Loading...
429, Addition to SFR of more than 2, Studies & ReportsCOASTLINE GEOTECHNICAL CONSULTANTS, INC. • CONSULTING GEOTECHNICAL ENGINEERS JAW i 7 2001 PROCESSING CENTER LAND DEVELOPMENT DIVISION 16 W. 178TH ST. (310) 217-1504 ...IDENA, CA 90248 FAX (310) 217-1909 GEOTECHNICAL ENGINEERING INVESTIGATION REPORT DISTRESSED RESIDENCE NO. 3 FLYING MANE ROAD ROLLING HILLS, CALIFORNIA PREPARED FOR DR AND MRS. MICHAEL WELLER PROJECT NO. 315C-030 MAY 8, 2000 COASTLINE GEOTECHNICAL CONSULTANTS, INC. COASTLINE GEOTECHNICAL CONSULTANTS, INC. CONSULTING GEOTECHNICAL ENGINEERS 1446 W. 178 TH STREET 'GARDENA, CALIFORNIA 90248-3202 Project No. 315C-030 Dr. and Mrs. Michael Weller No. 3 Flying Mane Road Rolling Hills, CA 90274 Subject: Geotechnical Update and Manometer Survey Distressed Residence No. 3 Flying Mane Road Rolling Hills, CA 90274 X-Reference: Geotechnical Engineering Investigation Distressed Residence No. 3 Flying Mane Road Rolling Hills, California Project No. 315C-020 by Coastline Geotechnical Consultants, Inc. dated April 20, 1990 Preliminary Engineering Geology Investigation Distressed Residence No. 3 Flying Mane Road Rolling Hills, California Project No. 1183-030 by George DeVries dated May 4, 1990 Dear Dr. and Mrs. Weller: Tel. (310) 217-1504 Fax (310) 217-1909 May 8, 2000 At your request, we have prepared this updated and supplemental report regarding underpinning the northwest side of the distressed residence. This update presents the results of observations made at the referenced site in relation to earlier investigations and the results of the manometer survey. Earlier investigations of the site were summarized int he reports listed in the X-Reference section of this report, copies of which are contained in the appendix. Project No. 315C-030 2 Weller/Rolling Hills SITE CONDITIONS The subject site is located on the west side of Flying Mane Road, south of Crest Road in the City of Rolling Hills. The site is on the south flank of the Palos Verdes Hills upon the west flank of a ridge that descends westerly about 200 feet to a drainage ravine. The building pad is occupied by a one-story, wood frame and stucco residence, constructed in 1974. From the rear yard, the site descends about nine feet at 1% (horizontal to 1 vertical), which consists of fill placed to create the level building pad. The recently disced, natural slope of the site descends westerly at about 4 (horizontal) to 1 (vertical) to a 1 to 1 cut slope on the east side of Southfield Drive. UPDATED INVESTIGATION A visit to the site was made on April 5, 2000, to conduct the manometer survey and to observe the geotechnical conditions. Field observations indicate the geotechnical conditions at the site to be essentially the same as described in the above referenced report. No additional subsurface investigation was performed as part of this update. Some modifications had been made to the rear yard area. A brick patio has been constructed west and southwest of the existing residence. A previously existing pool, located in the southwestern portion of the pad, was reportedly filled to allow construction of the patio in that area. The existing residence shows signs of past distress in the form of walls and ceiling cracks. The cracks have mainly been observed in the family, dining, breakfast and living rooms as well as hairline cracks in the ceiling of the bathroom near bedroom No. 3, and settlement along the west side of the family and dining rooms. Manometer Survey The manometer (floor level) survey was performed on April 5, 2000, in order to determine the approximate elevation difference in the existing residence. Due to different levels, the residence floor is divided into three areas. The results show the maximum difference in elevation to be approximately 1.8 inches, which has occurred in area II. (See Plate A). The highest point is in the southeast corner of the living room and the lowest point is in the west side of the family room. Faulting and Seismicity A number of regulatory requirements concerning seismic conditions have recently been implemented. The 1997 Uniform Building Code quantifies site -specific seismic parameters. Project No. 315C-030 3 Weller/Rolling Hills California Division of Mines and Geology (CDMG) Special Publication 117 summarizes procedures for evaluating the earthquake -induced landslide and liquefaction potential for the state. Additionally, the Alquist-Priolo Earthquake Fault Zoning Act requires evaluation of fault surface -rupture potential for specific areas. As noted in the earlier reports, the site is not located within an Alquist-Priolo Earthquake Fault Zone (Hart, 1997, SP42) and no active faults were observed during this investigation. The nearest active fault, the Newport -Inglewood Structural Zone (NISZ) is located approximately 10 miles (16 km) to the northeast (CDMG, 1992, OFR 92-03). The potentially active Cabrillo (CFZ) and Palos Verdes Fault Zones. (PVFZ) are located approximately 0.5 and 3 miles (0.8 to 4.8 km), respectively to the northeast (Dibblee, 1999, DF-70; CDMG, 1992, OFR 92-03). Under criteria published in the Uniform Building Code (UBC, 1997), the NISZ, and the PVFZ would be considered "seismic source type "B" (Table 1, book of Maps...). The Type "A" Cucamonga Fault Zone is located approximately 47 miles (75 km), to the northeast. Using the above data, selected UBC seismic coefficients are presented on Plate Z. "Guidelines for evaluating and mitigation seismic hazards in California" (CDMG, 1997, SP 117) summarizes procedures for evaluating the earthquake -induced landslide and liquefaction potential for the state. A review of the Redondo Beach Seismic Hazards Zone Map (SHZM) show the site is not within a zone mapped as requiring evaluation of earthquake -induced liquefaction or landslide or landslide potential. Much of the slope west of the site, along the ravine and along portions of Southfield Drive, are within a zone noted by the State of California as requiring evaluation of the earthquake -induced landslide potential. Stability analysis were performed during the initial investigation, the results of which are presented in the appendix. A number of northwest -trending subsurface fault zones have been mapped throughout the Los Angeles basin and vicinity. Movement on these "blind -thrusts" in the Whittier Narrows and Northridge areas of California cause considerable damage during the earthquakes of October 1, 1990 (Whittier) and January 17, 1994 (Northridge). The site is subject to ground shaking typical of the Southern California area and, thus any construction should conform to seismic design provisions of the Uniform Building Code and/or other regulatory codes. CONCLUSIONS AND RECOMMENDATIONS Based on the recent site inspection, the geotechnical conditions at the subject site have not changed significantly since the original geology and soils reports. Therefore, the analysis and conclusions of the original reports are still considered valid with the additions/changes noted below. All footings and foundation systems are to be founded in comptetent bedrock material as indicated int he above referenced reports. SEISMIC DESIGN PARAMETERS 1997 UNIFORM BUILDING CODE PROJECT ADDRESS: No. 3 FLYING MANE ROAD ROLLING HILLS, CA CLIENT: DR AND MRS. MICHAEL WELLER PROJECT NO.: 315C-030 DATE: MAY 9, 2000 UBC SEISMIC ZONE - TABLE 16-I = 4 Z = 0.4 UBC SOIL TYPE - TABLE 16-J UBC CLASSIFICATION * Sets Identifying Value = ROCK =S* s NEAREST TYPE A FAULT - CUCAMONGA FAULT ZONE DISTANCE = 75 Km (USE > 15 Km in Tables) NEAREST TYPE B FAULT - PALOS VERDES FAULT ZONE DISTANCE = 5 Km SEL'E(:I'k D UBC SEISMIC COEFFICIENTS, Na (Table 16-S) = 1.0 Nv (Table 16T) = 1.2 Ca (Table 16-Q) = 0.40 Na = 0.40 g. Cv (Table 16-R) = 0.40 Nv = 0.48 g. Ts (Figure 16-3) = Cv / 2.5 Ca = 0.48 sec. To (Figure 16-3) = 0.2 Ts = 0.10 sec. Plate Z COASTLINE GEOTECHNICAL CONSULTANTS, INC. Project No. 315C-030 Weller/Rolling Hills 4 Based upon our previous field investigation and laboratory expansion and consolidation tests, it has been concluded that distress to the subject residence is primarily due to one or more of the following items: 1. Settlement of fill and natural soils; the settlement of the residence is mainly along the westerly side of the building area. During our prior field investigation in 1990, it was found that more fill was placed on this side of the pad in order to create a level building area during the original grading time of the site. This portion of the residence settled a maximum of 1.8 inches which was caused by long time fill settlement. 2. Expansive soil; movement caused by the changes in moisture content of the clay upon which the foundations are placed. 3. Creep force; creep which is a nearly imperceptible movement of surficial soil downslope caused by the forces of gravity - one of the primary causes of creep is the alternating expansion and contraction of surface materials by wetting and drying. The following is recommended to repair the distressed residence: Underpinning of the foundations at least 12 inches into the firm bedrock along the west walls of the family, dining and living rooms. The bedrock can be reached by either use of conventional footings, piers, or belled caissons and grade beam system. Slot cutting is required for continuous footings underpinning and should be limited to a maximum six feet wide in the ABC manner. Respectfully submitted, COASTLINE GEOTECHNICAL CONSULTANTS, INC. Ot-z-f7( Amir Khalaj -caLA Richard A. Martin, RGE`,� �cH�����%/ George DeVries, CEG 1141 RAM/GD/AK/jm (5) Addressee NOTES : t THE FLOOR LEVEL OF THE RESIDENCE IS DIVIDED NTO THREE AREAS DUE TO DFFERENT FLOOR LEVEL 2 ALL THE ELEVATIONS WERE MEASURED SEPARATELY N EACH AREA BASED ON THE LOWEST PONT. 3. THIS DRAWNG IS BASED ON SKETECH USING TAPE MEASUREMENT AND MONOMETER READNGS SHOWNG LEVEL OF FLOOR. N NCH. 16 LIVNG ROOM AREA II - N� \0.2-� 0.4 ' pN O LOWEST PONT 02 J 0. 08 _772- zo 1 AREA III t2 SCALE: DATE: 0.4 i AREA I 0( BEDROOM P 0. 3 OP DLOWEST PONT C) RA7fiAN3 h 0.8 HIGHEST PONT GARAGE MANOMETER SURVEY NO.3 FLYNG MANE ROAD ROLLING HLLS, CALFORNIA '.. 