every 2 foot intervals and not less than one test per 500 cubic yards of fill placed. 8. Rocks less than 6 inches in greatest dimension may be placed in the fill, provided: a. They are not placed in concentrated pockets; and b. The fine-grained materials surrounding the rocks are sufficiently compacted. 9. Rocks larger than 6 inches in greatest dimension shall be removed from the site or placed in accordance with specific recommendations of the soils engineer. 10. No fill soils shall be placed during unfavorable weather conditions. When work is interrupted by rains, fill operations shall not be resumed until the field tests by the soils engineer indicate that the moisture content and density of the fill are as previously specified. 11. Planting and irrigation of cut and fill slopes and installation of erosion control and drainage devices shall comply with the requirements of the Grading Code of controlling agencies. P.N. 4572-99 Page 20 SLOPE SURFACE STABILITY We recommend that the homeowner maintain an adequate debris, erosion and fire control program to protect the property. As is the case with most hillside properties, the possibility of sloughing and slumping on slopes within the site and site area cannot be ruled out, especially during rainy seasons. It should be noted that excessive landscape watering, rodent burrows and uncontrolled surface runoff may cause instability of the slope surface. The following recommendations are provided so as to reduce the risk of erosion and slope failures. 1. The slopes shall be planted and maintained with a suitable deep-rooted ground cover. Additional protection may be provided by the use of jute mesh or suitable geofabrics. If adequate ground cover is not maintained, sloughing and slumping of the surficial soils may occur. It is imperative that landscape watering be kept to the minimum required for normal plant growth. 2. Any paved drainage swale and downdrain on the slopes and drain inlet should be kept free of soils and debris. 3. Adequate site drainage shall be provided. All roof and surface drainage shall be conducted away from foundation and slope areas via engineered non -erosive devices to suitable disposal areas. In no case shall water be allowed to pond within the site, drain towards structures or flow in a concentrated and uncontrolled manner down the slopes. Drainage control is imperative for site stability. The risk of unusual settlement or stability of structures can be reduced by proper drainage control and maintenance of yards. It is the responsibility of the owner to maintain the drainage facilities and correct any deficiency found during occupancy of the property. Water and sewer lines within the site shall be checked for leakage periodically and repaired if necessary. P.N. 4572-99 Page 21 Any crack in paved surfaces should be sealed to limit infiltration of surface water. Slopes and yards should be provided with low maintenance, erosion control vegetation. Care should be taken not to over -irrigate the site. Landscape watering shall be kept to the minimum necessary for normal plant growth. Planting around the structures should be minimized. Planters located adjacent to the structures should be sealed and properly drained. The feasibility of utilizing contained planters should be considered. EXCAVATION Where necessary construction space is available, temporary unsurcharged excavations may be considered to the depths and slope ratios tabulated below: Maximum Depth Maximum Slope Ratio of cut (Feet) (Horizontal to Vertical) Fill/Soil 0 - 4 4+ Bedrock Vertical 1:1 0 - 5 Vertical 5 -10 s/:1 10+ 1:1 Soils exposed in the cuts should be kept moist but not saturated, to reduce the tendency for raveling and sloughing during construction. The top of the cut slopes should be barricaded to keep vehicles and heavy storage loads at least five feet away from the top of the slopes. During the rainy season, berms should be constructed and maintained along the top of the slopes and plastic sheets should be placed over the slopes to prevent runoff water from eroding the slope faces. I I I I I I I I I I I I I I I I I I P.N. 4572-99 Page 22 The contractor shall determine sequence of construction and method. Where construction space is not available or where the excavation will be surcharged by the existing footings, the cuts shall be shored or made in slots. A cut is considered to be surcharged if it is made below a plane projected 1:1 (45 degrees) downward from the outer edge of a footing. The shoring system shall be designed for an equivalent fluid pressure of 30 pounds per square foot per foot. The slots shall be no more than 6 feet wide and shall be made in an A-B-C-A-B-C sequence. Care should be exercised when excavating adjacent to the existing footings such as not to unduly undermine the existing footings and cause damages. We recommend that no more than 6 feet of the existing footings be exposed at one time. It may be necessary to brace portions of the existing footings prior to excavation for the new foundations or for recompaction of the subgrade soils. Although no significant amount of soil caving was encountered in the exploratory test trenches, other excavations may experience caving. Construction methods shall meet the requirements of the California Occupational Safety and Health Association (CAL - OSHA) and other public agencies having jurisdiction. CONSTRUCTION SITE MAINTENANCE It is the responsibility of the contractor to maintain a safe construction site. When excavations exist on a site, the area should be fenced and warning signs posted. All deep excavations must be properly covered and secured. Temporary erosion control measures and protection of excavation from drainage and erosion during the rainy season is required. P.N. 4572-99 Page 23 Earth materials generated from foundation and subgrade excavations should be either removed from the site