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HomeMy WebLinkAbout1988-12-01 Soil Investigation Report! ' o I ^ 3^ C^^OOfLCl K’ JOB NO. X-88169 SUPPLEMENTARY SOIL INVESTIGATION SINGLE FAMILY DNELLINQ 1635 CONCORDIA STREET ORONO, MINNESOTA Betz Builders, Inc. A report prepared for MR. DAVID EISS December, 1988 SMBttKRAmAN IMOINltRIMC tORP. mmmmammRemmmmmmmmmmmmmm (>H'’S (iS N I POMox^JVm Miliiu aiM'lis. MN SStiJ ^U| I r.i\» It rs 1 rail Hurnstillt \f\SSW (M ^IO JOB NO. X-88111 TION REPORT ON SUPPLEMENTARY SOIL INVESTIGATION SINGLE FAMILY DWELLING 1635 CONCORDIA STREET ORONO,MINNESOTA Su bterranean E ngine ering Corp. performed a previou• ao 1 1 inv estig ation at this site in Se ptember, 1988. T hat inves ti gat ion revealed loose aand and soft organic soil which wa• ju d ged unsuita bl e for sup port of conventional shallow strip foot tn1• because of th e pot ential for harmful settlement. We w er e retained by Mr. Thomas Betz of Betz Builders, ac ting in beha lf of Mr. Dave Eiss to further investigate soil and ground water c onditions at two �lte rnative propo sed house locations, and to prepare a report of our findings including r ecommendation& for the foundation design and installation. ' i n €> k By -»r.«».„t ^ith the Client two (2) .tender- t..t hole, were drilled within . »-"«tr.t1on HOU., end two (2, t T within 'tanderd penetr.tlon te.t hole, were drills, -‘thin en ere. north of the prevloo . »,ole.. The field work wee performed ... .^vember ie - . truck-moonted CM2-«B drill unit T^e 1 .. . .. drllllnB end •‘••crlptlon of the e«i«,ling procedure. 1. eppended. Brewing No. 2 1e a elt. . . locetlon. In rel.tlon t * "» ‘he m,i,reietlon to outline, of the __ __ locetlon.. Surfec. el.v.tlone r *>«><»••<» houee All soil uampU, obteln.d were brought to our i k. axemlnetlon. c1.ee1fic.t1on .nd . limited fating to eld In . , Tbor.tory cherecterletlce. The eon TT Iblllty fflned for . period o [7 *>• thl. report ef" n h ^ .....................;tiT,. - --------------------- 7 *A75 Hi, , 65 h i Bo« JJJOe iS4J/ SITE AND GEQLQQY This is a lakeshore lot on the west arm of Lake Minnetonka. The surface of the lot presently is generally about 3’ to 6* above the lake level. There is an existing house on the lot, which is to be demolished. The major underlying soil type in this area is clayey glacial till related to the Oes Moines ice lobe of the Wisconsin glaciation. During the later recessional phase of the Wisconsin glaciation, layers of alluvial silt and sand were deposited over the clayey till. Post-glacial organic deposits have subsequently formed at the surface, particularly within depressional areas having no drainage outlets. According to information published by the State of Minnesota Geological Survey, the uppermost bedrock stratum under this property is believed to be either Jordan sandstone or St. Lawrence dolomite, and occurs at considerable depth below ground surface, in excess of 200*. o P: •ncount«r«d In this h« prsvIoMS tsst hols sncountsrsd In this sand or fill; smsop 11. Ins to msdlum ssnd, snd to bstwssn 13* snd IS- »srsd to bstMOsn IB* sfid I locations. Ths bisck I consldsrabls amount of IS In this uppar sand and avaraga lass than S B condition. This sand n support bacauaa of ths within and balow It. - ,r sand at th. location of taat hola oiractly balo« th. upp „q«.nc. of 3 a. and 6 1- • a-1/2* to 8* thicK a-a-P ..............n^Jiroo Of th, P..V.OU. - aspo.1t layar pr.aant at which a-a.P -.POBita vary fr«« a d r to . asrk brown sponpyi *o structuralthin layra of dark „„su1tabl. for sr. highly co«pr..aibla a support. ot occur at th. loc* taat hoia B« I lannw (llttgisl extandlng ,^sn.p dBPP«'«* , B.10W th. upp.r .BP- t,.t hol,B. IB p.,ond th, 26- to 31- t.ra.1oal P of “• r:r:.:t^ «■ - - “•*this formation varl.a irr u *1. .t taat hoi. «• 1 snd 2. to 13* -BP"*' c rr^ o Mm^ 6 The Dee Moines clayey glacial till consists primarily of grey sandy clay with traces of fine gravel throughout. Standard penetration tost values in the clay till vary between 14 and 24 blows per foot, indicative of a tough to very tough conaiatoncy. The natural moisture content of the clay till is between 17* and 