7 8• ' I APPROVED BY: - APR 2000 IDRAWN BY REVISED AK COASTLINE GEOTECHNICAL CONSULTANTS PROJECT NO. 315C - 030 IDRAWING NUMBER A George DeVries Consulting Geologist 4520 E. Slauson Ave., Maywood, California 90270 — (2.13) 771-3046 May 4, 1990 Project No. 1183-030 Dr. and Mrs. Michael Weller c/o Coastline Geotechnical Consultants 1446 W. 178th St. Gardena, CA 90248 Subject: Preliminary Engineering Geology Investigation Proposed Residential Addition No. 3 Flying Mane Rd. Rolling Hills, CA Dear Dr. & Mrs. Weller, This report presents the results of an engineering geology investigation performed on the referenced lot. It is prepared in conjunction with a soils engineering investigation by Coastline Geotechnical Consultants, Inc. dated April 20, 1990. The purpose of this investigation was to evaluate the existing geological conditions as they would apply to the contemplated development and to offer suggestions and recommendations for mitigating potential hazards if fund to be present. In addition, conclusions concerning the feasibility of the proposed development from the geological standpoint were formulated. While no detailed plans were available at the time of the investigation, it is understood the proposed development will consist of two, one-story additions to the west and north portions of the existing residence. The general location of the site is shown on Plate 1 while the site geologic map is presented in Plate 2 (A-B). The investigation consisted of surficial field mapping, subsurface exploration of seven (7) hand -excavated test pits, analysis of collected data, as well as a review of pertinent. geologic data for the vicinity, and preparation of this report.. Field investigations were conducted March 8 & 9, 1990. The • results of the study are present in Plates 2 through 9: GeoIogic Map, Geologic Cross Section, and subsurface exploration logs.. Registered Geologist Certified Engineering Geologist 1183-030/ May 4, 1990 Page 2 Michael Weller/ Rolling Hills SITE CONDITIONS Location and Topography The subject site is located on the west side of Flying Mane Rd. south of the junction with Southfield Dr. in the City of Rolling Hills, Los Angeles County. The lot is irregular in shape measuring approximately 350 feet by 150 feet. The lot is bounded on the north, south, and west by developed lots and on the west by Southfield Dr. and an undeveloped lot along an existing drainage (Plate 2B). From a nearly level building pad west of Flying Mane Rd., the lot descends an approximately 25 degree slope to Southfield Dr.. From Southfield Dr. the slope continues approximately 150 vertical feet to the drainage below. Topographic relief on the site is approximately 100 feet, while the relief on the overall slope is on the order of 250 feet. The site location and topography are depicted on Plates 1 and 2 (A-B). Drainage and Groundwater Site drainage is comprised of essentially sheet flow runoff from precipitation derived primarily within parcel boundaries. Drainage off site is predominately to the west where it flows off -site to Southfield Dr.. Ground water was not encountered in any of the excavations and none is anticipated. No active springs or surface seeps were observed during this investigation. Geologv Fill: The western portion of the building pad consists of variable thickness of fill material over natural soil and bedrock. Measured fill thicknesses ranged from 2.5 to 6.5 feet in depth. The fill material is typically firm, moist, mottled brown and yellow -brown Silty Clay with locally abundant siltstone clasts. Locally a 0.5 foot layer of fine-grained sand was present as a landscape fill. Soil: A soil layer was observed above the bedrock in all the test pits except the two footing excavations (TP-1 & TP-2). The soil ranged from 0.5 foot to 4 feet thick. The soil is generally stiff, moist, dark -brown to black Silty Clay with some siltstone clasts. The lower contact is generally gradational. Bedrock. Monterey Formation (Tma): •The site is underlain by sedimentary rocks of the Altamira Shale Member of the Miocene 1183-030/ May 4, 1990 Page 3 Michael Weller/ Rolling Hills Monterey Formation. This unit was observed in all test pits except TP-1 & TP-2. The unit was also observed in outcrop along road cuts along Southfield Dr. and Flying Mane Rd. The Altamira Shale Member in the site and vicinity consists of predominantly light -gray to medium yellow -brown, moderately hard, moderately well -bedded, poorly fractured Diatomaceous Siltstone with locally some interlayered dolomitic and siliceous siltstone layers. Bedding attitudes are generally consistent where observed on the site with some local variation. The bedding attitudes observed on the site near the proposed additions generally dip approximately 20 to 30 degrees (range from 10 to 34) to the south and southwest. The attitudes observed are generally neutral to the slope some local component of outdip (Plate 3). Bedding attitudes observed in the road cuts in the site vicinity are generally similar with a slightly more westward component of dip. Bedrock observed in test pits TP-6 & TP-7 showed a significant' range in bedding attitudes. The bedrock was poorly bedded, locally folded and locally fractured. The material appears to have been subject to fracturing and folding due to local faulting or intraformational deformation. No fault was observed in the test pits. FAULTS The site does not lie within an Alquist-Priolo Special Studies Zone and no active faults were observed during this investigation. The nearest active fault, the Newport -Inglewood, is located approximately 10 miles to the northeast. The potentially active Cabrillo and Palos Verdes Fault Zones are located approximately 0.5 and 3 miles, respectively, to the north and northeast. Recently, a northwest trending subsurface fault zone has been postulated to extend below the Palos Verdes Hills. A similar subsurface fault zone is postulated to extend below the Whittier Narrows area and movement on this fault is believed to be the cause of the October 1, 1990 earthquake in that area. The site is, therefore, subject to ground shaking typical of the Southern California area and, thus any construction should conform to seismic design provisions of the Uniform Building Code. The bedrock observed in test pits TP-6 & TP-7 displayed features which may be indicative of nearby local faulting. No fault plane was observed in the test pits TP-6 or TP-7 and the fractures and folding observed in the two test pits was not observed in any of the other test pits. No active or potentially active faults are known to exist on the site. 1183-030/ May 4, 1990 Page 4 Michael Weller/ Rolling Hills SLOPE STABILITY No signs of surficial or deep seated instability were observed on the property. Creep, which is the nearly imperceptible movement of surficial soils down -slope due to the force of gravity, was observed on the slopes, and is believed to extend to the depths of fill and/or soil material. CONCLUSIONS AND RECOMMENDATIONS In the opinion of the undersigned, the proposed development, as contemplated, is feasible from the engineering geology standpoint, provided adherence is given to the recommendations of this and other related reports. Additionally, no adverse effects from geologic hazards of landslide settlement or slippage are % anticipated for the site or adjacent properties given the same adherence to the stated recommendations. 1. Foundation systems will be embedded in accordance with the soil engineering report. 2. The stability of the site shall be determined by the soil engineer. The factor -of -safety should meet regulatory agency requirement. 3. Bedrock units appear capable of supporting the structural loads and it is recommended that all foundations, founded in this material extend a minimum depth to be determined by the soil engineer. As a minimum, all foundations should extend below any weathered bedrock into competent material. 4. All roof, pad, and site drainage shall be conducted to appropriate drainage systems via non -erosive devices. 5. The site is subject to ground shaking typical of the Southern California area and any construction should conform to seismic design provisions of the Uniform Building Code. 6. Inspection of all foundation excavations shall be performed by the engineering geologist to verify that they are founded in competent geologic materials. REMARKS This investigation was made in accordance with generally accepted engineering geology procedures and within the limits prescribed 1183-030/ May 4, 1990 Page,5 Michael Weller/ Rolling Hills by the client. No other warranty, expressed or implied, is made as to the professional advice included in this report. Although no significant variations in bedrock or soil conditions are anticipated, it conditions are encountered during future restoration work and these conditions appear to be different from those disclosed by this preliminary report, this office shall be notified so as to consider the need for modification. While caving was not observed within the excavations, other excavations may act differently and may require shoring during future restoration work. In this regard, all shoring and bracing if necessary, shall conform to current standards of the Industrial Accident Commission of the State of California nd other pubic agencies having jurisdiction. This report has been prepared for the exclusive use of Dr. and Mrs. Michael Weller and their authorized representative. It shall not be transferred to, or used by; a third party, to another project, or applied to any other project on this site, other than described herein, without consent, and/or thorough review by this office. Should this project be delayed beyond a period of two years after the date of this report, the site and report shall be reviewed by this office to consider possible changed conditions. This report is subject to review by controlling public agencies having jurisdiction. Respectfully submitted, eorge DeVries CEG 1141 GDV:ga ' Distr: Addressee (5) Coastline Consultants (1) Attachments: Plates 1 thru 9 1 N EXF'L.ANAT I ON Tma - Monterey Formation Altamira Shale Member ' r - Geologic Contact (approx.•located) Strike & Dip of Bedding Location ("/ / / / // / / //// /// /r / 2p. / / // /0-g/ � .- / ////2;. TP #3 /ft//'. , ` o PROPOSED__/ ir. ADDITION Approx. Test Pit REFERENCE PLAN ROOF PLAN BY FULLER & KUFUS INQATEII o// //. / ' //// 1p S 34 Fill overTma /i» 4 0 1 // l / / ' ( 3i45 _L / . /. ��, o�_• ' oh oo � EXISTING RESIDENCE 0• Michael Weller - No. 3 Flying Mane Rd. �•, Rolling Hills, CA 1 "..201 APPROVED BY: APR 90 II 8"3- 030 SCALE: DATE: MAP GEOLOGIC George DeVries' . _- ._ Consulting Geologist 0 cc z 2 Z_ DRAWN BY JG REVISED I DRAWING NUMBER `2 A CONTRACTOR: ADDRESS: ARCH/ENG: ADDRESS: ORK DESCRIPTION: i'v r I a = Mir — StgfN` ABET WORKS PLEASE FILL OUT THE FOLLOWING INFORMATION l % G,w-'( .�O`'B ADDRESS: ��/ Y S r Ae/ W E // e Y ��T Fv� 1'� ate UNIT NO. : ITY/LOCALITY: (? a ill 1yP 1 )% 4 C G 7,-2 7 y CROSS-ST: ASSESSOR INFORMATION NO.: _ TENANT: OWNERS NAME: ADDRESS: diMM (LAST NAME/BUSINESS NAME) (LAST NAME/BUSINESS NAME) (FIRST) (FIRST) (MI) (MI) (14 e t,ty , 6 /2)- (LAST..NAMEIBUSINESS NAME) (FIRST)f (MI) DRESS: I c 7 f,� 2 S "R F� �f��'GU %�PHONE:( ) LIC. NO.: I OWNER/BUILDER: YES _ NO_ PHONE:( ) EXT: (LAST NAAME/BUSINESS NAME) (LAST NAME/BUSINESS NAME) (FIRST) (MI) PHONE:( ) LIC. NO.: (FIRST) (MI) PHONE:( ) Ztc1FY L�iAUJ+y`'(9 ALUATION: $ 9 d or) BUILDINGS ON LOT: PROJECT SIZE: SQ.FT NO. OF STORIES: _ CONSTRUCTION TYPES: OCCUPANCY GROUPS: EXT: CLASS: EXT: CLASS: EXT: 10/96 (THIS DOCUMENT IS TWO SIDED) FOR BUILDING AND SAFETY USE ONLY MN MN EN M - I MN N - MN MN I NE 111111 M i - I Rossidi • , • I ! !Ch I iii/- 1 i r ...: 1.. • 1_, L...1,-. : " i i :is...' n if Z.iv-r-tql - INV , ,.., ,... 4. . : ! r'... :• • , : i.Af...----/ I .---:-.-'-‘, MI . - , • I r A r...,. / iiittilitIA ifj. , S I' 1 • 11 1r7 PWINTEIBON NO. ROOONGIARPRINT• 1 V • \ %.0 A ‘011 '-c4\‘ 1 • \ N V\ I ser5 //' /7 // ,1.7, k. ki ! 1 It \ I \ '" ss1 A\ .A. / / : ! i !! : i / ,' f ...'\ ---=--7,-.. .1:11\.,___,LIIIN\ li6drP.yiD6Ff44.:71Y1ffe--6.PLUATilli-118t.Y*ieUH_ 6-6 4 Hsq`: / : .- ..../..----- • / /2-4,....--- .' 4 1",,,..:.-V-1.,' s'-'..-'k'" ' . ' . . • \._ • N % . •:(1,--...9 kI•:.5.15\lss ___/1 isli ,' i ,• • .4'2. --. / • : .. • • i zi .1./ t•-: - ii . ,...