or properly compacted. Fill temporarily stockpiled on the site should be placed in a stable area, away from slopes, excavations and improvements. Earth materials must not be spilled over any descending slope. Workers should not be allowed to enter any unshored trench excavations over five feet deep. REGULATORY AGENCY REVIEW This report is subject to review by regulatory agencies and these agencies may require their approval before the project can proceed. No guarantee that the regulatory public agency or agencies will approve the project is intended, expressed or implied. The regulatory agency may ask questions regarding the information presented in this report and may require additional fieldwork and/or additional evaluations. Any additional work will be performed on a time and expense basis. PLAN REVIEW AND CONSULTATION Project plans and specifications shall be reviewed by us to verify compatibility with our recommendations. It is recommended that prior to proceeding with construction, consultation among the homeowner, structural engineer, geologist, soils engineer, and the contractor be scheduled to discuss the project. Any additional consulting, such as for plan reviews, foundation reviews, meetings, response to review sheets, etc., will be performed on a time and expense basis. I I I I I I I I I I I I I I I I I I P.N. 4572-99 Page 24 RECOMMENDED INSPECTIONS It is strongly recommended that the homeowner insist that each phase of construction be properly inspected and approved by the focal building department official, the structural engineer, geologist and soils engineer. As a necessary requisite to the use of this report, personnel of this facility shall observe the following: 1. Temporary excavations and shoring. 2. Removal of unsuitable soils in areas of proposed slabs. 3. Bottom of excavation prior to placement of compacted fill. 4. Backfill placement and compaction. 5. Surface and subsurface drainage systems. 6. Foundation excavations. I � PNa57z99 Page=s COMMENTS The conclusions and recommendations presented in this report are based on research, site observations and limited subsurface information. The conclusions and recommendations presented are based on the supposition that subsurface conditions do not vary significantly from those indicated. Although no significant variations in subsurface conditions are anticipated, the possibility of significant variations cannot be ruled out. If such conditions are encountered, this consultant should be contacted immediately to consider the need for modification of this project. This report is subject to review by regulatory public agencies and these agencies may require their approval before the project can proceed. No guarantee that the regulatory public agency or agencies will approve the project is intended, expressed or implied. One of the purposes of this report is to provide the client with advice regarding the geologic and soils engineering conditions on the site. It is important to recognize that other consultants could arrive at different conclusions and recommendations. This report has been prepared in accordance with generally accepted professional engineering principles and practice. No warranties of future site performance are intended, expressed or implied. P.N. 4572-99 APPENDIX I FIELD INVESTIGATION Field investigation was performed using a backhoe. Twelve exploratory test trenches were excavated to depths of approximately 4 to 16 feet below the existing ground surface. The approximate locations of the exploratory test trenches are shown on the Geologic Map, Plate 1. The soils were logged by our field personnel and classified by visual examination. Descriptions of the soils encountered in the test trenches are shown on the Log of Test Trenches. Representative undisturbed and bulk samples of the subsurface soils were obtained and returned to the laboratory for subsequent testing. PROJECT NO. 4572-99 TRENCH NO. 1 PROJECT #9 MAVERICK LANE, ROLLING HILLS, CA METHOD OF EXCAVATION LOG OF TEST TRENCH GROUND ELEVATION LOCATION 0 SEE SITE PLAN LOGGED BY D. LONGSTRETH DATE FILL: 0.0 — 3.5 feet Fill consists of orange -brown rock mix with silty clay, stiff, slightly moist. 12-28-99 NATURAL SOIL: 3.5 — 5.5 feet 5 Natural soil consists of dark brown to orange -brown silty clay, slightly moist, stiff, scattered roots and pebbles. BEDROCK: 5.5 — 9.0 feet Bedrock consists of orange -brown siliceous siltstone, hard, tight, volcanic 10 - intrusions, very poorly defined bedding with an estimated orientation of N30E 8SE. 15 20 • SCALE: 1 "=5' I III- I I I 14\ - _ - !FILL- _ 1 I I ' NATL RAL $OI.L - _ r III1 I I I I BEDROCK • I I I I III I I I I I I I I 1 1 1 1 I I I 1 I I I ill I I I I 1 1 1 1 I I I I KEITH W. EHLERT PROJECT NO. 4572-99 TRENCH NO. 2 PROJECT #9 MAVERICK LANE, ROLLING HILLS, CA_ METHOD OF EXCAVATION LOG OF TEST TRENCH GROUND ELEVATION LOCATION SEE SITE PLAN LOGGED BY D. LONGSTRETH DATE 12-28-99 44, NATURAL SOIL: 0.0 — 2.0 feet - Natural soil consists of dark brown to orange -brown silty clay, slightly moist, stiff, - scattered roots and pebbles. 5 10 • 15- 20-- BEDROCK: 2.0 — 4.0 feet Bedrock consists of orange -brown siliceous siltstone, hard, tight, volcanic intrusions, well defined bedding with an orientation of N43E 14SE. SCALE: 1 "=5' • I I I I I I I I NATURAL SOIL I I I I I ',BEo o I I I I I I I I I I I I I IIHHHHHHHHH I I I I I 11 11 1 1 I 1 I I I I I I 1 l Fill KEITH W. EHLERT PROJECT NO. 4572-99 TRENCH NO. 3 PROJECT #9 MAVERICK LANE, ROLLING HILLS, CA METHOD OF EXCAVATION LOG OF TEST TRENCH GROUND ELEVATION LOCATION 0 SEE SITE PLAN FILL: 0.0 — 4.5 feet LOGGED BY D. LONGSTRETH DATE 12-28-99 Fill consists of orange -brown rock mix with clay, soft, dry. - . NATURAL SOIL: 4.5 — 7.5 feet 5 - Natural soil consists of dark brown to orange -brown silty clay, slightly moist, stiff, scattered roots and pebbles. BEDROCK: 7.5 — 10.0 feet Bedrock consists of orange -brown siliceous siltstone, hard, tight, volcanic 1 o - intrusions, very poorly defined bedding with an estimated orientation of N35E 9SE. 15- 20 SCALE: 1 "=5' I I I I ( I I I FILL—> I 1111 NATURAL SOIL — 1 1 1 1 1 I I 1 I I I I IIII IIIHIIIIIIHIIH — BEDROCK 1 1 1 1 1 1 I 1 I I 1 I I I I I 1 1 1 1 I I I I I I I 1 KEITH W_ EHLERT PROJECT NO. 4572-99 TRENCH NO. 4 PROJECT #9 MAVERICK LANE, ROLLING HILLS, CA METHOD OF EXCAVATION LOG OF TEST TRENCH GROUND ELEVATION LOCATION SEE SITE PLAN LOGGED BY D. LONGSTRETH DATE 12-28-99 _ NATURAL SOIL: 0.0 — 4.0 feet _ Natural soil consists of black to dark brown silty clay, slightly moist, stiff, scattered roots and pebbles. 