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585, Construct detached garage, gra, Studies & ReportsRESIDENTIAL DRAFTING SERVICE INC. 3706 Woodruff Ave. Long Beach, California, 90808 - 2123.c HILLS Ph. (562) 421 - 0919 Fax. (562) 420 - o� pppsoved PLANNING DEPARTMENT March 4, 1999 Mrs. Lola M. Unbar Planning Dept. City of Rolling Hills # 2.Portuguese Bend Road Rolling Hills, Calif. 90274 Date �ct:YZ '77b :.�l11 pvp�T Ph. (310) 377 - 1521 401 Fax. (310) 377 - 7288 Subject: Bob Barth New Garage, Zone Case 585, 29 Portuguese Bend Road Additional Grading Required per Soils Engineers Report. Dear Lola; Original design and Site Plan indicated a Two to Three Foot Stem Foundation wall on rear and Right Elevation. In discussions with the Rolling Hills Community Association, they indicated the Foundation Stem wall was not desirable. The requested a Three Foot flat area around Garage, on Rear and Right Elevations and raise grade elevation to within 6" of top of Foundation Curb. The existing grade slope is approximately 4 to 1. With raising the grade around the Garage, this in turn extended the 2 to 1 slope, and increased the bottom of slope out from Garage from approximately Ten Feet to approximately Twenty Five feet. My original Foundation Design was to use continuous Footing, depth into grade as required or into Bedrock. When the Soils Report was requested, it indicated that the ground would not support the Garage Floor or Footings. The Soils Report requested a 27 inch deep footing into recompacted, engineered fill, minimum Three Feet below bottom of Footing, with Keyway at bottom of Slope. This increase the cut - fill from the original expected 15 Cubic Yards to the engineered cut and fill of approximately 202 cubic yards and imported or soil gathered from Site to approximately 320 Cubic Yards. Mr. Barth applied for a Building Permit on October 7, 1997, and was due to expire on October 7,1998. The Soils report took Three Months to obtain and then had to revise structural engineering. We applied and received a Six month extension for permit, extended to March 7, 1999. Plans now are in L.A. Co. Building Dept, Lomita Office for recheck. Now need to apply for Geology and Grading Permits before Building Department will issue Building permit. Will have Rolling Hills approved Final plans, before permits issued. Sincerely Yours, ,1a6errt Cf. V e W(o Draftsman, President _Western Laboratories 1 . Geotechnical Engineering March 1, 1999 Work Order 98-2556 MR ROBERT BARTH #29 Portuguese Bend Road Rolling Hills, California 90274 Subject: Addendum No. 2 Geotechnical Engineering & Engineering Geologic Investigation Proposed Garage #29 Portuguese Bend Road Rolling Hills, California Dear Sir: CITY OF ROLLING HILLS Approved T,G aff, PLANNING DEPARTMENT Date At the request of Mr. Bob Demoss, this addendum to our Geotechnical Engineering and Engineering Geologic Investigation, dated July 15, 1998, Work Order 98-2556, is submitted. We have been asked to address three statements presented by the City of Rolling Hills with regard to the proposed grading operation to be performed at the subject property. The statements are repeated herein and a copy of the statements are attached. 3. (a) construction of a structure on the lot or parcel has commenced, It is the understanding of this firm that the permit application is approaching it's expiration date. Construction of the garage on the lot has not commenced. 3. (b) that the need to import or export the soil could not have been foreseen prior to commencement of construction, and The engineering reports require that the existing fill and colluvium be removed and recompacted. A keyway should be excavated at the toe of the fill slope and the bedrock should be benched as the grading operation progresses. 3. (c) that either the structure cannot be completed without the requested import or export of soil or that an emergency condition exists due to the threat of land subsidence or other imminent danger. Grading operations will be required to provide foundation and slab support. 3665 West 240th Street, Torrance, CA 90505 (310) 791-9001 — FAX (310) 791-0248 March 1, 1999 Work Order 98-2556 We appreciate this opportunity to be of service to you. • Very truly yours, WESTERN LABO ' • e_ ��FES Kirk S eller Senior Engineer R.C.E. 4 2 Western Laboratories v Geotechnical Engineering 15.04.170 2. No grading plan for which a permit is required shall be approved unless the amount of soil to be cut from the site equals the amount of soil to be filled on the site. 3. The City Manager may grant an exception to the requirements of parts 1 and 2 of this paragraph to allow for the import or export of soil not to exceed 500 cubic yards if he or she finds, based upon written reports and other information submitted, that all of the following conditions are present: construction of a structure on the lot or par- cel has commenced, (b) that the need to import or export the soil could not have been foreseen prior to commencement of construction,.. and (c) that either the structure cannot be completed without the requested import or export of soil or that an emergency condition exists due to the threat of land subsidence or other imminent danger. 4. The City Manager may grant an exception to the requirements of parts 1 and 2 of this paragraph to allow for the import or export of soil not to exceed 500 cubic yards for remedial repair of a hillside or trail if he or she finds, based upon written reports and other information submitted, that all of the fol- lowing conditions are present: (a) the project does not require a grading permit (a cut that is less than three feet or a fill that is less than three feet or covers less than 2,000 square feet), and (b) the import or export of soil is no greater than necessary to avoid a threat of land subsidence or other imminent danger. (Ord. 273 §5, 1998: Ord. 257-U §1(part), 1995). 174-1 (Rolling Hills 4/98) FAX COVER SHEET Wednesday, March 03, 1999 11:14:18 AM To: Lola Unbar At: Rolling Hills Planning Fax #: 13103777288 From: ROBERT DeMOSS Company: RESIDENTIAL DRAFTING SERVICE INC. Fax #: 562-420-3359 Voice: 562-421-0919 Fax: 2 pages and a cover page. Wednesday, March 03, 1999 11:14:18 ,RESIDENTIAL DRAFTING SERVICE INC. Page 1 of 2 March 2, 1999 Mrs. Lola M. Unbar Planning Dept. City of Rolling Hills # 2 Portuguese Bend Road Rolling Hills, Calif. 90274 :13 EgEHET))1 MAR 0 31999 CITY OF ROLLING HILLS !�V Ph. (310) 377 - 1521 Fax. (310) 377 - 7288 Subject: Bob Barth New Garage, Zone Case 585 Additional Grading Required per Soils Engineers Report. Dear Lola; At time of obtaining City of Rolling Hills approval for Garage, the existing Soil conditions where unknown. Construction has not started, but we are in the process of obtaining required permits. Mr. Barth obtained a Building Plan Check Extension, on September 16 th. to extend time to obtain permit until March 7 th. 1999. Due to Work overload, Residential Drafting Service Inc. has been behind in getting Engineering and Plans revised for submittal. The Building plans have now been revised, regarding Structural Engineering, and are in for Structural recheck at this time at the Lomita Office, Los Angeles County Building Department. The Soils Engineer, Western Laboratories of Torrance, California is requiring excavation of area at proposed Four Car Garage from Four feet up to Eight Feet deep, than reuse soil and recompact for Garage. To bring exterior grade up to within Six Inches of top of Foundation, and raise grade to provide a level pad for Garage is going to require obtaining additional soil from site or possibly importing soil. The Soils Report is requiring a minimum of Three Feet of Engineered, Compacted Soil under the required Twenty Seven inch deep footing along with a earth key way at bottom of slope. This is requiring us to submit Grading Plans plans to Los Angeles County Grading, Geology Division for Grading Plan Check which we need to do this week. Our Los Angeles County Plan check expires March 7 th. but if the Grading Plans are in Plan check we have a Thirty Day Extension to April 6 th. to obtain permits. Seaboard Engineering is now preparing this Grading Plan, and will have complete this afternoon, and I will deliver to you this