Loading...
none, New foundations for new additi, CorrespondenceSWN SLTECH CONSULTANO, INC. Geotechnical Engineering 3140 West Main Street, Alhambra, California 91801 June 5, 2008 Mr. Ed La Charite 23 Caballeros Road Rolling Hills, California 90274 By (626282-6 JUN 0 9 2009 CITY OF ROLLING HILLS • Subject: Excavation for Proposed Residential Development 23 Caballeros Road Rolling Hills, California Project Ref. 4744-07 Ref. Report Of Soils Engineering Investigation dated July 20, 2007 Dear Mr. La Charite: Approximately 200 cubic yards of soils were generated at the subject site during construction of foundations for the proposed additions to the existing residence and removal of the abandoned septic tank. The foundation excavations ranged from approximately 2 feet to 10 feet. The excavation of the septic tank was about 9 feet deep. Please call if you have any question regarding excavation at the subject site. Respectfully submitted, SWN Soiltech Consulta 'Y Stephen W. Ng GE 637 SWN ObILTECH CONSULTA!S INC. Geotechnical Engineering 3140 West Main Street, Alhambra, California 91801 (626) 282-6838 Project Ref. 4744-07 July 20, 2007 Mr. Ed La Charite 23 Caballeros Road Rolling Hills, California 90274 Subject: Report of Soils Engineering Investigation Proposed Residential Development 23 Caballeros Road Rolling Hills, California Dear Mr. La Charite: In accordance with your request, we are pleased to submit this report of a soils engineering investigation for the proposed residential development of the above referenced site. The accompanying report has been substantiated by surface and subsurface exploration and mathematical analysis made in accordance with generally accepted engineering practice, including those field and laboratory tests considered necessary in the circumstances. This report has been prepared for you and your design consultants to be used for evaluation of the subsurface soil conditions for the proposed construction at the subject site. This report has not been prepared for the use by other parties or for other purposes, and may not contain sufficient information for other than the intended use. Services performed by this facility at the subject site were conducted in a manner consistent with that level of care and skill ordinarily exercised by members of the profession currently practicing in the same locality under similar conditions. No other warranties are expressed nor implied. It is the professional opinion of the undersigned that this report presents fairly the information requested by you. Respectfully submitted, SWN Soiltech Consulta Stephen W. Ng GE 637 Q%OF_0 /6 . (YI'1 i ,7 11 No. 637 :,c R� SWN Soiltech Con ants, Inc. Project Ref. 4744-07 July 20, 2007 INTRODUCTION Page 1 of 20 This report presents the results of a soils engineering investigation for the proposed development of the subject site located at 23 Caballeros Road, in the City of Rolling Hills, California. The purpose of this investigation was to obtain information on the subsurface soils conditions at the areas of the proposed development at the subject site and to provide recommendations pertinent to foundation design, temporary excavations and other relevant parameters for the design and construction of the proposed development. Our soils engineering investigation has been conducted in conjunction with an engineering geologic investigation by Coast Geotechnical, whose report (W.O. 321106-02) dated July 11, 2007 should be reviewed in conjunction with this report. PROPOSED CONSTRUCTION The proposed development is shown on a Site Plan dated April 2007, prepared by Jan Trobaugh and Associates. A copy of the Plan is included in the Coast Geotechnical report. We understand that the proposed development will consist of the following: • Room additions to the north and southwest of the existing house; • Demolition of the existing pool house and portion of the existing garage; • Relocation of the septic system. Information on the design loads of the proposed structures is not available at the time of this report. Specific construction plans, have not been prepared and await the conclusions and recommendations of this report. Specific construction plans shall be reviewed by this facility, when available, so as to determine the need for further soils engineering study and revised recommendations pertinent to the proposed development. Further geotechnical study may include additional field exploration, laboratory testing and engineering analysis. SWN Soiltech ConsiOints, Inc. Project Ref. 4744-07 July 20, 2007 SCOPE OF WORK • Page 2 of 20 Our scope of work for this report included the following: 1. Review of available geotechnical data; 2. Subsurface exploration by means of 5 test pits excavated with hand tools; 3. Logging and sampling of the soils encountered in the exploratory test pits; 4. Laboratory testing of the acquired samples to determine the pertinent soils engineering properties of the subsurface soils; 5. Soils engineering analysis; and 6. Preparation of this report that summarizes the field and laboratory finding and provides recommendations pertinent to the design and construction of the project. The following attached Appendices complete this report: Appendix I - Procedures and findings of field exploration Appendix II - Procedures and findings of laboratory testing Appendix III - Grading Guidelines Appendix IV -. Results of corrosivity tests on a sample of the on -site soils SITE CONDITIONS The subject site is located easterly of Caballeros Road (Caballeros Road is assumed to trend North -South at the site) and at a short distance north of Crest Road East, in the City of Rolling Hills. The location and topographic features of the subject site, as well as the locations of the existing residence and the proposed structures, are shown on the Geology Map and Cross Section