„;', \ ',,,; ... .,,k.. •..:-;,....,- \ .... ../ i ..,....• • :1 —....,., \*.s., ; its,. s. i . IA. ._k VIC.INI TY GEOLOGIC MAP , -c•-•—,_----_,4..._.-r:---.--. v• .....h ..1. .. '. 8' i fs. . _ \ -4 k— _ S. , DATE: ‘.. ..,' . I-‘.t : SCALE: MichaelApR90 Weller No. 3 Flying Plane Rd. Rolling Hills, CA . REVISED I ; k j. 7\ .4-- — '-'1"----.) ‘ s's-?- ... *-•. ‘k-7.----77 ' 1183-030 - • , . . \ .1 .. _George, DeVries i Consulting Geologist • :•-•• • 1,1,11.11'.-- 14"..,P.-- • : • . • ,.• ;: t ;12 . t • • - • -,;• 1 / /1 7, -It iv / . I I - • I ty •I II 1'4: II I,.\\ • I • \\‘'• "w•1001 I APPROVED BY: DRAWN BY JG I DRAWING NUMBER 2 B G E O L O G I C CROSS -SECT' I ON Q 3NVIN ONIAld 1 \ N 3 N a 't1a a131d HinOs z I i O 0 O 0. ar (133A) NOIIVA3'13 Michael Weller No. 3 Flyign Mane Rd. Rolling Hills, CA t 1 0 0 0 0 rr) N SECTION A -A' a) o • W •-Z Ai ° wc1) A 0 •a 0 W E A �(j 0)1d g Hi 0 0 B4k)/vc oTia,,is Proj. N2 ilaa-o30 Plate 3 0ear gDeaVr i err se;—ClorlSSu I t i'ng G®o 1 og i SE A SUBSURFACE EXPLORATION LOGS DEPTH INTERVAL DEPTH ATTITUDES DESCRIPTION TP-1 0.0-2.0 TP-2 0.0-2.0 Fill: Sandy Clay, mottled light and dark brown, firm, moist, some angular siltstone clasts; existing footing extends to approximately one foot depth TD=2.0 No water, No caving Fill: Sandy Clay, mottled light and medium brown, firm, moist, some angular siltstone clasts; existing footing extends to approximately one foot depth 01.0 -becomes black sandy and silty clay TD=2.0 No water, No caving PLATE 4 $UBSURPACB EXPLORATION LOGS DEPTH INTERVAL DEPTH ATTITUDES DESCRIPTION TP-3 0.0-0.5 0.5-6.5 6.5-9.0 9.0-12.0 N7OW, 90-70N N20E, vert. D10.0 N7OW, 10S 011.0 N55W, 22S TD=12.0 Landscape Fill: Sand, fine grained, some silt, medium brown, damp to moist, loose to medium dense, contact sharp and horizontal Fill: Silty Clay, dark brown, firm, moist; some angular siltstone clasts, abundant in upper 2 feet, clasts are platy and blocky; abundant roots in upper 4 feet Soil: Silty Clay, black, stiff, moist; some angular siltstone clasts; upper and lower contacts gradational and irregulalr Bedrock (Tma): Monterey Formation, Altamira Shale Member; Diatomaceous Siltstone, light gray and medium yellow brown, hard, moderately bedded, poorly fractured, some roots and soil pods in upper 1 foot -joint attitudes -bedding attitude -bedding attitude No water, No caving PLATE 5 SUBSURFACE EXPLORATION LOGS DEPTH INTERVAL DEPTH ATTITUDES DESCRIPTION TP-4 0.0-2.5 2.5-6.5 6.5-10.0 N75W, 90-80N N20E, vert. Fill: Silty Clay, mottled dark brown and yellow brown, firm, moist, roots; abundant siltstone clasts, angular, platy; lower contact gradational; lower contact gradational and approximately parallel to slope ( N15E, 20W) Soil: Silty Clay, black, stiff, moist; some angular siltstone clasts, clasts are platy and blocky; lower contact is very irregular over 0.5 to 1.0 foot and approximately parallel to slope ( N15E, 25W) ; Bedrock (Tma): Monterey Formation, Altamira Shale Member; Diatomaceous Siltstone with some minor interbedded dolomitic siltstone, light gray to medium yellow brown, dry to damp, hard, moderately well bedded, poorly fractured; some soil pods and rodent burrows in upper 1 to 2 feet - joint attitudes, poorly developed 07.0 N5OW, 20S -bedding attitude 08.0 N5OW, 20S N15W, 20W - bedding attitude, some minor folding and local variation 09.0 N35W, 20W -bedding attitude TD=10.0 No water, No caving PLATE 6 1 SUBSURFACE EXPLORATION LOGS DEPTH INTERVAL DEPTH ATTITUDES DESCRIPTION TP-5 0.0-0.5 0.5-4.0 Landscape Fill: Sand, fine grained, some silt, medium brown, damp to moist, loose to medium dense, contact sharp and horizontal Fill: Silty Clay, mottled brown and yellow brown, firm, damp to moist, some roots; some angular siltstone clasts, less abundant in lower 2 feet; lower contact gradational with slight dip to west ( 10W) 4.0-7.0 Soil: Silty Clay, black, stiff, damp; some angular siltstone clasts; lower 7.0-11.5 N7OW, 90-80N N-S, 90-80E 09.0 N3OW, 27W 0110.0 N40W, 34W TD=11.5 contact gradational and slightly irregular, slight west dip ( 10W) Bedrock (Tma): Monterey Formation, Altamira Shale Member; Diatomaceous Siltstone, some dolomitic and siliceous siltstone layers, light gray to yellow brown, very hard, moderately bedded, very poorly jointed; some roots and soil pods in upper 2 feet - joint attitudes, approximately perpendicular to bedding - bedding attitude - bedding attitude No water, No caving PLATE 7 SUBSURFACE EXPLORATION LOGS DEPTH INTERVAL DEPTH ATTITUDES DESCRIPTION TP-6 0.0-0.5 0.5-7.0 04.0 N15W, 40W @4.5 N35W, 35W @5.5 N3OW, 45W @6.0 Soil: Silty Clay/Clayey Silt, dark brown, firm, damp to moist; some angular and blocky siltstone clasts; soil poorly developed; lower contact gradational, approximately parallel to slope Bedrock (Tma): Monterey Formation, Altamira Shale Member; Diatomaceous Siltstone with interbedded dolomitic and siliceous siltstone, gray to yellow brown, dry to damp, hard; highly fractured and weathered in upper i to 2 feet, becomes moderately fractured below 2 feet; some local folding and variation of bedding predominantly along north side of test pit, local over -steeping of bedding may indicate local fault in vicinity - bedding attitude - bedding attitude -bedding attitude - poorly bedded below 6 feet, some zones of highly fractures/ brecciated bedrock along north side of test pit, approximately parallel to shear zones noted in test pit TP-7 (N3OW, 80S), appears to be a fault zone of approximately northwest orientation TD=7.0 No water, No caving PLATE 8 SUBSURFACE EXPLORATION LOGS DEPTH INTERVAL DEPTH ATTITUDES DESCRIPTION TP-7 0.0-1.0 Soil: Silty Clay/Clayey Silt, dark brown, firm, damp to moist; some angular and blocky siltstone clasts; lower contact gradational ( E-W, 25N) 1.0-6.0 N60E, 80-70N N3OW, 80S @3.0 N50E, 40S @4.0 N7OW, 32S TD=6.0 Bedrock (Tma): Monterey Formation, Altamira Shale Member; Dolomitic and Siliceous Siltstone with some interbedded diatomaceous siltstone, light to medium brown, hard, well bedded, moderately fractured; some weathering and soil pods in upper 1 foot - joint attitudes, approximately perpendicular to bedding -N3OW, 80S joint set displays some shearing and local offset; some gypsum fracture filling - bedding attitude -bedding attitude No water, No caving GEOTECHNICAL ENGINEERING INVESTIGATION PROPOSED RESIDENTIAL ADDITIONS NO. 3 FLYING MANE ROAD ROLLING HILLS,'CA PREPARED FOR DR. & MRS. MICHAEL WELLER APRIL 20, 1990 COASTLINE GEOTECHNICAL CONSULTANTS, INC. - CONSULTING GEOTECHNICAL ENGINEERS 1446 W. 178 TH STREET _'GARDENA, CALIFORNIA 90248-3202 April 20, 1990 Project No. 315C-020 Dr. and Mrs. Michael Weller No. 3 Flying Mane Road Rolling Hills, California 90274 Project Reference: Geotechnical Engineering Investigation Proposed Residential Additions No. 3 Flying Mane Road Rolling Hills, California Dear Dr. and Mrs. Weller: Tel. (310) 217-1504 Fax (310) 217-1909 Submitted herewith are the findings of a geotechnical engineering investigation for the referenced project. This investigation was made for the purpose of obtaining information on subsurface soils and bedrock on which to base recommendations for a suitable foundation design for the proposed residential additions. This investigation was coordinated with a geologic investigation by George DeVries, Consulting Engineering Geologist. Location of the site, relative to general topography, streets, and landmarks, is shown on the attached Vicinity Map, Plate 1. As outlined in the proposal of February 22, 1990, our work consisted of geotechnical observations, subsurface explorations and sampling, field and laboratory testing, calculations and analyses, and the preparation of this report. PROPOSED DEVELOPMENT Although detailed building plans have not been developed as yet, it is understood that the two additions will be one story in height, constructed of wood frame and stucco walls. Maximum wall loads will be approximately 1500 pounds per lineal foot. DESCRIPTION OF SITE The subject site is located on the west side of Flying Mane Road, south of Crest Road in the City of Rolling Hills. The site is on the south flank of the Palos Verdes Hills upon the west flank of a ridge that descends westerly about 200 feet to a drainage ravine. Project No. 315C-020 2 Weller/Rolling Hills The building pad is occupied by a one story, wood frame and stucco residence, constructed in 1974. From the rear yard, the site descends about nine feet at.11 (horizontal to 1 (vertical), which consists of fill placed to create the level building pad. The recently.disced, natural slope of the site descends westerly at about 4 (horizontal) to 1 (vertical) to a 1 to 1 cut slope on the east side of Southfield Drive. FIELD INVESTIGATION Seven test pits were excavated by means of hand equipment to depths ranging from 2 to 12 feet at the locations shown on Plate 2. The approximate locations of test pits were determined by tape measurement from the existing residence., Approximate elevations of test pits were determined by interpolation between contours on a Roof Plan, prepared by Fuller and Kufus, undated. The locations and elevations should be considered accurate only to the degree implied by the method used. A continuous record of the soils and bedrock encountered during the excavating was made by our field representative and is presented on Plates 4 through 7, Summary of Test Pits. The lines designating the interface between materials on the Summary of Test Pits represent approximate boundaries. The actual transition between materials was gradual. Undisturbed and bulk samples were secured at frequent intervals from the test pits for laboratory testing. SUBSURFACE CONDITIONS A wedge of moderately firm fill had been placed to create the building pad. The fill consisted of sandy, silty clay with bedrock fragments, and was a maximum thickness of 61 feet in the test pit, but is expected to be 8 to 10 feet deep nearer the crest of the slope. The natural materials consist of 21 to 41 feet of stiff, black, silty sandy clay overlying hard, yellow -brown, diatomaceous siltstone bedrock. In the cut areas of the pad, only minor amounts of the black clay were observed. For a more detailed description of the bedrock, refer to the engineering geology report by George DeVries. No signs of surficial or deep-seated instability were evidenced on the site, nor upon immediately adjacent properties. Creep, which is a nearly imperceptible movement of surficial soils downslope caused by the forces of gravity, was observed on the property. It is believed this movement extends to the full depth of the fill and residual soil in the near vicinity of the slope. Project No. 315C-020 3 Weller/Rolling Hills Groundwater and Drainaae Groundwater was not encountered, and none is anticipated within depths pertinent to the proposed construction. Surface drainage is comprised of sheet flow run-off of incidental rainfall derived primarily within the parcel boundaries. No signs of significant adverse erosion or instability were observed during the course of this investigation. LABORATORY TESTS Laboratory testing was programmed following a review of the field investigation, and after considering the