afternoon. As the Grading Office is closed on Friday, I need to submit these grading plans no latter than Thursday, March 4 at the Alhambra Office, County Building Dept. Grading Division. According to the revised Grading Plan, this amounts to removing and recompacting approximately 202 Cubic Yards and obtaining from site or importing approximately 320 Cubic Yards of Soil, all to be compacted per Soils Report for 2 : 1 Slope. Exposed slopes and area outside of Garage to be landscape to control erosion. The original estimation of 15 Cubic Yards of removed and recompacted soil did not take in account of Soils report, which we did not have that time. Would appreciate your approval of extra grading required as soon as possible. Sincerely Yours, Wednesday, March 03, 1999 11:14:18 ,RESIDENTIAL DRAFTING SERVICE INC. Page 2 of 2 Ro C, V e i/(o Draftsman, President FAX COVER SHEET Wednesday, March 03, 1999 11:23:53 AM To: Lola M. Umbar At: Rolling Hills Planning Fax #: 13103777288 From: ROBERT DeMOSS Company: RESIDENTIAL DRAFTING SERVICE INC. Fax #: 562-420-3359 Voice: 562-421-0919 Fax: 1 page and a cover page. Wednesday, March D3, 1999 11:23:53 .RESIDENTIAL DRAFTING SERVICE INC. Page 1 of 1 RESIDENTIAL DRAFTING SERVICE INC. 3706 Woodruff Ave. Long Beach, California, 90808 - 2123 Ph. (562) 421 - 0919 Fax. (562) 420 - 3359 March 3, 1999 Mrs. Lola M. Unbar Planning Dept. City of Rolling Hills # 2 Portuguese Bend Road Rolling Hills, Calif. 90274 Ph. (310) 377 - 1521 Fax. (310) 377 - 7288 Subject: Bob Barth New Garage, Zone Case 585 Additional Grading Required per Soils Engineers Report. Dear Lola; At time of obtaining City of Rolling Hills approval for Garage, the existing Soil conditions where unknown. Construction has not started, but we are in the process of obtaining required permits. Mr. Barth obtained a Building Plan Check Extension, on September 16 th. to extend time to obtain permit until March 7 th. 1999. Due to Work overload, Residential Drafting Service Inc. has been behind in getting Engineering and Plans revised for submittal. The Building plans have now been revised, regarding Structural Engineering, and are in for Structural recheck at this time at the Lomita Office, Los Angeles County Building Department. The Soils Engineer, Western Laboratories of Torrance, California is requiring excavation of area at proposed Four Car Garage from Four feet up to Eight Feet deep, than reuse soil and recompact for Garage. To bring exterior grade up to within Six Inches of top of Foundation, and raise grade to provide a level pad for Garage is going to require obtaining additional soil from site or possibly importing soil. The Soils Report is requiring a minimum of Three Feet of Engineered, Compacted Soil under the required Twenty Seven inch deep footing along with a earth key way at bottom of slope. This is requiring us to submit Grading Plans plans to Los Angeles County Grading, Geology Division for Grading Plan Check which we need to do this week. Our Los Angeles County Plan check expires March 7 th. but if the Grading Plans are in Plan check we have a Thirty Day Extension to April 6 th. to obtain permits. Seaboard Engineering is now preparing this Grading Plan, and will have complete this afternoon, and I will deliver to you this afternoon. As the Grading Office is closed on Friday, I need to submit these grading plans no latter than Thursday, March 4 at the Alhambra Office, County Building Dept. Grading Division. According to the revised Grading Plan, this amounts to removing and recompacting approximately 202 Cubic Yards and obtaining from site or importing approximately 320 Cubic Yards of Soil, all to be compacted per Soils Report for 2 : 1 Slope. Exposed slopes and area outside of Garage to be landscape to control erosion. The original estimation of 15 Cubic Yards of removed and recompacted soil did not take in account of Soils report, which we did not have that time. Would appreciate your approval of extra grading required as soon as possible. Sincerely Yours, Draftsman, President Western Laboratories o V 7 Geotechnical Engineering February 26, 1999 Work Order 98-2556 MR. ROBERT BARTH #29 Portuguese Bend Road Rolling Hills, California 90274 Subject: Addendum No. 1 Geotechnical Engineering & Engineering Geologic Investigation Proposed Garage # 29 Portuguese Bend Road Rolling Hills, California Dear Sir: This addendum to our Geotechnical Engineering and Engineering Geologic Investigation, dated July 15, 1998, Work Order 98-2556, is submitted. The dimensions of the keyway to be excavated to support the proposed fill may be reduced to a minimum width of twelve feet and a minimum depth of three feet into approved bedrock, measured at the toe of the key. We appreciate this opportunity to be of service to you. Very truly yours, WESTERN LABORATORIES Kirk L. Sheller Senior Engineer R.C.E. 4683 741E OF CO 3665 West 240th Street, Torrance, CA 90505 (310) 791-9001 — FAX (310) 791-0248 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 'MOM _N__o --w IAia&10.MOft IV IV O V Laboratories Geotechnical Engineering GEOTECHNICAL ENGINEERING & ENGINEERING GEOLOGIC INVESTIGATION PROPOSED GARAGE #29 PORTUGUESE BEND ROAD ROLLING HILLS, CALIFORNIA JULY 15, 1998 WORK ORDER 98-2556 PREPARED FOR: MR. ROBERT BARTH #29 PORTUGUESE BEND ROAD ROLLING HILLS, CALIFORNIA 90274 3665 West 240th Street, Torrance, CA 90505 (310) 791-9001 — FAX (310) 791-0248 1MM_ — Western Laboratories ws T V Geotechnical Engineering July 15, 1998 Work Order 98-2556 MR. ROBERT BARTH #29 Portuguese Bend Road Rolling Hills, California 90274 Subject: Geotechnical Engineering & Engineering Geologic Investigation Proposed Garage #29 Portuguese Bend Road Rolling Hills, California Dear Sir: Pursuant to your authorization for geotechnical engineering and engineering geologic consulting services, the accompanying report has been prepared. Based upon the subsurface conditions that were encountered during our investigation, it is our conclusion that the proposed garage is considered feasible from geotechnical engineering and engineering geologic standpoints, provided the recommendations contained herein are incorporated into the planning, design, and construction of the development. The contents in this report should be reviewed in detail and be made a portion of the design package. Please contact this office if any questions arise regarding the contents of this report. Very truly yours, WESTERN LABORATORIES ,itSSION4z Kirk L. Sheller Senior Engineer R.C.E. Ray,.. Eastman C. G. 423 3665 West 240th Street, Torrance, CA 90505 (310) 791-9001 — FAX (310) 791-0248 Table of Contents Introduction 4 Purpose and Scope of Work 4 Site Description 4 Field Exploration 5 Geologic Conditions 5 Groundwater 6 Seismic Conditions 6 Slope Stability 7 Conclusions 7 Recommendations 8 Notification of Governing Authorities 8 Site Grading and Compaction 8 Slope Construction 10 Utility Trenches 10 Spread Footing Foundations 11 Retaining Structures 12 Slabs -on -Grade 13 Site Surface Drainage 15 Closure 15 Supplemental Services 16 Maintenance 17 Selected References 17 Specifications for Compacted Fill 1 g Appendix A - Test Pit Logs Appendix B - Laboratory Testing Appendix C- Geologic Maps & Cross Sections Plot Plan Western Laboratories • • Geotecnnrcal Enarneenno July 15, 1998 Work Order 98-2556 Introduction This report presents the results of our geotechnical engineering and engineering geologic investigation performed for the proposed garage to be constructed at #29 Portuguese Bend Road, Rolling Hills, California. The proposed development will entail construction of a one-story garage with exterior masonry block or poured -in -place concrete walls combined with timber and stucco or wooden siding, and a concrete slab -on -grade floor. A maximum anticipated foundation loading of 2.5 kips/lin.ft. for continuous foundations was utilized for testing and design purposes. If the actual design loading should exceed this value, this firm should be notified in order that we may review, and if necessary, amend our recommendations. Purpose and Scope of Work The purpose of our exploration was to evaluate the soil conditions at the site and to provide geotechnical engineering and engineering geologic recommendations for design