21*. The Oes Moines clayey till has moderate load bearing capacity and low compressibility, and is a very good foundation 8Ub80l1. GROUND WATER COtJDITIQMS Free ground water was encountered in all S tost holes between 3-1/2’ and S’ depths, corresponding to elevations 924.3’ to 927.8’. Had the period of observation in tost holes 3 and 4 been longer the water levels would also have risen to the 926’- 928* range. The ground water level at this site ie directly related to the prevailing water level in Lake Minnetonka. At the time of our field work, the lake water elevation was 926.3’, corresponding to between 6’ and 7’ below present ground surface. The 100-year floor elevation of Lake Minnetonka is 931.6’. /i umumAmAH —/ FO Bo. K.W6 Zrl Hmnnpaia Wi 0433 \;,'v ^ A^ ti~ ••■ !' . insists primarily of ihrou9hout. Standard batwaen 14 and 24 y touph conaiatancy* is between 17* and derate load bearing ery good foundation n all 6 teat holes to elevations 924.3* In test holes 3 and 4 risen to the 926*- s directly related to ;s. At the time of our 1.3’, corresponding to lurface. The 100-year relatively light. ‘‘‘‘‘ZZZZZZZTZZ - -<«'■ —- ' ne and wae presumably supported on shallow stone foundation walls, and was p footings. It undoubtedly underwent some settlement, a d the- some significant cracKIng In the visible portion t ,„rn.r but nevertheless It apparently foundation wall. . . .one corner, but .. . . . . .. performed adequately over the years. On aegree of settlement and cracKIng would not be tolerabl. . . . . house. 6«75 H» » A5 M one story, slab-on- lith attached ;y, north of the old Foundations will be thick mortared field supported on shallow lament, and there was la portion of the theless it apparently I other hand the same be tolerable in a new TO. loc-Uon* I,... 1<» ,0... °.;r.od.TOt.» co»TO~"»- “ TO.d b..rln. ■»»“’« •" .» codV.dtim« «■- “ -or '■ .. . “Ttldn... - .on. . . . . .,Unoo. . . . . . . . . . .. . . .. corr«.«» ..„,«»o0. o. • .„oit 10 0itr.oo"tui 1000 00 ^„..lolo •»” .oooooTOO 00 ...no. TO. 00.0 ro. .00—..' ,» ooor .on. TO «».0 r«.oTO. ......OWO, „ ..TOO. .. O'... .. ..TO.....' ; to !"• ’7.* ,„o r...«. •” ““ .„.r 0....O. oon..*...'"" ...t th... .- ““ .To’^l......foundation alternative in order of our preference. G y’‘ ► ; -j ^ a.H75 H» i t PO bot MN5S432 ATternatIvft ] - This Is ths most positivs foundation solution, would result In the best building performance, and could be carried out at any time. The house and garage may be supported on driven piles that transmit the structural loads down Into the competent Inorganic Oes Moines clayey glacial till below the overlying loose sand and 4wamp deposits. If this alternative Is selected the floor slabe should be structural slabs, also supported on piles. Class B timber pi lee treated with creosote, conforming to UBC or ASTM standards for trsated piles would be suitable for this site. The piles should be Installed to achieve at least 20* of embedment Into the competent Des Moines clayey glacial till, below the overlying loose sand and compressible swamp deposits. At our test hole locatlone piles of approximately 30’ to 45’ length, measured from present grade, would be required. In general, the shorter pile length could be utilized within the northwest portion of the presently proposed building location; the longer piles will be required within the south and east portions of the building area. iV- f I The pjjos should ba driven to The sctua, design ‘ •hould bo limited to is tone, to allow T"" —elated with the slow consolida 1 !............... ^ J ■■*““■ ““ "“'lain, »m -Mn. “"•• t,- r ..................................................... ; «'•“« ...o™ ......,» ................................. ;............. *• ■ <...t '• “"«■ *-» »l... -------- • ‘-"--.H »•" to . ^ -“••• - -- “">■ ~»t. .............. t„„ W-'^y 65 Nf M,V554J2 The center-to-center pile spacing should be not less than three times the largest diameter of the piles. The elevation of each pile top should be determined immediately after It is driven, and after all piles are driven. Where heave of more than 1/4** is measured, the pile should be re-driven to its original elevation or lower. There is a distinct tendency for the ground directly adjacent to a building on piles to settle with respect to the structure. This can adversely affect sidewalks, patio slabs, etc. The grading plan for the structure, driveway and landscaped areas should conform with closely as possible to the existing grades, to minimize new fill loadings on the compressible subsoil, and reduce this tendency. Alternative 2 - Rigid Raft Foundation This alternative would be less costly than driven piles, and could be carried out almost at any time, subject only to non- freezing weather conditions. 