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HomeMy WebLinkAboutHORSETOOTH BUSINESS PARK - AMENDED MASTER PLAN - 78-88A - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORT• 0 REPORT OF A GEOTECIMICAL INVESTIGATION FOR PAVEMENT DESIGN COLLINS BUSINESS PARK �'lD�sE7aoirl ,B vs/"VEss PRRK COLLINS PARK VENTURE DENVER, COLORADO PRUJLCT NO. 4703-82 WA EMPIRE" LABORATORIES, INC. 214 NORTH HOWES STREET FORT COLLINS, COLORADO 80521 • 0 TAF31_E: of CONTENTS Table of Contents ........................... 6.................. I Letter of Transmittal .......................................... ll Report ................................................... 0.. 0. 0 1 Appendix A . . . . . ... ...... . ... . .... . .. ... ..... .. . .. .. .. . .... . . . . A-1 Test Boring Locatiun Plan .................................... A-2 Key to Borings..................................0............ A-3 Log of Borings ............................................... A-4 Appendix B.....................................0.4............ E3-► liveein Stabllometer Results .................................. E3-2 Summary of Test Results ..................................... 13-3 Appendix C.................................................... C-1 Empire LabOatories, Inc. MATERIALS AND FOUNDATION ENGINEERS 214 No. Howes Fort Collins, Colorado 80522 P.U. Box 429 (303) 484.0359 March 30, 1982 Collins Park Venture 1660 South Albion Street Dcnver, Colorado 80222 Attention: Mr. Phil Christensen Gentlemen: We are pleased to submit our Report of a prepared for the streets In Collins Business Purt Collins, Colorado. . Branch Offices 1242 Bramwood Place Longmont, Colorado 80501 P.O. Box 1135 1303) 776 3921 3151 Nation Way Cheyenne, Wyoming 82001 P.O. Box 10076 (307) 632 9224 Geotechnlcal Investigation Park located in southeast Based upon our findings In the subsurface, we feel that tho site Is sultable for the proposed roadway construction, providing the design criteria and recommendations set forth In this report are met. The accompanying report presents our findings In the subsurface and our recomn►clld3tions based upon these findings, Very truly yours, EMPIRE l_A[301tAT0 ES, It P e I R. Shurrud Sertlor Engineering Geologist Reviewed by: , ` t � Chester C. Smith, P.E. President clC cc:: James H. Stewart and Associates, 111c. MEMBER OF CONSULTING ENGINEERS COUNCIL REPORT OF A GEOTECHNICAL INVESTIGATION SCOPE This report presents the results of a geotechnicai evaluation prepared for the design of the proposed streets In Collins Business Park, located at the southwest corner of Horsetooth and Timberline I%'c,ads in southeast Fort Collins, Colorado. The scope of the project included trst brings and laboratory testing of samples obtained fror:i these horinils. The objectives of this study were to (1) determine they soil and groundviz,tor conditions at the site, (2) determine criteria for paverilerit dci,lyn, and (3) make recommendations regarding tho proposed street impruvcments, pavernent types, and thicknesses kit the site. SITE EXPLORATION The field exploration, carried out on March 16, 1982, consisted of drilling, logging, and sampling five (5) test borings. The locations of the test borings are shown on the Test Boring Location Plan Included in Appendix A of this report. Boring logs prepared from the field logs are shovin in Appendix A. These logs show soils encountered, location of sampling, and groundwater at the time of the exploration. The borings were Advanced with a four -inch diameter, continuous - type, puwcr-flight auger drill. During the drilling operations, a gE()technical engineer from Empire Lriboratorles, Inc. was present and made continuous observations of the soils encountered. 