5- 10- 15- 20 - BEDROCK: 4.0 — 7.0 feet Bedrock consists of orange -brown siliceous siltstone, hard, tight, volcanic intrusions, very poorly defined bedding with an estimated orientation of N5W 20SE. SCALE: 1 =5' B=DROCK -- j I I 1 1 t l I J t t t NATURAL SOIL — I I I I 1 1 I 1 I11I 1111 I I I I I I I I I I ! I I I KEITH W. EHLERT PROJECT NO. 4572-99 TRENCH NO. 5 PROJECT #9 MAVERICK LANE, ROLLING HILLS, CA METHOD OF EXCAVATION LOG OF TEST TRENCH GROUND ELEVATION LOCATION SEE SITE PLAN LOGGED BY D. LONGSTRETH DATE 12-28-99 5- 10 - 15- 20 - FILL: 0.0 — 0.5 feet Fill consists of dark orange -brown rock mix with silty clay, stiff, slightly moist. BEDROCK: 0.5 — 4.0 feet Bedrock consists of orange -brown siliceous siltstone, very hard, tight, blocky, breaks into boulders, volcanic intrusions, well defined bedding with an orientation of N10W 15SE. SCALE: 1 "=5' FILL BEDROCK I IIII IIII IIII HHIIIHHHHH I _ � 1 I I I I I I I I I I I I I I I I I I I KEITH W. EHLERT PROJECT NO. 4572-99 TRENCH NO. 6 PROJECT #9 MAVERICK LANE, ROLLING HILLS, CA METHOD OF EXCAVATION LOG OF TEST TRENCH GROUND ELEVATION LOCATION SEE SITE PLAN LOGGED BY D. LONGSTRETH DATE 12-28-99 4, 0 FILL: 0.0 —2.5 feet Fill consists of mottled orange -brown rock mix with clay, soft, dry. NATURAL SOIL: 2.5 — 4.5 feet 5 • Natural soil consists of dark brown to orange -brown silty clay, slightly moist, stiff, scattered roots and pebbles. 10 15. 20 BEDROCK: 4.5 — 6.0 feet Bedrock consists of orange -brown siliceous siltstone, very hard, tight, volcanic intrusions, well defined bedding with an orientation of N2OW 3SE. SCALE: 1 °=5' 1 I I I I I I 1 �� FILL III '^1 I I I I ,v� rI I I HI1 1 111 I I I 1 I I I I I I Cs'.:. - -- 'NATURAL SOIL — BEDROCK 'Ill IIIIIII1IIIIIIII IIIIIIII lift I I I! till It It tilt l i t! I I I KEITH W. EHLERT PROJECT NO. 4572-99 TRENCH NO. 7 PROJECT #9 MAVERICK LANE, ROLLING HILLS, CA METHOD OF EXCAVATION LOG OF TEST TRENCH GROUND ELEVATION LOCATION 44/ SEE SITE PLAN LOGGED BY D. LONGSTRETH DATE 12-28-99 NATURAL SOIL: 0.0 — 3.0 feet Natural soil consists of dark brown to orange -brown silty clay, slightly moist, stiff, scattered roots and pebbles. 5 ` BEDROCK: 3.0 — 6.0 feet - Bedrock consists of light orange -brown siliceous siltstone, very hard, tight, well - defined bedding with an orientation of N36E 26SE. 10 - 15- 20 - SCALE: 1 "=5' NATURAL SOIL !` 11 I I 1 IIII IIII IIII - - 4 6Dxo c i IIII IIII IIII IIII IIII 1111 IIII ill 1 1 1 1 I I I I III I I I I I KEITH W. EHLERT PROJECT NO. 4572-99 TRENCH NO. 8 PROJECT #9 MAVERICK LANE, ROLLING HILLS, CA METHOD OF EXCAVATION LOG OF TEST TRENCH GROUND ELEVATION LOCATION 0 5• 10- 15- 20 - SEE SITE PLAN LOGGED BY D. LONGSTRETH DATE 12-28-99 NATURAL SOIL: 0.0 — 3.5 feet Natural soil consists of dark brown to orange -brown silty clay, slightly moist, stiff, scattered roots and pebbles. BEDROCK: 3.5 — 7.0 feet Bedrock consists of mottled white and orange -brown siliceous siltstone, very hard, tight, well defined bedding with orientations of N15E 28SE and N30E 15SE. SCALE: 1 "=5' I I I+ 1 I I I \�- NATURAL SOIL — IIII I I I I 1 1 BEDROCK 1 1 1 1 V I 1 I I 1 1 1 1 I I I I IIII 1 1 1 1 I I I I I I I I I I I I KEITH W. EHLERT PROJECT NO. 4572-99 TRENCH NO. PROJECT #9 MAVERICK LANE, ROLLING HILLS, CA_ . METHOD OF EXCAVATION LOG OF TEST TRENCH GROUND ELEVATION LOCATION SEE SITE PLAN LOGGED BY D. LONGSTRETH DATE 12-28-99 0 _ NATURAL SOIL: 0.0 — 3.0 feet Natural soil consists of dark brown to orange -brown silty clay, slightly moist, stiff, scattered roots and pebbles. 5 - BEDROCK: 3.0 — 7.0 feet - Bedrock consists of orange -brown siliceous siltstone, very hard, tight, well - defined bedding with an orientation of N38E 24SE. 10- 15- 20 SCALE: I I 1 "=5' ,NATURAL SOIL I I I I I I t \-t i I i I -I ,III I III 1 11 I BEDROCK — 1111111I IIII�Hit lllllll�_IIII 1 IIII1 1! I. 1 1 1 1 i 1 I 1 1 1 1 KEITH W. EHLERT PROJECT NO. 4572-99 TRENCH NO. 10 PROJECT #9 MAVERICK LANE, ROLLING HILLS, CA METHOD OF EXCAVATION LOG OF TEST TRENCH GROUND ELEVATION LOCATION SEE SITE PLAN LOGGED BY D. LONGSTRETH DATE 12-28-99 0 - SLUMP DEBRIS/NATURAL SOIL: 0.0 — 12.0 feet - Natural soil consists of dark brown to black silty clay, slightly moist, stiff, - scattered roots and pebbles. Contact with bedrock consists of a chocolate -brown - planar clay layer, paper thin with slickensides, an orientation of N48E 12 SE. 5 - BEDROCK: 12.0 — 16.0 feet - Bedrock consists of yellow to orange -brown siliceous siltstone, very hard, tight, _ well defined bedding with an orientation of N48E 12SE. 10 15• 20 - SCALE: 1 "=1 O' - BEDROCK I IIII {{IL ill t I I t t , 11 I I I t l t 1 I 1 I I 1 I I I I KEITH W. EHLERT PROJECT NO. PROJECT METHOD OF LOCATION q 5- 10 15- 20 - 4572-99 TRENCH NO #9 MAVERICK LANE, ROLLING HILLS, CA EXCAVATION LOG OF TEST TRENCH GROUND ELEVATION SEE SITE PLAN LOGGED BY D. LONGSTRETH DATE 12-28-99 11 NATURAL SOIL: 0.0 — 3.0 feet Natural soil consists of dark brown to orange -brown silty clay, slightly moist, stiff, scattered roots and pebbles. BEDROCK: 3.0 —10.0 feet Bedrock consists of yellow to orange -brown siliceous siltstone, very hard, tight, well defined bedding with an orientation of N20E 30SE. SCALE: 1 °=5' I I I I 1 1 - NATURAL SOIL --> u '�IIII - BEDROCK - ill IILI I I I I 1 I I I I I I 1 KEITH W. EHLERT PROJECT NO. 4572-99 TRENCH NO. 12 PROJECT #9 MAVERICK LANE, ROLLING HILLS, CA METHOD OF EXCAVATION LOG OF TEST TRENCH , GROUND ELEVATION LOCATION SEE SITE PLAN LOGGED BY D. LONGSTRETH , DATE 12-28-99 0 - NATURAL SOIL: 0.0 — 2.5 feet Natural soil consists of dark brown to orange -brown silty clay, slightly moist, stiff, - scattered roots and pebbles. 