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Home My WebLink AboutCT 00-16; Poinsettia Properties; Addendum to Geotechnical Investigation; 2001-11-21GEOCON INCORPORATED GEOTECHNICAL CONSULTANTS Project No. 06514-52-03 November 21,2001 John Laing Homes 895 Dove Street, Suite 110 Newport Beach, California 92660 Attention: Mr. Pablo Leon Subject: POINSETTIA PROPERTIES CARLSBAD, CALIFORNIA ADDENDUM TO GEOTECHNICAL INVESTIGATION Reference: 1. Geotechnical Investigation [for] Poinsettia Properties, Sewer Pump Station, Carlsbad, California, prepared by Geocon Incorporated, dated October 16, 2001 (Project No. 06514-52-03). 2. Update Geotechnical Investigation [for] Poinsettia Properties, Carlsbad, California, prepared by Geocon Incorporated, dated July 20, 2000 (Project No. 06514-12-01). Gentlemen: In accordance with your request, this letter has been prepared to provide supplemental geotechnical information for a subsurface soil investigation performed on September 26, 2001. The purpose of this investigation was to drill through the stockpile fill material, obtain relatively undisturbed samples for laboratory testing, and to estimate shrinkage factors of the fill materials. This work was conducted in conjunction with the investigation for the pump station (reference no. 1). Using a truck mounted Ingersoll-Rand A-300 drill rig, 3 borings were advanced to depths ranging from 26.5 feet to 31 feet below existing grade. Relatively undisturbed samples were obtained from the borings by driving a three-inch O.D. tube sampler 12 inches into the undisturbed soil mass with a 140-pound hammer falling 30 inches. Standard Penetration Tests (SPT) were also performed at various depths in the borings. Bulk samples were also collected. The soils encountered in the excavation were visually examined and logged. The logs of the borings are presented in Figures A-l through A-4. Borings were placed in the undocumented stockpile fill located on the eastern portion of the property. Boring B-2 was located at the south of the stockpile, Boring B-3 was located at the center of the stockpile and Boring B-4 was located at the north end of the stockpile (Boring B-l was associated with the pump station study, see reference 1, and not included in this report). The undocumented fill ranged in thickness from approximately 2.5 feet to 8 feet. The stockpile material is characterized as loose to medium dense, dry to moist, light tan brown silty sand and silty clay. The stockpile fill is underlain by unconsolidated alluvial soils ranging in thickness between 2 to 3 feet. 6960 Flanders Drive • San Diego, California 92121-2974 • Telephone (858) 558-6900 • Fox (858) 558-6159 The alluvium is underlain by dense terrace deposits that overlie Tertiary-aged Santiago Formation. Groundwater was encountered at depths that ranged from 13 to 16 feet below the existing ground surface. Laboratory tests were performed on selected soil samples obtained during the field investigation to evaluate the pertinent physical properties of the soil types encountered. Laboratory tests were performed in general accordance with the test methods of the American Society for Testing and Materials (ASTM). The results