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HomeMy WebLinkAboutINDIAN HILLS WEST PUD - Filed GR-GEOTECHNICAL REPORT/SOILS REPORT - (2)Empire Laboratories, hia, $ranch Offices 1242 Bramwood Place MATERIALS AND FOUNDATION ENGINEERS Longmont, Colorado 80501 P.O. Box 1135 214 No. Howes Fort Collins, Colorado•,80522 (303> 776-3921 P;O. Box 429 (303) 484-0359 3151 Nation WayFe6wxtrVt$o 1979 Cheyenne, Wyoming 82001 P.O. Box 16076 307) 632.9224 d d Lo Siva +rd Ae.6oa4e F04 C * Cott 5#534 We ed t u&ate R -ad a .SULU 'Fdr uu a/ mWGeotatnse6tdgatton m 60A the p40¢,d Uwtd 4A . 4#4ut Fob Coo , Co do. Wed - upon oux RaddV4 U the A' Uh zgc dev va Jed 4kt the 4" t4U {ea a wutudt,4on, - pA6WA&4 the da64a a ka 6a& ad aa$ Q NE1L SHERRDD 10 2575 NRSdawtad ® .` RiWaftId bys 1r; a11u egyrr Ce ftfoi- F. Q 480 a o o N OOCI. q O % : • rs 4 0 p®oa FNt? & Poo o -, A oe000000 P 04ar MEMBER OF CONSULTING ENGINEERS COUNCIL REPORT ' Of A SOILS ANO FOUNDATION AND ttOLOGIC .° HVESTIGATIOPi SCOPE This report presents the results ®f a soils and foundation and geologic investigat on.prepared for the.Indian Hills West Subdivision., " located one Stuart Street in northeast Fort Col -lies, Colorado.. The investigation was carried out by means of test borings.and laboratory testing of samples obtained from.these borings. The obJectives of this investigation were to (1) determine the* suitability of the. :site. for construction 'purposes, (2) make ream ndaft tions regarding''the design of the ,substructures, (3) recommend certain precautions.which; should=be taken because of adverse soil and/or ground- water conditions, and (4)°.determine the 06.Iogic:`chir'acteristics-of the site. SITE INVESTIGATION The 'field' investigation carried out ;on February 14, 19790, consisted og.drilling, logging, and sampling eight (8) test borings. The locations of the .test borings are shown on the Test Boring location. Plan included in -Appendix A of this'report. Baring logs prepared from the field logs are shown.in Appendix.A. 'These logs show soils encountered, location of sampling;., and groundwater at'tile time of the, investigation. . All borings were advanced with -a four -inch diameter, continuous`,. type, power -flight. , auger drill. During tine dri t ,l i rng operations, an. engineering geologist from Empire.Labor atories, Inc. was present.snd made a.coatinuous visual -inspection of -the soils encountered. SIT> 4 TION 0 RIPTiON The' proposed sits is boated 'on. Stuart' Street. east.'of Bush Court end west; of. -S ver :street in Fort Collihss Colorado. More particelariy the site is desariied as Indian -Hills West a.subdiVision situate in'the no hWest ll4'.`of Section Zap Township•9 North, Range 89 West of the Sixth P.M.'j °fort Collins, Colorado. The majoelty pf the site ,consists of the Sunset drive-in Theater. The .theater ''consisti-of a. large 4ravel -parking area a large timber screen.structurmp'a masonry block concession stand, and a'sm$11 ticket booth. Much,of the crest and.east-property,lines are bordered with trees andshrubs The Arthur Ditch form the south property line. The south one- third (1/3) of the property consists of an open, grass -covered field. A row of high juniper trees is located near.the west property line fin the southeast corner of the —site. The southern portion of the property slopes gently to moderately to the northwest. The minder of the site is relatively flat -and has minor drainage to the.north. Spring Creek is located west and north of the site, and the flood plain of the stream.crosses._th.e northern portion of the tract. The property is surrounded by.rresidential housing. LABORATORY TESTS AND EXAMINATION samples obtained from the test borings were subjected to testing_ and inspection in the laboratory to provide a sound basis for determining the physical properties of the soils encountered.. Moisture contents, dry unit weights, unconfined compressive strengths, water soluble sulfates, swelling potentials, and the Atterberg limits were determined. A summary of the test results is included in Appendix B. Consolidation