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HomeMy WebLinkAbout10.20.1978 Soil Foundation Investigation Report SOIL FOUNDATION INVESTIGATION ACCESS ROAD EXTENDING BAY AREA BLVD. ACROSS F.M. 528 FRIENDSWOOD, TEXAS FOR: ENGINEERING SCIENCE , INC. HOUSTON, TEXAS 307 EAST PASADENA FREEWAY 7701 IRVINGTON 1515 S. PRUETT PASADENA, TEXAS HOUSTON, TEXAS BAYTOWN, TEXAS 477-0121 697-8485 October 20, 1978 Engineering Science, Inc. 16915 E1 Camino Real Houston, Texas 77058 Attention: Mr. David P. Guggemos , P.E. Reference: Soil Foundation Investigation Lab Job No. : 78-545 Report No. : 7810-1013 Dear Mr. Guggemos , We are pleased to transmit herewith our report on the foundation in- vestigation made recently at the site of the proposed access road extending Bay Area Boulevard across F.M. 528 in Friendswood, Texas . - This investigation reveals relatively expansive surface and shallow formations consisting of silty clay and clay underlain by more stable clays interbedded with sandy clay seams . This stratigraphy is typical of Beaumont clay formation of deltaic origin. These surface soils are classified as poor subgrade soil and therefore, require stabilization for pavements , A section for the flexible pave- ment is given in the report. Driven pile foundations are recommended for bridges . Pile. skin friction curves for three locations are given in the report. It has been a pleasure working with you on this project. If we may be of any further assistance, please call us . Respectfully, COASTAL TESTING LABORATORY 0F � JA _Al Jasbir Sin h, E .i 42505: f • f r � c CTL-1 7 P R E F A C E The recommendations contained in this report are based on data gained from test borings at the drilling site as shown on Figure one (1 ) , a reasonable volume of laboratory tests and professional interpretation and evaluation of such data in view of the project information furnished. Soil conditions different than those described in this report may be encountered at locations other than those indicated on Figure one (1 ) or at depths greater than those as drilled. Coastal Testing Laboratory connot be responsible for such un- forseeable conditions or for recommendations which are based on inaccurate or inadequate project information furnished to us. The reproduction of this report, or any part hereof, in plans or other engineering documents supplied to persons other than the owner , should bear language indicating that the information contained therein is for general information only and not for bidding purposes and that the owner and this ; laboratory are not liable to such other persons for any representation made therein. I' i I. I' i COASTAL TESTING LABORATORY I REPORT OF FOUNDATION INVESTIGATION TEMPORARY ACCESS ROAD BAY AREA BOULEVARD ACROSS F.M. 528 FRIENDSWOOD, TEXAS TO: ENGINEERING SCIENCE , INC. 16915 EL CAMINO REAL HOUSTON, TEXAS 77058 ATTENTION : MR. D. P. GUGGEMOS , P.E. SCOPE AND PURPOSE This report presents the results of the foundation investigation made re- cently at the subject site to determine the nature and condition of sur- face and sub-surface soils as affects the design of foundations . In par- ticular; it was desirable to determine the feasibility of slab-on-ground type construction , depth to water table in various sections of the site , most suitable type and depth of structural foundations , safe soil bearing pressures and skin friction values. The investigation was made in. accordance with your instructions . EXPLORATION , SAMPLING