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HomeMy WebLinkAboutCT 75-04; La Costa El Fuerte Street Lot 75; Soils Report; 1987-08-31- - - - - - - - - - - - - - Job #1288-85 MV EhGINEERING, INC. 2450 Vineyard Avenue. #102 Escondido. California 92025-I 330 619/743-1214 August 31, 1987 Mr. Richard Spanjian 7315 Borla Place Carlsbad, California 92008 ENGINEERING DEPT. LIBRARY City of Cartsbad 2075 Las Palmas Drive CarlsbaQ CA 92009-4859 Update of Preliminary Soil Invesitgation for Lot 75, Carlsbad Tract 75-4, El Fuerte Street, La Costa - dated October 10, 1985 by MV Enqineering, Inc. This letter is to confirm that we have reviewed the subject report and made a site inspection of Lot 75, located on the west side of El Fuerte Street, in La Costa. It is understood that the proposed residence will be a wood-frame structure and the foundation will use continuous concrete footings with slab-on-grade or raised wood floors. On August 27, 1987 a visual inspection of the subject site revealed that the lot is in a natural condition similar to that encountered during the initial investigation. It is our opinion that the recommendations contained in the subject report are still valid and should be adhered to. Pertinent recommendations and additions are listed below. A. It is recommended that the preparation of the native soil and any grading be done in accordance with the enclosed "Specifications for Construction of Controlled Fills" except if superseded by the following recommendations. B. It is recommended that any septic tanks or other large buried objects detected during the grading be removed. The voids should be filled with compacted soil and tested per soil engineer in charge. All roots, irrigation lines, and other objectional debris should be hand picked and removed from the site. C. The cut portions of any transition lots shall be undercut a minimum depth of three feet below the proposed pad grade or to a minimm depth of 12 inches below the bottom of the footing, whichever is greater, and replaced as structural fill. This pre- caution will decrease the potential of cracking of the slab along the daylite line. -. Mr. Richard Spanjian Page 2 August 31, 1987 -. - D.. Footing and Slab Recommendations (Alternative tl): l- Cap the pad with a minimum of three feet of granular, - non-expansive soil (to be approved by this office). 2 - For a non-expansive capping soil it is recommended that norma concrete wall footings be used in accordance with - Uniform Building Code design (i.e. 12 inches wide by 12 inches deep and 15 inches wide by 18 inches deep for one- and two-story structures respectively, minimum depths, measured - from the lowest adjacent ground surface). 3- Use two #4 reinforcing rods in the footings. Place one rod three inches from the top and the other rod three inches - from the bottom of the footing. 4 - Use 6x6/10x10 welded wire mesh placed mid-height in all slabs. Use 3f-inch minimum thick slabs and a minimum of four inches of clean sand under all slabs. A plastic moisture barrier is optional. If used it should be placed mid-height in the sand. Provide weakened plane joints spaced 15 feet on center each way for all slabs. 5- All spread footings should be a minimum of 24 inches in width and length and embedded a minimum of 24 inches below nearest adjacent finished grade. Spread footings should include a minimum of two #4 bars each way. 6 - An allowable bearing capacity of 1500 psf for continuous and isolated footings can be used. E. Footing and Slab Recommendations (Alterntive #2): 1 - Excavate to firm material and recompact the loose upper topsoil to 90% of the maximum dry density at 5% to 8% over the optimum moisture content prior to placing any fill or structures. The excavation will be in the order of approximately one to two feet. The exact depth will be determined during the excavation by the soil engineer on site. 2 - Foundation Recommendations: a) Dig the footings to a minimum depth of 30 inches below the lowest adjacent ground surface. Footings should have a minimum width of 12 inches for one- and two-story structures. b) Use four #5 reinforcing rods in both interior and exterior footings. Place two rods three inches from the top and the other rods three inches from the bottom of the footing. MV ENGINEERING, INC. l 24.50 VINEYARD AVENUE, HO2 l ESCONDIDO, CALIFORNIA 92025-I 330 l 9191743-1214 sOIL*TEsTINO PERCTEST solLlN”E*TlGATlONS DEOTECHN,CILIN”E*TIO*TIONB -. . . Mr. Richard Spanjian - Page 3 August 31, 1987 - - - - - - - - - c) Dowel the slab to the footings using 114 reinforcing rods spaced 24 inches on center extending 18 inches into the footing and slab. The dowels should be placed mid- height in the slab. Alternate the dowels each way for all interior footings. d) After the footings are dug and cleaned, place the reinforcing steel and dowels, and pour the footings. 3 - Presaturation of the Interior Slab Sub Grade: a) Once the concrete for the footings has cured, Place four inches of pea gravel ($-inch rock) over the slab sub grade. Flood with water to the top of the pea gravel and allow the slab sub grade to soak for seven to ten days. The required moisture content of the slab sub grade soils is 5% to 8% over the optimum moisture content at a depth of 30 inches. After the slab sub grade soils have soaked notify this office and schedule appropriate moisture testing. 4 - Interior Slab Reinforcing: a) When the required moisture content has been achieved, place a 6-mil plastic moisture barrier over the pea gravel and place two inches of clean sand on top of the plastic. b) Use X3 reinforcing rods spaced 18 inches on center each way placed mid-height in all slabs. All slabs should be a minimum of five inches in thickness. cl Provide weakened plane joints spaced 15 feet on center each way for all slabs. 5- Exterior Slabs (patios, sidewalks, and driveways): a) Use four-inch minimum thick slabs reinforced with 6x6/10x10 welded wire mesh placed mid-height in all slabs. Use six inches of clean sand (S.E. 30 or greater) under all slabs. b) Provide weakened plane joints spaced six feet on center each way for all slabs. 6- Bearing Capacity and Lateral Load Designs: a) An allowable bearing capacity of 1000 psf for continuous and isolated footings can be used. MV ENGINEERING, INC. l 2450 VINEYARD AVENUE, X102 l ESCONDIDO, CALIFORNIA 92025-1330 l 6191743-1214 - SOILSTE8TINO PERC TEST SOILIN”ESTIO**wNs DEOTECHNlCILlNVEJTlOlTlONB - - - - - - - - - - - - - - - Mr. Richard Spanjian Page 4 August 31, 1987 F. This office should be notified to inspect the footing trenches after they are dug to verify the foundation conditions. G. Footings located on or adjacent to top of slopes should be extended to a sufficient depth to provide a minimum horziontal distance of five feet between the bottom edge of the footing and the face the of the slope. H. Use cut and fill slope ratios of 2:l (horizontal:vertical) for overall gross slope stability. I. Finish grading should direct and maintain drainage away from all slopes and buildings. J. It is recommended that a pre-grading meeting be held between the owner, grading contractor and a representative of this firm to discuss the operation and to arrange a testing schedule. Finalised development plans should incorporate these recommendations and be reviewed and approved by this office. If the finialized development plans significantly change or if they were not available at the time of this investigation, further investigation by this firm will be required. Thank you for choosing MV Engineering, Inc. If you have any questions concerning this report, please do not hesitate to call us. Reference to our job #1288-85 will expedite our response to your inquiries. MV ENGINEERINY INC. / - MV ENGINEERING, INC. l 24.50 VINEYARD AVENUE, #IO2 l ESCONDIDO, CALIFORNIA 920251330 l 61917431214 .- SOlLSTESTlNO PERCTEST *MLIN”EsvoLTIoNs MOTECHNlCILlNVESTlOITlONS