characteristics were also determined, and curves showing this data are included. in.Appehdix S. 1) Silty Topsoil and Fill Material: The southern portion -of the site is overlain by .:a. one (1) .foot layer of sil-ty topsoil. The upper six (6) inches of the topsoil have been penetrated by plant roots and organic matter and -should not be.used as bearing soil or as backfial material. One and one -half OAO to three and one-half -(3) feet of fill was encountered in Borings 1, 2, and 3. The fill consists -of a mixture of silty clay, sandy silty clay, and gravel and has been placed during site grading of the theater area.. 2) Sander Silty Clay: The clay stratum underlies the topsoil and fill. and extends to depths.five (5} to greater than fourteen and one-half 0%) feet below the. surface The silty clay is, plastic, contains varying.amounts of sand'and traces of gravel,. and exhibits moderate bearing characteristics in its damp to moist natural state. When wetted,'the.clay exhibits slight swelling potarrtials,.and upon. loading, .,consolidation occurs. 3) Sand and gravel:- The gravel stratum was encountered below the clay in Borings 1, 2, 3,.and 4 and extends to.depths thirteen 13) to greater than fourteen and one-half ('94) feet below the.surface. The sand and gravel contains. minor amounts of' silt,,.is poorly graded, and exhibits moderate to high bearing characteristics in its medium dense to dense in situ con- dition, 4) ,Siltstone.(Bedrock): The bedrock was encountered.in Boring l at a depth thirteen.(13) feet below the surface and extends to greater depths. The upper one (1) foot of. -the siltstone is w 4a highly weathered; !waver, the underlying rock is firm and exhibits. very high bearing characteristics. S) fr2gag tat!er: At the time of the investigation. free grounch ter was encountered in Borings 1, 2. and 3 at depths five (6) to eight (R) feet below the surface. No free groundtiater was encountered in, the remfmiming test borings. hater levels In this area are subject to change due to seasonal variations, irrigation -demands on and adjacent to the site, and the flan i n Spri ng a Greet, c ti ch . i s adjacent to the property. REC ENDATIONS AND DISCUSSION It is our understanding that single-family toWn houses are -proposed for the site. Tennis courts are proposed along,the west property line in the enter of the property. In viers of the topography,, a moderate amount of site grading is anticipated. Gee., l The proposed development is located within the Colorado piedmont section of the Groat .Plains physiographic.provinee. The Colorado Piedmont, formed during late Tertiary and Early quaternary time (approximately 66 million years ago), is.a broad, erosional trench which separates the Southern Rocky Mountains from the High Plains. Structurally, the project area lies.along the western flank of the Denver Basin. During the Late sozoic 'end Early. Cenozoic Periods (approximately 70 millon years ago), intense tectonic.'apti-vity occurred, causing the. uplifting of to Front Range and the associated dommarping of the Denver Basin to the east. Relatively flat uplands and broad valleys characterize the present-day topography of the Colorado Pies nt in this region. The site is under-.. lain by the Cretaceous Pierre Formation. The bedrock is overlain by alluvial grants and pediment deposits of Pleistocene and Rat Age. d 116 bedrock outcrops were encountered at the site. Bedrock was ncvuntsred 3n the northwest canner of the proIMrq' at a depth thirteen 13) feet, below the surfues and 7t is anticipated that it underlies the reminder ..of the site approximately fifteen (16) to, twenty-five (25). feet flow the surface. 