AND FIELD TESTING Three (3) test borings to a depth of ten (10) feet and three (3) borings to COASTAL TESTING LABORATORY CTL-': - I a depth of fifty (50) feet were made at the locations shown on Figure one (1 ) . These were made with a core-drill machine using no drilling water in order to secure reliable data on ground water and sub-surface soils . Cohesive soils were sampled by pushing thin-wall steel core barrels ("Shelby tubes" ) into the natural soil at the bottom of each boring as the drilling progressed. The penetration resistance of each such undisturbed core was determined in the field using a Soiltest, Inc. field penetrometer as an aid in classification and in order to group the same for subsequent detailed tests . Samples were taken from all formations pertinent to the design of the struc- tural foundations . The Logs of Test Broings are shown on Figures fifteen (15) through twenty (20) . The definitions of symbols and abbreviations used on the logs are shown on Figure twenty-one (21 ) . LABORATORY TESTING All samples were tested to determine their natural moisture content. Typical samples of the. surface and shallow formations were tested to determine their Atterberg plasticity limits . 'Jndistur.bed cores typical of each cohesive formation likely to, have a. ,bearing on the structural foundation design were tested to determine moisture content, density and unconfined compressive strength. I - 2 - COASTAL TESTING LABORATORY CTL•1 Optimum lime content tests were made on composite samples of surface and shallow -formations using five (5) , six (6) and seven (7) percent lime. Standard Proctor and California Bearing Ratio tests were made on typical samples of the surface soils . The results of all tests are summzri.zed on Figures two (2) through twelve (12) . ENGINEERING ANALYSES The expansive potential of the surface and shallow formations was determined by comparing their natural moisture contents with the results of Atterberg limits tests . Experience has shown that plastic soils having moisture con— tents equal to or less than their plastic limits are potentially expansive, with the expansion pressure varying directly with the moisture content. On the other hand, soils having either low plasticity indices or moderate plas- ticity indices and moisture -contents -above their plastic limits are essen- tially non-expansive. Soils having high plasticity indices are subject to seasonal volume changes regardless of their existing moisture contents . Safe soil bearing pressures for cohesive formations were calculated from depth and compressive. strength , using a suitable safety factor against total dead and live load. The most suitable type and depth of foundation was determined by a review of the logs of test borings and the test results . The most suitable depth was selceted as the minimum depth below the zone of seasonal moisture �! - 3 - �' COASTAL TESTING LABORATORY fluctuations affording reasonably. uniform footing support, reasonably high safe soil bearing pressure, and adequate vertical clearance with physical features of the proposed structures . For soil conditions requiring driven pile foundations , the allowable static resistance was determined from the results of unconfined compressive tests on cohesive soil . The safe static load capacity of a pile of given length and perimeter may be determined from the skin friction curves shown on figures thirteen (13) and fourteen (14) . ' Total thickness of the flexible pavement