probable foundation designs to be evaluated. Laboratory testing included the determination of density, moisture content and shearing resistance of the materials, as well as consolidation, compaction and expansion characteristics. The results of the tests are plotted or tabulated on the Summary of Test •Pits, Plates 4 through 7, Direct Shear Test Results on Plates 8 though 10, and Consolidation Tests on Plates 11 and 12. A compaction test was performed on'the fill. The sample was taken from Test Pit No. 3, at 4 to 411 feet. The test, performed in accordance with ASTM D-1557-78, indicated a maximum dry density of 90.5 pounds per cubic foot'at an optimum moisture content of 29.5 percent. An expansion test was performed on the finest grained soil found at the ground floor level. The sample was obtained from Test Pit No. 3, at a depth of 4 to 41 feet, and is classified as sandy, silty clay. The purpose of this test was to evaluate the potential for volume change and pressure increases with changes in moisture content. The test, performed in accordance with the Uniform Building Code Standard Test No. 29-2, indicated an Expansion Index of 83. The material would be classified as having a "moderate" potential for expansion. Details of the sampling and test procedures are given in the Appendix. SLOPE STABILITY - ANALYSES Gross and surficial stability analyses were performed on the westerly descending slope. A circular gross stability analysis was performed on the sections shown on Plate 3, which extends from Flying Mane Road to the ravine. The results of these calculations are presented on Plates 12 and 13. Although not a very high slope, the surficial stability analysis was performed on the 1k to 1 (horizontal to vertical) fill slope descending from the building pad. The calculations are presented on Plates 14 and 15. Project No. 315C-020 4 Weller/Rolling Hills Based upon these analyses, it was found that the factor of safety against sliding exceeds the normally accepted minimum for "stable" slopes. DISCUSSION AND GENERAL COMMENTS Based on the findings summarized in this report, and provided the recommendations of this report are followed, and the designs, grading and construction are properly and adequately executed, it is our opinion that construction within the building site would not be subject to hazards from landslides, slippage or excessive settlement. Further, it is our opinion that the proposed building and anticipated site grading would not adversely effect the stability of the site, nor adjacent properties, with the same provisos listed above. It is understood the additions planned at this time are in the northwest corner of the existing residence, and an extension to the living room in the west -central section. From Dr. Weller, and observation on it's performance, it is believed the small addition adjacent to Test Pit No. 1 is on a system of piers and grade beams. It is understood the piers are about ten (10) feet deep and resting on the bedrock. Therefore,. a similar system of piers, or belled caissons, and grade beams, with either wood or self-supporting floors are recommended for both additions. This may require deepening of the existing footings in the vicinity of Test Pit No. 5, or providing footings independent of the existing foundations. CONCLUSIONS AND RECOMMENDATIONS Foundations on Bedrock An allowable bearing value of 2500 pounds per square foot, for square and continuous footings, is recommended for foundations placed at a depth of at least 24 inches below the lowest adjacent final grade (top of slab -on -grade for interior footings) bearing 12 inches into the firm bedrock. Settlement of footings up to 2 feet wide continuous and 5 feet square is not expected to exceed 1/2 inch under the recommended fully applied bearing pressure. Differential settlement between footings is expected to be on the order of 1/4 inch. The bearing capacities given are net allowable bearing values and the weight of the concrete foundations can be ignored. The bearing value is for dead plus live load and may be increased by one-third for momentary wind or seismic loads. The maximum edge pressure of any eccentrically loaded footing should not exceed the values recommended for either permanent or momentary loads. Project No. 315C-020 5 Weller/Rolling Hills Lateral Loads - Spread Footinas An allowable lateral bearing value against the sides of footings of 350 pounds per square foot, per foot of depth, to a maximum of 4000 pounds per square foot may be used provided there is positive contact between the vertical bearing surface and the bedrock. Friction between the base of the footings, and/or floor slabs, and the underlying soil may be assumed as 0.35 times the dead load. Friction and lateral pressure may be combined, provided either value is limited to two-thirds of the allowable. The above values may be increased by one-third for short durations of seismic and wind forces. Creep Piers placed within five (5) feet on a slope steeper than:5:1 (horizontal to vertical), in contact with the fill and residual soil, shall be designed for creep loads. For design purposes, the lateral creep pressures may be assumed as one kip per foot of depth for isolated foundations in contact with the creeping soils. Retainina Walls Walls retaining drained earth may be designed for the following: Surface Slope of Equivalent Retained Material Fluid Pressure Horizontal to Vertical Pounds per Cubic Foot Bedrock Fill or Residual Soil Level 30 45 4 to 1 35 53 2 to 1 43 63 1ls to 1 55 82 Backfill should consist of clean sand and gravel. While all backfills should be compacted to the required degree, extra care should be taken working close to walls to prevent excessive pressure. Temporary Excavation Slopes Temporary excavation slopes in the existing surface soil may be made vertical for cuts of less than 5 feet. For deeper cuts, temporary excavation slopes shall be made no steeper than 1:1 (horizontal to vertical). Project No. 315C-020 6 Weller/Rolling Hills In areas where soils with little or no binder are encountered, shoring or flatter excavation slopes shall be made. Your attention is directed to the fact that while caving was not encountered in the test excavations, it is possible that a trench or excavation could react in an altogether different manner. All excavations shall be made in accordance with the regulations of the State of California, Division of Industrial Safety. These recommended temporary excavation slopes do not preclude local raveling and sloughing. Drainage Site drainage should be dispersed by non -erosive devices in accordance with the grading regulations of controlling agencies to preclude concentrated run-off and erosion over the site. In no case shall water be allowed to pond or drain down the slope in a concentrated and uncontrolled manner. Floor Slabs -on -Grade The surface soils found on -site are primarily sandy, silty clay. Based on expansion tests, these soils are considered moderately expansive. Due to the existence of fill within the area of the proposed construction, it has been recommended that either raised wood floors or self-supporting slabs be used. This being the case, no special design for the expansive soil is deemed necessary. A moisture barrier beneath the slabs -on -grade, preferably consisting of at least four (4) inches of rock, with a waterproof vapor barrier, such as a plastic membrane of at least six mils in thickness, covered with two inches of clean sand, is recommended in areas where slab moisture would be detrimental. Grading The following general specifications are recommended: 1. Areas to be graded or paved shall be grubbed and stripped of all vegetation, debris and other deleterious material. All loose soil disturbed by the removal of trees and existing fill shall be removed. 2. In all cases where the ground slope is steeper than 5 (horizontal) to 1 (vertical), the existing ground shall be keyed and benched into bedrock, as the fill thereon is brought up in layers. That existing ground which slopes flatter than 5 to 1 may also require benching, if the foundation engineer considers such to be necessary. Project No. 315C-020 7 Weller/Rolling Hills 3. All new fill shall be brought to near optimum moisture content, placed in layers not exceeding six (6) inches thick and compacted to at least 90 percent. 4. All other fills and backfills shall be compacted to at least 90 percent. 5. The compaction characteristics of all fill soils shall be determined by ASTM D-1557-78. The field density and degree of compaction shall be determined by ASTM D-1556, or by other acceptable ASTM standard methods which are acceptable to the governing public agency. 6. All new fill shall consist of clean soil, free of vegetation and other debris, and shall be placed in layers not exceeding six (6) inches at near optimum moisture content. No rocks over three (3) inches in greatest dimension shall be used. No soil shall be imported to the site without prior approval by the foundation engineer. The surface soils on the project would be suitable for use in compacted fills, provided it's expansive nature is considered in design. 7. No jetting or water tamping of fill soils shall be permitted. 8. Care shall be exercised during rough grading so that areas involved will drain properly. Water shall be prevented from running over slopes by temporary berms. 9. At all times, the contractor shall have a responsible field superintendent on the project, in full charge of the work, with authority to make decisions. He shall cooperate fully with the foundation engineer in carrying out the work. 10. No fill shall be placed, spread or rolled during unfavorable weather. When the work is interrupted by rain, operations shall not be resumed until field tests by the foundation engineer indicate that conditions will permit satisfactory results. Inspection As a necessary requisite to the use of this report, the following shall be observed by the soils engineer: 1. Inspection of grading operations. 