12 Even though there would be a tendency for different parts of the structure to settle differentially, with estimated settlements of 1/2" min. to about 1-3/4" max., the structural rigidity of the raft would mitigate the uneven settlement pattern, and should result in tolerable performance of the superstructure. Furthermore areas of most settlement could potentially be raised by pressure injection of an appropriate grouting compound below the raft slab, a process commonly referred to as "mud -jacking. To prepare the site for a raft -type foundation, all obviously organic surface topsoil should be removed from the proposed building pad area, and a minimum 4' subcut should be made below design subfloor elevation. All fill should be a clean well graded sand and gravel containing less than 7% fines. It should be spread in loose lifts limited to 8" in thickness and compacted with a large smooth drum vibratory roller to achieve at least 95% Maximum Modified Proctor Dry Density, ASTM D-1557. fwfLRRA�AN i11. GsiNlriR��i _I 61i7�e5 .VE TiT PO so. 1:70! 1 M ^nrepo^. MN SS= • ‘ ‘ ■ • ••:1>'^ 11 ff•rent parts of VI 1th estimated K., the structural uneven settlement lerformance of the settlement could n of an appropriate process commonly >e foundation, all s removed from the 4» Bubcut should be il should be a clean ,s than 7* fines. It 0- In thickness and roller to achieve at ity, A8TM 0-1657. MKAS The raft-type foundation should consist of a relatively .hicK and heavily reinforced. thicKened-ed,e .ith inter^-^ .. . . . . . .- in both directions, placed over a .ini.u»^4^ thicKnees of densely compacted sand. The foundation ays em ,e designed by a structural engineer experienced in thi. type f construction. Structural loads on the subsoil under bearin, w i1. or columns should be limited to 1200 p.a.f.. “ proportionment of the widths of thicKened edges or ribs th. underside of the raft, under bearing points. 3 - rrnlnn^l surcharge- - ,M. .mr™.... r-ov.1 Of a considerable amount of fill. •'’I would also delay the * a ntha to 1 year, based on our preliminary project by at least 0 months to 1 year. pad area to compress or consolidate under a mound o weighing more than the house, then to remove the surcharge fill and support the building on shallow footings. 643! b976 Him 65 N £ PO Bom 3230$MHSS40 rrriwaii:i.i rSTiTTil IP niilWiM?] 1 Driveway Major soil correction is not necessary in the driveway area. Existing surface vegetation should be stripped and removed. The grading plan should provide for a minimum of 1-1/2* of clean sand and gravel sub-base below the pavement subgrade. Both sub­ base course fill and the aggregate base course should be compacted to 96X Maximum Modified Proctor Dry Density, A8TM D- 1667. Once the stable subgrade has been established a conventional flexible pavement design may be used. Such a design may consist of 6** compacted granular base course, overlain by a minimum 2" of hot-mix bituminous wearing surface. GENERAL The soil conditions have been established at our specific test hole locations only. Conditions between and around the borings are likely to vary, and interpolation or extrapolation of the results is not warranted. During construction all excavation, earthwork, fill placement and compaction, piling installations snd foundation and pavement installations should be monitored and tested by a Soil Engi.ieer or qualified Engineering Technician. We would be pleased to provide the necessary field engineering observation and testing services. j mmmikmMm r7 cMssMccaiwe 6.»'i 65 N£ n' tio. 3L ’J06 c*. 