section was determined using C.B.R. values at ninety-five (95) percent compaction . Standard design curves were used for wheel loads up to 1200 lbs . for medium to heavy traffic. However, the thickness of sub-base and base are determined from past experience in this area. SUMMARY OF RESULTS - SITE CONDITIONS The subject has varying topography. It has some low spots and sloping sur- face near creeks. In some areas the site is heavily wooded. Therefore, prior to construction the entire site should be cleaned of all vegetation and deletereous matter and shaped to provide drainage to the ex- . isting surficial soil- and, avoid any ponding of surface water. SUMMARY OF RESULTS - STRATIGRAPHY The surface formation consists of a stratum from three (3) to seven (7) feet - 4 - COASTAL TESTING LABORATORY CTL-:. in thickness of stiff dark gray silty clay and clay having plasticity indices ranging from thirty (30) to forty (40) percent. These soils are generally poorly drained and have very low C.B.R. values . This is underlain to depths of ten (10) feet to twelve (12) feet by a stratum of stiff to light gray tan clay and silty clay having plasticity indices ranging from thirty-five (35) to fifty-six (56) percent. The soil underlying the surface and shallow formations descirbed above is stiff to very stiff light gray and red clay interbedded with sandy clay seams of varying thickness . Hydrostatic water was encountered at depths from eighteen (18) to thirty- one (31 ) feet. A more detailed stratigraphy may be seen on the logs of test borings . SUMMARY OF RESULTS - RECOMMENDATIONS I SITE PREPARATION : Strip and scarify the top four (4) to six (6) inches of surface soil in all building areas to remove the organic and deletereous matter. Adequate drainage should be provided to drain off the surficial soils. Any additional fill required under floor slabs should be bank sand or a sandy select soil having maximum plasticity index of twenty (20) percent. The scarified sub- grade and all fill should be compacted at approximately optimum moisture con- tent to a minimum of ninety-five (95) percent of Standard Proctor Density (AASHO Method T-99) . COASTAL TESTING LABORATORY CTL-1: II APPROACH SLABS: It is recommended that the top six (6) inches of surficial clay soil under all the slabs areas should be stabilized using six (6) percent lime by dry weight. Compact the stabilized subgrade at approximately optimum moisture content to a minimum of ninety-five (95) percent of Standard Proctor Density (AASHO Method T-99) . III FLEXIBLE PAVEMENT: Following pavement section is recommended for this site. The total thick- ness is -based on the C.B.R. value of 4.0 percent .and for the wheel loads up to 1200 pounds. For the sub-base stabilize top ten (10) inches of the surficial clay soil using six (6) percent lime by dry weight. After adequate curing of soil lime mixture it should be compacted at approximately optimum moisture con- tent to a minimum of ninety-five (95) percent of Standard Proctor Density. (AASHO Method T-99) . Compaction should be done in not more than six (6) inch lifts . For the base provide nine (9) inches in thickness of crushed limestone or any other approved equal . Compact the base at approximately optimum moisture content to a minimum of ninety-five (95) percent of Modified Proctor Density (AASHO Method T-180) . The surface treatment should consist of a two (2) inches in thickness of hot mixed-hot laid asphaltic concrete conforming to Texas