2. Geologic inspection of all cuts. 3. Inspection of all backfill wedges, drainage blankets, and weep holes for retaining walls. Project No. 315C-020 8 Weller/Rolling Hills 4. Inspection of all foundation excavations for the structure or retaining walls. The consultants should be notified at least two days in advance of the start of construction. A joint meeting between the client, contractor and soils and geology consultants is recommended prior to the start of construction to discuss specific procedures and scheduling. REMARKS The conclusions and recommendations contained herein are based upon findings and observations made at the seven test pit locations. While no great variations in soil conditions are anticipated, if conditions are encountered during construction which appear to differ from those disclosed by the test excavations, this office should be notified, so as to consider the • need for modifications. ' No responsibility for construction compliance with the design concepts, specifications, orrecommendations is assumed unless on - site construction review is performed during the course of construction which pertains to the specific recommendations contained herein. Footings should be located below a line measured at a 45 degree angle from the bottom of any utility trench, unless reviewed and approved by the foundation engineer. This report is subject to review by controlling public agencies having jurisdiction. This report has been compiled for the exclusive use of Dr. and Mrs. Michael Weller and their authorized representatives. It shall not be transferred to, or used by; a third party, to another project, or applied to any other project on this site, other than as described herein, without consent and/or review by this facility. Should the project be delayed beyond the period of one year after the date of this report, the site and report shall be reviewed to consider possible changed conditions. Samples obtained in this investigation will deteriorate with time and will be unsuitable for further laboratory testing within three months from the date of this report. Unless otherwise advised, the samples will be discarded at that time. This investigation was made in accordance with generally accepted engineering procedures and included such field and laboratory tests considered necessary in the circumstances. In the opinion of the undersigned, the accompanying report has been substantiated by mathematical data in conformity with generally accepted engineering principles and presents fairly the information requested. Project No. 315C-020 Weller/Rolling Hills 9 No other warranty, expressed or implied, is made as to the professional advice included in this report. Respectfully submitted, COASTLINE GEOTECHNICAL CONSULTANTS, INC. ,t a. Richard A. Martin, RAM/ac Distribution: (2) Addressee (2) Edward Carson Beall (1) Rich Marshall (1) George DeVries • • . h t {!'taAl t'11- {1ti t/ i i e ri II X 17 711Wim ON NO. 10001 WMMIINT• • N. O1 t :t : d%\;Y � \ \ •••;0 1 \ 1� t t'TT 0 11 • SCALE: e • 1; t: REFkRE.N'CE; :'€OPO .RC)V(Q {1RFftc PLAN `.BY. S UT.•H'B . l' \.\ VICINITY MAP #3 FLYING MANE ROAD CLUNG HILLS .CALIFORNIA II_ low • I DRAWN APPROVED BY: _ BY JG DATE: APR 90 REVISED COASTLINE GEOTECHNICAL CONSULTANTS 7 PROJECT NO.315C-020 I DRAWING NUMBER I APPENDIX A EXPLORATION AND TESTING [I M Field exploration was accomplished using a truck mounted bucket auger of I6to24 inches in diameter and/or by using a backhoe with on 18 to 30 inch scoop bucket,unless otherwise noted. The earth materials encountered were continuously logged by our field representative and visually classified in accordance with the Unified Soil. Classification 'System. Undisturbed samples of the soil and/or rock were secured at. frequent intervals from the excavations by driving a thin walled, steel, sampling tube into the ground ahead of the drilling with successive drops of the drilling bar. The drive energy required for twelve inches of°penetration is shown on the Summary of Borings. Samples of earth materials were retained in one inch high, two and one half inch diameter, brass rings. Representative bulk samples were obtained and placed in water tight, polyethylene bogs for transport. The field classification was reviewed in the laboratory by visual examination and may have been aucjmente by A.S.T.M. classification tests such as grain size analysis, and Atterberg Limits tests. Unit dry weight and field moisture content may have been determined for most of the undisturbed samples. Shear tests performed on selected samples which were vertically loaded then sheared in the Direct Shear Machine at a constant strain rate. Consolidation tests may have been performed on selected undisturbed samples confined in an apparatus designed tc cccomodate a one inch high sample. Loading is applied to the specimen in several increments over selected time inrervals,and the vertical defamation recorded. Unconfined compression tests ore performed on undisturbed samples having a length at least two and one times the diameter, under constantly increasing vertical loading. All other laboratory tests are performed in accordance with A.S.T.M. or U.B.C. designat-ed procedures. SYMBOLS AND ABBREVIATIONS Some or all of the' following symbol figures .of this report: . i iP - Strike and dip of bedding - Approximate strike and dip - Strike and dip of fracture - Strike and dip of foliation — .-.Property line - Geologic contact - Approximate geologic contact • - Location of boring - Location of pit - Assumed datum point - Fault - Shear zone and abbreviations have been used within the text, plates, U -Undisturbed sample B - Bulk sample S -Direct shear test C - Consolidation test E -Expansion test G - Gradation test A - Atterberg Limits test F - Unconfined compression test T -Mechanical Analyses Q - Sand Equivalency test R - 'R' Value test M - Maximum density -Optimum moisture and test 1 N L REFERENCE PLAN ROOF PLAN BY FULLER & KUFUS UNDATED II X 11 MIRID ON NO. 100001 OUAIIMNT• //// /�' / ///ram / / / // // /////// / / / / /�/////,//t / l / /////// lTP 1//////a,!// / // OPOSE l / ////// 9 D-J ////////,' ADDITION 0f") // ////////// / ///////// 1 /Y g° / /// /� // / x // // (/ •/ i/ / f/‘ c• /. i EXISTING RESIDENCE 1 a 0 cc W a Z J U. SOILS VESTIGATION 3FLYING MANE ROAD ROLLING HILLS. CALIFORNIA SCALE: 111,•201 I APPROVED BY: DRAWN BY JG DATE: APR 90 I REVISED COASTLINE GEOTECHNICAL CONSULTANTS PROJECT N0.315C-020 IDRAWING NUMBER 1 J 3 I — b-1" .o.t nBA •76.‘ wa4e.."''IVT",-:., 61 co% D or 7./. /, - • • , - • • , , • , , JUL-27-00 07:26 PM WELLER 310 541 7871 P.a� I I Na MIGUEL A. CASTILLO Structural & Civil Engineering 15432 Firmona Ave. Date: / / Cats by: Job No.: Lawr,dale, CA 90260 I (310) 679-2355 FAX (310) 879.2354 t I Zw i 11.4Y • 1 1 1 1 1 1 1 1 1 1 ti dot+-; :Lc .:.t !o". 9,Ks+ bo`ib WtA.L 63 4'- 6K'(4e. /� �t7 G.. t` .f2 R!%w -(..% 0E.X- ). S7 T k.i1C �s�C i w .1 Sheet of O O iv-V NOI1O38 N O O c 0 W O O ELEVATION (FEET) O 0 O 0 SOUTH FIELD DR. Geotechnical Engineering Investigation No. 3 Flying Mane Road Rolling Hills, California FLYING MANE JOB N2 PLATE 3 COASTLINE GEOTECHNICAL CONSULTANTS, INC. 315C=O2O DATE 3/7/90 co w I— - c d - = H cr a) 'i F- 2 F- w 0 Z W (n d a w wC. w w v 0 s UB r 72 23.0 SUMMARY OF TEST PIT NO. Grade Beam DESCRIPTION S" FILL: CLAY ° 17.1 bedrock fragments 1 s ° 2 sandy, with Bottom of Pit @ 2 feet No Water No Caving ELEVATION 100 >- U c Z O Iw— co O U) U O U Mottled Tan Moderately and Dark Brow Firm DATE 3/7/90 SUMMARY OF TEST PIT NO.2 ELEVATION 100 °' \ FILL: CLAY = sandy, with Mottled Moderately A. bedrock fragments Brown Firm G CLAY - silty, sandy Black 76 25.7 r E. 2 Bottom of Pit @ 2 feet No Water No Caving Geotechnical Engineering Investigation No. 3 Flying Mane Road Rolling Hills, California PROJ. NO. 315C-020 PLATE 4 COASTLINE GEOTECHNICAL CONSULTANTS DATE 3/7/90 w w >- } p a s r Q: (A J I-M F- W 0 z ▪ c/ a a. w w W 3 cr.) W W p 2 UB 70 31.6 II 75 27.4 U 78 25.9 II5 SUMMARY OF TEST PIT NO. 3 DESCRIPTION FILL: CLAY - sandy, silty, with bedrock fragments - Y 0 -J 0 0 ELEVATION 100 0 z w z 0 0 Mottled Moderately Brown Firm Mottled Brown and Yellow -Brown 77 26.2 IICLAY - silty, sandy with some Black Stiff bedrock fragments 84 24.6 It 10 — BEDROCK - Siltstone, diatomaceous Yellow -Brown Hard DATE 3/7/90 67 30.3 • 75 20.7 U 75 25.0 $ 86 21.8 II 93 23.3 5 10 Bottom of Pit @ 12 feet SUMMARY OF TEST PIT NO. FILL: CLAY - silty, sandy, bedrock fragments, roots CLAY - silty, sandy with some -- bedrock fragments a 4 ELEVATION 95 Mottled Moderately Brown Soft Black Stiff BEDROCK - Siltstone, diatomaceous Yellow -Brown Hard End of Pit @ 10 feet No Water No Caving Geotechnical Engineering Investigation No. 3 Flying Mane Road Rolling Hills, California PROD. NO.315c-o2o PLATE 5 COASTLINE GEOTECHNICAL CONSULTANTS DATE 3/7/90 'CO w >- J i-. y„ I o O a = F- CC Cn J H 2 I- w p Z ▪ V) Q n- w LT- O ff) Q l'- 0 U B r 67 21.5 65 24.8 86 24.2 78 21.4 86 19.6 88 12.0 DATE 3/7/90 83 16.0 71 30.7 111111 77 22.4 SUMMARY OF TEST PIT NO. 5 DESCRIPTION FILL: CLAY - sandy, silty _ r 5 _ CLAY - silty, sandy, with some bedrock fragments 10 — 5 — 10 ELEVATION 100 ✓ U z O H J cn O (!) U O U Mottled Orange -Brown Dark Brown Moderately Soft to Firm Black Stiff BEDROCK - Silstone, weathered Yellow Firm resher Brown Hard End of Boring @ 112 ft. SUMMARY OF TEST PIT NO.6 CLAY -silty, sandy BEDROCK-Siltstone, weathered diatomaceous, fresher Bottom of Pit @ 6 feet No Water No Caving Geotechnical Engineering Investigation No. 3 Flying Mane Road Rolling Hills, California ELEVATION 102 Black M. Soft Yellow -Brown Firm Hard PROJ. NO. 315C-02C PLATE 6 COASTLINE GEOTECHNICAL CONSULTANTS DOTE 3/7/90 SUMMARY OF TEST PIT NO. cn _ W W a - w DESCRIPTION Z W C W v s U B 6 82 22.4 88 17.4 DATE 5 — 10 — CLAY - silty, sandy BEDROCK-Siltstone, diatomaceous, weathered fresher End of Pit @ 6 feet No Caving No Water SUMMARY OF TEST PIT NO. Geotechnical Engineering Investigation No. 3 Flying Mane Road Rolling Hills, California 7 ELEVATION 101 r U Z o J C/) O (f) V O 0 Black M. Firm Yellow Firm Brown Hard ELEVATION PROJ. NO.315C-020 PLATE 7 COASTLINE GEOTECHNICAL CONSULTANTS RESISTANCE( kips SHEARING 5 4 3 2 C 0 RESULTS OF DIRECT SHEAR TEST All samples were soaked for 24 hours prior to testing to simulate extreme moisture conditions. 2 4 5 CONFINING PRESSURE ( kips per sq. ft.) O - Test Pit No. 3 @ 1 ft. FILL. C] _ Test Pit No. 4 @ 1 ft. FILL. Geotechnical Engineering Investigation No. 3 Flying Mane Road Rolling Hills, California Pro j. N 2 315C-020 Plate 8 COASTLINE GEOTECHNICAL CONSULTANTS, INC. SHEARING 5 0.7 0.47 0 RESULTS OF DIRECT SHEAR TEST All samples were soaked for 24 hours prior to testing to simulate extreme moisture conditions. I 2 3 4 5 CONFINING PRESSURE (kips per sq. ft.) Test Pit No. 4 @ 7 feet. BEDROCK 0 - Normal Shear ❑ - Repeated Reshear Geotechnical Engineering Investigation No. 3 Flying Mane Road Rolling Hills, California Proj. Ne 315C-020 Plate 9 COASTLINE GEOTECHNICAL CONSULTANTS, INC. 5 4 co RESISTANCE ( kips SHEARING 3 2 0 0 RESULTS OF DIRECT SHEAR TEST A11 samples were soaked for 24 hours prior to testing to simulate extreme moisture conditions. 