5 - BEDROCK: 2.5 — 6.0 feet Bedrock consists of yellow to orange -brown siliceous siltstone, very hard, tight, blocky, breaks into boulders, volcanic intrusions, well defined bedding with an - orientation of N40E 38SE. 10- 15- 20 - SCALE: 1 11=5' III I I I I 1III IIII II / — BEDROCK. 1111 1111 111 111 IIII I I I IIII I I I I r I I I I I I I I I I► I I I I I I I I I I I I KEITH W. EHLERT P.N. 4572-99 I APPENDIX II LABORATORY TESTING Laboratory testing was performed after review of the field data and in consideration of the geotechnical engineering conditions of the areas of the proposed development to be evaluated. Laboratory testing included determinations of in situ moisture content, density, shear strength, consolidation characteristics and expansion potential of representative samples of the on -site soils. Moisture Density The moisture -density information provides a summary of soil consistency for each stratum. The dry unit weight and field moisture content were determined from undisturbed samples, and the results are shown below: In Situ In Situ Sample Soil Dry Moisture Location Description Density Content T.T. 1 @ 6' Bedrock — siltstone 87.2 pcf 34.9% T.T. 2 @ 1' Soil — silty clay 82.9 pcf 23.6% T.T. 2 @ 3' Bedrock — siltstone 111.9 pcf 7.3% T.T. 4 @ 7' Bedrock — siltstone 83.9 pcf 38.1% T.T. 6 @ 6' Bedrock — siltstone 85.8 pcf 25.1% T.T.10 @ 12' Slide plane — clay 88.1 pcf 23.5% T.T.12 @ 5' Bedrock — siltstone 99.1 pcf 21.0% 1 1 P.N.4572-99 Shear Shear tests were made with a direct shear machine at a constant rate of strain. The machine is designed to test the soils without completely removing the samples from the brass rings. A normal load was applied vertically on each sample and the soil shear strength was determined at this load. Samples were also tested at higher and/or lower normal loads in order to determine the cohesion and angle of internal friction. The test results are plotted on "Direct Shear Test Plot," Plates C-4 to C-9. Consolidation The apparatus used for the consolidation test is designed to test the soils without removing the samples from the brass rings. Loads were applied to the samples in several increments, and the resulting deformations were recorded at selected time intervals. Porous stones were placed in contact with the top and bottom of the samples to permit the ready addition or release of water. Samples were tested at the field and increased moisture contents. The test results are shown on the "Consolidation Test Plot," Plates D-3 and D-4. Expansion Potential To determine the expansion potential of the on -site soils, a sample was remolded at near 50% saturation and then allowed to absorb moisture under a surcharge of 144 psf in accordance with UBC Standard No. 18-1. The result is shown below: Sample Soil Expansion Potential Location Description Index Expansion T.T.2 @ 1' Soil — silty clay 78 Medium SHEAR STRESS IN KSF STRESS IN KSF U) 2.0 1.0 .0 .0 1.0 2.0 3.0 4.0 5.0 NORMAL STRESS IN KSF 4.0 2.0 _0 .00 .06 .12 .18 .24 _D 0 -Et-0 E El HORIZONTAL DEFORMATION IN INCH .30 BORING/SAMPLE : T.T.2/S.1 DEPTH (ft) : 1 DESCRIPTION : Soil - silty clay STRENGTH INTERCEPT (C) .393 KSF (RESIDUAL STRENGTH) FRICTION ANGLE (PHI) 19.3 DEG MOISTURE DRY DENSITY VOID NORMAL PEAK RESIDUAL SYMBOL CONTENT (5g) (pcf) RATIO STRESS (ksf) SHEAR (ksf) SHEAR (ksf) O 36.0 82.9 .994 .55 .69 .56 O 36.0 82.9 .994 1.10 1.00 .82 O 36.0 82.9 .994 2.20 1.32 1.14 0 36.0 82.9 .994 4.40 2.18 1.94 Remark : Undisturbed samples, soaked Project 4572-99 Shoemaker - Maverick Lane SWN Soiltech Consultants DIRECT SHEAR TEST Plate No. C-4 SHEAR STRESS IN KSF SHEAR STRESS IN KSF 4.0 2.0 o .0 2.0 4.0 6.0 8.0 10.0 NORMAL STRESS IN KSF 4.0 2.0 .0 .00 .06 .12 .18 .24 HORIZONTAL DEFORMATION IN INCH .30 BORING/SAMPLE : T.T.10/S.1 DEPTH (ft) : 12 DESCRIPTION : Slide plane - clay STRENGTH INTERCEPT (C) .407 KSF FRICTION ANGLE (PHI) 20.4 DEG (RESIDUAL STRENGTH) MOISTURE DRY DENSITY VOID NORMAL PEAK RESIDUAL SYMBOL CONTENT (;s) (pcf) RATIO STRESS (ksf) SHEAR (ksf) SHEAR (ksf) O 31.9 88.1 .877 .55 .73 .58 O 31.9 88.1 .877 1.10 .95 .81 O 31.9 88.1 .877 2.20 1.48 1.28 0 31.9 88.1 .877 4.40 2.26 2.02 Remark : Undisturbed samples, soaked Project 4572-99 Shoemaker - Maverick Lane SIM Soiltech Consultants DIRECT SHEAR TEST Plate No. C-5 SHEAR STRESS IN KSF STRESS IN KSF 4.0 2.0 .0 10.0 5.0 7A V O .0 2.0 4.0 6.0 8.0 10.0 NORMAL STRESS IN KSF a-0-0 ?00(;00 w co .0 .00 .06 .12 .18 .24 HORIZONTAL DEFORMATION IN INCH .30 BORING/SAMPLE : T.T.1 /S.1 DEPTH (ft) : 6 DESCRIPTION : Bedrock - siltstone STRENGTH INTERCEPT (C) .578 KSF FRICTION ANGLE (PHI) 34.1 DEG (RESIDUAL STRENGTH) MOISTURE DRY DENSITY VOID NORMAL PEAK RESIDUAL SYMBOL CONTENT (%) (pcf) RATIO STRESS (ksf) SHEAR (ksf) SHEAR (ksf) O 35.8 87.2 .897 .55 1.45 .95 o 35.8 87.2 .897 1.10 1.62 1.22 O 35.8 87.2 .897 2.20 2.68 2.23 0 35.8 87.2 .897 4.40 4.74 3.50 Remark : Undisturbed samples, soaked Project 4572-99 Shoemaker - Maverick Lane SIM Soiltech Consultants DIRECT SHEAR TEST Plate No. C-6 SHEAR STRESS IN KSF SHEAR STRESS IN KSF 10.0 5.0 .O .0 5.0 10.0 15.0 20.0 25.0 NORMAL STRESS IN KSF 10.0 5.0 ' -0 0 0 o-9-0 DUO -8 .0 .00 .06 .12 .18 .24 HORIZONTAL DEFORMATION IN INCH BORING/SAMPLE : T.T.1/S.1 DEPTH (ft) : 6 DESCRIPTION : Bedrock - siltstone STRENGTH INTERCEPT (C) .801 KSF FRICTION ANGLE (PHI) 41.5 DEG .30 (PEAK STRENGTH) MOISTURE DRY DENSITY VOID NORMAL PEAK RESIDUAL SYMBOL CONTENT (5g) (pcf) RATIO STRESS (ksf) SHEAR (ksf) SHEAR (ksf) O 35.8 87.2 .897 .55 1.45 .95 O 35.8 87.2 .897 1.10 1.62 1.22 O 35.8 87.2 .897 2.20 2.68 2.23 0 35.8 87.2 .897 4.40 4.74 3.50 Remark : Undisturbed samples, soaked Project 4572-99 Shoemaker - Maverick Lane S►NN Soiltech Consultants DIRECT SHEAR TEST Plate No. C-7 SHEAR STRESS IN KSF SHEAR STRESS IN KSF 4.0 2.0 .0 .0 2.0 4.0 6.0 8.0 10.0 NORMAL STRESS IN KSF 4.0 2.0 _0 .00 .06 .12 .18 .24 HORIZONTAL DEFORMATION IN INCH BORING/SAMPLE : T.T.6/S.1 DEPTH (ft) : 6 DESCRIPTION : Bedrock - siltstone STRENGTH INTERCEPT (C) .474 KSF FRICTION ANGLE (PHI) • 29.1 DEG .30 (RESIDUAL STRENGTH) MOISTURE DRY DENSITY VOID NORMAL PEAK RESIDUAL SYMBOL CONTENT (%) (pcf) RATIO STRESS (ksf) SHEAR (ksf) SHEAR (ksf) O 34.5 85.8 .928 .55 1.20 .69 ❑ 34.5 85.8 .928 1.10 1.40 1.14 O 34.5 85.8 .928 2.20 2.37 1.77 0 34.5 85.8 .928 4.40 3.49 2.88 Remark : Undisturbed samples, soaked, sheared along bedding Project 4572-99 Shoemaker - Maverick Lane SWN Soilte ch Consultants DIRECT SHEAR TEST Plate No. C-8 SHEAR STRESS IN KSF SHEAR STRESS IN KSF 4.0 :2.0 .0 .0 2.0 4.0 6.0 8.0 10.0 NORMAL STRESS IN KSF 4.0 2.0 E ❑ 0-B-0-9 C - .0 .00 .06 .12 .18 .24 HORIZONTAL DEFORMATION IN INCH BORING/SAMPLE : T.T.6/S.1 DEPTH (ft) : 6 DESCRIPTION : Bedrock - siltstone STRENGTH INTERCEPT (C) .851 KSF FRICTION ANGLE (PHI) 31.5 DEG .30 (PEAK STRENGTH) MOISTURE DRY DENSITY VOID NORMAL PEAK RESIDUAL SYMBOL CONTENT (%) (pcf) RATIO STRESS (ksf) SHEAR (ksf) SHEAR (ksf) O 34.5 85.8 .928 .55 1.20 .69 ❑ 34.5 85.8 .928 1.10 1.40 1.14 O 34.5 85.8 .928 2.20 2.37 1.77 0 34.5 85.8 .928 4.40 3.49 2.88 Remark : Undisturbed samples, soaked, sheared along bedding Project 4572-99 Shoemaker - Maverick Lane SWN Soiltech Consultants DIRECT SHEAR TEST Plate No. C-9 PERCENT CHANGE IN HEIGHT 10' 0 2 4 6 COMPRESSIVE STRESS IN KSF 1) 102 1.027 .986 .945 .905 8 .864 10 BORING : T.T.2/S.1 DESCRIPTION : Soil — silty clay DEPTH (ft) : 1 LIQUID LIMIT : SPEC. GRAVITY : 2.69 PLASTIC LIMIT : MOISTURE DRY DENSITY PERCENT VOID CONTENT (%) (pcf) SATURATION RATIO INITIAL 23.6 82.9 62 1.027 FINAL 35.1 86.4 100 .945 Remark : Undisturbed sample, water added at 0.80 ksf Project 4572-99 Shoemaker — Maverick Lane SWN Soiltech Consultants .824 CONSOLIDATION TEST Plate No. D-3 VOID RATIO PERCENT CHANGE IN HEIGHT 10' 0 2 4 6 8 10 COMPRESSIVE STRESS IN KSF 1) BORING : T.T.4/S.1 DEPTH (ft) : 7 SPEC. GRAVITY : 2.76 DESCRIPTION : Bedrock — siltstone LIQUID LIMIT : PLASTIC LIMIT : 102 MOISTURE DRY DENSITY PERCENT VOID CONTENT (%) (pcf) SATURATION RATIO INITIAL 38.1 83.9 100 1.055 FINAL 36.6 85.6 100 1.013 Remark : Undisturbed sample, water added at 1.60 ksf Project 4572-99 Shoemaker — Maverick Lane SWN Soiltech Consultants 1.055 1.013 .972 .931 .890 .849 CONSOLIDATION TEST Plate No. D-4 VOID RATIO P.N. 4572-99 1 APPENDIX III SLOPE STABILITY ANALYSIS ' Stability of the subject site, as shown along Section C-C', has been analyzed by Bishop's Simplified Method. Searches have been made to determine the most critical failure ' surfaces. Both static and seismic loading conditions have been considered. In the seismic analysis, the seismic force is represented by a pseudostatic horizontal inertial force equal to 0.15 ' times the total weight of the potential sliding mass acting out of the slope. The shear strengths for the siltstone of the Monterey Formation are based on direct shear tests on undisturbed samples of the siltstone under soaked conditions. The ' residual shear strength (Plate C-2 of our April 14, 1999 Report and Plate C-6 of this Report) has been used in the static loading conditions, while the peak shear strength ' (Plate C-3 of our April 14, 1999 Report and Plate C-7 of this Report) has been used in the seismic loading conditions. It is our professional opinion that peak shear strength of the bedrock is likely to be available during an earthquake. The shear strength for the schist is based on data presented in the following report: "Response to County of Los Angeles Geologic and Geotechnical Engineering Review ' Sheets dated June 12, 1995, 7 Maverick Lane, Rolling Hills, California," by A.G.I. Geotechnical, Inc. (Project No. 3-1332-06), dated January 3, 1996. The analyses presented in the report concluded that the schist would have an angle of internal friction of 61 degrees and a cohesion of 10,368 psf. For the analyses presented ' herein, the shear strength has been arbitrarily reduced. I I I I I I I I I I I I I I I I I I P.N. 4572-99 Density, Cohesion Friction Anale Siltstone, Static 120 pcf 560 psf 30 degrees Seismic 120 pcf 880 psf 33 degrees Schist, Static 135 pcf 1000 psf 45 degrees Seismic 135 pcf 1000 psf 45 degrees Calculations are included on Plates III-10 through III-22. Factors -of -safety in excess of 1.50 and 1.10 have been obtained for static and seismic loading conditions, respectively. 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' I • , • " , -I- • • ' i 1 I. 1 ' : _. , .1 • : ' ' • ' • '-i ' ,.....!Shi.',.--t,...i.. ' . • , : ., . -• , 11.:,;,•,. ..... ..i : . _.,...-„,••.•-; -4; '. .--i". ' ..r`i"^...... rn- . . . . . . . . . . . 1 '. i ! ; • . , • •: • '' F, • ; ' 1 I , • • • I • , I : : , ! • i; ; 1 • :• • • T-4-- - • i...- 1 -1.. ; .; :.• : ..: • i 1,....' - • ..i:•. , :,: : ; . ; ' I. -1 ; . ! • ! I . , p 1II . ! : ' i i : I • . • I 1 i ; ' ; I . ; jr...I 1:1 1,i'l 1,11•11"., • ' I'i, .., 1•••••4 •1••:1.-11, I 11i.1 -t---....i.. I. : i .• . ;!.; 1 ! •;t; .; : .1.1•! f -i•i it:',1;:;. ! 1.1i' , ! ; , • ; I ; I : • .• •. . ; . i ; I ; : . I : i : • • •-•370 •••• 777— 7-7° : • •••- I , • -Surfce 1, Center .@, (590;7130), ,,St.€1.0 .Pirfape; 2., ....cntex'' @' (950;7590); I$t.413,a IFS 1 2'.228 Project Name: Shoemaker — Maverick Lane Project No. 4572-99 By: SN Date:1/6/00 Keith W. Ehlert, Consulting Engineering Geologist t'i•:. .