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Home My WebLink AboutTRAILS END Soil InvestigationLST Civil Engineers JAMES W. ROONE¥o P, E, MALCOLM A. MENZIES, P,E,, JAMES H. WELLMAN, P.E. R&M EN.r INEERiNG & GEOLOG'i :AL CONSULTANTS 229 EAST 51st. AVE. - P.O. BOX 608~ -- ANCHORAGE, ALASKA 99503 TELEPHONE 907-279-0483 TELEX 090'35419 Geolo.qist$ ~ Land Surveyor. · . . RALPH R. MIGLIACCI¢ " Engineering Geologist 'June' 15, 1973 R & 1Vt No. 36619 Air. William Swain' Alaska Bank Shares .'400L. Borland Drive Anchorage, Alaska Re: 99503 Subsurface S°il Investigation for Sanitary System in Trails End Subdivlsioq Anchorage, Alaska· Dear /V[r. Swalr~ We are submitting herewith results of the f{eld exploration program . and our comments regarding soil conditions encountered at subject site.· 'This investigation was performed in accordance with our discussion of June 6, 1973 and your verbal direction to proceed on June 7, 1973. Pro- cedures followed in this investigation were directed to Jde-.Pifying the major soil deposits and their characteristics in 'acco~danc'e with those requirements set out by tile Departmen~J of Environmental 'Quaiit~y and the Greater Anchorage Area Borough.. A tdtal of six teSt holes were put kiown at separate lot locations as follows: Test Hole .Block Lot 1 4 2 5 3 7 4 5 5 8 6 8 1 10 .6 10 3 The appro×ima.te locations of each test hole on 'the individual lots is shown'-on Drawing A-01, attached.' Drilling operations were accomplished utilizing a t~xlck-mounted CA4E 55 hydraulic drilling unit and 6 inch solid skezn augers. Representative samples were selected from the auger flights. These samples will be retained for a period of slx months ..for ANCHORAGE JUNEAU M~ W~liam ~ .in June 15, lP73 .Page 2 visual examination and further testing if soft'quested;' Final logs for the test borings are shown on the attached Drawings B-03 and B-04. Soil conditions encountered at the site are typ{caI of the lateral morainedeposi~:s which extend along the footslope of the Chugach 1NIountain Range. The nature and extent of this deposit has been generally described by 1Miller and Dobrovolney in the Geological Sur- vey Bulletin 1093. 'The predominant till material' ot~ this deposit has. been described as being looser in..the upper brown weathered zone, ~ransit{ort{ng 'to an underlying more dense light gray gravelly till. Random surl~{cial' deposits of peat are generally found to occupy ket- tles or low areas within abandoned-ice margin channels. The soil strata disclosed by the test holes have been iden6ified on the at!ached, boring logs. These boring records reflect the soil as identi- £-~ed in accordance with the Unifqed Soil ClasSification S. ystem' as utili- zed by. the Borough's Department of Environmental Quality. The c/assi- fications were made Visually. in the field at the time the .borings were being performed. Test Holes 2, 3 and 4 showed a tiredominance of silty, sandy gravel (GM) soils underlying a relatively thin overlay of highly organic r~,ater- iai (peat). However, Test Hole 2 did show a sl~g:',t variation' in condi- tlons having a layer of silt (ML) soll oc.curring betxv~en 'k~e depths of 1.0 and 5.0 feet. These test holes were placed within the easterly portion of the subdivision. Test Hole 6, drilled in the s0uthwesherly portion of the subdivision also showed a predominance of the cOarser· grained materials containing a fractional portion of silts and sands. Previous records derived from data supplied by the Department of' Environmental Quality indicates that in Block 2, fn~rther to the west within the subdivision, similar soil conditions were encountered on Lots 7 and 8. Test Holes 1 and 5,-located along Browder Avenue in the central portion o~ the subdivision