1e "regional dip of tM bedrock In this'arm is a few .degrdes to the east, ON to the relatively flat to gently .sloping tqwgraphy of the site® no geologic hazards caused by mass covement due to gravity are anticipated. The northern portion of the site lies Within 03 dn3 haftdM6 year flood plain of Spring C kg and the extreme nortMmst cernar of the site lies within the flood waY Of the aka lb construction should be undertaken.in the,flood,ways, and the finished first 00006 of, al l structures built within the ' ono hundred year food plain of the steam should be elevated eighteen. (18) inches above the one hundred year flood plain elevation.. with proper site grading around all structures, no erosioml problum we anticipated. it is suggested that site grading be done such that theme is only liwAted cutting along the south prop3rty lie ad a pt to the Arthur Ditch. This will help prevveant-seepage through tjwdifthe Sim jEadins'and Utilities Proposed grading of the site i ndi tes that foaunftti ons and/or slabs on grade in portions of the site will ' W founded an eight (8) inches or more of fill. Since tyre will ba building ?oundations resting an filled orowtd &_ Wor th6 septa of M11 lulu floor slabs in portions of the site tjJ11' exceed that permitted by the Minim ftgMCjX n s , fill Pl4cennt.should to . oarri ed out In accordance with FRA 130ata Shoat 796.1 speefflettions pertaining to site grading are Included below and in Appendix C of this reporte it is rewmmWad that -the upper six (6) inns of all topsoil telow filled and paw arms tag stripped and stockpi 1 ed for rem 4n pleated areas. Alt,t s,,.limbs, brushe existing structures• and other debris should also be rewad& r. The Upper six (B) ' inches of all subgrade below filled areas should be scarified and recompacted two percent (2S) wet of optima moisture to at least ninety-five percent (95S) of Standard Proctor Density ASTM D.698-70. (See Appendix C.) The upper one -(I) foot of existing fill should.be scarified and recompacted two percent 2S) wet of optimum moisture to -at least ninety-five percent (90.) of Standard Proctor Density ASTM.D.698-70. All fill should consist of the on -site soils or imported material. approved by the soils engineer. The fill should be placed in uniform st-k (6) to eight (8) inch lifts: Because of the expansive nature of the subsoils., all'fill-.should be compacted two percent (2S) wet.of optima moisture to at least ninety- five -percent (95%) of Standard-Proctor.Densily ASTM D.698-70 for stability. All cut and fill slopes should -be designed on grades no steeper than 3t10 it is recommended that cutting along the south property line adjacent to the Arthur'Ditch not exceed one (i).to two (2) feet so that seepage from the ditch will be minimized. All utility trenches excavated four (4) or more feet in depth should be placed on,shopes no steeper than 10'.' If this is not practical, shoring of the excavation will be .required. All utility trenches dug.. below groundwater should be dewatered during construction to insure proper placement of piping and' backfilLL. All piping should _be bedded to insure proper load distribution and to eliminate breakage during back - filling operations. All backfill placed in utility trenches in open and planted areas should be compacted in uniform rifts at optimum moisture to at least ninety percent (90%) of Standard Proctor Density ASTM D 698770 the full depth of the trench. The"upper four (4)-feet of backfill placed in uti1l.ty trenches under roadways. and paved areas should be compacted at or near optimum moisture to it least ninety-five percent (95%) of Standard Proctor Density ASTM D-698-70,.and the_lowe.r portion of.these trenches should be compacted to at least ninety.percent (90%) of Standard Proctor Density..ASTM V 698-70. Addition. ofr Moisture and/or drying of the subsoils may be required to assure proper compaction. All stripping, grubbing,subgrade preparation, and fill placement should be done under continuous,observetion of the soils engineer., Field density tests should be taken daily in the compacted subgrad®, fill, and backfill under thedir tion'of the soils engineer. Foundations In view of the loads. transmitted by the proposed construction and the soil conditions encountered at the site, it is recommended that the structures -be supported by conventional -type spread footings and/or continuous grade beams. All footings -and/or continuous grade beam should be founded on the original