included in the Coast Geotechnical report. The subject site consists of a relatively gentle slope that descends northeasterly from Caballeros Road. Past grading had created a driveway and a level pad for the existing residence, the pool house and swimming pool. The proposed room additions will also be located on the level pad. A barn and an adjacent arena are located on a lower level pad. i SWN Soiltech ConsSnts, Inc. Project Ref. 4744-07 July 20, 2007 SOIL CONDITIONS Page 3 of 20 Subsurface exploration consisted of 5 test pits excavated with hand tools. No significant amount of soil caving was observed in the test pits. No ground water was encountered in the exploratory test pits to the depths explored and none is anticipated to be within depths pertinent to the proposed development. It should be noted that fluctuations in the level of ground water might occur due to variations in rainfall, temperature and other factors at the time observations are made. Fill Up to approximately 5 feet of fill soils were encountered in the test pits. It should be noted that, due to the presence of the existing residence and underground utilities, fill soils of unknown depths may be. present at other locations of the site. Where encountered in the test pits, the fill soils consist generally of light to dark -colored, moist, soft, silty clay with varying amount of bedrock fragments. Soil/Colluvium The subject site is generally mantled with a layer of soil/colluvium. The soil/ colluvium encountered in the test pits are asintich°'wa's', 5 feet thick. Where encountered, the soil/colluvium consists generally •of'dark colored, moist, medium stiff to stiff, silty clay with varying amount of bedrock fragments. Some of the bedrock fragments are cobble -sized. Bedrock The fill soils, soil/colluvium are underlain by bedrock. The bedrock was encountered at the following depths inthe"test pits: Test Pit 1: 1.5 feet Test Pit 2: 4.5, feet Test Pit 3: 7.0 feet Test Pit 4: 7.0 feet Test Pit 5: 5.0 feet+ Where encountered in the test pits, the bedrock consists predominantly of slightly clayey, weathered basalt. The bedrock is generally light to medium -colored, moist to very moist, and stiff to hard. • SWN SOILTECH CONSULTANTS, INC. Soil Mechanics - Foundation Engineering 3140 West Main Street, Alhambra, Califomia 91801 Tel: (818) 282-6838 NOTICE OF FIELD OBSERVATION Date `f'I240 b' Project Name Address il-1) (An- e-Aro `6 �A (z"111„ ;A5 Requested by �G,.�.i 5 —6 r \,,c-v-Atr1 Met With 1 Notice Left With Time \-•oco?M SWN Soiltech Consultants Report dated Plan by Ref. -fTN--07-7 Dated We have observed -9f nAG.+,b1n P xr car 'ors �� Approved Not Approved See Below General Comments and Conditions of Approval: 1 '�i nA..,._A-:, av, Pxrn‘ick-1ONns ,v\C QacA 4\06-1-,vca3 c v C ' vinyl.,nhti---► � 1 tl ilr \to -ritro-N . 1,r 0 c _kc.. - rz) Tv' yos, J (� 5 ruc.k,(A -, C 0v--F. 1 \ I` \c,t, e c n 1 S /; tA. C1 A e.1,) r 'i 5 c-In o I' 1P}e, 1ret^'\-0v .t bI ` Tb rr ;v\ J • Additional Site Visit V Required Not Required For SWN Soiltech Consultants, Inc. Total Hours Time Approved by June 3, 2008 Yolanta Schwartz, Planning Director City of Rolling Hills 2 Portuguese Bend Road Rolling Hills, California 90274 Re: Soils Exportation Dear Yolanta: In the construction of our foundation we generated approximately 200 cubic yards of dirt from the trenching process. The soils engineer test pits indicated bedrock was 5-7 feet deep. As these footings were trenched it became apparent that we needed to go as deep as 9 feet to reach competent bedrock. From this point we needed to trench a minimum of 18 inches into bedrock. The removed soil was not competent for recompaction purposes. Therefore, 180 cubic yards of slurry mix was used to bring compaction to an acceptable level for the foundation. We will spread about 120-cubic yards of this fill on our property within acceptable depth levels and export the remainder...approximately 80 cubic yards. This dirt will be used by the City of Rolling Hills for their road compaction areas. I hope that this answers your needs. Best regards, Ed La Charite 23 Caballeros Road Rolling Hills, California 9274 310-544-4212 CITY OF ROLLING HILLS Approved PLANNINb DEPARTMENT Date 6/4 g c_av Etbu-e.„ 6v3 - Spit S/3/-5 is t- CC7 11^e--d ILJ2- ,vv-v 7 / Ad s eat, 110.0_1,1A,IRY 24, 1957 50TH ANNIVERSARY 1957 - 2007 B. ALLEN LAY Mayor DR. JAMES BLACK Mayor Pro Tem THOMAS F. HEINSHEIMER Councilmember FRANK E. HILL Councilmember GODFREY PERNELL, D.D.S. Councilmember February 23, 2007 Mrs. Kristen Raig Manager Rolling Hills Community Association 1 Portuguese Bend Road Rolling Hills, CA 90274 NO. 2 PORTUGUESE BEND ROAD ROLLING HILLS, CALIF. 90274 (310) 377-1521. FAX: (310) 377-7288 In follow-up to our conversations, I am writing to confirm and document that the license agreement approved by the Rolling Hills Community Association at its meeting of January 11, 2007 for 23 Caballeros Road (LaCharite) will not be recorded until the appropriate City approvals are granted. As briefly described in the meeting minutes, the construction will necessitate Planning Commission approval and, the County will be looking for the City's approvals prior to issuing building permits. If it is not already the practice, it may be valuable for the RHCA to advise applicants that the recording of an easement license is contingent upon the City's approval of the building plans. As such, the Association may also, in the future, consider withholding "final" approval of a license agreement until the plan review process is complete. We may address this graphically through the "flow chart" that we mutually agreed to develop that will explain the plan review process. Thank you. Sincer ahlerbruch Manager AD/ 02-23-07rai g2-1 tr.doc cc: Mayor and City Council Yolanta Schwartz, Planning Director Prin t e d on n ec ycl,•d P.pei