and construction of the proposed garage. Our work was based upon preliminary planning information and was conducted in accordance with generally accepted practice for the particular circumstance. The scope of our services included: review of selected geologic maps; field geologic examination of the site; subsurface exploration by three exploratory test pits; classification; laboratory testing; evaluation of the units encountered with respect to the proposed development; and analyzing the results of the field and laboratory work to provide the information contained in this report. Site Description The main residence site occupies approximately one thousand square feet that is situated at the northerly flank of the Palos Verdes Hills. It is bounded on the southeast by Portuguese Bend Road, on the northwest by a tributary to Spring Canyon, and in general by scattered residential development. Topography consists of two main aspects: a level parking area and a moderately steep, northwesterly facing slope that is formed by the aforementioned canyon. The slope has an approximate relief of approximately forty-five feet. An overview of the site and topography is also shown on the accompanying base maps. .._- "il'aVWestern Laboratories 4 V Georecnnrcar Enarneenng July 15, 1998 Work Order 98-2556 Field Exploration The subsurface conditions at the site were explored by excavating three (3) twenty-four inch wide exploratory test pits at the locations indicated on the attached Geologic Map. The test pits were logged by an Engineering Geologist and disturbed and undisturbed samples were obtained for laboratory testing and analysis. Descriptions of the materials encountered in our test pits are presented on the logs in Appendix A. The logs only depict subsurface conditions on the dates shown on the logs and at the approximate locations shown on the Geologic Map. Subsurface conditions may differ across the site from the conditions encountered in our test pits. Bulk and relatively undisturbed soil samples were obtained at depths appropriate to the exploration. The soil sampler utilized in our exploration included a 23/8-inch inside diameter and 3'/4-inch outside diameter drive barrel, lined with numerous 1 inch brass rings. The central portion of these ring samples were retained for testing. All samples were immediately sealed in airtight containers and transported to the laboratory. Bulk, remolded, and relatively undisturbed soil samples serve as the basis for the laboratory testing and engineering conclusions contained in this report. Geologic Conditions The moderately rugged Peninsular Range comprises the geologic province and same extends southeasterly from the Santa Monica and San Gabriel Mountains into Baja California. The major geologic formations in the region include alluvium at the valley floors and sedimentary, granitic and metamorphic bedrock in the mountainous terrain. Major fault lines include the nearby Palos Verdes and Inglewood. Geology at the site consists of three basic units, including: sedimentary bedrock, colluvium and fill. The accompanying geologic maps, sections and logs present an overview. The bedrock is assigned to the Altamira member of the Monterey Formation. It consists mainly of firm, gray and brown, diatomaceous shale with interbeds of tan tuffaceous sandstone, hard brown chert and gray brown marlstone. The tuffaceous sandstone is dominant at this site and same is thickly and crudely bedded with dips of approximately 30 to 40 degrees toward the northwest. The colluvium is present as a cover of approximately four feet on the bedrock. It consists mainly of soft to stiff, dark brown, silty clay with rootlets. "EST Western Laboratories Iffur V V Georecnnical Engineering July 15, 1998 Work Order 98-2556 The fill occupies a surficial and localized wedge along the edge of the parking area. It is anticipated to consist mainly of poorly compact, dark brown, silt and clay with rock fragments. Groundwater Groundwater was not encountered in our exploratory test pits. Fluctuations in the groundwater level at the site could occur due to variations in precipitation and numerous other factors. Seismic Conditions The nearest active faults of significance to the site include the following: Fault Zone Palos Verdes Inglewood San Pedro Basin Santa Monica Whittier Hollywood Raymond Approximate Location 2 miles north 8 miles northeast 14 miles southwest 20 miles northwest 22 miles northeast 22 miles north 25 miles northeast (*) Maximum probable moment magnitude, CDMG 1996. Earthquake Magnitude* 7.1 6.9 6.6 6.6 6.8 6.4 6.5 The associated ground motion parameters may be bracketed by the following: Fault Zone Palos Verdes Inglewood Whittier (*) Seed 1983 Western Laboratories Anticipated Horizontal Acceleration -Peak (g)* 0.60 0.37 0.16 6 Anticipated Horizontal Acceleration-65% Peak(g)* 0.39 0.24 0.10 ♦ ♦ udctec^nrc , July 15, 1998 Work Order 98-2556 The accompanying fault and earthquake epicenter maps present an overview. Slope Stability Slope stability analyses were performed utilizing cross section A. The slope stability analyses were performed using TENSLO1, a slope stability program that uses Bishop's Modified method of Analysis. The resulting factors of safety exceeded the commonly accepted engineering standards of 1.5 for static conditions and 1.1 for pseudostatic conditions at all evaluated tangent depths. Calculations and cross sections are provided in Appendix C. A surficial slope stability analysis was performed for the near surface soils along the descending slope face. The resulting factors of safety exceeded the commonly accepted engineering standards of 1.5 for static conditions and 1.1 for pseudostatic conditions. Calculations and cross sections are provided in Appendix C. It should be realized that even though the factors of safety were satisfactory; surficial sloughing may occur. Conclusions The proposed development is considered feasible from geotechnical engineering and engineering geologic standpoints, subject to the conclusions and recommendations that follow. The site is grossly stable in as much as landslides or active faults are not known to be present. Moreover, the site topography and firm, thickly bedded and steeper than natural slope dip characteristics of the bedrock are favorable for gross stability. Fills and colluvium situated on the slope areas are typically subject to sloughing and down slope creep. Nearby active fault lines include the Palos Verdes and Inglewood. These have associated. postulated maximum probable earthquake magnitudes of 6.9-7.1. The related. repeatable ground motion accelerations range upwards to approximately 0.39g. In accordance with Section 111, the proposed construction will be safe from a geotechnical engineering and engineering geologic standpoint against hazard from landsliding, settlement or slippage. The proposed construction and grading operations will not have an adverse effect on the project site or adjacent properties, provided the work is performed according to the recommendations of this office. Total and differential foundation settlements should be on the order of one-half inch and one - quarter inch, respectively. 