1 D f 'VL^ I Th« r«comm«ndat1on« contained In this raport ara Intandad aolaly for a projact of tha typa daacribad harain. In tha avant that any changaa In tha natura, daaign or location of tha houaa la plannad, tha conclualona and racommandatlona containad In thia raport ahall not ba conaldarad valid unlaaa thaaa changaa ara ravlawad, and tha conclualona of thia raport ara modiflad or varlflad In writing. Thia raport haa baan praparad for tha axclualva uaa of Mr. Oava Elaa, Batz Bulldara Inc., and thair aganta, for apacific application to a propoaad aingla family dwelling, 1635 Concordia Straat, Orono, Minnaaota In accordance with generally accepted aoll and foundation engineering practicaa. 6*75 65 Nl PO BotiOOi 55*32 t 17 The soil testing services performed by Subterranean Engineering Corp. for this project have been conducted in a manner consistent with that level of skill and cars ordinarily exercised by other members of the profession currently practicing in this area, under similar budgetary and time constraints. No other warranty, expressed or implied, is made. Submitted December 9, 198S SUBTERRANEAN ENGINEERING CORP.SUBTERRANEAN ENGINE! Geotechnical Engineer Mervyn mndessMervyn Registered Professional Engineer WEF:HM/pg Distribution: 3 cc Betz Builders, Inc. Attention: Mr. Tom Betz 1 cc Fran Feyereisen 1 cc File rf7?r ’I ^ APPENDIX DRILLING AND SAMPLING PROCEDURES _ The field work wee performed on November 16 and 29, 1988 uelng a truck-mounted CME-46B drill unit. The teat holee were advanced with 3-1/4“1.d. x 7-o.d. continuoue flight, hollow etem augers which act as a temporary casing to prevent collapse of the sides of the hole. Standard penetration tests were performed In advance of the auger tip at 2 to S foot Intervals of depth. In accordance with procedures designated 1n ASTH D-1586. In this procedure, a 2**o.d. split barrel sampler Is driven Into the soil by repeated blows of a 140 lb. weight falling 30**. Aft - an Initial set of 8", the number of blows required to drive the sampler an additional 12" Is recorded as the penetration resistance of N value (blows per foot). This value Is an Index of the relative density of cohenslonless soils (sands) and a consistency of cohesive soils (clay). In addition, thin-walled tube samples of cloy soils were obtained according to ASTM D-1587 at the depths Indicated by appropriate symbol on the boring logs. _ 6iN£—y »«>•H MN Si43J m As * a samples were obtained in the field, they were visually and manually classified by the crew chief in accordance with ASTH D’-2487 and D-2488. Representative portions of the samples were then returned to the laboratory for further examination, testing and verification of field classification. Detailed soil descriptions together with results of field and laboratory testing are given on the Borehole Logs. The capital letters represent the appropriate group symbols of the Unified Soil Classification System. A chart explaining this system 1e appended. IT' I — I (pe.rc.n.) iio.o US <1 _jli^oi. in I S-A rONTKNT (s> I l.f.0 ?S.8 UKN;?irv ------______ S8..3 •’Ki'fjfn' W'JKAUon /0|M «Aflo IfKI<1 tH5 . CltKy P'oJwL No.^OU,„„ SubUrriiiion,, S‘*‘'*o”.‘n«. «•..,,,. wcuwiNE D co«p„„s^.,„~ "V. T;,' No. I H0F r L*9*nd: Symbol: D#»criptlon: fill Symbol: D«»cription: ^ «r ^ ^ TOPSOIL SPND: Looso SAND: Modium Donso GRAOEL SILT CLRY LIMESTONE ! standard ponetraition >•tost.140 lb. hsm~ roer droppod 30" p Undisturbod thin I wall Shelby tube L_..J Depth of water at the time of dr i11io9 Notes: *' onlw. »nd «r.suDject to '/er if 1C at ion by a Land Surveyor. «»mpl.s r.cov*r.d «r. rwort.d the 109s. Abbreviations used are: Wp - natural dry density <pcf> moisture content <X> Ou ■ Unconfined compression <psf> LL PI Liquid limit Plasticity index STANDARD SYMBOLS ON BOREHOLE LOGS SUBTERRAKcAN ENGINEERING CORP. A" H C) BOREHOLE LOG BOR1N0 1 project: Single Faimilg Duelling LOCATION: 1635 Concordi^i Street CITY: Orono» Minnesotn Approx, depth to grounduiaiter: 3.5' LO00ED by: db/'MM test hole: 1 JOB NO.: X-88169 elevation: 929.8 DATE: August 3, 1988 •OIL (YTiaCLS •441TLCII nmtOLt M4ll riKLb TCtT Description TT5T M.C. X <»cf> •>K9n«ln.4 SUBTERRANEAN EN0INEER1NO CORP. •>. : BOREHOLE LOG BORING 2 PROJECT: Singl* F»mily Duelling LOCATION: 1635 Concordia Str**t CITY: Oronof Minnesota Approx- depth to groundwater: 4.5' LOGGED by: DB/'MM TEST HOLE: 2 JOB NO.: X-88169 ELEVATION: 932.2 DATE: August 17$ 1988 CLCV M»TN sou SVT1KX.S SVt»»X.S FICLS TKST MT* ♦SO- 1-4 1^4 3^4 3 •4 4.