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Home My WebLink About2694-3; La Costa South Unit 3; Soils Report Final; 1970-01-16l .‘.I L : -i . ,~ .i . . . . .~BENl’ON ENGINEERING. INC. APPL1f.D SOIL HLCHANICS -. FOUHD*TIO”S G7.1 EL c*,cm BO”IE”AFlO . . . *AH DICGO. C*LIFORNL* 0211, . . . _’ PHlLlP “EIIK!HC: BENTOH P”L1,OTHT ElYlL T.+CI”EEII Joruary 16, 1970 0.” DlrCO; ,83.565‘ LA HLZA: r169.5614 Ranch0 La Costa, Inc. -. _ Route 1, Box 2550 - Encinitoj, California 92024 Subject: . Project No. 69-lo-25D Final Report on Compacted Filled Graund- > _’ Lots 207 to 237, inclusive, Lots 239, 243, 246 to 248, inclusive . Lok 2.50. ond 25 1, .y$aq$i’; incluh ,La...Cos wou:h Un! t..h’o. 3~ m lc&I-& Son Diego eo;‘Kty, California Gentlemen: . This is to report the results of tests and observations made in order to itipect the cw;zction of filled grourd placed oil ccrtoin areas of Lots 207 to 237, inclusive, 239, 243, 24-6 to 2<:3, inclusive, 250 ard 251, ard 255 to 257, inclusive, of La~Ccsta Scuth Unit No. 3, San Die20 Cwnty, Californio. The fills were placed during the period between October 20 OKI December 5, 1969. ._ i : The approximate arecs O,XI depths of filled grbuti, placed under our inpecti‘on in ddco:dcnce with the cy)proved s,xcificatiors ore shown on the attached Drowiq No. i, entitled “Locction oJ.&c’mr;acted Filied Ground. ‘I The grodiq plan used for the placement of filled grourd wcz preporcd by Rick Et-Gineering Ccmpany and dated September 30, 1969. .’ The apprnximote location at which the tests were taken and the final test results ore presented un p’;“~~cs 4 to 10, inclusive; under the “Table of Test Results.” The laboratory determinations of the maximum dry densities and optimum moisture contents of the major fill motericls are presented on t:ee. IO, under the “Lab oratory Test Results. ” Some of fhe moximLgm dry dcrsi!ics shov+in the “Table of Test Results” were combinations of these. The tests weie t&n duriq the weekly periods indicated below: ..* Test Number :Week Endi r;3 *- . lard2 October 25, 1969 3 to 59, inclusive Novemb~er 1, 1969 60 to 123, inclusive Novcmbcr 8, 1969 124 to 168, inclusive.” . : November 15, 1969 169 to 197, inclusive November 22, 1969 198 to 2 13, inclusive November 29, 1969 SlOlO 214 to 2&,1, inclusive Deccmbcr 6, 1969 . - .~ - - _- - - - - - .- LU LOSKI South ticlIt NO. .5 ’ . ,’ The finaj’re&fts of tests and observattons indicate that the compacted filled ground has been ptaced at~90 percent of the maximum dry density or grcator. It has been dctormined that the fiil materiais, compacted to 90 percent of the maximum dry density, have a safe beartr‘g value of at least 2000 pounds per square foot for ones foot wide continuous footir(3s founded at a minimum depth ard placed five fcot or more inside the top of ccmpacted filled grcund slopes. ff ioatirgs are placed closer to the exposed slop thon 5 feet inside the top of compacted filled ground slopes, theso shwld be deepened one foot belo,w a 1 l/2 horizonbl to 1 vertical line projected outward and downward from a point 5 feet horizontally inside the top of compacted filled ground slopes. Tests indicate that the compacted filled ground is odequote. to satisfac- torlly support one or two story wood frame dwslli~r designed for the rccommoraled boring : voh~e, without In our report of dated May 22,l969), we stated that scme “expansive” soils existed on the site and if they were allov.Gt~o remain in the upper 3 feet below finished grade some of ihe lots would require specially designed footings and slabs. We further stated that these lots would be listed upon the completion of grading. The lots where e2pansive soils ,were observed to remain within the uoner 3 feet, arc tabulated OS follows: . Type A: Lots 2!9, 220, 250 at-d 25r Ty& B: Lots 221 to 224, inclusive; 226 229, 231 and 232, and 248 ‘and 249. 3 4 It is reconmerded that the following special design precautions be taken for the hwses‘ to be constructed on the above-listed lots: . Type A Lok . 1. Isolated interior piers should not be used. Continuous footings should be used throughout, and these shculd be placedat a minimum depth oftwo feet below the jowest adjacent exterior final ground surface. -‘“!?i ’ Reinforce and interconnect continuously with steel bars all interior and cxterlor footlr(Els with two fi4 bars at 3 inches above the bottom of all footings and two 64 bars placed’ 1 l/2 inches below the top of the stems of the footings. ? .‘ 9 .Usc iaised wood floors that span between continuous footings, or reinforce all 1 concrete slobs with 6 x 6 - IO/IO woven wire fabric and privide a minimum of 4 inches of clean sand beneath all concrete slabs. Provide a moisture barrier ?> 2 inches below slabs under livirg areas. 4. Separate garage slobs from perimeter footings by l/2 Inch thickness of construc- tion felt or cqulvalont, to allow independent movement of garage slobs rclativo to perlmotor footiqs. ;.5. Provide posltlve drainage away from all porlmctcr footlrgs to a hwlzonfal distance of at least 6 feet wtsldo tho houso walls.. . * DLNTON CNGINEERINC. INC. . - 1- I 1 t r L i. .1 F 1 2’ >. . -i ;: -i [ - .I f -I I. -I - ! i ! _ 1 ,i - 1 - 1 ‘. I - I I ‘f I ,+oject NO. 6% IO-25 D ~0 Co;ta South Unit NO. 3 e... 3 ‘ , ‘. . .~ January 16, 1970 , .: 2pe B Lots yhose lot: listed on pqe 2 as Type B lok should follow all the above-Ilstcd recommendations 4th the two following exceptions: .l. The continuous footings may be placed at o niinimum depth of 18 inches below the lowest adjacent exferior final ground surface rather than the t\vo feet recommerded for Type A lots. 2. Single #4 bbrs placed as direcfed (above) near tops and bottoms of all Interior and exterior footir\3s may be substituted for the two c4 bars recommended for Typ:Alots. . , . . . Recornmendationr 3 to 5, inclusive, as listed for Type A lots, are applicable to the Type B lok also. Respectfully submitted, BENTON ENGINEERING, INC. By (;. ,;Y& / - Philip H. Benton, Civil ErQineer Distr: (4) Addressee (I) tick Eqineerirg Company (2) 5qn Diego County Buildirg Impection Visk2 Office .<t.II‘. a ?: . , , . .:.. . . ,L’. _ : - _ 7;‘. .’ 1.;;. . . : ,