1:-.1117Western Laboratories ww ♦ . Geotecnntcal Engineering July 15, 1998 Work Order 98-2556 Detailed recommendations to be utilized in the design and construction of the proposed development are presented in the following sections of this report. Recommendations The recommendations provided in this report are based upon observations made in the field, the results of laboratory tests on samples of the materials encountered during the subsurface exploration, and the past experience of this office. Notification of Governing Authorities Site grading operations should be performed in accordance with the local building and safety codes and the rules and regulations of those governmental agencies having jurisdiction over the subject construction. A pre -grade meeting should be conducted with the owner's representative, the grading contractor, the grading inspector, and the Soils Engineer prior to initiating grading operations. The grading contractor is responsible to notify the required governmental agencies and the Soils Engineer prior to initiating grading operations, and any time grading is resumed after an interruption. Site Grading and Compaction All vegetation and the upper few inches of soils containing organic matter should be stripped and hauled from the proposed fill areas prior to the start of the grading operations. Utility lines to be abandoned should be excavated and removed from the site. The fill soils and colluvium are not suitable in their present condition for slab, structural, or pavement support. These units should be excavated to approved bedrock, which should be observed and approved by the Soils Engineer and Engineering Geologist. The proposed fill should be supported by a keyway excavated at the toe of the proposed fill, having a minimum width of fifteen feet and excavated to a minimum depth of 5.0 feet into approved bedrock, measured at the toe of the key. Western Laboratories ww 3ec;eCni71car E.mmneenng July 15, 1998 Work Order 98-2556 A subdrain should be placed at the heel of the key to accommodate drainage. The proposed subdrain should be constructed of a minimum 4-inch diameter PVC Schedule 40 or ABS Class SDR 35 pipe. The pipe should have a minimum of 8 uniformly spaced perforations per foot of pipe installed, with perforations pointing downward. A cap should be provided at the upstream end of the pipe, and a minimum slope of 2 percent should be provided to the outlet pipe. A 4-inch diameter non -perforated outlet pipe should carry the collected water to the face of the slope. The outlets should be spaced at a minimum of 100 foot intervals measured horizontally, and should extend 12 inches beyond the face of the slope at the time of rough grading. The effluent should be carried from the face of the slope by a non - perforated pipe or drainage swail to an appropriate discharge point. The perforated pipe should be encased within a filter material, having a minimum sand equivalent of 50, a minimum of one cubic foot per foot of pipe. The filter material should be wrapped in filter fabric, Mirafi 140NL or equivalent. As the grading operation proceeds, the exposed bedrock should be benched to create a level surface to receive compacted fill soils. Proposed fill soils should be cleansed of any root structures and deleterious debris, and be brought to proper moisture content. Fill soils should be spread in 8-inch thick loose lifts, moisture conditioned as required, and compacted to at least 90 percent relative compaction, in accordance with the "Specifications for Compacted Fill Soils". Successive layers of fill should be continually benched into undisturbed soil or bedrock. A keyway will not be required if a retaining wall supports the downslope edge of the proposed fill; however, benching, compaction and draining of the retained soil will be required. Foundations should not transition from a condition where they are underlain by bedrock to one where they are underlain by engineered fill soils (cut/fill transition). If this will occur, the entire building pad extending a minimum horizontal distance of five feet outside of perimeter foundations should be overexcavated to a minimum depth of three feet beneath proposed foundations. Concrete slabs -on -grade and pavement located outside of the building pad and located in areas having cut/fill transitions should be underlain by a minimum of two feet of compacted fill soils. This overexcavation should be accomplished by excavating to a minimum depth of 1.0 foot beneath the bottom of the proposed pad elevation or to approved bedrock, whichever is deeper. The exposed native subgrade should be processed to a minimum depth of 12 inches and compacted to a minimum of 90 percent of ASTM D 1557-91. The excavated soils should then be replaced in 8-inch thick loose lifts, moisture conditioned as required, and compacted to a minimum of 90 percent of ASTM D 1557-91. Western Laboratories v Geotechnrcal Engineering 9 July 15, 1998 Work Order 98-2556 Unstable subsurface conditions are frequently encountered when grading operations are conducted when the ground is wet. If areas of unstable subgrade are encountered during grading operations, stabilization will be required prior to placement of fill soils, construction of slabs, foundations, or roadways. These areas are best evaluated for appropriate stabilization during the grading operation. Any proposed import fill soils should be approved by the Soils Engineer prior to importing to the site. Any additional fill soils placed should also be compacted in accordance with the attached "Specifications". Slope Construction Any temporary excavation without shoring should be cut at a maximum slope of 1:1 (1 horizontal to 1 vertical), to a maximum height measured vertically of 15.0 feet. A visual inspection should be performed during the excavation by a representative of this firm. Temporary construction cut slopes are suitable for a short time duration, not to exceed six weeks. In areas where a temporary 1:1 slope is not feasible, shoring designed by a Registered Professional Engineer knowledgeable and qualified in shoring design should be provided to support adjacent soils, structures, streets, and appurtenances, and to safeguard personnel. Permanent cut and fill slopes should be no steeper than 2:1 (2 horizontal to 1 vertical). In areas where steeper grade changes are desired, retaining walls should be utilized to accommodate the recommended slope gradient. Slopes should be planted with fast-growing, deep-rooted ground cover to reduce sloughing and erosion. Utility Trenches Backfill of utilities within right-of-ways should be placed in strict conformance with the requirements of the governing agencies. Following placement of utility lines within private property, the space under and around the line should be backfilled with clean sand or approved granular soil to one foot over the pipe. The sand backfill should be uniformly jetted into place before the remainder of the backfill is placed over the sand. All backfills over the bedding material should be mechanically compacted to at least 90 percent of the maximum density obtainable by the ASTM D 1557-91 method. Jetting or flooding of the backfill over the bedding should not be permitted. WY' Western Laboratories - 1 0 - V Geotecnnicai Enci^eennq July 15, 1998 Work Order 98-2556 Utility trench backfills should be observed and tested during backfill operations as the work progresses. If the testing of a backfill is performed after completion, without observing the backfill operations, then only the test results at the test locations can be given. Spread Footing Foundations Following completion of the bulk grading operation and compaction testing, the proposed garage should be supported on conventional foundations excavated to a minimum width of 12 inches and a minimum depth of 27 inches below lowest adjacent grade, into engineered fill soils. Continuous foundations having the preceding dimensions and founded into engineered fill soils should be designed utilizing an allowable bearing pressure of 1700 pounds per square foot (psf). Resistance to lateral loadings may be provided by friction acting on the base of foundations that are in contact with the engineered fill soils. A coefficients of friction of 0.25 may be applied to dead load forces. Passive earth pressure should be computed as an equivalent fluid of 200 pounds per cubic foot (pcf), to a maximum value of 2000 psf, for the portion of the foundations that are founded into engineered fill soils. As an alternative to excavating foundations into the engineered fill soils, the proposed garage should be supported on conventional foundations excavated to a minimum width of 12 inches and a minimum depth of 27 inches below lowest adjacent grade, of which a minimum of 12 inches should be excavated into approved bedrock. Continuous foundations having the preceding dimensions and founded into approved bedrock should be designed utilizing an allowable bearing pressure of 3000 pounds per square foot (psf). Resistance to lateral loadings may be provided by friction acting on the base of foundations that are in contact with approved bedrock. A coefficient of friction of 0.35 may be applied to dead load forces. Passive earth pressure should be computed as an equivalent fluid of 350 pounds per