-4 3'4 3^4 I". 1^4 1^4 I-'4 I-'4 3'4 3'4 I3SCS DescrIption S^T Tt*T H«t.r.l a-,Un;on4ln.4 •low.. M N.C. X <»cf> SM Black Silty Sand Topsoil. Organic -fines. Moist to a wet. Very loose. 3 SP Brown -fine to medium Sand Wet. Loose. SH Black -fine to medium Silty Sand. Organic -fines 3 Saturated. Very loose. • SP Grey -fine to medium Sand Saturated. Loose. 9 OH Dark grey Organic Clay. A -few pieces o-f wood. 1 Highly plastic. So-f t. PT Dark brown Peat. Spongy, so-ft. Saturated. II S3 CL Grey-olive green Silty -ML Clay. Varved. Low plast. Tough. 7*13 CL Grey Sandy Clay With A Little Gravel. Medium plasticity. Tough. SUBTERRANEAN ENGINEERING CORP. BOREP •_ OC t PROJECT: Single Family Dwelling Li►C'ATIOW:1b�5 Concur dia Street CITY: Orono, Minnesota, APPVox- depth to groundwa.tet,: g LOGGED BY: DB%JD TEST HOLE: 3 AV :va Ell 'LL ,«,,,, Desc r 1 P t i On 11y , aft,," to ttm.. JIB NO.: X-88169 ELEVAT I OIJ: 932.3 DATE: November 15r 19881 •r r.. .r w•en :.r.. SM Black Silty S3.nd Topsoil. ' } Organic fines. Moist to 1 wet. Very loose. SM Brown -dark grey Silty (fine to medium Sand With i A Little i,r•avel. Wet to �s3.t��.rated below 8' I�ledium dense tq vet -y loose. r s i F , M1 i I • OL Black Organic Silty Clay. ILow Plasticity. Soft. Sm Dark grey Silty fine to �,» coarse Sand With A Little Gravel- Saturated. Medium (dense. +I I CL Gr e d Sande C la,4 With A Little Gr Avc-I . Mc dl!iR, Plasticit,-j. Tau9t,. I SUBTERPANEAN Ef4G I NEER I NG COPP. c 4 BOREHOLE LOG BORING 3 PROJECT: Single Family Dwelling LOCATION: 1635, Concordia Street CITY: Orono, Minnesota JOB NO.: X-88169 ELEVATION: 932.3 Approx. depth to 9#10undwater: 8' LOGGED BY: DB/JD TEST HOLE: 3 DATE: November 159 1988 SUBTERRANEAN ENGINEERING• CORP. 4^ J BOREHOLE LOG BORING 4 PROJECT: SiP9l* FimiilM Owviling location: 1635 Concordia Street CITY: Oronof Hlnnosota Rpprox. depth to groundwater: 7.3' LOGGED BY: DB/'JD TEST HOLE: 4 JOB NO.: X-88169 eleyation: 931.9 DATE: November ISt 1988 toil. -9 mF t'4 5* 4-A 2'A i'A 1-4 1^4 #• / /I "i 5^4 4 4 «« y >/ •or In. rmllnu*. SUBTERRANEAN ENGINEERING CORP, W4C4 Description VT T«4T H«t<«r«|9rv •»‘r*l»v • iMMrAt H.C. n (»C4< Fill, brown Sano And Gravel. Damp. Looxe. 4 OL Black Organic Silt^ Claw Topsoil. Low plasticity. j . • It SM Brown Silty Fine to med. Sand Hith A Little Gravel « Hoist. Hedium dense to loose. i 4} ( ■ OL Light grey Organic Clay. Shell Fragments. Low1plasticity. SoFt.r CL Dark brown->grey Sandy Clay. Hedium plasticity.24 StiFf. CL Grey Clay. Hedium to high“CH Plasticity. Tough.IS CL Grey Sandy Clay With A Little Gravel. Hedium plasticity. Tough to very tough. 14 14 •*ic«n«ln.4 Co«». Stranttn <44•> borehole log project : Slnale , „ BORIng 4 LOCftTION: 1635 Coo ** ®“*Hin9 7.,. --------- test HOLE: 4 BCRTm it 9 B*«crlptjon JOB NO.: X-88169 elevation: 9St.9 WTE: Nov,n,b»r ig. 1,89 »P» TE8T •Mt«n4|n»4 C«^. SUBTERr^ANEAN ENGImthRIHO C0«. k BOREHOLE LOG BORING 5 project: Single F»mily Dwelling LOCRTIOH: 1635 Concordia Street CITY: Oronoy Ninneeota Rpprox. depth to groundwater: 3.7' LOGGED by: DB-^TM TEST HOLE: 5 JOB NO.: X-88169 eleortion: 931.2 DRTE: November 29t 1988 *OlL ifnrx'! «•« rirLb TC(i mtm / • In* <on» Irw.. Black Organic Silty Sand Topsoil. Damp. Loose. Grey-black Silty Fine Sand. Slightly organic from 4*-7’. Met to saturated. Loose. Description irr air..*. «t Black Organic Clay. Some roots-wood. Medium plast. Grey Sandy Clay Uith R Little Gravel. Medium plasticity. Stiff to very tough. n.c. !« Drw Strtr>tth <».•> Rttempted Shelby tube sample at 20*. Zero recovery. SUBTERRRNERN ENGINEERING CORP. oft ►+ztempxea Shelby tube SUMP10 at 20'. Zero recovery. SUPT=RRANFAPJ FNGINEFRING CnPP, BOREHOLE LOG BORING 5 PROJECT: Single Family Dwelling LOCATION: 1b'35 Concordia Street CITY: Orono, Minnesota ` Approx. depth to grou.ndo,)a.tAr: 2' LOGGED BY: DBXTM TEST HOLE: S JOB NO.: X-88169 ELEVATION: 431.2 • « BOREHOLE LOG _ boring 6 PROJECT: Sin9l» Fsimily Duelling LOCATION: 1635 Concordia Street CITY: Oronof Minnesota Approx, depth to srounduiater: 5.4' logged by: DB.