Highway Department Specifications , Item 340 , Type "D" . COASTAL TESTING LABORATOP?Y 1 IV STRUCTURAL FOUNDATIONS : (a) BRIDGES : It is recommended that the structural loads be supported on driven pile foundations . These piles should be designed for skin friction only. Load bearing capacity of the piles may be determined from the pile skin friction curves given on Figures thirteen (13) and fourteen (14) . A point on the curve at required depth should be multiplied with the effective perimeter of the pile. A safety factor of two (2) is included in the skin friction values . (b) CULVERTS : Structural loads for these type of structures may be supported on shallow spread footings founded at a depth of eight (8) to ten (10) feet. These footings should be pro- portioned for a net allowable soil bearing capacity of 4300 PSF for total dead and live loads . This includes a factor of safety of two (2) . V SLOPES : All embankments should be sloped at one to three (1 :3) , vertical to hori- zontal unless supported by earth retaining systems . These slopes should be protected from erosion by using vegetation or any other stabilizing material . COASTAL TESTING LABORATORY CT�-: LOCATIONS OF TEST BORINGS r D �G -G • D I m D F.M. 528 B-1 0 -v 0 N m D D B-2 ® v co r C fl DRAINAGE DITCH B-3 LOW SPOT B-4. _ PROPOSED BLACK HANK gL VD. B-5 J��-- C.L. CREEK -,WOODED B-6 � • I I Not to Scale COASTAL TESTING LABORATORY CTL-' Figure 1 RESULTS OF LABORATORY TESTS PROJECT:- BAY AREA BLVD. EXTENSION - - ---- - - ------------`- - COMPRESSION TEST 78-545 9-21-78 Z In a w r JOB NO.: DATE: O J Z y u �v o w N 0 0 ci F TYPE OF MATERIAL r r J W(n DRY ATTERBERG LIMITS Q a TYPE HOLE DEPTH co w w NO. BELOW MOIST DENSITY 0 FAILURE . GROUND PCF LL PL PI 1 0-2 36.7 54 19 35 1 .2 Silty clay 3-5 33.5 86 61 21 40 0.77 9.1 0 Bulge 1 .4 Silty clay B-10 35.3 82 1 .16 5.9 0 450 Shear 1 .7 Silty clay 2 0-2 41 .5 55 20 35 1 .6 Silty clay 3-5 36.5 80 66 21 45 1 .00 8.5 0 Bulge 2.2 Silty clay 8-10 29.4 2.5 Silty clay 3 0=2 34.1 61 21 40 3.8 Silty clay 3-5 32.6 85 78 24 54 3.57 6.9 0 450 Shear 3.4 silty clay 450 Shear 2.6 Silt cla 8-10 32.8 84 1 .25 3.2 0 lickensided y y --------- ------------- ----- -- -----..__..----- -- -- - 4 5 hear 13-15 30.9 91 2 .54 9,6 0 8lickensided 3.3 Clay ----------- . -� --- ---- -;- -- ------------------- ---------- -- -- -- 450 Shear m 18-20 31 .9 87 2.13 8.5 0 lickensided •8 Clay N - - -------- - ------- - --- -------------23-25 22.1 101 1 .58 10.7 0 Vertical 3.5 Sandy clay Shear 28-30 18.3 106 2.43 12.8 0 Shearple 3.5 Sandy clay 33-35 20.4 105 4.13 16.5 0 Multiple 4.5+ Sandy clay Shear CTL-G RESULTS OF LABORATORY TESTS PROJECT: BAY AREA BLVD. EXTENSION --- -- -- COMPRESSION TEST U. h W N 78-545 9-21-78 z Q w W JOB NO.: DATE: O w `n Z v `2 V in Oz o v Q TYPE OF MATERIAL w a � wv) DEPTH DRY ATTERBERG LIMITS F- ¢ TYPE m w w HOLE LE BELOW MOIST. DENSITY. "---- -- - O0 FAILURE CL GROUND PCF LL PL PI 3 38-40 25.4 96 3.25 9.6 0 Multiple 4.:5+ Clay - ---- .- - --- ------ --- S h ea r - - - - 43-45 25.0 130 3.46 9.6 0 450 Shear 2.5 Clay 48-50 26.2 94 4.87+ 3.2 0 NONE � 3.8 Clay 4 0-2 33.5 49 19 30 2.0 Silty clay 3-5 34.6 84 54 19 35 1 .57 9.1 0'. MultipleShear 2.0 Silty clay 8-10 22.8 100 1 .95, 10.1 0 Vertical 2.0 Silty sandy clay Shear 13-15 32.9 86 1 .38 4.3 0 450 Shear 2.32.3 Clay 5_18-20 28.8 91 1 .79 8.5 0 sli Shear ckensided 2.3 Clay Vertical 2.3 clay 23-25 22.4 100 1 .29 10.7 0 Shear Multiple 28-30 19.5 75 4.28 14.9 0 Shear 2.3 Clay - ------------ 33-35 24.7 98 2.99 6.9 0 450 Shear 2.5 Clay 38-40 21 .5 102 4.65 10.7 0 Multiple 4.5+ Clay fD Shear `o 43-45 17.6 4.0 Sandy clay 48-50 18.7 4.0 Sandy clay CTL-G RESULTS OF LABORATORY TESTS PROJECT:- BAY AREA BLVD. EXTENSION - - --- - --- -'--------""-` - -- COMPRESSION TEST Cew 78-545 9-21-78 z ~- JOB NO.: DATE:_ -_-- O Q Z N O v w Q w N o J F< TYPE OF MATERIAL .