cubic foot (pcf), to a maximum value of 3500 psf, for the portion of the foundations that are founded into approved bedrock. The allowable soil pressures may be increased one-third for combinations of vertical and horizontal forces where permitted by the Uniform Building Code. Foundations should be stepped as necessary to produce level tops and bottoms. Foundations should be deepened to provide a minimum of H/3 feet of horizontal confinement between the bottom of the foundation and the face of the nearest slope. We recommend that the minimum setback should be 10.0 feet, and need not exceed 40.0 feet. - 11 - Western Laboratories V V Gectecnnical Engmeenng July 15, 1998 Work Order 98-2556 Foundations constructed adjacent to utility lines should be excavated to a depth so that its surcharge, extending at a one horizontal to one vertical projection (1:1) down from the bottom of the foundation, will not impact the utility line. Continuous foundations should be reinforced with a minimum of one #5 Bar, top and bottom. A continuous foundation system is recommended throughout the structure. Foundation excavations should be observed by the Soils Engineer prior to the placement of reinforcing steel to verify uniform soil conditions and conformance with the recommendations in this report. Retaining Structures Retaining structures constructed at the site should be designed to resist active lateral earth pressures plus surcharge loadings resulting from loads acting on the retention portion, of the structure. Retaining structures should be designed to resist equivalent fluid pressures presented in the following table. Surface Slope of Equivalent Retained Material Fluid Density (Horizontal to Vertical) (Lbs./Cu.Ft.) Level 45 2 to 1 60 Retaining walls that are restrained from horizontal movement at the top should be designed using an equivalent fluid pressure of 65 pcf. Retaining walls should be supported on spread footing foundations designed in conformance with the recommendations presented in the preceding portions of this report. Retaining walls should be designed to have a minimum factor of safety of 1.5 in resisting sliding and overturning. Retaining walls should be backdrained to collect accumulated moisture and prevent hydrostatic pressures from accumulating. A 4-inch diameter rigid perforated drain line. PVC Schedule 40 or ABS with SDR of 35 or better, encased in a minimum of 1 cu.ft./ft. of clean, free -draining crushed rock or gravel, should be placed at the base of the stem wall to collect any accumulated moisture. The pipe should be sloped to drain to appropriate receptacles by gravity. - 12- Western Laboratories V V Gectecnnrcat Enatneerrnc July 15, 1998 Work Order 98-2556 The crushed rock should be wrapped in filter fabric (i.e. Mirafi 140NL or equivalent). The remainder of the backfill should be comprised of a clean sand, having a minimum width of 1.0 foot on top of the gravel and filter fabric extending vertically to within two feet of proposed final grade. The remaining two feet of the backfill should be comprised of fill material compacted in accordance with the grading recommendations. In areas where moisture migration through retaining walls undesirable, retaining walls should be waterproofed. Retaining walls should be backfilled prior to building on or adjacent to the walls as the walls will yield slightly during backfilling. Slabs -on -Grade Building area concrete slabs -on -grade constructed upon engineered fill soils should be a minimum of 5 inches thick. The slabs should be reinforced with a minimum of #5 Bars, placed 18 inches on center in both directions and positioned in the center of the slab. The reinforcement should be supported upon concrete dobies in order to ensure proper positioning during concrete placement. Diagonal reinforcing bars should be placed at all re- entrant comers to keep cracks from opening excessively. Two #3 bars about 2 feet 6 inches long should be located about 2 inches and 5 inches from each comer in the center of the slab. Slabs should be structurally tied to perimeter foundations, utilizing bar ties that match the slab reinforcement and wrap around foundation reinforcement. The bar ties should extend a minimum distance of 3.0 feet into the slabs. - In building areas where moisture intrusion through the slab is undesirable, the slabs should be underlain with a capillary moisture break consisting of a minimum of 4 inches of clean, free -draining crushed rock or gravel, with a minimum dimension of /4 inch and a maximum dimension of 3/4 inch. An impermeable membrane moisture vapor barrier (6 mil polyethylene or equivalent) should be utilized between the capillary moisture break and slabs where migration of moisture vapor through slabs would be detrimental. The membrane should be encased within a minimum of 2 inches of sand to protect it during construction. The expansion potential of the subgrade soils should be reduced by moisture conditioning the subgrade to 140 percent of optimum moisture content to a depth of 33 inches. The contractor should be responsible for supplying the concrete mix design for the slab to the owner. A pea gravel pump mix is not recommended. The contractor should use a well graded conventional crush rock aggregate mix (i.e. 1-inch maximum aggregate size). Western Laboratories -13- V V Geotechnical Engineering July 15, 1998 Work Order 98-2556 Joints should be utilized within the slab to induce and control cracking. Control joints should be spaced a maximum distance of 15 feet in each direction. Control joints should be cut to a depth equivalent to one -quarter of the thickness of the slab. Joints made with a power blade are usually cut within 4 to 12 hours after the slab has been placed and finished. Joints must be cut as soon as the concrete surface is firm enough not to be torn or damaged by the blade, and before random shrinkage cracks can form in the concrete slab. Joints for sidewalks should be spaced at intervals equal to the width of the sidewalk. The concrete contractor should provide concrete designs and should place, finish, and cure concrete in accordance with ACI recommended practices. These minimum concrete thickness and reinforcement recommendations are based upon the expansion potential of the on -site soils only. The Structural Engineer for the project may need to address other factors which may require modification of the preceding recommendations. The following recommendations are provided with the intent of reducing the risk of substantial differential movement and cracking of exterior concrete slabs -on -grade, and supplement the previous recommendations for slabs -on -grade. Exterior slabs that are immediately adjacent to the proposed structure should be structurally continuous with the proposed structure, or a separation should be provided. In order to minimize the potential for differential movement of the outer edge of the concrete slabs -on - grade, cut-off walls should be provided having a minimum width of 8 inches and a minimum depth of 24 inches below lowest adjacent grade. Cut-off walls should be reinforced with a minimum of one #5 Bar, top and bottom. The slabs should be structurally tied to perimeter foundations by bar ties matching slab reinforcement that wrap around foundation reinforcement and extend a minimum of 3.0 feet into slabs. The expansion potential of the subgrade soils should be reduced by moisture conditioning the subgrade to 140 percent of optimum moisture content to a depth of 33 inches. A 4-inch thick layer of Class 2 aggregate base material should then be spread, moisture - conditioned as necessary, and compacted to at least 95 percent relative compaction. The aggregate base material should also be smooth and nonyielding. - 14- Western Laboratories v Geotecnn;cai Engmeenng July 15, 1998 Work Order 98-2556 Exterior concrete slabs -on -grade should be a minimum of 5 inches thick. The slabs should be reinforced with a minimum of #5 Bars, placed 18 inches on center in both directions and positioned in the center of the slab. The reinforcement should be supported upon concrete dobies in order to ensure proper positioning during concrete placement. Concrete sections that are to be stamped should be a minimum of 6 inches