undisturbed soil or on the structural fill placed in accordance with- the recommendations discussed in the Site Grading" section of this report. The identification and undis- turbed nature of the soil as well as the structural integrity of the fill should be -verified by'an experienced soils engineer prior to place," went of any foundation concrete .It is recommended that.density tests be tzken'under the direction of the -soils engineer in all footing excava- tions founded on fill to insure a minimum compaction of ninety-five percent (95%) of Standard Proctor Density. ASV 0 698-70: Footings and/or grade beams founded at.the above level May be designed for a maximum allowable bearing capacity of two thousand (20000) pounds per square foot (dead load plus maxi n live load). 10 counteract swelling pressures, which will develop 1 f the subsoils become wetted., all footings and/or grade beams should be designed for a minimum dead load of five hundred (500) pounds per square foot. The predicted settlement under the above maximum loading, as determined by-.;labbratory consolidation tests, should be less than 0.50 Inch, generally considered to be within acceptable tolerances. Basements and Slabs on Grade Basement.construction is feasible over the majority of the site* providing the finished basement oo slabs.ara placed a minimum of three (3) feet, above ,existing' groundwator. Due to the shallow depth to groundwater in the northern portion of the site in the area of Borings l and 2, basement construction is not feasible in this area. 'It is recow mended that garden -level, crawl -spaces or slab -on -grade construction be w9.. utilized in this area. All 'lower garden -level slabss.lower crawl -space elevations, and slabs on grade should be placed a minimum of three (3), feet above existing groundwater..levels. The finished first floor eleva- tions in this arda should be placed a,minimum of eighteen (18) inches above the one hundred year flood plain elevation of Spring Creek, as is discussed in the "Geology" section of this report. The existing,solls encountered near the surface at the site are adequate for supporting, normal floor loads., The upper six (6) inches of topsoil should be:.removed from within the limits of the structures. Fill material supporting slabs on grade should be constructed in accordance with the recommendations discussed in the "Site Grading" section, All slabs on grade should be underlain by a minimum of four (4) inches of gravel or crushed rock devoid of fines. The gravel layer will act as a,capillary break and will.help.to distribute floor loads. It 1s.recommended that all -slabs on grade be.'designed structurally independent of all bearing members. To minimize and control shrinkage cracks which will develop in slabs on grade, it is suggested.that con- trol joints be placed every fifteen (15) to twenty (20) feet and that the total area contained within these joints be no greater than four hundred (400) square feet. Tennis Courts and Paved Areas. All grading for the proposed tennis courts should be done in accordance with the recommendations set forth in this report in the "Site Grading° section. All fill should be placed in uniform lifts compacted two percent (2%).wet of optimum.moisture to at least*nine.tyfive percent 95%) of Stand ard.Pro ctor Density'ASTM D 69840. (See Appendix C.) The upper six (6) inches'of the subgrade below the paved courts in cut sections should be scarified and recompacted slightly wet of optimum moisture to at least ninety-five percent (95%) of Standard Proctor Density'ASTM D 698-70. The paved -courts should be underlain by at least six (6) Inches of crushed gravel base course meeting the specifications discussed below in the section.entitled "Paved Areas,." The gravel base course will act as a capillary -break -and leveling course. The base r w course -should be compacted at'optimum moisture to at least ninety-five percent (gat) of Standard Proctor.0ensity ASTH 0 698-70. It is suggested that the tennis courts be paved with a six (6) inch thick reinforced Concrete slab.or