0 0 SITE LOCATION A14D DESCRIPTION The property Is located at the southwest corner of 11orsetooth and Tiaibe:rline Toads In southeast Fort Collins, Colorado. More particularly, the site is described as Collins Business Park, First Filing, situate in the northeast 114 of Section 31. Township 7 North, Range 68 West of the Sixth P.M., Lariner County, Colorado. The site consists of fallow farm land bordered on the north by Ijursetuoth road, on the east by Timberline Road, and on the %vest by the Union Pscific railroad. The property currently is sparsely vegetated with grass and weeds. The tract is relatively flat and has minor drainage to the east. LA801-ZATORY TESTS AND EVALUATION Samples obtained from the test borings were subjected to testing in th:: 16horatory to provide a sound basis for evaluating the physical properties of the soils encountered. Moisture contents, dry unit weights, and the Atterberg Ilinits were determined. A summary of the test results is Included In Appendix B. Hveem stabilometer tests were run to d0crailne "R" values, and curves showing these data are Included In Appendix 11. SOIL ACID GROUNDWATER CONDITIONS The: soil proflica at the site consists of strata of materials ar- ranged in diffe:reot caribinations. In order of Increasing depths, they are as follows: (1) Silt rL Topsoll: A six (6) to twelve (12) inch layer of silty to psoll was encountered in Borings 1, 3, and 5 at the surface. The upper sb. (6) inches of the topsoil has been penetrated by root growth and organic matter and should not be used for roadway $Ubgrade or as embankment inaterial. 0 • (1) Fill Haterial: A six (6) Inch layer of fill material was encountered at the surface of Boring 4 and consists of a heterogeneous mixture of slit, sand, and gravel. Six (6) Inches of gravel base and/or subbase material was encountered tit thr surface of boring 2. (3) Sandy Silty Clair; This stratum underlies the topsoil and fill and extends to the depths explored. The silty clay is plastic and contains varying amounts of sand. It varies from a brown slightly sandy silty clay to a tan to red sandy silty clay containing traces of gravel. In general, the cljy stratus► is moderately plastic and Is damp to molst in Its natural in situ condition. (4) Groundwater: At the time of the Investigation, free groundwater was encountered In Boring 5 at o depth of sever► (7) feet below the surface. No free groundwater was encountered In the remaining test borings to depths eight (8 ) feet below the surface. iliater levels in this area may be sut)ject to change due to seasonal variations and irrigation demands on and/or adjacent to the: site. RE:COlAHENDATIONS AND DISCUSSiON It Is our understanding that East Ilorsetooth lZoad is to be vilder►ed, Timberline ko:,d Is to be Improved and reconstructed, and local corninercial streets will ba built within the proposed Collins Business Pork. binied on profiles provided to us by James Il. Stewart arid Astiociates, Inc., maximum cut:, arid fills of less than two (2) feet are proprised fur all streets within the business park. Eloth rigid ai►d flexible pavement sections have been evaluated for the hrupusad structs at the site. The street design is based on the City of Fort Collins "Desicin Criteria and Standards for Streets," dated September 1961. E lghtcen (18) kip equivalent daily load applicaations for liursetouth and Timberline Roads wera provided by James 11. Stewart and -3- r Associates, Inc., and elghteen (18) kip equivalent dally load applications for the local commercial streets %vk:rc assumed by Empire Laboratories, Inc. The City of Fort Collins "Desiin Criteria and Standards for Streets," a projected eighteen (18) kip e(Itilvalent dally load application of fifty (50) for Cast Horsetooth and Timberline Roads and twenty (20) for thu local commercial streets, and an "KII value of 15 determined from Ilvuem stahlkimeter tests correlated with a "K" value of one hundred tvicitty (120) pounds per square Inch per inch were utilized for the; Pavi..'aw►t dosl�n. Site: Gradin_ea It Is re:coinrne nclod that the upper six (6) Inches of topsoil below prohused streets be stripped and stockpiled for reuse In planted areas. The existing asphalt along Timberline Road should