indicated silt soils (ML) under- lying .silty sandy gravels· (GM) at depths· of.12 feet and 8 feet,, res- pectively. Also, a perched water table was found at those same depths. Groundwater observations are shown on the attached boring logs. Based on the information obtained a deeper hydrostatic ground water table was not noted in any of the. borings. However; {n order to determine actual hydrostatic ground water conditions, it would be necessary to record wa~er table readings over an extended period. R&M ENGINEERING & GEOLOGICAL CONSULTANTS irk'; William ,,S,.atain June 15, 1973': Page" 3 Further, we feel that the long term hydrostatic water table is located at considerable depth below ground surfaced'Also, it is expected thai: the perched ground 'water level will vary, depending on precipitation, topography and surface runoff conctitions. ' ' On the basis of information obtained, from the bo~ng program it is ' felt that onsite sewage disposal is feasible for this subdivision pro- vided that max{mum size systems for the soil types encountered are ut~/ized. It should be anticipated that ~equ~rements for individual lots may vary somewhat.and possibly some may be found to have 'potentially high.er seepage rates;however, these lbts should be evaluated on an indi- .v~du..al basip 'in .order to allow fo~ modif/ca~ions, With respect ot Test Holes 1 and 5, it is felt that' further testing in the area near these borings will probably result in acceptable conditions being typically found for an onsite sewage system. We appreciate being given this opportunity Go be of service to you. Should you have .any questions with regard to the above'information, please do not hesitate to contact us. · Vert truly yours, · R&M ENGINEERING & GEOLOGICAL CONSULTANTS CORRAL ! BROWDER T.H.-3 DOGGIE STROGANOF , ' AVENUE AVENUE AVENUE T.H..-2, T.H.-4 DRIVE - sTATE p.4RI¢ F-ngineering ~ Geological Consultonf~ Trails End Subdivision · LOCATION DIAGRAM Anchoro,ge Alaska l,c~,o n'r R.W It. [,~RoJ ~'~o. 36.319 o;vo ~'.'o. (~" ORGANIC MATERIAL ~ CLAY SILT SAND .GRAVEL STAND/~RD SYMBOLS COBBLES 8 BOULDERS ~ CONGLOMERATE ~ 'SANDSTONE ~ MUDSTONE ' ~ LIMESTONE St ..... 1.4'* SPLIT ·SPOON Ss....,. 1.4" SPLIT SPOON SI ..... 2.5" SPLIT SPOON · Sh ..... 2.5" SPLIT SPOON Sx ..... 2.0" SPLIT SPOON Sz ..... 1.4" SPLIT SPOON Sp ..... 2.5" SPLIT SPOON, 'Hs ..... 1.4" SPLIT SPOON HI . . . ~ · 2.5" SPLIT SPOOr '--I';'OTE: IGNEOUS ROCK METAMORPHIC ROCK ICE, MASSIVE ICE -SILT ORGANIC SILT SAMPLER TYPE' S'~MBOLS WITH 47-/~ HAMMER . '" WITH 140~ HAMMER' WITH 140~ HAMMER WITH 340~,? HAMMER WITH 1409~ HAMMER WITH 340,,~ HAMMER PUSHED DRIVEN WITH AIR HAMMER DRIVEN WITH AIR HAMMER SAMPLER TYPES.ARE .EITHER NOTED ABOVE THE BORING ~-OG SAMPLE DEPTH. SANDY SILT SILT GRADING TO SANDY SILT SANDY' GRAVEL, SCATTERED COBBLES (ROCK FRAGMENTS) INTERI:AYERED SAND 8, SANDY GRAVEL SILTY CLAY w/TR. SAND Ts .... SHELBY TUBE Tm .... MODIFIED SHELBY TuBE Pb .... PITCHER BARREL Cs .... CORE BARREL WITH SINGLE'TUBE Cd.. ;. CORE BARREL WITH DOUBLE TUBE Bs .... BULK SAMPLE A ..... AUGER SAMPLE G ..... GRAB SAMPLE OR ADJACENT TO IT AT THE RESPECTIVE TYPICAL BORING LOG DATE u~.cu...~.I 0 - 2 I- 70 All Sore pies Ss-'*"'SAMPLER TYPE ORGANIC MATERIAL I' · ICE -SILT SAMPLER TYPE%. F.f~Y~ Estimate 65% Visible Ice . . . 56.2 % CHANGE SANDY SILT Ss FROZEN GROUND Cd ;o0~ lf,; O. - ~VHILE' DRILLING,. ~.,,~APPROXII~fATE STRATA CHANGE - 12' Little toNoVisible Ice 13'-30' Vx ~ICE', DESCRIPT/ON Zt CLA..~SIFICAT/ON · 'SI. FICATION \ \ ~ DRY DENSITY ~ \ -- V/A TEl? CON TEN T ~ BLOIYSXFOOT SAMPLE NUACBER SANDY GRAVEL 95 26' SCHIST .-,.--- GENERALIZED SOll OR RO~K DESCRIPTIOll SA,;fPLE LOCATION ~ O' .