� win a ~ w w m Z vl HOLE DEPTH % DRY ATTERBERG LIMITS --- w Q a TYPE w w NO. BELOW MOIST DENSITY FAILURE a ce . GROUND PCF LL PL PI 5 0-2 43.8 67 22 45 1 .6 Silty clay 3-5 40.8 74 80 24 56 0.89 8.0 .0 Multiple 0.9 Silty clay Shear _ 8-10 31 .3 88 1 .70 9.6 0 450 Shear 1 .4 Silty clay 6 0-2 30.6 - 43 18 25 _ 3.0 Clay Multiple 3-5 24.2 97 58 20 38 4.19 7.5 0 Shear 4.2 Clay 8-10 21 .9 99 1_80 5.9 0 Multiple Shen 3.7 Clay - - 13-15 29.1 91 2.15 11 .7 0 450 Shear 3.3 Clay 18-20 21 .2 102 3.02 17.6 0 450 Shear 3.8 Clay 23-25 21 .6 101 2 .99 6.9 0 450 Shear 4.1 Clay 28-30 19.9 102 3.30 4.8 0 450 Shear 4.1 Clay 33-35 25.7 94 0.74 12.8 0 450 Shear 4.5 Clay - sandy clay -r, -'• -__ ---- - -- ertica 38-40 19.3 105 2.19 16.0 0 Shear •5+ Sandy clay ID - - - A 43-45 18,3 ,4 Sandy clay ----------------------------------------- --------------- -- ---------- ----------- - ----------- 48-50 17.3 109 1 .66 6.9 0 Shearcal �4 2 Sandy clay I CTL-6 OPTIMUM LIME CONTENT 1 . COMPOSITE SURFACE SAMPLE DEPTH: 0'-2' Feet MATERIAL : Dark gray silty clay Lime Liquid Plastic Plasticity Raw Content Limit Limit Index Plasticity Index 5% 55 37 18 40 6% 56 40 16 40 7% 53 39 14 40 2. COMPOSITE SAMPLE : DEPTH : 3' -5 ' MATERIAL : Gray & tan clay Lime Liquid Plastic Plasticity Raw Content Limit Limit Index Plasticity Index 5% 57 39 18 54 6% 56 39 17 56 7% 55. 42 1.3 56 I I COASTAL TESTING LABORATORY - CTL-I: Figure 5 STANDARD PROCTOR TEST Dark gray clay, slightly sandy (Sample No. 3) MAXIMUM DRY DENSITY: 89.5 PCF OPTIMUM MOISTURE : 28.8% P U_ + U + • • + e • } + F— + • • Z + W + + >— + • o + + + ' + + + + ' + 0.4 + 75 + + .+ + + + + + + + +. + + + + + + + + + + 20 MOISTURE CONTENT - PERCENT 0.8 Figure 6 STANDARD PROCTOR TEST Dark gray clay, slightly sandy (Sample No. 5) MAXIMUM DRY DENSITY : 86.7 PCF OPTIMUM MOISTURE: 29.4 U ..F I + + F- + • • ~ + • • Z + ' W + o + + .+}. • c + + • + • + • + • 0.4 + ' 75 + + + + + + + + + + + + + + + + + + + + + + 20 MOISTURE CONTENT - PERCENT 0.8 Figure 7 sSTANDARD PROCTOR TEST Dark gray clay, slightly sandy (Sample No. 4) MAXIMUM DRY DENSITY : 94'.8 PCF OPTIMUM MOISTURE 22.4% L!._ } . • U + • • + cn + z + c + • + • } + + + • + + + + • + • + + . + • + + + • 0.4 + 80 + + + + + + + + + + + + + + + + + + + + + + + 14 MOISTURE CONTENT - PERCENT 0.8 Figure 8 CALIFORNIA BEARING RATIO Sample No. 1 60 50 CBR @ 0.2" =4.0% Yd.95 H 40 w i a -yd.90 0 -H w CBR @ D'J "=3.2% CBR @ 0. 2" = 2.3% G 0 30 b ro 0 a CBR @ 0.1" =, 2.4% 20 10 0 0 .l .2 Penetration - Inches - Figure 9 CALIFORNIA BEARING RATIO Sample No. 3 60 50 yd.95 CBR @ 0.2" = 2. 9% H 40 a i • G O N R' CBR @ 0.1" = 3.4% G ° 30 b ro - '° yd.90 CBR @ 0. 2" = 1 . 7' 20 CBR @ 0.1" = 1.8% 1.0 0 0 l .2 Penetration - Inches Figure 10 CALIFORNIA BEARING RAT10 Sample No . 