27° 20° I2 3 4 CONFINING PRESSURE (kips per sq. ft. ) Test Pit No. 6 @ 3 feet. BEDROCK 0 - Normal Shear ❑ - Repeated Reshear Geotechnical Engineering Investigation No. 3 Flying Mane Road Rolling Hills, California Proj. N° 315C-020 Plate 10 COASTLINE GEOTECHNICAL CONSULTANTS, INC. EXPANSION CONSOLIDATION (in percent) 5 .1 2 CONSOLIDATION TESTS PRESSURE (KIPS PER SQUARE FOOT) .2 .3 .4 II 1 • — WATER ADDED Geotechnical Engineering Investigation No. 3 Flying Mane Road Rolling Hills, California 2 3 4 5 6 7 8 I I I I i I 1 I I 1 I 1 I I I I 11 I I ' 1 I I I I I 1 I I i I I I t Boring 5 @ 5 ft. Boring 4 @ 92 ft. i I I I PROJ # 315c=o2o PLATE 11 COASTLINE GEOTECHNICAL CONSULTANTS EXPANS ION CONSOLIDATION (IN PERCENT) 4 .1 M 2 0 2 4 6 CONSOLIDATION TESTS PRESSURE (KIPS PER SQUARE FOOT) .2 .3 .4 .5 .6 .8 1.0 2 I I i • — WATER ADDED ► i Geotechnical Engineering Investigation No. 3 Flying Mane Road Rolling Hills, California 3 ► Test Pit 4 5 6 7 3 @ 7 feet• PROJ #.315C-020 PLATE 12 COASTLINE GEOTECHNICAL CONSULTANTS SLOPE STABILITY Calculations were performed to determine the stability of the existing slope. The results are as follows: Reference: "Design Manual; Soil Mechanics, Foundations, and Earth Structures", NAVFAC DM-9, March 1971, pg. 7-7-8. PROPERTIES: C (cohesion) = 870 psf r (saturated density of soil) = 110 pcf H (slope height) = 210 feet p (slope angle) = 25 degrees 0 (angle of friction) = 27 degrees COMPUTATIONS: cp r H tang 110 (210) Tan 27° _ = 13.5 C 870 From Reference Figure 7-4 Ncf = 44 Factor of Safety = Ncf C r H 44 (870) _ = 1.66 110 (210) This factor of safety is greater than the normally accepted minimum for stable slopes. Project No. 315C-020 Plate 13 SLOPE STABILITY Calculations were performed to determine the stability of the existing slope. The results are as follows: Reference: "Design Manual; Soil Mechanics, Foundations, and Earth Structures", NAVFAC DM-9, March 1971, pg. 7-7-8. PROPERTIES: C (cohesion) = 700 psf r (saturated density of soil) = 110 pcf H (slope height) = 210 feet Q (slope angle) = 25 degrees 0 (angle of friction) = 38 degrees COMPUTATIONS: r H tan0 110 (210) Tan 38° co _ _ = 25.8 C 700 From Reference Figure 7-4 Ncf = 76 Factor of Safety = Ncf C r H 76 (700) 2.30 110 (210) This factor of safety is greater than the normally accepted minimum for stable slopes. Project No. 315C-020 Plate 14 SURFICIAL SLOPE STABILITY ANALYSIS Reference: "Soil Slips, Debris Flows, and Rainstorms in the Santa Monica Mountains and Vicinity, Southern California", Geological Survey Professional Paper 851, dated 1975. CALCULATIONS: F.S. = Where: C + ( r - rw ) Z ( cosfl ) 2 tan0 r Z sing cosy F.S. is the Factor of Safety. C (cohesion) = 260 psf r (saturated density of soil) = 110 pcf rw (density of water) = 62.4 pcf Z (depth of slide) = 4 ft Q (slope angle) = 34 degrees 0 (angle of friction) = 26 degrees 260 + 47.6 (4) cos 34° tan 26° 110 (4) sin 34° cos 34° 260 + 63.8 F.S. = 204.0 = 1.59 This factor of safety is in excess of the normally accepted minimum for stable slopes. Project No. 315C-020 Plate 15 A 1 1 1 1 1 1 1 1 1 1 1 SURFICIAL SLOPE STABILITY ANALYSIS Reference: "Soil Slips, Debris Flows, and Rainstorms in the Santa Monica Mountains and Vicinity, Southern California", Geological Survey Professional Paper 851, dated 1975. CALCULATIONS: F.S. = Where: C + ( r - rw ) Z ( cosp ) 2 tan0 r Z sing cosp F.S. is the Factor of Safety. C (cohesion) = 330 psf ✓ (saturated density of soil) = 110 pcf ✓ • (density of water) = 62.4 pcf Z (depth of slide) = 4. ft fi (slope angle) = 34 degrees ¢ (angle of friction) = 14 degrees F.S. = 330 + 47.6 (4) cos 342 tan 14° 110 (4) sin 34° cos 34° 330 + 32.6 204.0 = 1.78 This factor of safety is in excess of the normally accepted minimum for stable slopes. Project No. 315C-020 Plate 16 GEOTECHNICAL ENGINEERING INVESTIGATION PROPOSED RESIDENTIAL ADDITIONS NO. 3 FLYING MANE ROAD ROLLING HILLS, CA PREPARED FOR DR. & MRS. MICHAEL WELLER APRIL 20, 1990 1446 •W: 178TH ST. GARDENA. CA 90248 COASTLINE GEOTECHNICAL CONSULTANTS, INC. CONSULTING GEOTECHNICAL ENGINEERS April 20, 1990 (213) 217-1504 Project No. 315C-020 Dr. and Mrs. Michael Weller No. '3 'Flying Mane Road Rolling Hills, California 90274 Project Reference: Geotechnical Engineering Investigation Proposed Residential Additions No. 3 Flying Mane Road Rolling Hills, California Dear Dr. and Mrs. Weller: Submitted herewith are the findingsof a geotechnical engineering investigation for the referenced project. This investigation was made for the purpose of obtaining information on subsurface soils and bedrock on which to base recommendations for a suitable foundation design for the proposed residential additions. This investigation was coordinated with a geologic investigation by George DeVries, Consulting Engineering Geologist. Location of the site, relative to general topography, streets, and landmarks, is shown on the attached Vicinity Map, Plate 1. As outlined in the proposal of February 22, 1990, our work consisted of geotechnical observations, subsurface explorations and sampling, field and laboratory testing, calculations and analyses, and the preparation of this report. PROPOSED DEVELOPMENT Although detailed building plans have not been developed as yet, it is understood that the two additions will be one story in height, constructed of wood frame and. stucco walls. Maximum wall loads will be approximately 1500 pounds per lineal foot. DESCRIPTION OF SITE The subject'site is located on the west side of Flying Mane Road, south of Crest Road in the City of Rolling Hills. The site is on the south flank of the Palos Verdes Hills upon the west flank of a ridge that descends westerly about 200 feet to a drainage ravine. Project No. 315C-020 2 Weller/Rolling Hills The building pad is occupied by a one story, wood frame and stucco residence, constructed in 1974. From the rear yard, the site descends about nine feet at 12 (horizontal to 1 (vertical), which consists of fill placed to create the level building pad. The recently disced, natural slope of the site descends westerly at about 4 (horizontal) to 1 (vertical) to a 1 to 1 cut slope on the east side of Southfield Drive. FIELD INVESTIGATION Seven test pits were excavated by means of hand equipment to depths'; ranging from 2 to 12 feet at the locations shown on Plate 2. The approximate locations of test pits were determined by tape measurement from the existing residence. Approximate elevations of test pits were determined by interpolation between contours on a Roof Plan, prepared by Fuller and Kufus, undated. The locations and elevations should be considered accurate only to the degree implied by the method used. A continuous record of the soils and bedrock encountered during the excavating was made by our field representative and is presented on Plates 4 through 7, Summary of Test Pits. The lines designating the interface between materials on the Summary of Test Pits represent approximate boundaries. The actual transition between materials was gradual. Undisturbed and bulk samples weresecured at frequent intervals from the test pits for laboratory testing. SUBSURFACE CONDITIONS A wedge of moderately firm fill had been placed to create the building pad. The fill consisted of sandy, silty clay with bedrock fragments, and was a maximum thickness of 61/2.feet in the test pit, but is expected to be 8 to 10 feet deep nearer the crest of the slope. The natural materials consist of 2; to 42 feet of stiff, black, silty sandy clay overlying hard, yellow -brown, diatomaceous siltstone bedrock. In the cut areas of the pad, only minor amounts of the black clay were observed. For a more detailed description of the bedrock, refer to the engineering geology report by George DeVries. No signs of surficial- or deep-seated instability were evidenced on the site, nor upon immediately adjacent properties. Creep, which is a nearly imperceptible movement of surficial soils downslope caused by the forces of gravity, was observed on the property. It is believed this movement extends to the full depth of the fill and residual soil in the near vicinity of the slope. Project No. 315C-020 Weller/Rolling Hills Groundwater and Drainage Groundwater was not encountered, and none is anticipated within depths pertinent to the proposed construction. Surface drainage is comprised of sheet flow run-off of incidental rainfall derived primarily within the parcel boundaries. No signs of significant adverse erosion or instability were observed during the course of this investigation. LABORATORY TESTS ;Laboratory testing was programmed following a review of the field investigation, and after considering the probable foundation designs to be evaluated. Laboratory testing included the determination of density, moisture content and shearing resistance of the materials, as well as consolidation, compaction and expansion characteristics. The results of the tests are plotted or tabulated on the Summary of Test Pits, Plates 4 through 7, Direct Shear Test Results on Plates 8 though 10, and Consolidation Tests on Plates 11 and 12. A compaction test was performed on the fill. The sample was taken from Test Pit No. 3, at 4 to 42 feet. The test, performed in accordance with ASTM D-1557-78, indicated a maximum dry density of 90.5 . pounds per cubic foot at an optimum moisture content of 29.5 percent. An expansion test was performed on.the finest grained soil found at the ground floor level. The sample was obtained from Test Pit No. 3, at a depth of 4 to 4; feet, and is classified as sandy, silty clay. The purpose of this test was to evaluate the potential for volume change and pressure increases with changes in moisture content. The test, performed in accordance with the Uniform Building Code Standard Test No. 29-2, indicated an Expansion Index of 83. The material would be classified as having a "moderate" potential for expansion. Details of the sampling and test procedures are given in the Appendix. SLOPE STABILITY - ANALYSES Gross and surficial stability analyses were performed on the westerly descending slope. A circular gross stability analysis was performed on the sections shown on Plate 3, which extends from Flying Mane Road to the ravine. The results of these calculations are presented on'Plates 12 and 13. Although not a very high slope, the surficial stability analysis was performed on the 11/2 to 1 (horizontal to vertical) fill slope descending from the building pad. The calculations are presented on Plates 14 and 15. Project No. 315C-020 Weller/Rolling Hills 4 Based uponthese analyses, it. was found that the factor of safety against sliding exceeds the normally accepted minimum for "stable" slopes.. 'DISCUSSION AND GENERAL COMMENTS Based on the findings summarized in this report, and provided the recommendations of this report are followed, and the designs, grading and construction are properly and adequately executed, it is our opinion that construction within the building site would not be subject to hazards from landslides, slippage or excessive settlement. Further, it is our opinion that the proposed•building and anticipated site grading would not adversely effect the stability' of the site, nor adjacent properties, with the same provisos listed above. It is understood the additions planned at this time are in the northwest corner of the existing residence, and an extension to the living room in the west -central section. From Dr. Weller, and observation on it's performance, it is believed the small addition adjacent to Test Pit No. 1 is on a system of piers and grade beams.' It is understood the piers are about ten (10) feet deep and resting on the bedrock. Therefore, a similar system of piers, or belled caissons, and grade beams, with either wood or self-supporting floors are recommended for both additions. This may require deepening of the existing footings in the vicinity of Test•Pit No. 5, or providing footings independent of the existing foundations. CONCLUSIONS AND RECOMMENDATIONS Foundations on Bedrock An allowable bearing value of 2500 pounds per square foot, for square and continuous footings, is recommended for foundations placed at a depth of at least 24 inches below the lowest adjacent final grade (top of slab -on -grade for interior footings) bearing 12 inches into the firm bedrock. Settlement of footings up to 2 feet wide continuous and 5 feet square is not expected to exceed 1/2 inch under the recommended fully applied bearing pressure. Differential