equivalent asphalticconcrete surface.: Good positive. drainage should be provided on the court surfaces. Positive drainage should also -be provided away from the courts on all sides, it is recommended• that len percent (10%) for the -first ten (10) feet away from. the courts be provided. Paved Areas The soils were classified and group indexes Were determined at various locations within the site.for the purpose of developing criteria for pavement design. Group indexes of the upper clay soils at the site grange from 3;S to 9.5. Using these as criteria for pavement design,, it is recommended that pavement thicknesses for the project be as follows: Passenger Car Parking and'DriVeways; Select Gravel Base Course 4" Asphaltic Concrete 2" Total Pavement Thickness 6" Streets Select Gravel Base .Course, 5" Asphaltic Concrete 2i' Total Pavement Thickness 7" All topsoil, organic matter, and other unsuitable material should be removed from the parking and. street areas. All subgrade should be scarified - a minimum of six (6) inches and recompacted to at least ninety percent ( 90%) of Standard Proctor Density ASTM. D.'698-70 (See Appendix Additional fill material placed in the parking and street areas should bean approved, granular -type material compacted at or near optimum moisture to at least ninety-five percent (95t).'of Standard Proctor Density AS'11<1 0 6.98-70. The surface of the subgrade should be hard, vniform,'smooth,, and true to grade. To prevent the growth of weeds, '.it, is suggested that all subgrade under parking areas be treated with a soil sterilant. The base course overlying the subgrade should consist of a hard, durables -crushed reef or stone and filler and should have a minimum C.B.R. value of.80,. The composite base coarse material should be free from vegetable matter and lumps or balls of clay and should meet the City of Fort Collins Specification Class-6.Aggragate Base Course which follows:~ Sieve Size % Passing 90-100 3/4" r7tY'L 4 30-65 10 20-55' 20t? 50:1 Liquid Limit • 25, Maximum Plasticity'Index 5 Maximum The'base course should be placed on the sabgrade at or near optimum moisture and compacted to at least ninety. -five percent (95%) of Standard Proctor Wnsfty AS174 0 698-70. It is.important that the base course be shaped -to grade so that proper drainage of the -parking area 1s obtained, GENERAL -RECOMENDATIONS 1) laboratory test results indicate that rater soluble sulfates in.the soil are positive. A Type II cement should.,be used in all, concrete exposed to subsoils 10- 2) Finished grade should be -sloped away from'the structures on all sides.to giveoposl Live drainage. Ten percent (10%) for the first ten'(10) feet away from the structures is the suggested slope, 3) Backfill around the outside perimeter of the structures should be mechanically compacted at optimum moisture to at least ninety percent (90%) of Standard Proctor Density ASTM D 698-70. (See Appendix C.) Puddling should not be permitted: as a method of compaction. 4). -Gutters and downspouts should be designed to carry roof runoff water well beyond the backfill area. 5) Underground sprinkling systems should not be installed within ten (10) feet of the structures, and this recommendation should be taken into account in the landscape planning. 6} Footing and/or:'grade beam sixes should.be proportioned to equalize the unit loads applied to.the soil and thus minimize' differential settlements. 7). It is recommended that all compaction requirements specified herein be verified in the field with density tests performed under the supervision of an experienced.soils engineer.