of in-situ density and moisture content are presented on the boring logs. The results of the laboratory maximum dry density and optimum moisture content are shown in Table I. All unsuitable surficial soils, including alluvium and undocumented fill should be removed and recompacted prior to receiving additional fill or settlement sensitive improvements. Based on a review of the laboratory test results it is estimated that the undocumented fill may shrink between approximately 2 to 5 percent when properly compacted to a minimum of 90 percent relative compaction. If you have any questions regarding this letter, or if we may be of further service, please contact the undersigned at your convenience. Very truly yours, GEOCON INCORPORATED AS:JH:dlj Addressee(4) (2/del) JOHN HOOBS NO 1524 CERTIFIED ENGINEERING GEOLOGIST 12-31-02 Project Design Consultants Attention: Mr. Curtis Turner Project No. 06514-52-03 -2-November 21,2001 TABLE I SUMMARY OF LABORATORY MAXIMUM DRY DENSITY AND OPTIMUM MOISTURE CONTENT TEST RESULTS ASTM D 1557-91 Sample No. B2-2 Description Greyish brown, silty, fine to medium SAND with little clay Maximum Dry Density (pcf) 121.0 Optimum Moisture Content (% dry wt.) 12.3 Project No. 06514-52-03 November 21,2001 PROJECT NO. 06514-52-03 DEPTH IN FEET - 2 - - 4 - — - 6 - - 8 - — 1 n1U - 12 - - 14 - - 16 - - 18 - on2\j - 22 - - - 24 - - - 26 - - - 28 - SAMPLE NO. B2-1 5 B2-2 > B2-3 1 f B2-4 B2-5 IF[ B2-6 1 1 B2-7 CD0 o M_l '•}}''.' j-L F ^ft"fc.i-}•^f-"1-L -1 -- | ~i i -i -::-•:•-. - - ' / _" \'// ~</:/s ty, ':_//- •-H"-"i •(• -\ \ - \ ~ 1 1 -1•:[:•:£ •£iH-•*f [• OI^H* rrUJ <c o o CO I SOIL CLASS (USCS) SM SM SP SC SM SM BORING B 2 ELEV. (MSL.) 56 DATE COMPLETED 9/26/01 EQUIPMENT IR A-300 MATERIAL DESCRIPTION FILL Loose to medium dense, damp to moist, brownish-gray and orange, Silty, fine to medium SAND -Becomes Silty SAND with some clay ALLUVIUM Loose to medium dense, damp, dark reddish-brown, Silty, fine to medium SAND TERRACE DEPOSITS Very dense, damp to very moist, dark gray to gray, fine to medium SAND Becomes very dense, saturated, dark gray and light reddish-brown, Clayey, fine to medium SAND Becomes light brownish-tan, Silty, fine to coarse SAND -Becomes gravelly, hard drilling at 23 feet SANTIAGO FORMATION Very dense, wet, light grayish white and some orange, slightly cemented, Silty, fine to coarse SANDSTONE with some clay ZtlJ~ H^^i ^ii^<Er-sC •" \fv JTT yj LlJ t n C3 u£mCL >ta/ 16 - 15 - 67 - 60 53 SQ/S s- 1— |d j£^o 111.2 107.9 ~ o:^ »i Eg o 17.0 15.6 Figure A-l, Log of Boring B 2 PPR SAMPLE SYMBOLS D... SAMPLING UNSUCCESSFUL 13 . . . STANDARD PENETRATION TEST B... DRIVE SAMPLE (UNDISTURBED) ... DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE T. ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. PROJECT NO. 06514-52-03 DEPTH IN FEET 30 -I SAMPLE NO. B2-8 CDo o H H'Khl•!»Nx- a:LUt-<r D na:CD SOIL CLASS (USCS) SM BORING B 2 ELEV. (MSL.) 56 DATE COMPLETED 9/26/01 EQUIPMENT IR A-300 MATERIAL DESCRIPTION ^ -Becomes very moist with trace clay ^ BORING TERMINATED AT 31 FEET Groundwater encountered at 16 feet gu~ H^H l-?FU-<c£\OL\r.V> •"H3 UJ^CO 50/4.5" > ID(J ofQ ^ ce~ |g gz u Figure A-2, Log of Boring B 2 PPR SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL S ... DISTURBED OR BAG SAMPLE C... STANDARD PENETRATION TEST •... DRIVE SAMPLE (UNDISTURBED) B ... CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. PROJECT NO. 06514-52-03 DEPTH IN FEET - 2 - - - 4 - - 6 - - - 8 - - - 10 - - 12 - 14 - 16 -1 " - 18 - 2U - 22 - - 24 - - 26 - SAMPLE NO. 1IL 1 B3-2 I B3-3 * B3-4 j j rB3-5 1 f B3-6 1 B3-7 .J1 -: 1 i .I: I. / - [: .