4 yd.95 60 Corr. CBR @ 0.2" = 4.0% 50 Corr. CBR @ 0.1" = 4.4% 40 H ' a i G 0 04 a 30 0 b W 0 a 20 yd. 90 CBR @ 0.2" = 1.2 CBR @ 0.1" = 1.2% 10 0 0 .1 , 2 Penetration - Inches Figure 11 CALIFORNIA BEARING RATIO Sample No. 5 -yd.95 60 Corr. CBR @ 0.2" = 4.I% 50 II I 40 Corr. CBR @ 0.1" = 4.3% U) I w i o yd.90 m R CBR @ 0.2" = 2.3% G 0 30 -o ro o CBR @ 0.1" = 2.4% 20 10 0 0 1 .2 Penetration - Inches Figure 12 i SKIN FRICTION PILL CURVE j; (Concrete or Treated Wood Piles) I li �! BORINGS : 3 and 4 I 0 �+ 5+ 1.0 ; i� I 20 I If , 30 'I i 40 t1 50 13.5 it i f 60 I - II .0 4 3 12 16 20 24�' UNIT St%FL LL RING CAPACITY, TONS Per-Foot Note: Multiply point on curve by effective perimeter of pile in feet (F.S . = 2) li it I --- COASTAL TESTING LABORATORY ` Figure 13 SIUN FRICTION PILE CURVE 1} (Concrete or Treated Wood Piles) li BORING: 6 . i it 0 I: • II 5 I I I 20 i I I ,{ 30 if, ia4 t ca l 40 I, i I! if 50 13.25 60 +� 4 8 12 16 20. 24 j 1 o UNIT SAFE ilrAF.I::G CAPACITY', TOMS Per-Foot I' I:ote: !Multiply point on curve by effective perimeter of pile in feet (F.S. = 2) ,I 1� - - - COASTAL TESTING LABORATORY Figure 14 LOG OF BORING PROJECT: BAY AREA BLVD. EXTENSION BORING NO: 1 FOR: ENGINEERING SCIENCE , INC. LOCATION : See Figure 1 DATE: 9-21-78 JOB N0: 78-545 ORING TYPE: 4"Auger, 2"Shelby tube DRILLER: HP REPORT NO. 7810-1 013 GROUND ELEV.: Existing LEGEND S-Shelby Tube D-Denison Barrel P-Penetration Test J-Jar I. o _ o aL !-Core ®-Penetration Sample 0-No Recovery s � z a. o ., Q-Static Water Table V-Hydrostatic Water Table > 3 0 0 > 2 ° 1 DESCRIPTION OF STRATUM o m w m Stiff dark gray silty clay Stiff light gray silty clay 5 becomes light gray & tan @ 9.0' 1 Complete @ 10.0' No Water Encountered COASTAL TESTING LABORATORY Figure 15 CTL-15 LOG OF BORING PROJECT: BAY AREA BLVD. EXTENSION BORING NO: 2 FOR: ENGINEERING SCIENCE, INC. LOCATION: See Figure 1 DATE: 9-21-78 JOB NO: 78-545 BORING TYPE: 4°AUger, 2"Shelby tube DRILLER: HP REPORT NO. 7810-1013 GROUND ELEV.Existin LEGEND ` n _` `o S-Shelby Tube D-Denison Barrel P-Penetration Test J-Jar r o L v Z o o a L ®-Core ®-Pe nefrotion Sample O-No Recovery _ w a a o LL 0-Static Water Table ®-Hydrostatic Water Table E aE 3 DESCRIPTION OF STRATUM o in U) w m Stiff dark gray silty clay Stiff gray silty clay 5 - light .gray, tan & ._red with calcareous nodules @ 8.0' 10 Complete @ 10.01 No Water Encountered COASTAL TESTING LABORATORY Figure 16 CTL-15 LOG OF BORING PROJECT: BAY AREA BLVD. EXTENSION BORING NO: 3 FOR: ENGINEERING SCIENCE , INC. LOCATION : See Figure 1 DATE: 9-21-78 JOB NO: 78-545 BORING TYPE: 4"Auger, 2°Shelby tube DRILLER: HP REPORT NO. 7810-1013 GROUND ELEV.: Existing LEGEND c , n o S-Shelby Tube D-Denison Barrel P-Penetration Teat J-Jor CL o c _ o u- '-Core ®-Penetration Sample 0-No Recovery • _ • . _• Z a o LL • Q-Static Water 'Table �-Hydrostatic Water Table 0 0 > DESCRIPTION OF . STRATUM p N h W m Very stiff dark gray silty clay Very stiff gray silty clay 5 - becoming tan @ 5.0' - light gray & tan @ 8.0' 10 \ Very sti.ff light gray & red clay 15 \ \ Stiff tan clay, becoming slickensided 20 Stiff light gray very sandy clay 30 -Stiff tan sandy clay, with silt stones-- _ - hard light gray & tan sandy clay, with silt. & 5ilt. stone 49 Hard light gray & red slightly gray clay Ld Z - very stiff light gray & tan slightly- clayey 50 Complete @ 50.0' V) Water Level @ Completion 23.0' w H 0 z COASTAL TESTING LABORATORY CTL-15 Figure 17 LOG OF BORING PROJECT: BAY AREA BLVD. EXTENSION BORING NO: 4 FOR: ENGINEERING SCIENCE, INC. LOCATION : See Figure 1 DATE: 9-21-78 Joe No: 78-545 BORING TYPE: 4"Auger, 2"Shelby tube DRILLER: HP REPORT NO. 7810-1013 GROUND ELEV.: FXistinq LEGEND n `o S-Shelby Tube D-Denison Barrel P-Penetration Test J-Jo► � a ,-Core ®-Penetration Sample O-No Recovery .t Z a ' o a o : . Q-Static Water Table V-Hydrostatic Water Table. E ccEX. o' c c N h - m DESCRIPTION OF STRATUM VWX Stiff dark gray silty clay 5 Stiff red silty sandy clay 10 Stiff tan &:-light gray clay, becoming slickensided 15 20 Stiff light gray & tan slickensided clay,becoming silty clay - encountered water @ 22.0' Stiff light gray & tan , sandy clay 30 Stiff light :gray & red slickensided clay, with silt & silt stone - hard red & light gray, slickensided clay, with silt seams Hard light gray sandy clay CD 40 ..' hard tan sandy clay w J - hard tan sandy clay, with calcareous nodules w 0 Complete @ 50.0' Water Level @ Completion. 18.0' COASTAL TESTING LABORATORY cry-ts Figure 18 LOG OF BORING PROJECT: BAY AREA BLVD. EXTENSION BORING NO: 5 FOR: ENGINEERING SCIENCE , INC. LOCATION : See Figure 1 DATE: 9-21-78 JOB NO: 78-545 BORING TYPE: 4"Auger, 2°Shelby tube DRILLER: HP REPORT NO. 7810-1013 GROUND ELEV.: Existing LEGEND f a c S-Shelby Tube D-Denison Barrel P-Penetration Test J-Jar o F- c _ c tz v-Core N-Penetration Sample -No Recovery c Z �° o . Q-Static Water Table V-Hydrostatic Water Table n > 3 o Eo aE o o DESCRIPTION OF STRATUM p N to w m Stiff dark gray silty clay - medium dark gray silty clay 5 Stiff light gray, red silty clay, with calcareous nodules 10 Complete @ 10.0' No Water Encountered COASTAL TESTING LABORATORY CTL-15 Figure 19 LOG OF BORING PROJECT: BAY AREA BLVD. EXTENSION BORING No: 6 FOR: ENGINEERING SCIENCE , INC. LOCATION : See Figure 1 DATE: 0-211-78 JOB NO: 78- 545 BORING TYPE: 4°Auger, 2°Shelby tube DRILLER: _ REPORT NO. 7810-1013 GROUND ELEV.: Existing LEGEND n `o S-Shelby Tube D-Denison Barrel P-Penstration Test J-Jar - c _ `o - u_ I-Core N-Penetration Sample O-No Recovery r � Z 0 � . D Q-Static Water 'Table V-Hydrostatic Water Table U. o o m o o DESCRIPTION OF STRATUM Stiff gray clay Hard light gray & tan clay 5 Very stiff light_.gray, 'red clay, with calcareous-nodules 10 15 - water @ 18.0' 20 Very stiff light gray, tan clay, with calcareous nodules - hard. li ht gray, tan & red clay, with c Medium red very sandy clay 30 Hard light gray & tan sandy clay W 40 Z s U 111 - calcareous nodules @ 48.0' a 50 N Complete @ 50.0' Water Level @ Completion 15.0' 0 COASTAL TESTING LABORATORY Figure 20 CTL-15 i Key to Soil Symbols and Description Used in Laboratory Logs Gravel Very i Silty Sandy Sandy Organic ! '. ;: Silt Clay Sand Silty - Silt Organic Sand a Clay _ Clayey Clayey \`. Silty Sand . Silt _ Clayey = Rock �. ;;. Clay .�., Color In color.description of sample-, the predominating color is stated first Consistency of Cohesive Soils Field Identification: Laboratory Identification: Very soft - Tall core will slump 0. - 0. 25 tsf Soft - Core can be pinched 0. 25 - 0.50 tsf Firm - Easily imprinted with fingers 0. 50 - 1. 00' tsf Stiff - Can be imprinted with finger 1 . 00 - 2. 00 tsf j Very Stiff - Can be imprinted very slightly 2. 00 - 4. 00 tsf with fingers Hard - Cannot be imprinted with fingers Over 4:00 tsf Relative Density of Cohesionless Soils Classification by Standard Penetration Resistance: Loose - 0 to 10 Blows per foot Dense - 30 to 50 Blows per ft. Med.Dense 10 to 30 Blows per foot Very Dense.- 50 and above Blows per ft. Soil Structure Slickensided - Cut.by old fracture planes which are slick and glossy. Fractured - Containing cracks, filled with various materials. Varved - Composed of thin laminae of varying color and soil types. Interbedded - Composed of alternate layers of different soil types. Calcareous - Contains deposits of calcium carbonate. COASTAL TESTING LABORATORY Figure 21