• I • : • , • • . • 1 L..' . . Sheet 1 of 13 Plate 111-10 *********************************************** * ******************************************* * * * * * * * * TSTAB slope stability analysis * * Revision 2.52 - 01/06/86 * * * * * * * * TAGA Engineering Software Services * * Berkeley, California USA * * * * * IBM PC & 8086/8088 MS-DOS Version by * * * * * Design Professionals Management Systems * * * Kirkland, Washington USA * * * * * copyright (c) 1983,84,85 TAGA * * copyright (c) 1983,84,85 DPMS * * * * ******************************************* * *********************************************** ********************************************************************* Shoemaker - Maverick Ln, Section C-C', Surface 1, Static ********************************************************************* ****************************************** ANALYSIS BY BISHOP'S SIMPLIFIED METHOD ****************************************** ************** INPUT DATA ************** CONTROL DATA, AUTOMATIC NUMBER OF NUMBER OF NUMBER OF NUMBER OF NUMBER OF NUMBER OF NUMBER OF Project Name: Project No. SEARCH FOR CRITICAL CIRCLE DEPTH LIMITING TANGENTS VERTICAL SECTIONS SOIL LAYER BOUNDARIES POINTS DEFINING COHESION PROFILE CURVES DEFINING COHESION ANISOTROPY BOUNDARY LINE LOADS BOUNDARY PRESSURE LOADS 0 6 3 0 0 5 0 Shoemaker - Maverick Lane By: SN 4572-99 Date:1/6/00 Keith W. Ehlert, Consulting Engineering Geologist Sheet 2 of 13 Plate III-11 SEISMIC COEFFICIENT = .000 ATMOSPHERIC PRESSURE = .000 UNIT WEIGHT OF WATER = 62.400 UNIT WEIGHT OF WATER IN TENSION CRACK = 62.400 SEARCH STARTS AT CENTER ( 600.0,-100.0),WITH FINAL GRID OF 10.0 ALL CIRCLES PASS THROUGH THE POINT ( 590.0, 182.0) GEOMETRY SECTIONS .00 365.00 590.00 750.00 800.00 1600.00 T. CRACKS 65.00 65.00 182.00 268.00 300.00 300.00 W IN CRACK 65.00 65.00 182.00 268.00 300.00 300.00 BOUNDARY 1 65.00 65.00 182.00 268.00 300.00 300.00 BOUNDARY 2 182.00 182.00 182.00 268.00 300.00 300.00 BOUNDARY 3 400.00 400.00 400.00 400.00 400.00 400.00 SOIL PROPERTIES LAYER DENSITY COHESION FRICTION ANGLE DELTA PHI 1 120.00 560.00 30.00 .00 2 135.00 1000.00 45.00 .00 BOUNDARY FORCES AND PRESSURES LINE LOADS X COORDINATE MAGNITUDE INCLINATION WITH VERT - DEG 310.00 2000.000 00 320.00 2000.000 00 330.00 2000.000 00 340.00 2000.000 00 350.00 2000.000 .00 Project Name: Shoemaker - Maverick Lane By: SN Sheet 3 of 13 Project No. 4572-99 Date:1/6/00 Plate III-12 Keith W. Ehlert, Consulting Engineering Geologist *********** RESULTS *********** NUMBER TANGENT RADIUS (X) CENTER (Y) CENTER F.S. 1 182.2 282.2 600.0 -100.0 1.823 2 182.2 282.2 580.0 -100.0 1.779 3 182.2 302.2 600.0 -120.0 1.774 4 183.6 283.6 620.0 -100.0 2.009 5 182.2 262.2 600.0 -80.0 1.874 6 182.0 302.0 590.0 -120.0 1.736 7 182.2 312.2 600.0 -130.0 1.756 8 182.7 302.7 610.0 -120.0 1.844 9 182.2 292.2 600.0 -110.0 1.800 10 182.2 302.2 580.0 -120.0 1.768 11 182.0 312.0 590.0 -130.0 1.727 12 182.0 292.0 590.0 -110.0 1.745 13 182.2 312.2 580.0 -130.0 1.767 14 182.0 322.0 590.0 -140.0 1.727 15 182.2 312.2 600.0 -130.0 1.756 16 182.2 322.2 580.0 -140.0 1.773 17 182.2 322.2 600.0 -140.0 1.745 18 182.2 302.2 600.0 -120.0 1.774 19 182.2 302.2 580.0 -120.0 1.768 F.S. MINIMUM= 1.727 FOR THE CIRCLE OF CENTER ( 590.0,-130.0) Execution complete, time = .11 seconds Project Name: Shoemaker - Maverick Lane By: SN Sheet 4 of 13 Project No. 4572-99 Date:1/6/00 Plate III-13 Keith W. Ehlert, Consulting Engineering Geologist *********************************************** * ******************************************* * * * * * * * * * * * TSTAB slope stability analysis * * * * Revision 2.52 - 01/06/86 * * * * * * * * * * * * TAGA Engineering Software Services * * * * Berkeley, California USA * * * * * * * * IBM PC & 8086/8088 MS-DOS Version by * * * * * * * * Design Professionals Management Systems * * * * Kirkland, Washington USA * * * * * * * * copyright (c) 1983,84,85 TAGA * * * * copyright (c) 1983,84,85 DPMS * * * * * * * ******************************************* * *********************************************** ********************************************************************* Shoemaker - Maverick Ln, Section C-C', Surface 1, Seismic ********************************************************************* ****************************************** ANALYSIS BY BISHOP'S SIMPLIFIED METHOD ****************************************** ************** INPUT DATA ************** CONTROL DATA, AUTOMATIC NUMBER OF NUMBER OF NUMBER OF NUMBER OF NUMBER OF NUMBER OF NUMBER OF Project Name: Project No. SEARCH FOR CRITICAL CIRCLE DEPTH LIMITING TANGENTS VERTICAL SECTIONS SOIL LAYER BOUNDARIES POINTS DEFINING COHESION PROFILE CURVES DEFINING COHESION ANISOTROPY BOUNDARY LINE LOADS BOUNDARY PRESSURE LOADS 0 6 3 0 0 5 0 Shoemaker - Maverick Lane By: SN 4572-99 Date: 1/6/00 Keith W. Ehlert, Consulting Engineering Geologist Sheet 5 of 13 Plate 111-14 SEISMIC COEFFICIENT = .150 ATMOSPHERIC PRESSURE _ .000 UNIT WEIGHT OF WATER = 62.400 UNIT WEIGHT OF WATER IN TENSION CRACK = 62.400 SEARCH STARTS AT CENTER ( 590.0,-130.0),WITH FINAL GRID OF 10.0 ALL CIRCLES PASS THROUGH THE POINT ( 590.0, 182.0) GEOMETRY SECTIONS .00 365.00 590.00 750.00 800.00 1600.00 T. CRACKS 65.00 65.00 182.00 268.00 300.00 300.00 W IN CRACK 65.00 65.00 182.00 268.00 300.00 300.00 BOUNDARY 1 65.00 65.00 182.00 268.00 300.00 300.00 BOUNDARY 2 182.00 182.00 182.00 268.00 300.00 300.00 BOUNDARY 3 400.00 400.00 400.00 400.00 400.00 400.00 SOIL PROPERTIES LAYER DENSITY COHESION FRICTION ANGLE DELTA PHI 1 120.00 880.00 33.00 .00 2 135.00 1000.00 45.00 .00 BOUNDARY FORCES AND PRESSURES LINE LOADS X COORDINATE MAGNITUDE INCLINATION WITH VERT - DEG 310.00 2000.000 00 320.00 2000.000 00 330.00 2000.000 .00 340.00 2000.000 .00 350.00 2000.000 .00 Project Name: Shoemaker - Maverick Lane By: SN Sheet 6 of 13 Project No. 4572-99 Date: 1/6/00 Plate III-15 Keith W. Ehlert, Consulting Engineering Geologist *********** RESULTS *********** NUMBER TANGENT RADIUS (X) CENTER (Y) CENTER F.S. 1 182.0 312.0 590.0 -130.0 1.588 2 182.6 312.6 570.0 -130.0 1.606 3 182.0 332.0 590.0 -150.0 1.572 