- 8) it is recommended that a registered professional' engineer design the substructures and that he take into account the findings and recommendations of this report. GENERAL COMMENTS This report has-been prepared to aid in the evaluation of the puroperty'and to assist the architect and/or engineer in the design of this project. In the event that any changes in the design of the- struc.tures or,their1ocations..are. planneds the.conciusions.and recon-. mendations contained'in this .report.will not bo:considered valid unless said changes are reviewed and conclusions of this report modified or approved in writing by Empire Laboratories, Inc., the soils engineer of record. Every effort was made to provide comprehensive site coverage through careful locations of the test borings, while keeping the,site investigationeconomically feasiblee,,Variat'ions in.soil .anO groundwater conditions between tost borings.may be encountered during construction. In . order to permit correlation., between the ,reported subsurface con- ditions and the actual conditions encountered during construction and to aid in carrying out the plans and specifications as originally con- templated, it is recommended .that Empire Laboratories,.Inc. be retained to perform continuous construction review'during the excavation and foundation phases of the work. Empire Laboratories, Inc. assumes no responsibility for compliance with the'rrecommendationsA ncluded in this report unless they have been retained to -perform adequate ors -sate. construction review oaring the.course of construction, 1 2- APPENDIX A. KEY TO BORING LOGS 7 TOPSOIL GRAVEL FILL SAND & GRAVEL SILT ie SILTY SAND & GRAVEL CLAYEY SILT 1s4 COBBLES i . SANDY SILT SAND, GRAVEL & COBBLES CLAY WEATHERED BEDROCK i SILTY CLAY SILTSTONE BEDROCK SANDY CLAY CLAYSTONE BEDROCK SAND SANDSTONE BEDROCK i.'. SILTY SAND LIMESTONE CLAYEY SAND a x tax GRANITE SANDY SILTY CLAY SHELBY TUBE SAMPLE STANDARD PENETRATION DRIVE SAMPLER WATER TABLE 24 HOURS AFTER DRILLING C HOLECAVE.D T 5/12 Indicates that 5 blows of a 140 pound hammer failing 30 inches was required to penetrate 12 inches. A-3 FMPIRF LARORATORIFS INC 65 e e o Q. 2 2 60 TgM SnikP in Assume tPlPnhnna,plP at cniithwps,t prnnart,v rnrnar_ - Plpvatinn Inn-n'_ A4 EMPIRE LABORATORIES, INC. APPENDLX B. 11 I Mll 0 a- 0 48 45 U. I to APPLIED PRESSURE—TONS/SCE.. FT. cm W Z a 0 B-4 z= U, N N cm N N N N N N_ Q'.Z gm ui H j O Ch O O F-- to W LU tflp OW f]C;Q W N J W V N H Z Ln F— p W W Q C C) C)O F• p C) Co . N Cil tCVp Q O Z Z N N r r lC! Ix6LLL. O ZN r m uj a W N co Imo. WU. LJ CO co C) C)tD as r- O r ON p r a. w Ix Ln M N M co M p LO LO LO Ln Lo CD O O O O O O CD O O aH N M co M cf- w m Cn U) LO Co M I 1 1 1 1 11 1 i 1 1. 1 1 1 . UJ - Ln Lf7 Lo O C> O O Lo O O C) O O C) LO r N f'- N M f-' CO M lV M d Lo f_, CO M pZ m. B=5 Z,W px U Q.Z N N N N N N W3 O CM 01 n N Z 0 N W am I W to gmW J. 3 N N J W W u ti Z CC . a Ui IV2tA W CD_O O CD Lfw M r N U. ZW Q OImZNN O ZN Q cd Q ul W. t O N O ui a N CD O a O W LO I Ln u i O O 1 C) Ln O O In N Cl N f coMr— W 0 O O 1.f') u'y lf) O M 00 M t-- f 7 ZZ co m B-6 SUMMARY OF TEST RESULTS Swelling Pressures_ Boring Depth. Moisture Dry Density Swelling Number Ft..) Before. Test PCF Pressure PSF 4 1.5-2.5 9.5 112.4 875 6 2.0-3.0 9.4 87.8 160 7 7.0-8.0 5.9 115.7 520 8 1.5-2.5 6.3 95.8 500 Atterberg Summ4ry Boring Number 1 @ 4 @ 8 @ and Depth_ 2.0-3.0 1.5-2.5 1.5-2.5 Liquid Limit 31.5. 29.0 25.6 Plastic Limit 17.8 16.5 16.0 Plasticity Index 13.7 12.5 9.7 Passing #200 Sieve. 78.2 52.7. 52.5 Group Index 9.5 4.5 3.5 Classification Unified CL CL CL AASHTO A-6(10) A-6(5) A-4(4) B-7 APPENDIX C. APPENDIX C. Suggested Specifications for Placement of Compacted Earth Fill and/or Backfills. GENERAL A soils engineer shall be on -site to provide continuous observation during filling and grading operations and shall be the owner's repre- sentative to inspect placement of all compacted fill and/or backfill on the project. The soils engineer shall approve all earth materials prior to their use, the methods of placing,, and the degree of compaction obtained. MATERIALS Souls used for all compacted fill and backfill shall be approved by the soils engineer prior to their use. the upper two (2) feet.of compacted earth backfill placed adjacent to exterior foundation walls.shall be an, impervious, nonexpansive material. No material, including rock,.having a maximum dimension greater than six inches shall be placed in any fill. Any fill.containing rock should be carefully mixed to avoid nesting and creation of