thick. A minimum of 2 inches of concrete cover should be maintained from the surface of the slab or from the bottom of the stamped depth to the reinforcement. Site Surface Drainage Surface water should be diverted away from slopes and foundations. Roofs should be provided with gutters, and the downspouts should be connected to appropriate receptacles. Roof downspouts and surface drains should be maintained entirely separate from retaining wall backdrains. The outlets should discharge into erosion -resistant areas, and should be provided with rock rip -rap or other energy dissipaters, if they discharge onto the ground. Planters adjacent to building areas, driveways, and concrete flatwork areas, should be properly sealed to prevent the intrusion of moisture into these areas. The excess irrigation water from the planter should be collected in a drain or be allowed to spill over the top of the planter in areas where ample sheet drainage is available to disperse it. Closure This report is prepared for the specific use of Mr. Robert Barth for development of the proposed project described herein. Findings in this report are valid as of this date; however, changes in conditions of a property can occur due to the passage of time, whether they are due to natural processes or works of man, on this or adjacent properties. In addition, changes in applicable or appropriate standards occur whether they result from legislation or broadening of knowledge. Accordingly, findings of this report may be invalidated wholly or partially by changes outside our control. Therefore, this report is subject to review after a period of one year. Western Laboratories ww v v Geotechrncal Enomeernno - 15 - 1 1 July 15, 1998 Work Order 98-2556 Our services consist of professional opinions and conclusions developed by an Engineering Geologist and a Professional Engineer specializing in the field of soil mechanics. The warranty or guarantee made by the consultants in connection with the services performed for this project is that such services are performed with the care and skill ordinarily exercised by members of the same profession practicing under similar conditions at the same time and in the same or a similar locality. No other guarantee or warranty, either express or implied, is made or attempted by rendition of consulting services, or by furnishing written reports of the findings. The information and recommendations of this report are based upon the assumption that the soil conditions do not deviate from those disclosed in the explorations. If any variations or undesirable conditions are encountered during construction, or if the proposed construction will differ from that planned at the present time, Western Laboratories should be notified so that supplemental recommendations may be provided. This report is issued with the understanding that it is the responsibility of the owner or of his representative, to ensure that the information and recommendations contained herein are called to the attention of the Architect and Engineers for the project and incorporated into the plans and that the necessary steps are taken to see that the Contractors and Subcontractors carry out such recommendations in the field. This report is subject to review by the controlling authorities for the project. Our scope of work did not include evaluation of potential hazardous material contamination of soil or groundwater. Supplemental Services We should review the final plans for conformance with the intent of our recommendations. During construction, we should observe the conditions encountered in construction excavations and modify our recommendations, if warranted. We should observe footing excavations prior to placement of forms or reinforcement. We should verify that the subgrade soils beneath concrete slabs -on -grade are moisture conditioned a maximum of 48 hours prior to placement of visqueen over the subgrade. Our services during foundation construction are limited to observation of soil conditions, depth of excavation, and the condition of excavations prior to placement of reinforcement. Our services do not include observation or approval of steel, concrete, or asphalt; nor do they include establishing or verifying construction lines and grades. This should be performed by the appropriate party. We should summarize the results of this work in a final report. We Western Laboratories IN/ 1M - 16- Geotecnn,c3l Engineering July 15, 1998 Work Order 98-2556 These supplemental services are performed on an as -requested basis, and we cannot accept responsibility for items that we are not notified to observe. These supplemental services are in addition to this geotechnical engineering report, and are charged for on an hourly basis in accordance with our Professional Fee Schedule. Maintenance Periodic land maintenance will be required. Surface and subsurface drainage facilities should be checked frequently, and cleaned and maintained as necessary. Selected References Probabilistic Seismic Hazard Assessment, California Division of Mines and Geology, 1996, OFR 96-08; Ground Motions and Soil Liquefaction During Earthquakes, H. B. Seed, 1983, Earthquake Engineering Research Institute; Map Showing Late Quaternary Faults of the Los Angeles Region, U.S. Geologic Survey, 1989, MF-1964; Evaluating Earthquake Hazards in the Los Angeles Region, U.S. Geological Survey, 1985, Professional Paper 1360; Geologic Map of the Palos Verdes Hills, U.S. Geological Survey, 1946, Professional Paper 207. -17- =_. Western Laboratories V V Geotecnn,cal Engmeenna 1 1 1 July 15, 1998 Work Order 98-2556 Specifications for Compacted Fill Preparation The existing fill should be removed under the observation of the Soils Engineer to expose subgrade competent to support the engineered fill. After the foundation for the engineered fill has been exposed, it shall be scarified until it is uniform and free from large clods, moisture conditioned where necessary and compacted, as specified in the body of this report, in accordance with ASTM D 1557-91 (5 layers - 25 blows per layer; 10 lb. hammer - 18 inch drop). Materials On -site soils may be used for the fill, or imported fill materials shall consist of materials approved by the Soils Engineer, and may be obtained from the excavation of banks, borrow pits or any other approved source. The materials used should be free of vegetable matter and other deleterious substances and should not contain rocks or lumps greater than four inches in maximum dimension. Placing. Spreading and Compacting Fill Materials A. The selected fill material should be placed in layers which when compacted shall not exceed six inches in thickness. Each layer should be spread evenly and thoroughly mixed during the spreading to attain uniformity of material and moisture of each layer. B. Where the moisture content of the fill material is below the limits specified by the Soils Engineer, water should be added until the moisture content is satisfactory to attain thorough bonding and thorough compaction. C. Where the moisture content of the fill material is above satisfactory limits, the fill materials should be aerated, blended or dried by other methods until the moisture content is satisfactory. D. After each layer has been placed, mixed and spread evenly it should be compacted, as specified in the body of this report, in accordance with ASTM D 1557-91 (5 layers - 25 blows per layer; 10 lb. hammer - 18 inch drop) or other density tests which will attain equivalent results. Compaction should be by sheepsfoot roller, multi -wheel pneumatic tire roller or other types of acceptable rollers. Compaction equipment should be of such design that they will be able to compact the fill to the specified density. Western Laboratories v v Geotecnnicai Enorneenna - 18- July 15, 1998 Work Order 98-2556 Compaction should be accomplished while the fill material moisture content is within the compactable range. Compaction of each layer should be accomplished by covering the entire area and the roller should make sufficient trips to attain desired density. The final surface of the lot areas to receive slabs -on -grade should be rolled to a dense, smooth surface. E. The outside of all fill slopes should be compacted by