4 182.6 312.6 610.0 -130.0 1.726 5 182.0 292.0 590.0 -110.0 1.621 6 182.2 332.2 580.0 -150.0 1.576 7 182.0 342.0 590.0 -160.0 1.570 8 182.2 332.2 600.0 -150.0 1.603 9 182.0 322.0 590.0 -140.0 1.580 10 182.1 342.1 580.0 -160.0 1.578 11 182.0 352.0 590.0 -170.0 1.567 12 182.1 342.1 600.0 -160.0 1.593 13 182.1 352.1 580.0 -170.0 1.579 14 182.0 362.0 590.0 -180.0 1.568 15 182.1 352.1 600.0 -170.0 1.583 16 182.1 362.1 580.0 -180.0 1.583 17 182.1 362.1 600.0 -180.0 1.579 18 182.1 342.1 600.0 -160.0 1.593 19 182.1 342.1 580.0 -160.0 1.578 F.S. MINIMUM= 1.567 FOR THE CIRCLE OF CENTER ( 590.0,-170.0) Execution complete, time = .05 seconds Project Name: Project No. Shoemaker - Maverick Lane 4572-99 By: SN Date: 1/6/00 Keith W. Ehlert, Consulting Engineering Geologist Sheet 7 of 13 Plate III-16 *********************************************** * ******************************************* * * * * * * * * * * * TSTAB slope stability analysis * * * * Revision 2.52 - 01/06/86 * * * * * * * * * * * * TAGA Engineering Software Services * * * * Berkeley, California USA * * * * * * IBM PC 8, 8086/8088 MS-DOS Version by * * * * * * * * * * Design Professionals Management Systems * * * * * Kirkland, Washington USA copyright (c) 1983,84,85 TAGA * copyright (c) 1983,84,85 DPMS * * * ******************************************* * * *********************************************** ********************************************************************* Shoemaker - Maverick Ln, Section C-C', Surface 2, Static ********************************************************************* ****************************************** ANALYSIS BY BISHOP'S SIMPLIFIED METHOD ****************************************** ************** INPUT DATA ************** CONTROL DATA, AUTOMATIC NUMBER OF NUMBER OF NUMBER OF NUMBER OF NUMBER OF NUMBER OF NUMBER OF Project Name: Project No. SEARCH FOR CRITICAL CIRCLE DEPTH LIMITING TANGENTS VERTICAL SECTIONS SOIL LAYER BOUNDARIES POINTS DEFINING COHESION PROFILE CURVES DEFINING COHESION ANISOTROPY BOUNDARY LINE LOADS BOUNDARY PRESSURE LOADS 0 6 3 0 0 5 0 Shoemaker - Maverick Lane By: SN 4572-99 Date: 1/6/00 Keith W. Ehlert, Consulting Engineering Geologist Sheet 8 of 13 Plate III-17 SEISMIC COEFFICIENT = .000 ATMOSPHERIC PRESSURE = .000 UNIT WEIGHT OF WATER = 62.400 UNIT WEIGHT OF WATER IN TENSION CRACK = 62.400 SEARCH STARTS AT CENTER ( 920.0,-530.0),WITH FINAL GRID OF 10.0 ALL CIRCLES PASS THROUGH THE POINT ( 800.0, 300.0) GEOMETRY SECTIONS .00 365.00 590.00 750.00 800.00 1600.00 T. CRACKS 65.00 65.00 182.00 268.00 300.00 300.00 W IN CRACK 65.00 65.00 182.00 268.00 300.00 300.00 BOUNDARY 1 65.00 65.00 182.00 268.00 300.00 300.00 BOUNDARY 2 182.00 182.00 182.00 268.00 300.00 300.00 BOUNDARY 3 400.00 400.00 400.00 400.00 400.00 400.00 SOIL PROPERTIES LAYER DENSITY COHESION FRICTION ANGLE DELTA PHI 1 120.00 560.00 30.00 .00 2 135.00 1000.00 45.00 .00 BOUNDARY FORCES AND PRESSURES LINE LOADS X COORDINATE MAGNITUDE INCLINATION WITH VERT - DEG 310.00 2000.000 .00 320.00 2000.000 .00 330.00 2000.000 .00 340.00 2000.000 .00 350.00 2000.000 .00 Project Name: Shoemaker - Maverick Lane By: SN Sheet 9 of 13 Project No. 4572-99 Date: 1/6/00 Plate III-18 Keith W. Ehlert, Consulting Engineering Geologist I *********** I I I I I I I I I I I I I I I I I RESULTS *********** NUMBER TANGENT RADIUS (X) CENTER (Y) CENTER F.S. 1 308.6 838.6 920.0 -530.0 2.240 2 306.0 836.0 900.0 -530.0 2.261 3 308.4 858.4 920.0 -550.0 2.243 4 311.7 841.7 940.0 -530.0 2.247 5 308.8 818.8 920.0 -510.0 2.244 6 307.3 837.3 910.0 -530.0 2.249 7 308.5 848.5 920.0 -540.0 2.241 8 310.1 840.1 930.0 -530.0 2.240 9 308.7 828.7 920.0 -520.0 2.242 10 310.0 850.0 930.0 -540.0 2.238 11 311.7 841.7 940.0 -530.0 2.247 12 310.2 830.2 930.0 -520.0 2.245 13 308.-5 848.5 920.0 -540.0 2.241 14 309.9 859.9 930.0 -550.0 2.236 15 311.6 851.6 940.0 -540.0 2.242 16 308.4 858.4 920.0 -550.0 2.243 17 309.8 869.8 930.0 -560.0 2.236 18 311.5 861.5 940.0 -550.0 2.236 19 308.3 868.3 920.0 -560.0 2.244 20 311.3 871.3 940.0 -560.0 2.234 21 311.6 851.6 940.0 -540.0 2.242 22 308.5 848.5 920.0 -540.0 2.241 23 311.2 881.2 940.0 -570.0 2.232 24 313.0 873.0 950.0 -560.0 2.239 25 309.7 879.7 930.0 -570.0 2.238 26 311.1 891.1 940.0 -580.0 2.232 27 312.8 882.8 950.0 -570.0 2.233 28 309.6 889.6 930.0 -580.0 2.239 29 312.7 892.7 950.0 -580.0 2.231 30 313.0 873.0 950.0 -560.0 2.239 31 309.8 869.8 930.0 -560.0 2.236 32 312.6 902.6 950.0 -590.0 2.228 33 314.4 894.4 960.0 -580.0 2.237 34 310.9 900.9 940.0 -590.0 2.234 35 312.4 912.4 950.0 -600.0 2.228 36 314.3 904.3 960.0 -590.0 2.231 37 310.8 910.8 940.0 -600.0 2.234 38 314.1 914.1 960.0 -600.0 2.228 39 314.4 894.4 960.0 -580.0 2.237 40 311.1 891.1 940.0 -580.0 2.232 F.S. MINIMUM= 2.228 FOR THE CIRCLE OF CENTER ( 950.0,-590.0) Execution complete, time = .10 seconds Project Name: Shoemaker - Maverick Lane By: SN Sheet 10 of 13 Project No. 4572-99 Date: 1/6/00 Plate III-19 Keith W. Ehlert, Consulting Engineering Geologist *********************************************** * ******************************************* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * TSTAB slope stability analysis Revision 2.52 - 01/06/86 TAGA Engineering Software Services Berkeley, California USA IBM PC & 8086/8088 MS-DOS Version by Design Professionals Management Systems Kirkland, Washington USA copyright (c) 1983,84,85 TAGA copyright (c) 1983,84,85 DPMS * ******************************************* *********************************************** ********************************************************************* Shoemaker - Maverick Ln, Section C-C', Surface 2, Seismic ********************************************************************* ****************************************** ANALYSIS BY BISHOP'S SIMPLIFIED METHOD ****************************************** ************** INPUT DATA ************** CONTROL DATA, AUTOMATIC NUMBER NUMBER NUMBER NUMBER NUMBER