-TM TEST HOLE: « CLIV BC^TH •OIL tVTfBOLt ^»LE» Svn»JL« MELD TEfcT MTA f I WE SM OMcrlptlon Topsoil.Roots. Moist. Very loose, rated belou 5’. Loose. Sandy Clay With A Little Gravel. Medium Plasticity. So+t grey Silty -Pine Sand. Saturated. Very loose. pHjfSriirrl^L. tough. ^ JOB NO.: X-88169 ELEVATION: 933.8 DATE: November 29, 1988 ETT ieet • iMaS.'Et fc-W B.n.Uw <»f ♦> Coi». >trar>,tk <pa»> SUBTERRANEAN ENGINEERING CORP. BORING d ELEV - DEPTH 933 -1 413 BOREHOLE LOG BORING 2 1,. 2.. Sh 1,. 1�. 6 WT -3 SP SM 14 -SM T'4 ' • 1.. 6PT.: "•• yT.l 1-. 1PT.7 114 7 1�4 Vf-2 1�. CL SM .4 ' • 1.. 6PT.: I6 2-. CL a,a pT.t. 16,6 8.6 1.. SM t. pt.2 3'. SPT -7 a,{ SIP 7 • IPT•3 1-• t -a SM 1,. cPT.a 1•. 11. �+IPT.S 3.4 SP 6.5.6 ,.T.1 6.5,6 6.'516 om PT 3.6 6PT.11 CL -ML �•. SPT.. /vs /ball 1 va CL Pr o .i oc t No. X-88169 SUBTEc'RANEAN E' IG I NEER I N RP. GENERAL NOTES Descriptive Terminology CONSISTENCY TUM left Stiff T«w0h Very Teugfi N VAim 0-4 5-i 9-15 14-30 Over 30 APMOX UNCONFINfO COMFMISStON STRENGTH 0 1200 2000 4000 Over 1200 ptf 2000 ptf 4000 ptf •000 ptf •000 ptf ■ llATtVI PROPORTIONS liif Trace A little Seme With RANGE 0 - 5«/o 6 - l5«/e 16 - 30®/o 31 - 50®/o DENSITY li&M Very Leete loot# Mediwm Rente Rente Very Rente iLJflIUCf -;-4 ft-10 11-30 ^^S0 Over SO MATIRIM CLASSIFICATION TERM •oulder Cobble MeJ Courte Gravel Fine Grovel Sand Silt and Clay aii Over • incliee • — 4 incliet 4-3/t incliee • in - N* 10 eieve N® 10 sieve - N® 100 eieve Finer than 100 tieve MOISTURE DESCRIPTION DEGREE OF SATURATION Vg Dry thi«N4 Oomp Moist Wtt SoturoftP 0 1-25 25-50 50-75 75-99 too Boring Log Symbols Immediate Water Level 24 Hour Water Level !V'r--4 Loss Of Drilling Fluid Undisturbed Sample SUBTERRANEAN ENGWEERWG CXDRP. IMPORTANT INFORMATION ABOUT YOUR GEOTECHNICAL ENGINEERING REPORT More construction ,ire caused hy site subsur­ face conditions th.in any other lactor As troublesome as subsurface problems c.m U* their lrc\^uency and extent have been lessened considerably in rcxeril years, due in large measure to programs and (Hjblications of ASFt/ The Association of Engineering Firms Praeticing in the Geosciences The following suggestions and < bservations are offered to help you reduce the gt'oiechnical-related defays cost-overruns and other costly headaches that can occur during a construction pro;ect A GEOTECHNICAL ENGINEERING REPORT IS BASED ON A UNIOUE SET OF PROIECT-SPECIFIC FACTORS A gcxMechnical engin»vnng report is t.ascnl on a subsur­ face exploration filan designed to itu.orfxnate a unique set of proteci-sjHxifi* f.v:tors Thc’st' typically incluile the general nature of the struc ture involved its si/c ancf configuration the locatior of the strui-ture on the site and its orientiition [>hvsicai corn omitvints sue h as j;ccss nvjds parking lots and uri(ferground utilities, and the level of additional risk ’vhich the client assumed by virtue of limitations im|XTseci upon the exploratory program To help avc»id costly t>roolenis consult the geotechnical enginexT t(T determine how any fat t<vs which change subsequent to the date of the rc‘|KUt may affext its recommendations Unlc*ss your consulting gc*ot<s hmcal erigmct r iiuficates otherwise, tfour ^rifti\hnu ul rnjintrritui rcr i t stunihl nuf fv used • When the nature of ifie t>fofH)Scsf sirui lure is eft inged for example, if an office buiUling will tx.* erected instead of a fxirking garage or it a n triger- jtc'd '.vaiehouse will i'e built insteatl of an unre- frigeratc*d one. • when the si/e or configuration of the propt'seti strut lure is tjlterc*d • when the Itxalion cm orientatuMi of the protn-sed structure is mcKfifietf • when there is a change of ownershifv (m • for i|>|rlu atit»n to an atfiaienl site GcoR'iIrHual iTtaarctTs lUHiri'I UutTf rsf>ott'<ihlilu far (>r,il hw- uhuh may dtrelof if thru ah' nut u'Msuffo/ a/icr I'aifdrs ,,ufsi(F ereJ in their rerart s de\'t ’!,‘rnirn! tune ihanae.l MOST GEOTECHNICAl "FINDINGS ARE PROFESSIONAL ESTIMATES bile expItMatioii