settlement between footings is expected to be on the order of 1/4 inch., The bearing capacities given are net allowable bearing values and the weight of the concrete foundations can be ignored. The bearing value is for dead plus live load and may be increased by one-third for momentary wind or seismic loads. The maximum edge pressure of any eccentrically loaded footing should not exceed the values recommended for either permanent or momentary loads. Project No. 315C-020 Weller/Rolling Hills Lateral Loads - Spread Footinas An allowable lateral bearing value against the sides of footings of 350 pounds per square foot, per foot of depth, to a maximum of 4000 pounds per square foot may be used provided there is positive contact between the vertical bearing surface and the bedrock. Friction between the base of the footings, and/or floor slabs, and the underlying soil may be assumed as 0.35 times the dead load. Friction and lateral pressure may be combined, provided either value is limited to two-thirds of the allowable. The above values may be'; increased by one-third for short durations of seismic and wind forces. Creep Piers placed within five (5) feet on a slope steeper than 5:1 (horizontal to vertical), in contact with the fill and residual soil, shall be designed for creep loads. For design purposes, the lateral creep pressures may be assumed as one kip per foot of depth for isolated foundations in contact with the creeping soils. Retainina Walls Walls retaining drained earth may be designed for the following: Surface Slope of Equivalent Retained Material Fluid Pressure Horizontal to Vertical Pounds per Cubic Foot Bedrock Fill or Residual Soil Level 30 45 4 to 1 35 53 2 to 1 43 63 1Z to 1 55 82 Backfill should consist of clean sand and gravel. While all backfills should be compacted to the required degree, extra care should be taken working close to walls to prevent excessive pressure. Temporary Excavation Slopes_ Temporary excavation slopes in the existing surface soil may be made vertical for cuts of less than 5 feet. For deeper cuts, temporary excavation slopes shall be made no steeper than 1:1 (horizontal to vertical). J Project No. 315C-020 6 Weller/Rolling Hills In areas where soils with little or no binder are encountered, shoring or flatter excavation slopes shall be made. Your attention is directed to the fact that while caving was not encountered in the test excavations, it is possible that a trench or excavation could react in an altogether different manner. All excavations shall be made in accordance with the regulations of the State of California, Division of Industrial Safety. These recommended temporary excavation slopes do not preclude local raveling and sloughing. Drainage i Site drainage should be dispersed by non -erosive devices in accordance with the grading regulations of controlling agencies to preclude concentrated run-off and erosion over the site. In no case shall water be allowed to pond or drain down the slope in a concentrated and uncontrolled manner. Floor Slabs -on -Grade The surface soils found on -site are primarily sandy, silty clay. Based on expansion tests, these soils are considered moderately expansive. Due to the existence of fill within the area of the proposed construction, it has been recommended that either raised wood floors or self-supporting slabs be used. This being the case, no special design for the expansive soil is deemed necessary. A moisture barrier beneath the slabs -on -grade, preferably consisting of at least four (4) inches of rock, with a waterproof vapor barrier, such as a plastic membrane of at least six mils in thickness, covered with two inches of clean sand, is recommended in areas where slab moisture would be detrimental. Gradincr The following general specifications are recommended: 1 Areas to be graded or paved shall be grubbed and stripped of all vegetation, debris and, other deleterious material. All --loose soil disturbed by the removal of trees and existing fill shall be removed. 2. In all cases where the ground slope is steeper than 5 .(horizontal) to 1 (vertical), the existing ground shall be keyed and benched into bedrock, as the fill thereon is brought up in layers. That existing ground which slopes flatter than 5 to 1 may also require benching, if the foundation engineer considers such to be necessary. Project No. 315C-020 Weller/Rolling Hills 7 3. All new fillshall be brought to near optimum. moisture content, placed in layers not exceeding six (6) inches thick and compacted to at least 90 percent. 4. All other fills and backfills shall be compacted to at least 90 percent. 5. The compaction characteristics of all fill soils shall be determined by ASTM D-1557-78. The field 'density and degree of compaction shall be determined by ASTM D-1556, or by other acceptable ASTM standard methods which are acceptable to the governing public agency. 6-. All new fill shall consist of clean soil, free of vegetation and other debris, and shall be placed in layers not exceeding six (6) inches at- near optimum moisture content. No rocks over three (3) inches in greatest dimension shall be used. No soil shall be imported -..to the site without prior approval by the foundation engineer. The surface soils on the project would be suitable for use in compacted fills, provided it's expansive nature is considered in design. 7. No jetting or water tamping of fill soils shall be permitted. 8. Care shall be exercised during rough grading so that areas involved will drain properly. Water shall be prevented from running over slopes by temporary berms. 9. At all times, the contractor shall have a responsible field superintendent on the project, in full charge of the work, with authority to make decisions. He shall cooperate fully with the foundation engineer in carrying out the work. 10. No fill shall be placed, spread or rolled during unfavorable weather. When the work is interrupted by rain, operations shall not be resumed until field tests by the foundation engineer indicate that conditions will permit satisfactory results. Inspection As a necessary requisite to the use of this report, the following shall be observed by the soils engineer: 1. Inspection of grading operations. 2. Geologic inspection of all cuts.- 3. Inspection of all backfill wedges, drainage blankets, and weep holes for retaining, walls. Project No. 315C-020 Weller/Rolling Hills 8 4. Inspection of all foundation excavations for the structure or retaining walls. The consultants should be notified at least two days in advance of the start of construction. A joint meeting between the client, contractor and soils and geology consultants is recommended prior to the start of construction to discuss specific procedures and scheduling. REMARKS :The conclusions and recommendations contained herein' are based upon findings and observations made at the seven test pit locations. While no great variations in soil conditions are anticipated, if conditions are encountered during construction which appear to differ from those disclosed by the test excavations, this office should be notified, so as to consider the need for modifications. No responsibility for construction compliance with the design concepts, specifications, orrecommendations is assumed unless on - site construction review is performed during the course of construction which pertains to the specific recommendations contained herein. Footings should be located below a line measured at a 45 degree angle from the bottom of any utility trench, unless reviewed and approved by the foundation engineer. This report is subject to review by controlling public agencies having jurisdiction. This report has been compiled for the exclusive use of Dr. and Mrs. Michael Weller and their authorized representatives. It shall not be transferred to, or used by; a third party, to another project, or applied to any other project on this site, other than as described herein, without consent and/or review by this facility. Should the project be delayed beyond the period of one year after the date of this report, the site and report shall be reviewed to consider possible changed conditions. Samples obtained in this investigation will deteriorate with time and will be unsuitable for further laboratory testing within three months from the date of this report. Unless otherwise advised, the samples will be discarded at that time. This investigation 'was made in accordance with generally accepted engineering procedures and included such field and laboratory tests considered necessary in the circumstances. In the 'opinion of the undersigned, the accompanying report has been substantiated by mathematical data in conformity with generally accepted engineering principles and presents fairly the information requested. Project No. 315C-020 Weller/Rolling Hills 9 No other warranty, expressed or implied, is made as to the professional advice included in this report. Respectfully submitted, COASTLINE GEOTECHNICAL CONSULTANTS, INC. Richard A. Martin, RAM/ac Distribution: (2) Addressee (2) Edward Carson Beall (1) Rich Marshall (1) George DeVries r..-•.: L-5,31(5:::$•., "e1170:,0A2. ) . *.1363 flO. r IAr r VUI/ EXPLORATION AND TESTING Field exploration was accomplished using a truck mounted bucket auger of 16to24 inches in diameter and/or by using a backhoe with an 18 to 30 inch scoop bucket, unless otherwise noted. The earth materials encountered were continuously logged by our field representative and visually classified in accordance with the Unified S oil. Classification 'System. Undisturbed samples of the soil and/or rock were secured at. frequent intervals from the excavations by • driving a thin walled, steel, sampling tube into the ground ahead of the drilling with successive drops of the drilling bar. The drive energy required for twelve inches of•penetratton is shown on the Summary of Borings. Samples of earth materials were retained in one inch high, two and one half inch diameter, brass rings. Representative bulk samples were obtained and placed in water tight, polyethylene bogs for transport. The field classification was reviewed in the laboratory by visual examination cnd may have been augment: by _A.S.T.M. classification tests such es grain size analysis, and Atterberg Limits tests. Unit dry weight and field moisture cbntent may have been determined for most of the undisturbed samples. Shear , tests performed on s elected .sample's which were vertically loaded then sheared in the Direct Shear Machine at a constant strain rare Consolidation tests may have been performed on selected undisturbed samples confined in an apparatus designed tc cccomodate a one inch high sample. Loading is applied to the specimen in several increments over selected time inrervals,and the vertical deformation recorded. Unconfined compression tests are performed on undisturbed sample: having a length at least two and one times the diameter, under constantly increasing vertical loading. All other laboratory tests are performed in accordance withA.S.T.M. or U.E.C. designate.d procedures. SYMBOLS AND ABBREVIATIONS Some or c II of the following symbol figures .of this report: -'� - Location of boring • - Location of pit - Assumed datum point �P - Strike and dip of bedding Z. - Approximate strike and dip moo, Strike and dip of fracture 322A. - Strike and dip of foliation -- -. Property line — --.