NUMBER NUMBER Project Name: Project No. OF OF OF OF OF OF OF SEARCH FOR CRITICAL CIRCLE DEPTH LIMITING TANGENTS VERTICAL SECTIONS SOIL LAYER BOUNDARIES POINTS DEFINING COHESION PROFILE CURVES DEFINING COHESION ANISOTROPY BOUNDARY LINE LOADS BOUNDARY PRESSURE LOADS Shoemaker - Maverick Lane 4572-99 0 6 3 0 0 5 0 By: SN Date: 1/6/00 Keith W. Ehlert, Consulting Engineering Geologist Sheet 11 of 13 PlatelII-20 SEISMIC COEFFICIENT = .150 ATMOSPHERIC PRESSURE = .000 UNIT WEIGHT OF WATER = 62.400 UNIT WEIGHT OF WATER IN TENSION CRACK = 62.400 SEARCH STARTS AT CENTER ( 950.0,-590.0),WITH FINAL GRID OF 10.0 ALL CIRCLES PASS THROUGH THE POINT ( 800.0, 300.0) GEOMETRY SECTIONS .00 365.00 590.00 750.00 800.00 1600.00 , T. CRACKS 65.00 65.00 182.00 268.00 300.00 300.00 W IN CRACK 65.00 65.00 182.00 268.00 300.00 300.00 BOUNDARY 1 65.00 65.00 182.00 268.00 300.00 300.00 BOUNDARY 2 182.00 182.00 182.00 268.00 300.00 300.00 BOUNDARY 3 400.00 400.00 400.00 400.00 400.00 400.00 SOIL PROPERTIES LAYER DENSITY COHESION FRICTION ANGLE DELTA PHI 1 120.00 880.00 33.00 .00 2 135.00 1000.00 45.00 .00 BOUNDARY FORCES AND PRESSURES LINE LOADS X COORDINATE MAGNITUDE INCLINATION WITH VERT - DEG 310.00 2000.000 .00 320.00 2000.000 .00 330.00 2000.000 .00 340.00 2000.000 .00 350.00 2000.000 .00 Project Name: Shoemaker - Maverick Lane By: SN Sheet 12 of 13 Project No. 4572-99 Date: 1/6/00 Plate III-21 Keith W. Ehlert, Consulting Engineering Geologist *********** RESULTS *********** NUMBER TANGENT RADIUS (X) CENTER 1 312.6 902.6 950.0 2 309.4 899.4 930.0 3 312.3 922.3 950.0 4 316.1 906.1 970.0 5 312.8 882.8 950.0 6 310.7 920.7 940.0 7 312.1 932.1 950.0 8 314.0 924.0 960.0 9 312.4 912.4 950.0 10 310.6 930.6 940.0 11 312.0 942.0 950.0 12 313.8 933.8 960.0 13 310.5 940.5 940.0 14 313.7 943.7 960.0 15 314.0 924.0 960.0 16 310.7 920.7 940.0 F.S. MINIMUM= 1.701 FOR THE CIRCLE OF (Y) CENTER F.S. - 590.0 -590.0 - 610.0 -590.0 -570.0 - 610.0 - 620.0 -610.0 -600.0 - 620.0 - 630.0 -620.0 -630.0 -630.0 - 610.0 -610.0 1.706 1.706 1.703 1.725 1.713 1.703 1.701 1.705 1.704 1.704 1.702 1.703 1.705 1.702 1.705 1.703 CENTER ( 950.0,-620.0) Execution complete, time = .06 seconds Project Name: Project No. Shoemaker - Maverick Lane 4572-99 By: SN Date: 1/6/00 Keith W. Ehlert, Consulting Engineering Geologist Sheet 13 of 13 Plate III-22 P.N. 4572-99 APPENDIX IV SLOPE SURFACE STABILITY ANALYSIS Stability of the surface of the slopes at the subject site has been analyzed. The slopes are generally no steeper than 11/2:1 (Horizontal to Vertical) and are underlain at shallow depths by fill soils or natural soil. The shear strength adopted in the analysis is based on direct shear tests on representative undisturbed samples of the fill soils and natural soil under soaked conditions. The residual shear strength of the samples of the fill soils and soil (Plate C-1 of our April 14, 1999 Report and Plate C-4 of this Report) has been used. Density Cohesion Friction Angle Fill/Soil 105 pcf 390 psf 18 degrees . Calculations are included on Plate IV-1. A factor -of -safety in excess of 1.50 has been obtained for a 1'/:1 slope that has fill soils or natural soil within 4 feet of the slope surface. Slope Surface Stability Analysis Existing Slope, 11/2:1, 34 degrees CALCULATE THE SURFICIAL STABILITY OF THE FILL USING THE INFINITE SLOPE ANALYSIS WITH PARALLEL SEEPAGE. THIS METHOD WAS RECOMMENDED BY THE A.S.C.E. AND THE BUILDING AND SAFETY ADVISORY COMMITTEE (8/16/78) FILL PROPERTIES (All Saturated) REFERENCE: SHEAR DIAGRAM C-1. COHESION 390 psf PHI ANGLE 18 degrees SATURATED DENSITY 105 pcf SLOPE ANGLE 34 degrees WATER DENSITY 62.4 pcf DEPTH OF SATURATION 4 feet FACTOR OF SAFETY = 390 + (( 105 - 62.41 4 ((COS 34 1^2)TAN( 18 1) 105 x 4 COS 34 SIN 34 THE CALCULATED FACTOR OF SAFETY IS 2.19 CONCLUSIONS: CALCULATIONS INDICATE THE FILL HAS A FACTOR OF SAFETY OF 2.19 AND IS CONSIDERED SURFICIALLY STABLE. Project Name: Shoemaker — Maverick Lane Project No. 4572-99 By: SN Sheet 1 of 1 Date: 1/6/00 Plate IV-1 Keith W. Ehlert, Consulting Engineering Geologist A 1400 1300 - 1200 1100 SITE BEDROCK (Tmk SCHIST (pKc) SCHIST (pKc) 1 10 l P.N. 4572-99 I SCALE 1" = 5 GEOLOGIC CROSS SECTION PLATE 2 B FILL 14007 1' SITE l'' , '''"....,.......„ alak...... BUTTRESS F ''"•••-....,............_ . ith .... 6."'"" Z. k a or al b FILL BEDROCK (Tm)::: _._. - -"---_,.......„,.........- .,..BEDROCK (Tm) '40.4.....1.MiAlof 0.••••11.4miugoo...m............... 1300 1200 1100 SCHIST (pKc) SCHIST (pKc) RN. 4572-99 I SCALE 1" = 50' GEOLOGIC CROSS SECTION B' ire■ 1400 1300 1200 - 11 00 I PLATE 3 1400 - 1350 1300 -= 1250 - 1200 - 1150 - 1100 -. EXISTING HOUSE TEST TRENCH 3 FILL BEDROCK (Tm). APPARENT DIP OF BEDDING---___ SCHIST (pKc) THIN VENEER OF SOIL _ BEDROCK (Tm) TEST TRENCH 10 SLUMP SCHIST (pKc) C' _- 1400 - 1350 - 1300 - 1250 - 1200 1150 - 1100 P.N. 4572-99 !SCALE 1" = 50' I GEOLOGIC CROSS SECTION PLATE 4 D 1400 ----, 1350 1300 - 1250 - 1200 - 1150 - EXISTING HOUSE v.-I-EST TRENCH 1 FILL THIN VENEER OF SOIL BEDROCK (Tm) APPARENT DIP OF BEDDING TRUE DIP TOWARDS VIEWER SCHIST (pKc) TEST TRENCH 8 BEDROCK (Tm) SCHIST (pKc) D' - 1400 - 1350 - 1300 - 1250 - 1200 - 1150 P. N . 4572-99 I SCALE 1" = 50' GEOLOGIC CROSS SECTION PLATE 5 EXPLANATION ESTIMATED LOCATION OF BUTTRESS FILL PLACED BY AGI, 1997 132� 1300 1 MAVERICK LANE (NO 12°16° 10° �,r.137 5 Tm 40, • 0 M 7, 11 t-TIMATE�r ' R � PERT�� NE . . hi.,...... iiiiiliorill 1.011.101 0 ��1 BORINGS BY AGI qGj / 32° 1225 a,"1" sok t 4.1D Tm • O 8 M 1. � 15` 28. aurni 1666 Tm 1 Af = Fill Qis = SLUMP DEBRIS pKc = CATALINA SCHIST Tm = Monterey Formation = ESTIMATED TEST TRENCH LOCATION = STRIKE AND DIP OF BEDDING BY EHLERT, 1999 25 = STRIKE AND DIP OF BEDDING PG\ BY AGI, 1997 zs = STRIKE AND DIP OF BEDDING A 0 - A, BY BEACH-LEIGHTON, 1969 I I = CROSS SECTION LINE ESTIMATED CONTACT 1 00 1125 1150-�''�J-� on _ r'*%**% 11175 0 GEOLOGIC MAP SCALE 1“ = 50' P.N. 4572-99 PLATE 1