means of sheepsfoot rollers or other suitable equipment. Compaction operations should be continued until the outer face of the slope is compacted to a minimum of 90% relative compaction. Compacting of the slopes should be done progressively in increments not to exceed 4.0 feet as the fill is brought to grade. F. Field density tests should be made by the Soils Engineer of the compaction of each layer of fill. Density tests should be made at intervals not to exceed two feet of fill height provided all layers are tested. Where the sheepsfoot rollers are used, the soils may be disturbed to a depth of several inches and density readings should be taken in the compacted material below the disturbed surface. When these readings indicate the density of any layer of fill or portion thereof is below the required density, the particular layer or portion should be reworked until the required density has been obtained. Observation Observation by the Soils Engineer should be made during all filling and compacting operations so that he can verify that the engineered fill was consistent, competent and in compliance with the recommendations. Seasonal Limitations No fill materials should be placed, spread or rolled during unfavorable weather conditions. When work is interrupted by heavy rains, fill operations should 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. -19- ww Western Laboratories Geotecnnical En vneenng APPENDIX A TEST PIT LOGS • Western Laboratories ww V V Georecr.nrcai Engineenng Sample Type: Laboratory Tests: LEGEND R = Relatively Undisturbed Ring Sample B = Disturbed Bag Sample NR = No Recovery SP = Standard Penetration Test DS = Direct Shear Test CN = Consolidation Test El = Expansion Index EX = Expansion Index Test PI = Plasiticity Index Test LL = Liquid Limit PL = Plastic Limit RV = Resistance Value UC = Unconfined Compression Test Western Laboratories ww v v Geotecnnical Engineering Client: Project: TEST PIT 1 MR. ROBERT BARTH PROPOSED GARAGE en . TEST PIT LOG 3 3 4-4U C �.1 y = a F E a o A CZ Extension Backhoe w/24" Wide Bucket 0 0.0- 1.0' COLLUVIUM-Silty CLAY(CH)w/rootlets- 1.0- 3.5' Dk.Brown, soft, moist B COLLUVIUM-Silty CLAY(CH)w/rootlets- Dk.Brown, stiff, moist 3.5- 6.0' ALTAMIRA-Tuffaceous Fine SAND- 5 STONE -Tan, dense, moist - crudely bedded 6.0' l at N75E30N Hard Brown Cemented Tuff - Refusal Test Pit Halted and Backfilled No Groundwater Encountered 10 15 20 25 30 Western Laboratories v v Geotecnnicai Encineenna W.O. 98-2556 Date: 5-1-98 22.7 Client: Project: TEST PIT 2 MR. ROBERT BARTH PROPOSED GARAGE W.O. 98-2556 Date: 5-1-98 s e ao i TEST PIT LOG 'r. w °'' .- � � co :U wo a F. . rt"7 0 CI cn .4 m Extension Backhoe w/24" Wide Bucket 0 0.0- 1.0' COLLUVIUM-Silty CLAY(CH)w/rootlets- 1.0- 2.5' ! Dk.Brown, soft, moist R DS COLLUVIUM-Silty CLAY(CH)w/rootlets- 82.4 26.5 2.5- 6.0' 1 Dk.Brown, stiff, moist _ B EX ALTAMIRA-Tuffaceous Fine SAND- 16.6 E1=23 5 R DS STONE -Massive, Tan, dense, moist 102.5 15.2 6.0' )-Contact at N80W3ON Hard Brown Cemented Tuff - Refusal Test Pit Halted and Backfilled No Groundwater Encountered 10 15 20 25 30 __.Western Laboratories ww V V Geotechn:cal Engineering Client: Project: TEST PIT 3 MR. ROBERT BARTH PROPOSED GARAGE W.O. 98-2556 Date: 5-1-98 w ... TEST PIT LOG 1 3 0 U z :U 6) I. c = 1w Z i� H A ✓ a F 3 t.'-] c o c ▪ v o• o Extension Backhoe w/24" Wide Bucket 0 0.0- 1.0' COLLUVIUM-Silty CLAY(CH)w/rootlets- 1.0- 4.0' 1 Dk.Brown, soft, moist B COLLUVIUM-Silty CLAY(CH)w/rootlets- 24.5 EI=105 _. Dk.Brown, stiff, moist _ 4.0- 7.5' ALTAMIRA-Tuffaceous Fine SAND- 5 STONE -Massive, Tan, dense, moist B - irregular 2" Gray Bentonite lense at 6' 40.2 10 15 20 25 30 Western Laboratories ww Y Y Geotechnical Enaineenno Test Pit Halted and Backfilled No Groundwater Encountered APPENDIX B• LABORATORY TESTING c Western Laboratories INF ‘Ill V Geatechncal Engrneenna t 1 1 1 1 1 1 1 i 1 1 1 1 Now Laboratory Testing The natural water content and dry density were determined on selected samples of the materials recovered from the test pits. This information is recorded on the test pit logs at the appropriate sample depths. Direct Shear Tests (ASTM D 3080) were performed with a strain control type shear machine where the soil samples are subjected to a 0.002 inch per minute rate of strain, under varying loads and under conditions of saturation. Expansion Index Tests were performed on representative samples of the near surface soils in accordance with UBC 29-2. In this test, soil is compacted into a metal ring to ±50 percent saturation. The sample is then placed in a device producing confining pressure of 144 psf (1 psi). The sample is then inundated with water and the amount of swell expressed as a ratio of the initial sample height times 1000 is recorded as the Expansion Index. The results of these tests indicate the soils to be medium to high in expansion potential, according to the preceding standard. c Western Laboratories 15,11. 1 . Geotecrnicai Enaineenna (ASTM D 3080) 4.0 4.0 3.0 1.0 0.0 0.0 1.0 2 0 3.0 Normal S ress (psf) Thousands TP-2 AT 2.0 FEET Angle of internal friction = Cohesion = RA2 = 17.9 deg 560 psf 0.957 (75 t6 N 0) 3.0 1.0 0.0 0.0 1.0 2.0 3.0 4.0 4.0 Normal Stress (psf) Thousands `TP-2 AT 2.0 FEET * Residual 13.0 deg 265 psf 0.963 PROJECT: PROPOSED GARAGE WORK ORDER 98-2556 DIRECT SHEAR TEST Western Laboratories 7 V Geotechnrcal Engrneerrng 4.0 3.0 1.0 0.0 (ASTM D 3080) 0.0 1.0 2.0 3.0 4.0 Normal Stress (psf) Thousands TP-2 AT 5.0 FEET Angle of internal friction = Cohesion = RA2 = 38.5 deg 635 psf 0.997 4.0 3.0 2.0 1.0 0.0 0.0 1.0 2.0 3.0 4.0 Normal Stress (psf) Thousands `TP-2 AT 5.0 FEET Residual 33.0 deg 370 psf 0.999 PROJECT: PROPOSED GARAGE WORK ORDER 98-2556 DIRECT SHEAR TEST Western Laboratories v v Geotechnical Engineering APPENDIX C SLOPE STABILITY, GEOLOGIC MAPS & CROSS SECTIONS Western Laboratories ww • • Geotechnica! Engineering me an on is ea an sum Eli I• owe i i me no am me no um um Ueritcal height 140 - 120 - 80- 60- r 'TENSLOPE' Geometry Plot Title: PROPOSED GARAGE Soil Gamma CBAR Phi C ( 86.75 86.25 ) Project: #29 PORTUGUESE BEND 1 0.120 0.265 13.0 R=54.25 FS= 2.29 2 0.120 0.370 33.0 Case: SECTION A (STATIC)) Date: O7/ 15i98 1 2 1 1 1 1 i 1 1 1 20 40 60 80 100 120 140 160 180 Horizontal distance (feet) am an — — 0 an an lei ,inui um r an an i on m ,am 'CONTOUR' Data Plot 88- 87 — + 2.29 L a, +4- ry 2.29 t. 2.29 2.29 o� 86— + + + + + • P. 2.29 2.29 2.29 2.29 2.29 t rp U L co 85 — + 2.30 + 2.30 + + 2.29 2.30 1 1 I 1 I 86 87 88 89 90 Horizontal distance (meters) Tenslope, version Tenslope V1 - (c) 1986-1991 Slope stability by the modified Bishop method. Program by the Tensar Corporation, April 1986. Title: PROPOSED GARAGE Project: #29 PORTUGUESE BEND Case: SECTION A (STATIC) ) Date: 07/15/98 "Units: Kips/ft Rapid drawdown indicator: No (def) J Seimic forces: No Horizontal acceleration: 0.15 * Seismic forces acting at: Center Soil No. I 2 l Point data: No. X-coord. 1 0.00 2 69.50 3 121.00 4 142.50 5 156.00 6 174.00 7 0.00 8 69.50 9 121.00 10 174.00 I Line No. 1 2 3 4 5 6 7 8 information: GAMMA CBAR 0.120 0.265 0.120 0.370 Phi 13.0 33.0 Y-coord. 45.50 31.00 55.00 55.00 61.50 61.50 43.00 29.00 53.00 55.50 array: Left X Y * 1 0.00 45.50 2 69.50 31.00 3 121.00 55.00 4 142.50 55.00 5 156.00 61.50 * 7 0.00 43.00 8 69.50 29.00 9 121.00 53.00 RU Phreatic Phreatic Right X Y 2 69.50 31.00 3 121.00 55.00 4 142.50 55.00 5 156.00 61.50 * 6 174.00 61.50 8 69.50 29.00 9 121.00 53.00 * 10 174.00 55.50 ,Phreatic surface coordinates: No. X-coord. Y-coord. 1 0.00 32.50 2 69.50 29.00 3 121.00 53.00 4 174.00 55.50 "Unit weight of fluid = 0.0624 riezometric surface coordinates for soil A: No. X-coord. Y-coord. 111 1 .00 .00 Mu 0.00 0.00 Angle -11.78 24.99 0.00 25.71 0.00 -11.39 24.99 2.70 by the Tensar Corporatio Soil Topline 1 Yes 1 Yes 1 Yes 1 Yes 1 Yes 2 No 2 No 2 No "Stone columns: No Stone column zones: (porosity = 0.000 ) 1/ Zone Col Dia Spacing CBAR Phi Gamma Stress ratio * 1 .0 ..0 .000 .000 .000 .00 "Limits of stone columns: * Zone X-left X-right Y-top Y-bottom II 1 .00 .00 .00 .00 Tensar geogrid placement: ' Layer Elev. X-left X-right 1 .00 .00 .00 Tensar geogrid strength data: I Layer Geogrid Ult Strength Percent Design FS-Pull Percent type Kips/ftll Ult Strength out Coverage 1 .000 .000 %%.