-.Geologic contact, - Approximate geologiccontact F - Fault -Shear zone and abbreviations have been used within the text, plates, and U -Undisturbed sample B - Bulk sample S -Direct shear fest C - Consolidation test E -Expansion test G - Gradation lest A - Atterberg Limits test F - Unconfined compression test T -Mechanical Analyses Q - Sand Equivalency test R - 'RValue test M - Maximum density -Optimum moisture test J El El J --•••••-7 ,/' ••• '•-•=7 •/* • „/*-;/-./' „ • •••• • , / ' , ,, .. \ -- • N' •• •-. ,, '• ••••.... -- _,...,...--s / ' V: \ /* / 11 s. ...• / • : s -:• ss s , 's \ • ,,, '...'::::::::..: .:::•-•....., ..," .-. • „ •••••-•:::••---Z-.7."_:-,,e s*,-._.... f..„ ,.„ ...• • ,....••••• / -a ‘* N•• '‘'s if .-----,-- I-, ---- r• - • i I f 1t2IT I PH 01 1 I Notoi• 1111 t ' • • / '1 . ; ; ./\•••-:• r • • • ill I/ i• Ail ' \ • • • • • • • ' ... \i 'N" •,,, \ .„. -------.. • ''_5' / ••••• „...-.1 ' ••...-...-,-.-...,_........ I' ,...• . ..... ••••• ••••.-..............•••• ....••• .....•••••• .'t it \\ \ \0\\\ rcf)%\ i % , N \ IA I \ sve s \ • i r- • • i ,?C , \\ • ill \01 1 \ 1.-___,_ t .; ' x---- tk. tv- \ • i I k 1% , . \ •01‹. • 1 1 \ \ \ \ l 1 I • • / I ,' : /, / • • • ••••‘ 'I./ ;(,/ A r"/c I ° f`a • ,-\\ a =, X \ • • 1 ; fi•\ = 0 \I It_ , ,-.. ' • • i • . :• ....' • • '''' _‘.., ' ..22...:*........... ., ..w.... .. .• A• • : : . • . z .•• •. . . • • • ... .; : • ••• / . • • I ... • . 4......,0•. / " / f i i / • / , i I ; .. . . . . . . . ,.... , .., , • ,/, -•,/ -- / / ; ..,: . f ' .; ,,. . „ ••• / ; / • . „•-• • . • "1.‘ •••• /*/ , 7 • ; • \ • . • • /•••:•-••••"'/ / • = it Si / t , • 1 / • • RCP,. • / ,; i ; --,. • •• , • ‘-''‘ ....-• ., -:-. i \ '•?.1.. • "k,,•;. . ...• . . I t 1 ...**"17..---"'-'-••••• I a \‘‘ ,,,, ...„....;; ,....„ ,., k it:41s : ANN . 1•••.sk \ i...' \ Si • • SCALE: DATE: I 00' APPROVED BY: I 11= APR 90 ItjEE „ Li VICINITY MAP #3 FLYING MANE ROAD OLLING HILLS .CALIFORNIA RI • ' / • / GA; DRAWN BY JG REVISED COASTLINE GEOTECHNICAL CONSULTANTS PROJECT NO.315C-020 1 DRAWING NUMBER 11 X 17 PRINTED ON NO. 1000M CLEARPRINT • i i L REFERENCE PLAN ROOF PLAN BY FULLER & KUFUS UNDATED N / / // /////// 1 0/ / ////// / / / / / , / / / / ,l �� v, �7 --Z- / . 7' 1 /. .�� / • 0) oo 0 \o EXISTING RESIDENCE SCALE: 1 II= 2 0' DATE: APR 90 0 cc FLYING MANE SOILS INVESTIGATION # 3 FLYING MANE ROAD ROLLING HILLS, CALIFORN A APPROVED BY: DRAWN BY JG REVISED COASTLINE GEOTECHNICAL CONSULTANTS J 11 X 17 PRINTED ON NO. 1000H CLEARPRINT • PROJECT NO.315C-020 DRAWING NUMBER 2 • - ' • 3 I: — — — — N 0,1 -Is 01 0 0 0 0 0 0 0 0 0 0 I I I 1 01 0 1V-V NO1103S ELEVATION (FEET) SOUTH FIELD DR. FLYING MANE Geotechnical Engineering Investigation No. 3 Flying Mane Road Rolling Hills, California JOB N2 315C-020 PLATE 3 COASTLINE GEOTECHNICAL CONSULTANTS, INC. 1 DATE 3/7/90 0 w ✓ J r. >.. t_ 0 n. = F- Q: U7 J F- i F- w o z w cn acl- w w L- o Cl) US Li_ av s U B I' 72 23.0 II SUMMARY OF TEST PIT NO. 1 2 Grade Beam DESCRIPTION I 5" FILL: CLAY - sandy, with n e I bedrock 'fragments Bottom of Pit @ 2 feet No Water No Caving ELEVATION 100 U Z o H J cn o u) o Z 0 U Mottled Tan Moderately and Dark Brow Firm DATE 3/7/90 SUMMARY OF TEST PIT NO.' ELEVATION 100 �:L• 8„ FILL: CLAY - sandy, with Mottled Moderately D•o•bedrock fragment's Brown Firm c o CLAY - silty, sandy Black 76 25.7 11 o 2 Bottom of Pit @ 2 feet No Water No Caving Geotechnical Engineering Investigation No. 3 Flying Mane Road Rolling Hills, California PROJ. NO. 315C-020 PLATE 4 COASTLINE GEOTECHNICAL CONSULTANTS a DATE 3/7/90 c W Q: !n - F - " W Q Z W {n Q 0- W W Lt r Cl) w L1. Q Q UB n 70 31.6 75 27.4 78 25.9 77 26i,2'; SUMMARY OF TEST PIT NO. 3 DESCRIPTION FILL: CLAY - sandy, silty, with bedrock fragments w ELEVATION 100 ✓ cn z O W o E o z 0 0 Mottled Brown Mottled Brown and Yellow -Brown Moderately Firm CLAY - silty, sandy with some Black Stiff bedrock fragments 84 24.6 10 — BEDROCK - Siltstone, diatomaceous Yellow -Brown Hard DATE 3/7/90 67 30.3 75 20.7 75 25.0 86 21.8 93 23-.3 5 10 Bottom of Pit @ 12 feet SUMMARY OF TEST PIT NO. 4 ELEVATION 95 FILL: CLAY - silty, sandy, bedrock Mottled Moderately fragments, roots Brown Soft CLAY - silty, sandy with some bedrock fragments Black Stiff — BEDROCK - Siltstone, diatomaceous Yellow -Brown Hard End of Pit .@ 10 feet — No Water No Caving Geotechnical Engineering Investigation P R O J. N 0.315C-020 No. 3 Flying Mane Road Rolling Hills, California PLATE 5 J COASTLINE GEOTECHNICAL CONSULTANTS 3/7/90 W cn >- cc .J r. - D e: W w pz W• a n. w w O ( W p p v 2 U B 67 21.5 1 65 24.8 86 24.2 78 21t4` 86 19.6 88 12.0 DATE 3/7/90 83 16.0 71 30.7 m SUMMARY OF TEST PIT NO. 5 DESCRIPTION ELEVATION 100 >- U Z O F- .J o Cl) U z U FILL: CLAY - sandy, silty Mottled Moderately Orange -Brown Soft — to Firm Dark Brown V 5-- CLAY - silty, sandy, with some • Black Stiff bedrock fragments 10 — BEDROCK - Silstone, weathered resher End of Boring. @ 111/2 ft. Yellow Firm Brown Hard SUMMARY OF TEST PIT NO.6 CLAY -silty, sandy BEDROCK-Siltstone, weathered ELEVATION 102 Black M. Soft Yellow -Brown Firm El diatomaceous, fresher Hard _.� 77 22.4 in J 5 Bottom of Pit @ 6 feet No Water No Caving 10 — Geotechnical Engineering Investigation No. 3 Flying Mane Road Rolling Hills, California PROJ. NO. 315C-02C PLATE 6 COASTLINE GEOTECHNICAL CONSULTANTS 7 I J DATE 3/7/90 W >- J ),. F_ Q.. = F- = (n Eli F- M f' W C1 Z - (A Q o- W W Lt,. O (1) W li o S � B o . t 82 22.4 88 17.4 DATE SUMMARY OF TEST PIT NO. 5 — DESCRIPTION ELEVATION 101 >- Q_ O FW- J (n O U) U O 0 0 Z CLAY - silty, sandy Black M. Firm BEDROCK-Siltstone, diatomaceous, Yellow Firm weathered Brown fresher Hard — End of Pit @ 6 feet No Caving No Water 10 — SUMMARY OF TEST PIT NO. Geotechnical Engineering Investigation No. 3 Flying Mane Road Rolling Hills, California ELEVATION PROJ. NO.315C-020 PLATE 7 COASTLINE GEOTECHNICAL CONSULTANTS J • GO 147) RESISTANCE( kip E2 Cr) 5 4 3 2 C 0 RESULTS OF DIRECT SHEAR TEST All samples were soaked for 24 hours prior to testing td simulate extreme moisture conditions. 25° 2 4 5 CONFINING PRESSURE ( kips per sq. ft.) Q- Test Pit No. 3 @ 1 ft. FILL. 0_ Test Pit No. 4 @ 1 ft. FILL. Geotechnical Engineering Investigation No. 3 Flying Mane Road Rolling Hills, California Proj. N 315C-020 Plate 8 .COASTLINE GEOTECHNICAL CONSULTANTS, INC. RESULTS OF DIRECT SHEAR TEST J 7-7 RESISTANCE ( kips SHEARING 5 2 0.7 0.47 0 0 All samples were soaked for 24 hours prior to testing to simulate extreme moisture conditions. 2 3 4 5 CONFINING PRESSURE (kips per sq• ft.) Test Pit No. 4 @ 7 feet. BEDROCK 0 - Normai'Shear ❑ - Repeated Reshear Geotechnical Engineering Investigation No. 3 Flying Mane Road Rolling Hills, California Proj. NE 315C-020 Plate 9 .COASTLINE GEOTECHNICAL CONSULTANTS, INC. RESULTS OF DIkECT SHEAR TEST p a c. SHEARING 5 2 0 O All samples were soaked for 24 hours prior to testing to simulate extreme moisture conditions. 27° 20° 2 4 5 CONFINING PRESSURE ( kips per sq. fit. ) Test Pit No. & @ 3 feet. BEDROCK O - Normal Shear 0 - Repeated Reshear Geotechnical Engineering Investigation No. 3 Flying Mane Road Rolling Hills, California P ro j. N ° -315C-020 Plate 10 .COASTLINE GEOTECHNICAL CONSULTANTS, INC. • i 'J 9 EXPANSION Sr. CONSOLIDATION 5 .1 4 3i; 2 I I I 1 I I I • I I I I II I I CONSOLIDATION TESTS PRESSURE (KIPS PER SQUARE FOOT) .2 .3 .4 .5 .6 .8 I I I I I I 1 I I I I 1 I 1 I I I . I I ! 1 I I 1 1 I I I I 1 I 1 I 1 1 I 1 I 1 I II I I I I i I 1 I 1 II I I I 1 I I ! 1.0 2 3 4 5 6 I I 7 8 Boring 4 1 ; @ 9 z ft. I II I I I • — WATER ADDED Geotechnical Engineering Investigation No. 3 Flying Mane Road Rolling Hills, California PROJ # 315C-020• PLATE 11 J COASTLINE GEOTECHNICAL CONSULTANTS 1 J EXPANSION CONSOLIDATION (IN PERCENT) 4 2 2 4 6 .2 'A CONSOLIDATION TESTS PRESSURE (KIPS PER SQUARE FOOT) .3 .4 .5 .6 I I t I I I I I ! I I 1 ! i I I 1 I I I I I � I ' I I 1 I III 1 1 1 1 I 1 i I 1 I I 1 I ! I I 1 I I I t I 1 I I 1 I I I I I I 1 1 1 I I I I II • — WATER ADDED Geotechnical Engineering Investigation No. 3 Flying Mane Road Rolling Hills, California 2 4 5 6 7 8 I I I I I I I I ! I I I I I I I I , I I I I ! I I I I I I I I I I I I I I I I 1 I 1 I 1 I I I I I I I 1 1 I 1 I I 1 1 1 I 1 1 1 Test Pit 3 @ 7 feet PROJ # 315C-020 PLATE 12 COASTLINE GEOTECHNICAL CONSULTANTS J 1 p 4' SLOPE STABILITY Calculations were performed to determine the stability of the existing slope. The results are as follows: Reference: "Design Manual; Soil Mechanics, Foundations, and Earth Structures", NAVFAC DM-9, March 1971, pg. 7-7-8. 3 f• PROPERTIES: C (cohesion) = 870 psf 'I r (saturated density of soil) = 110 pcf H (slope height) = 210 feet Q (slope angle) = 25 degrees 0 (angle of friction) = 27 degrees COMPUTATIONS: r H tang) 110 (210) Tan 27° cc6 _ = = 13.5 C 870 IFrom Reference Figure 7-4 Na = 44 NaLI C 44 (870) Factor of Safety = = = 1.66 r H 110 (210) This factor of safety is greater than the normally accepted Jminimum for stable slopes. Project No. 315C-020 Plate 13 7 JI • J .SLOPE STABILITY.` Calculations were performed to determine the stability of the existing slope. The results are as follows: Reference: "Design Manual; Soil Mechanics, Foundations, and Earth Structures", NAVFAC DM-9, March 1971, pg. 7-7-8. i 1' PROPERTIES: C (cohesion) = 700 psf r (saturated density of soil) = 110 pcf H (slope height) = 210 feet (3 (slope angle) = 25 degrees 0 (angle of friction) = 38 degrees COMPUTATIONS:. r H tan cb C From Reference Figure 7-4 Na = 76 110 (210) Tan 38° 700 = 25.8 Na C 76 (700) Factor of Safety = 2.30 r H 110 (210) This factor of safety is greater than the normally accepted minimum for stable slopes.. Project No. 315C-020 Plate 14 a 4 b i J i SURFICIAL SLOPE STABILITY ANALYSIS Reference: "Soil Slips, Debris Flows, and Rainstorms in.. the: Santa''. Monica Mountains and Vicinity, Southern California", Survey Professional Paper 851, dated 1975. CALCULATIONS: F.S. _ Where: C + ( r - rw ) Z ( cosp ) 2 tan r Z sing cosy F.S... is the Factor of Safety. C (cohesion) = 260 psf r (saturated density of soil) = 110 pcf rw (density of water) = 62.4 pcf Z (depth of slide) = 4 ft p (slope angle) = 34 degrees 0 (angle of friction) = 26 degrees 260 + 47.6 (4) cos 34° tan 26° 110 (4) sin 34° cos 34° 260 + 63.8 F.S. = 204.0 = 1.59 Geological This factor of safety is in excess of the normally accepted minimum for stable'slopes. Project No. 315C-020 Plate 15 SURFICIAL'`'SLOPE STABILITY ANALYSIS,: Reference: "Soil Slips, Debris Flows, and Rainstorms in the Santa Monica Mountains and Vicinity, Southern California", Geological. Survey Professional Paper 851, dated 1975. CALCULATIONS: C + ( r_ ru ) Z ( cosO3 ) 2 tancp F.S. = r Z sinf3 cosf3 Where: F.S.\,is the Factor of Safety. C (cohesion) = 330 psf r (saturated density of soil) = 110 pcf rW (density of water) Z (depth of slide) f3 (slope angle) 0 (angle of friction) = 62.4 pcf = 4 ft 34 degrees 14 degrees 330 + 47.6 (4) cos 342 tan 14° F.S. = 110 (4) sin 34° cos 34° 330 + 32.6 204.0 = 1.78 This factor of safety is in excess of the normally accepted minimum for stable slopes. Project No. 315C-020 Plate 16