* :• •i fy% >cc 3 - -1 • N •J --1I •: '.ik|i ••j•]•A% )> ^j •"- I- • •"- . - . \ \ .r... . *L** *« »*L**r*« L•V *: ::t: :;F: ^% ^ IYUJ TQ O U> T — SOIL CLASS (USCS) SM SM SM SC SM SM CL BORING B 3 ELEV. (MSL.) 57 DATE COMPLETED 9/26/01 EQUIPMENT IR A-300 MATERIAL DESCRIPTION FILL Loose, dry, light tan yellow, Silty, fine to medium SAND ALLUVIUM Dense, dry to damp, brown to dark brown, fine to medium SAND with silt TERRACE DEPOSITS Loose to medium dense, dry to damp, light orange brown, Silty, fine to coarse SAND with some clay -Becomes medium dense to dense, damp to moist, light orange tan, Silty, fine to medium SAND with trace clay Becomes Clayey, fine to medium sand Becomes dense, wet to saturated, orangish-brown, Silty, fine to medium SAND with trace clay SANTIAGO FORMATION Very dense, wet, light gray, slightly cemented, Silty, fine to coarse SANDSTONE Becomes hard, very moist, Silty CLAYSTONE BORING TERMINATED AT 26.5 FEET Groundwater encountered at 15 feet o111^H°.|- fr ^^ \fy* '. _ y) UJ^O ui^mf^VC-^s - • - - - 15 - — - 29 - - 37 73 64 UJ(J^ • o:^Q 111'' /-x LUC toSHpf °0O 17 'I Figure A-3, Log of Boring B 3 PPR SAMPLE SYMBOLS D... SAMPLING UNSUCCESSFUL E . . . STANDARD PENETRATION TEST ... DISTURBED OR BAG SAMPLE B ... CHUNK SAMPLE ... DRIVE SAMPLE (UNDISTURBED) f. ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. PROJECT NO. 06514-52-03 DEPTH IN FEET _ r\ __ - 4 - - - 6 - — Q0 in1U - 12 - - 14 - - 16 - _ „ - 18 - - 22 - - - 24 - - 26 - SAMPLE NO. B4-1 B4-2 T>4 'I B4-4 B4-5 B4-6 CDO O 1- _l -:1-]"?".'-} i:!<l-- : \- -| ".i vi.iji •'){•!• " "* "1 "*1 ' "1/I- i" r I-L - ;-. • /** ^ ~ s / / /\,-/'/ y/:/ %ty/-" 1-1 J I. - :!]--- ;JV Wk, //v/S/C^ QLLU <T Q — >na:CD T SOIL CLASS (USCS) SM SM SP SC SM CL T* rf"\T» TTk-Trf^l T» ABORING B 4 ELEV. (MSL.) 58 DATE COMPLETED 9/26/01 EQUIPMENT IR A-300 MATERIAL DESCRIPTION FILL Dense, dry to damp, light gray to gray brown, Silty, fine to coarse SAND -Becomes light brown ALLUVIUM Medium dense, damp to moist, grayish -black, Silty, TERRACE DEPOSITS Loose to medium dense, moist, light gray, fine to medium SAND Becomes dense to very dense, very moist to wet, light orangish-brown and some tan brown, Clayey, fine to medium SAND Becomes very dense, wet to saturated, light gray with some orange, Silty, fine to coarse SAND with trace clay SANTIAGO FORMATION \ cemented, Silty CLAYSTONE / BORING TERMINATED AT 26.5 FEET Groundwater encountered at 13 feet 2UJ~ ft CJ t * jT |— f « Gj^mQ_"-\-f 35 ~ 32 - - 50 60 41 m * Lujj ^•* • >& o 114.7 99.8 ~ III ^Vo:~ Wu5 E| u 5.7 8.1 Figure A-4, Log of Boring B 4 PPR SAMPLE SYMBOLS D... SAMPLING UNSUCCESSFUL C ... STANDARD PENETRATION TEST •... DRIVE SAMPLE (UNDISTURBED) S ... DISTURBED OR BAG SAMPLE B ... CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.