%%% .00 .00 IIGeogrid forces derated: No * Derating constant of grid: 1.10 ,Option: Search * Grid point X-coord Y-coord )1 1 .00 .00 2 .00 .00 3 .00 .00 il 1-2 .00 2-3 .00 Automatic search for critical circle: ,Initial X = 87.00 feet 44 Initial Y = 85.00 feet 44 Delta X = 1.00 feet 44 Delta Y = 1.00 feet 44 ,Approximately 20 slices will be used at RMAX Minimum tangent elevation for any failure circle is 32.00 feet 44 Maximum tangent elevation for any failure -circle is 50.00 feet 44 There are 18 increments between tangent levels IIIII N S r— N N NM r ■r — r r MI NM G MI 'TENSLOPE' Geometry Plot 140 - 120 - a w 100- Title: PROPOSED GARAGE soil Gamma CBRR Phi C ( 86.75 99.25 ) Project: #29 PORTUGUESE BEND 1 0.120 0.265 13.0 R=67.25 FS= 1.61 2 0.120 0.370 33.0 Case: SECTION A (SEISMIC) Date: 07/15/98 1 I I I I I I I I 20 40 60 80 100 120 140 160 180 Horizontal distance (feet) — M M '— r 'r i„ /`11111i r M M— M r 10111 u• l L cu aJ 'CONTOUR' Data Plot 101 - 100- + 1.61 .+. 1.61 + + 1.61 1.61 o 99- + + + + + 1.61 1.61 1.61 1.61 1.61 a r 1 rp u L a 98 - + 1.61 1.61 1 1 1 1 I 86 87 88 89 90 Horizontal distance (meters) 1 Tenslope, version Tenslope V1 - (c) 1986-1991 Slope stability by the modified Bishop method. Program by the Tensar Corporation, April 1986. Title: Project: Case: Date: PROPOSED GARAGE #29 PORTUGUESE BEND SECTION A (SEISMIC) 07/15/98 Units: Kips/ft Rapid drawdown indicator: No (def) IISeimic forces: Yes Horizontal acceleration: 0.15 Seismic forces acting at: Center 1 Soil No. 1 2 Point 1N0. 1 2 3 5 6 7 8 9 10 Line INo. 1 2 3 5 6 7 information: GAMMA CBAR 0.120 0.265 0.120 0.370 data: X-coord. 0.00 69.50 121.00 142.50 156.00 174.00 0.00 69.50 121.00 174.00 Phi 13.0 33.0 Y-coord. 45.50 31.00 55.00 55.00 61.50 61.50 43.00 29.00 53.00 55.50 array: Left X Y * 1 0.00 45.50 2 69.50 31.00 3 121.00 55.00 4 142.50 55.00 5 156.00 61.50 * 7 0.00 43.00 8 69.50 29.00 9 121.00 53.00 RU Phreatic Phreatic Right X Y 2 69.50 31.00 3 121.00 55.00 4 142.50 55.00 5 156.00 61.50 * 6 174.00 61.50 8 69.50 29.00 9 121.00 53.00 * 10 174.00 55.50 IIPhreatic surface coordinates: No. X-coord. Y-coord. 1 0.00 32.50 I 2 69.50 29.00 3 121.00 53.00 4 174.00 55.50 "Unit weight of fluid = 0.0624 li Piezometric surface coordinates for soil A: No. X-coord. Y-coord. 1 .00 .00 Mu 0.00 0.00 by the Tensar Corporatio Angle -11.78 24.99 0.00 25.71 0.00 -11.39 24.99 2.70 Soil Topline 1 Yes 1 Yes 1 Yes 1 Yes 1 Yes 2 No 2 No 2 No "Stone columns: No Stone column zones: (porosity = 0.000 ) Zone Col Dia in Spac g CBAR Phi Gamma Stress ratio * 1 .0 .0 .000 .000 .000 .00 "Limits of stone columns: * Zone X-left X-right Y-top Y-bottom II1 .00 .00 .00 .00 Tensar geogrid placement: is Layer Elev. X-left X-right II 1 .00 .00 .00 Tensar geogrid strength data: I Layer Geogrid Ult Strength Percent Design FS-Pull Percent type Kips/ftll Ult Strength out Coverage 1 .000 .000 %o.o%o .00 .00 IGeogrid forces derated: No * Derating constant of grid: 1.10 IIOption: Search * Grid point X-coord Y-coord *- 1 .00 .00 11 2 .00 .00 3 .00 .00 * 1-2 .00 11 2-3 .00 -Automatic search for critical circle: IInitial X = 87.00 feet 44 Initial Y = 99.00 feet 44 Delta X = 1.00 feet 44 Delta Y = 1.00 feet 44 'Approximately 20 slices will be used at RMAX Minimum tangent elevation for any failure circle is 32.00 feet 44 - Maximum tangent elevation for any failure circle is 50.00 feet 44 There are 18 increments between tangent levels 1 1 1 1 1 , SURFICIAL SLOPE STABLILITY SLOPE CHARACTERISTICS • ATITTUDE OF SLOPE -A (DEGREES)= DEPTH TO BE ANALYZED-D (FEET)= 25.71 4 PROPERTIES OF SURFICIAL SOILS ANGLE OF INTERNAL FRICTION-PHI(DEGREES)= 13 COHESION-C(PSF)= 265 UNIT WEIGHT-G(PCF)= 120 CALCULATION -RE: STABILITY OF EARTH SLOPES, HUANG, 1983 FACTOR OF SAFETY = (C/GD)SEC(A)+.SCOS(A)TAN(PHI) STATIC SIN(A) FACTOR OF SAFETY = 1.7 > 1.5 Acceptable FACTOR OF SAFETY = (C/GD)SEC(A)+[.SCOS(A)-.15SIN(A)]TAN(PHI) SEISMIC SIN(A)+.15COS(A) FACTOR OF SAFETY = 1.2 > 1.1 Acceptable Western Laboratories V V ..Geotechnrcal Enarneenna 40 y \ . 30 -. •• ' . Af 1 .- • •i .. �`TP3 Proposed garage LEGEND Af Fill Qc Colluvium Tsh Tuffaceous sandstone and shale y Crude strata 1"-40' GEOLOGIC SKETCH MAP 1 • 1 1• 1 1 1 1 1 1 1 • • Proposed ----.._ \ ----"•• ...7---'. \ TP2Qc TP1 , - - - A-- - - , , •• , .. .... „ ••• •• e --* . ..•• • • • .* . • • • . •.* . .... , ..• •••• , .•• ..• , , .•• ...• , ..• •. , .. , •••• ....' ... ..- ..- strata .•••• ....- GEOLOGIC SECTION •'''F•N<•?5',Tm•t•• \. • . - •;/•47.'". . ; . • . •••••••,.::•, • ..ej, • • • • . • •• ;•-••••• . • •••••••irryl...• „ • • . • . Vis• , . • • ...:•*;-,•:-•:•••. `s• • '. • 4..;4e/..4-` • "•.%44. .-:: • • •;;;;;A:i • ',/* ,,C): • - • • . -,:cf • ... , • Ta • • *, ,;.. • •'• • .„, ......... • , • /)- • iI -m•••• • . .‘ AZ• ...... 1.>• • ../ I . ". • . , AREA GEOLOGIC MAP • . - • • . . „•-••••••..--.e •r • • se : 1 in - 2000 ft Qal Alluvium and artificial fill • I{rG.}`a��.�rt7 Stream terrace gravel QtmQtc Qpv �l Nonmarine terrace cover, Qtc (Reddisit-brown sand. rubble: upper Pleistocene to Recant) Marine terrace deposits, Qtm; those on lowest terrace consti- tute Palos Verdes sand, Qpv (Sand. gravel; upper Pleistocene) UNCONFORMITV IQtp, QI San Pedro sand, Qsp (Sand. silty sand, silt, crraveU Timms Point silt, Qtp ....?1 Lomita marl, QI (Marl, calcareous sand. trray.0 UNCONFORMI T Y Repetto siltstone (Glauconitie. foramini/eral siltstone) Malaga mudstone member (Radiolarian mudstone. diatomite) Tv Valmonte diatomite member (Diatomite. diatomaceous shale, diatomaceous mudstone) ,Tmt X • TTot I Altamira shale member (Porcelaneoue shale, cherty shale. chert, silty shale. siltstone, phosphatic shale, diatomite. limestone. sandstone. conglomerate. schist -debris breccia. tuff including Miralsste tuff bed. Trr.t, and Portuguese tuff bed. To:: x. sons of Mai , concretions) 1 cc 1— SEDIMENTARY ROCKS UNCONFORM(T METAMORPHIC ROCKS Franciscan (?) schist (Quartz-sericite schist, quarts -tale schist. guartz•glaucophane.chill, altered basic igneous rocks.) IGNEOUS ROCKS Basalt (Intrusive and extrusive ffl ) i 0 •t_ i� GEOMORPHIC PROVINCES AND SOME PRINCIPAL FAULTS OF CALIFORNIA I Generalized Geologic Units Oumunory sodimenrory rocks i� Ternary ledrmenrory 0u01une,7 CM Tamers soiccn. sects of CASCADE RANGE and M000C PLATEAU 4. • Crer f reeb M .t ironblcon-Ilne..dlo lseee M Ic-Peleerae rnorornoroRre and sporadic race$ ProcomDsidn re Recess sect + + corndlee of Ms BASIN and RANGE Mid MOJAVE DESERT ... Goaeor►Ise Prewneo eeuroory Gsoo .c w.l t»undesT — Foufl (F«+ + ♦ \ + + 4 + + + ♦ + } \\. ++M•p«++' ♦.P .`� 4 + + + + + + ♦ + + .G'- + • • + + + + +• •jr + + + + • qt.+ + 4 r. + + ♦ + + •.4 + + • + : + +\ T + + + + } + + + + + + + •1 +++•+++o.+ ♦+ ••t., • • + + + + + + TRAN:ntir.:r }= : , ; `d"`r' ;; 'Al`jGES' ♦' ♦' + tt 4 + * ' } i? • ♦ ♦ „1 + }i • ♦ • +l . • + + • ♦ • L ♦ ♦ SITE CDMG REGIONAL GEOLOGIC MAP 1 in -100 mi 1 0 0 .14 1923 1992 1906 1989 O Magnitude 6.0 to 6.9 OMagnitude 7 and greater 1868 0 �838 1927 SO 1812 19150 1954 0 0�a 1954 N. 0 1932 \ 0 0 •\ 1872\•\ 1857 0 N. CO \ 1952 0 \ 1812 1992 SITE 0 i e _....0-•,o CDMG EPICENTER MAP 1 in- 150 mi ,,, $$ • rim,' srmis 916 857 30 . ...._.......!.. 6-1.. , 11193\._ - -......; ENTURA ‘ ****"...;::-=`•--rfc. /.0. 43 1971 ,e...igj. t. .—,IZ --;'4 —.4rEPkaA.loo ..3.10... ITS kti.c.. ---...44o•.• ,/.-.....! 11355 ,76.1:„..mywco, i -144--.--,•T ...00F.'"C.:,.'" .:„..c "(MT 00)40 Ns" L .... ..„ 14T1JRA 1.465 1. ANGE ES $M ruspo.Noo nuu **--..:301439 k).% LOS 1920 trio ••••••• 44: SANTA 1.6116 • ORANG • cttr- "." • 14./2%. 1933 COMM.* IsAftwe 4550MM* OF ENGINEERING GEOLOGisT3 1973 I699 RIVERSIDE 1923 146.3 1910 .*:Ze...• • .p..,.si. Pr.row . '... • .„/ CAOr o aut.l. • \ • • S A.›. c..Pi '‘... N A.. 8 E R 1 s•\,. % -.5.\,..4. \\ 0 .15Gaff t...1.4 \ ‘'. 4'°0 C:14* S *) \\ . . SA IP • ... \ " 4. C., : ,:.• :•.\• • \ •!0. N..z..V% is • • it • I... 11 •: • :•.\,‘ 1907 „„..limi% T. e.,3!-Ve SAN OiEGO 4 INC40 • —_194— samits.; 1918 • ug. 146A Pau% SPNINGs 1899 1.17+ 1937 ra60 <)". t••••••...1t • le9S4 A N_ Alum --- G 1856 lin - 30mi MAJOR EARTHQUAKES AND RECENTLY ACTIVE FAULTS IN THE SOUTHERN CALIFORNIA REGION EXPLANATION' ACTIVE FAULTS FAULT MAP 1889 14 7* 1952 3177 EARTHQUAKE LOCATIONS Approximate epicentral orea of earthquakes