ufentilies at tual sulisurface londiiitMis only at those jMunts wfiere samples are taken whe n they are taken f)ata denvt'd thn tugfi sampling and suf* sequent l,ilxx.itt<rv tesfircg. ue exir irv»ljtetl Iw get>- techriicdl engineers who then render an opinion about overall subsurface conditions, their likely reaction to ptofxrscxi construction activity, and appropriate founda­ tion design Even unefer optimal circumstances actual conditions may differ hc^m those inferred to exist, Ix’cause no geotechnical engineer, no matter how qiialific-d ,md no subsurface exploration program, no m.mer how compre hensive can reveal what is hidden by earth rexic and time The actual interface between mate­ rials may be far nuMe gradual or abrupt than a report iridic.itc*s Actual cenditions in areas not sampled may differ from predictions Noffiirr^ lait he done to prevent the iinanth iruled hut i an he taken to help minimize their imraii For this reason nuxl cxtTru’Mird od'ners retain their aeateihnuai ien^iiltarh thnniah Uw .i'nstru<lion stage, to iden- tifv vanant es t oncluct .KUfilional tests which may be ncedcNl jrvl to recommend solutiims to prtrF^lems enctnintered - mi site SUBSURFACE CONDITIONS CAN CHANGE bubsurtj..c i ondilKMis ma\ U- modified by constantly- V hanging natural force's Because a gc'otechnical engi­ neering re[HMt IS basetl ('P conditions which exisltxl at the time of sut'surface exploration lonstruition decisions <hi>a!d not he luised ('ii a jccfcdrnua/ oraiMivrutg report ihlr'ijiiaiU Mian 'laiv Ivor affected (•y lime S|x*ak with the gtx>- tei hm- a! consultant to learn if additicMial te'sts ari‘ j(Kis.il»li i)e!< *re construction starts CeMistruction ope rations at or adiacent to the site and natural even is -ui h as llooxfs earthquake's m grevjnd- water llih.tuations rna\ jEo .itics t sul'surface conditions and thus the ccmlinuing adc'quaev of a geotechnical refHMt 'h- geotechnical emginevr should be kept apr'ret vl ot .inv sui fi r'venls and should l>e consulted to determine :f .nidition^.l tests arc necc'ssary GEOTECHNICAL SERVICES ARE PERFORMED FOR SPECIFIC PURPOSES AND PERSONS GcsMei hr. (.,1 1 tiginevrs repcMts ju' pic-fsaed to meet tfu' s|xv.itu. newis (*l specifu individuti s A regiorl pre- }v,jre.| ft It I ctMisulting civi! engincvr max mM fx* ade- qu.ite lor .1 umslriK tuMi conlrai lor cm even sonx' other V onsulting nvil c-tigintvr Unless indicated otherwise, the lefxMt was (irejxirisl extuc'ssly Icm the Jienl involved ari'l expresslv tor |'ur|K>s<*s indic ali'd by the client Use bv inv cMher |xrscM)s for any |Hjr|xTse or by the client for aditlereni |>urf>ose may result in fMof'lems NaiMifi- vuiuai Mer than the tluw arrlu Ihis KT<’d /'•' intended inirihy^e leitfum! firxf i .in/crnMa h iIIi the geoleihnual enginrer N.' stu'alJ arrfu f»rn rrrxvf kv airw purrece afisT than that oriainaHti onlrtni'lated n'lthoul first ionferring n'ltM the Ji'oteihnii al enaineer I ^ I I A GBOTECHNICAL ENGINEERING REPORT IS SUBIECT TO MISINTERPRETATION Costly problems can occur when other design profes ­ sionals develop their plans based on misinterpretations of a geotechnical engineering report. Tb help avoid these problems, the geotechnical engineer ^ould be retain^ to work with other appropriate design profes ­ sionals to explain relevant geotechnical findings and to review the adequacy of their plans and specifications relative to geotechnical issues BORING LOGS SHOULD NOT BE SEPARATED FROM THE ENGINEERING REPORT Final boring logs are developed by geotechnical engi­ neers based upon their interpretation of field logs (assembled by site personnel) and laboratory evaluation of field samples Only final boring logs customarily are induded in geotechnical engineering reports. Tfuse lo^ should not under any circumstances be redrawn for indusion in architectural or other design drawings, because drafters may commit errors or omissions in the transfer process Although photographic reproduction eliminates this problem. It does nothing to minimize the possibility of contractors misinterpreting the logs during bid prepara ­ tion When this occurs delays disputes and unantici­ pated costs are the all-too-frequent