-,,--- DRILL DEPTH A B-,~FTER DORING EXPLANATION OF. SELECTED SYMBOLS GLB ~ GENERAL soILs CLASSIFICATION, CdNSI~TENCY AND SYMBOLS -CLASSIFICATION: Identification and classification of ~15'~ soil is accomplished in accordance with the Unified Soil Classification System. Normally, the grain size' distribution determines classification of the soil... The soil iS defined according to major and minor constituents with the minor elements serving as modifiers of the major elements. For cohesive soils, the clay becomes the principal noun with the other major so{/constituents used as modifier; i.e. silty clay, 'when the clay particles a. re such that the clay dominates soil properties. Minor soil constituents 'may be added to the classlficat'{on breakdown in 'accordance w~th the particle Size'proportion listed below; i.e. sandy silt w/some gravel, trace clay. no call - 0 - 3% trace - 3 -.I2% some - 13 - 30% SOIL co~SIST'~.'NCY - CRITERIA: Soil consistency as defined below and determined by normal field and laboratory methods applies only to non-frozen mater~al.' Fo~ these materials, the influence of such factors as soil structure, i.e. fissure syste .ms, shrinkage cracks, slickens{des, etc., must be taken {nra consideration · in making any correlation with the consistency values listed below. In permafrost zones, the consistency and strength of frozen soils ma~ vary sign{.ficantly and ' .unexplainably with ice content, thermal regime and soil type; Cohesionless Loose N*Colows/ft) Relative Density 0- 10. 0to40% Medium Dense I0- 30 40 to 70%. Dense 30- 60 70 to 90% Very Dense - 60 90 to 100% *Stand,%rd Penetration "N": Blows per foot of . a 140-pound hammer falling 30 inches on a 2-inch OD split-spoon except where noted. DRILLING SYMBOLS Cohesive T- (tsf) · Very So'Et 0 - 0.25 Soft ~ 0.25 - 0.5 .Stiff 0.5 - !.0 Firm .l.0 - 2.0 Very Firm 2.0 -4.0 Hard .. - 4.0 WO: 'Wash Out WL: Water Level WCh Wet Cave In DCI: Dry Cave In WS: While Sampling WD: BCR: ACR: .AB: TD: While Drilling · Before Casing Removal After Casing Removal After Boring To tal Dep th .Note: Water levels indicated on. the boring logs are the levels measured in the .~oring at the times indicated. In' pervious unfrozen soils, the indicated elevations are considered to represent actual ground water conditions. In in%pervious and frozen sods, accurate determinations of ground water elevations cannot be obtained' within a l{mited..period of observation and other evidence on ground water elevations and conditions are requir.ed. ' Engineering ~ Geological Consuitont~ GLB GENERAl' NOTES B -01 .( T.H.-I 6.--11-73 ORGANIC SILT 00' I O' T.H.- 2 6-11- 7,,~' SILTY SANDY GRAVEL (GM) SANDY SILT TRACE TO SOME ' GRAVEL (TILL) (ML) 12.0' 15.0' T.D. T. H.- 3 6-11 -73 2'~)~' O.I ORGANIC MATERIAL (PEAT) · ORGANIC SILT W/SOME GRAV. SILTY SANDY GRAVEL (GM) WITH COBBLES, Dense 0.0t 1.0' 2.0' REFUSAL ON A COBBLE I~.O' No Water Table T.D. 1~'3te: Test holes extended with Auger type drilling equipment. ORGANIC MATERIAL (PEAT) SILTY 'SAND (SM) ..;)~- 0 SILTY SANDY GRAVEL (GM) SANDY GRAVELLY SILT (GM) No Water Table I 1.0' 15.0' T.D. Trails End Subdivision LOGS OF TEST HOLES Anch0r~ge Alaska R.W It J?aoJ ~JO. .35619 T. H.-4 6-11-73 T. H.-6 6-11-73 ORGANICS TRACE SILT · SANDY SILT TRACE GRAVEL (ML} SILTY SANDY GRAVEL WITH COBBLES (GM) GRAVI~LLY SAND SOME '/ SILT (GM) ~h~b No Water Table ORGANIC ,MATERIAL { PEAT) ORGANIC SILT O ,OI 5.0* 9.O" 15.O' O.OI 1.0' 2.0' T. H. - 5/j' 6 - I 1-73 ORGANIC SILT TRACE SAND - O.O SILTY SANDY GRAVEL Sl LT TRACE TO SOME SAND AND GRAVEL Dense 15,0' SILTY SANDY GRAVEL (GM) No ~,¥cter Table 15.0' T.D. Test holes extended with .Auger type drilling equipment· Pii~ [Engineering <~ Geological Consultant= Trails End Subdivision LOGS OF TEST FtOLES Anchorage Alaska jc,,~.o .7. R.V/.H. ],,,o.~. ~,o..~,~G,9 ~