voids. In no case shall frozen material be used as'a fill and/or backfill material. PREPARATION OF SUBGRADE All topsoil, vegetation (including trees and..brush), timber, debris, rubbish, and other unsuitable material shall be'removed to a depth satisfactory to the soils engineer and disposed of by.suitable means before beginning preparation of the subgrade. The subgrade surface of the area to. be.filled shall be scarified a minimum depth of six inches, moistened a's necessary, and compacted in a manner specified,below for C-2 the subsequent layers of fill. Fill shall not be placed on frozen or muddy ground. PLACING FILL No sod, brush, frozen or thawing material, or other unsuitable material shall be placed in the fill, and .no fill shall be placed during unfavorable weather conditions. All clods shall be broken into small pieces, and distribution of material in the fill shall be such as to preclude the formation of lenses of material differing from the surrounding material. The materials shall be delivered to and spread on the fill surface in a manner which will result in a uniformly compacted.fi'l.l Each layer- shalT-be thoroughly blade mixed during spreading to insure uniformity of.. _ material and moisture in each layer. Prior to compacting, each layer shall have a maximum thickness of eight inches, and its upper surface shall be approximately horizontal. Each successive.6" to 8".lift of fill being placed on slopes or hillsides should be benched into the . existing slopes, providing good bond between the.fill and existing ground. MOISTURE CONTROL While being compacted, the fill material in each.layer shal I as nearly as practical contain the amount of moisture required for optimum com paction or as specified, and the moisture.shall be uniform throughout the fill. The contractor may be. required to add necessary moisture to the fill.material and to uniformly mix the water with the fill material if, in the opinion of the soils engineer, it is not possible to obtain uniform moisture content by adding water on the fill surface.. If, in. F the opinion of the soils engineer; the material proposed for use in the, - compacted.fill is too wet to permit adequate compaction, it shall be dried in an acceptable manner prior to placement and compaction. c_ COMPACTION When an acceptable, uniform moisture content is obtained, each layer shall be compacted by a method acceptable to the soils engineer and as specified in the foregoing report as determined by applicable standards. Compaction shall be performed by rolling with approved.tamping rollers,, pneumatic -tired rollers, three -wheel power rollers, vibratory compactors, or other approved equipment well -suited to the soil being compacted. If a sheepfoot roller it used, it shall be provided with cleaner bars attached in a manner which will prevent the accumulation of material between the tamper feet. The rollers should be designed so. that effective weight can be increased. MOISTURE: -DENSITY DETERMINATION Samples of representative fill materials to be placed shall be furnished by the contractor -to the soils engineer for determination of maximum density and optimum moisture or percent of Relative Density for these materials. Tests for this determination will'be made using methods conforming to requirements of ASTM D 698, ASTM D 1557, or ASTM D 2049. Copies of the results of these tests will be furnished to the owner, the project engineer, and the contractor. These test results shall be the basis of control for all compaction effort. DENSITY TESTS The density and moisture content of each layer of compacted fill will be determined by the -soils engineer in accordance with ASTM D 1556, ASTM V. 2167, or ASTM D 2922. Any material found not to comply with the minimum specified density.=shall be recompacted until the required density is obtained. Sufficient density tests shall be made and submitted to support the soils engineer's recommendations. The results of density tests will also be furnished to -the owner, the project engineer, and the contractor by the soils engineer. C-4