result Tb minimize the likelihood of boring log misinterpreta­ tion. give contractors ready access to the complete geotechnical engineering report prepared or authorized for their use Those who do not provide such access may proceed un­ der the mistaken impression that simply disclaiming re­ sponsibility for the accuracy of subsurface information always insulates them from attendant liabilltv Providing the best available information to contractors helps pre ­ vent costly construction problems and the adversarial attitudes which aggravate them to disproportionate scale READ RESPONSIBILITY CLAUSES CLOSELY Because geotechnical engineering is based extensively on judgment and opinion, it is far less exact than oth« design disciplines This situation has resulted in wholly unwarranted daims being lodged against geotechnical consultants To help prevent this problem, geotechnical engineers have developed model dauses for use in writ­ ten transmittals These are not exculpatory dauses designed to foist geotechnical engineers’ liabilities onto someone else. Rather, they are definitive dauses which identify where geotechnical engineers’ responsibilities begin and end Their use helps all parties Involved rec­ ognize their individual responsibilities and take appro ­ priate action Some of the^ definitive dauses are likely to appear in your geotechnical engineering report, and you are encouraged to read them dosely. \bur geo ­ technical engineer will be pleased to give full and frank answers to your questions OTHER STEPS YOU CAN TAKE TO REDUCE RISK Vbur consulting geotechhka '*neer .vill be pleased to discuss other techniques wf • be employed to mit­ igate risk In addition. ASTL ».».s iieveloped a variety of materials which may be b^.ieficial. Contact ASFE for a complimentary copy of itS publications directory Published by INI ASSOCIA1ION OFHieiNiaiNGRIMI FtAcnctHe M INI etoioeicis 8811 Colesville Road/Suite C 106/Silver Spring. Maryland 20910/(301) 565-2733 I I my o o CLASSIFICATION OF SOILS FOR ENGINEERING PURPOSES ASTM OMiflnction: D 2417 > 66 T AND D 2486 - 66 T iSti^22ii£IS2iiiSJ^a»^2Sfc 4 Ma|«r dl«Mon« I S HIIII In fl i-MII3 iiill III III 1 u II I HliA Ore«ip •ymbolt GW Typical name* Wall-pradad pravaU. pravalcand mlKturai. Unit or no finat Poorly gtaCyd O'avali. prtval- tand miMtura*, litlla or no fine* Silly pravali, graval-Mnd-aili miaturaa !l s li* MH aayay gravalt. praval iand-clay miMiurat Laboralery alalliallow criiarto I I I iS I «>»{ 85 J oTuI a 13 fi Wall-sradad tandt. gravally •anda. litila or no finat Poorly gradad undi. gravally •andi. litlla or no finaa Silty aandt. aand-ailt miMiurat Gayay aanda. und-clay mia- twraa inorganic liitt and vary fina aat>da. rock flour, ailty or clay- ay fina aanda or clayay tilii aaith alight plaaticlty Inorganic ciaya of low lo ma- dium plaaticiiy, gravally clayi. aondy daya. ailty ciaya, laan daya Organic ailta and organic wily c aya of low plaaticlty Inorganic ailta. micacaoua or diatomacaoua fina aandy or ailty aoila alaatic ailta Inorganic daya of high plaa- ticity. fat ciaya Organic daya of madium to high plaaticity, organic ailta Paat and olhar highly organic aoila H y l! lit ; • !l»hI ill iriiiiIll's £>ao tOft* Cu«^~graatar than 4; baaaaaaai 1 and 3 Net maating all gradation raquiramanta for GW Atlarbarg limitabalow "A** line or P.l. laaa than 4 Abova **A” lina aaHh P.I. batwaan 4 and 7 ora bor«> darf/na eoaaa raqulring waa of dual aymbolaAttarbarg llmita abova "A" lirta with P.l. graatar than 7 O«o (Oiot^ c„. — .h„ ft 1 M 3 Not maating all gradation raquiramanta for SW Attarbarg linuta below "A" lina or P.l laaa than 4 Limita ptotilng in hatthad tor>a with P.l. batwaan 4 and 7 ara bord^Unt mtm raquit. ' ^ of dual tym- bolt.Attarbarg limita abova *‘A” lina with P.l. graatar than 7 1 1 1 1 1 For clanlflcation of fma-graii Milt ar«d fina fraction of com __gralnad aoila. Attarbarg Limita plotting hatchad araa ara bordarlirta di ficationt raqulrlrtg uaa of d __ aymbola. Md raa* y 1 N\In nai- kial CM / / Eo'• ation rl-0.7 of A-lli 3 ILL w: 20) / / a* /r OH ar 3 MH CL / / :LMii SP' y / ML ai dOL Liquid Limit Pfaailcitv Chan TUBtERRA^EAN ENGINEERING CORP. m