also be removed and wasted off the sit(,. The upper six (6) Inches of the natural subgrade or e;clstii19 gravel base which may be utilized as sui;grade should be ;carifled and rccompacted at or wet of optimum molsturc to at least ninety-five percent (95%) of Standard Proctor Density ASTM D 698-78. (Sce Appendix C.) All fill should consist of on -site soils or Imported material having an "f2" value of 15 or greater and approved by the geotechnic► l engineer. Tlw fill should bc: placed In uniform six (6) to eight (8) Inch lifts and cu1,1pactcd at or wet of optimum moisture to at least ninety-five percent (95%) of Standard Proctor Density ASTM D 698-78. Finished subgrade: In cut sections should be scarified a miniriium of six (6) inches and recompactred jt or wet of optimum moisture to at icast ninety-five percent (95%) of SL.-r►darel Proctor Density ASTM D 698-78. Cut and fill slopes should be placed on grades no steeper than 2:1. Each succc;,slvL: lift of fill placed on embankinent slopes should be benched ,lightly hito the existing grado. All street subgr;ide shnuid b:2 plt.cecJ a viiiiiuuirn of three (3) fact above existingg groundwater elevations, it Is recommended that all stripping, sribgrade preparation, and till plzcc;ment be inspected by the cgeotechnical engineer. Field eiunsity tt;sts should b:j taken in the compacted subgrade and fill under 0 • the supervision of the gcotechnical engineer to ensure proper compaction. Flexible Pavement It is our opli-don that flexible pavernent Is a sultitble alternate for roadway construction at the site. The flexible pavement alternate at the site should consist of asphaltic concrete underlain by crushod aggregate base course or asphaltic concrete undr-rlaln by plant mix bituminous bjse course. Using the City of Fort Collins "Design Criteria and Standards for Streets," a serviceabliity Index of 2.5, a regional factor of 0.75, an "R" valuo of 15, a twenty (20) year design life, an eighteen (18) kip equivalent cially load application of fifty (50) for Ilorsetooth and Timberlines Roads and twenty (20) for local commercial streets, and we lghtud structural nurabcrs of 2.85 for Ilorsetooth and Timberline Roads and 2.50 for local comrnerclal streets, the following pavement thicknesses are recommended: linrsetooth and Timberline Roads Aspi►ultic Concrete 4" Crushed Aggregate Base Course: 9" Total Pavement Thickness 13" Asphaltic Concrete 3" Nla,,,t tii;c i.situminous Haso Course 41" T-t.:l rlay.�ment Thickness 71" Local Commercial Streets A sph.,ltic Concrete 3" Crushed t,g(jregzt,e (lase Cours#i 10" Total Pavement Thickness 13" -5- Asphaltic Concrete 2" Plant Wx Biturninous Cease Course 31" Total Pavement Thickness 5l" Thy crushed aggregate base course should racet City of Fort Collins Class 6 The subgrade helow the proposed asphalt paver:lent should be prepared in accordance vrlth the; recommendations dlsr eased In the "Site Criding" scalon of this repurt. Upon proper prep.iration of the subgrada, the base course should be: placed and compacted at optirium raolsture to at least ninety-eight percent (98%) of Stzridard Proctor Density ASTI.t D 698-78. (Sea Appendix C. ) It Is recommended that the asphaltic eoneretc. and/or plant nix 1)ItUl.fli,ous base bu placed in two (2) to three (3) Inch lifts. All plant taix ba!;u course and asphaltic concrete should meet City of Fort Collins specifications and should he placed in accordance with these spe:cificatioies. All base course material should have a minimum "R" value of 78, the pl;5r,t mix bituminous base should have an Rt value of 90 or greater and the asphaltic concrete should have: an Rt value of 95 or grsate:r. Fleld cicrtsity te;;;ts should be taken in the ;aggregate base, bituminous base, and asphalt undf,r the direction of the geotechnical e;nclint,:r. fiend Pavement A foasible foundaticin alternate at the site would be rigid pavement. using the elghteen (18) kip equivalent daily load applications described ijt,ove, a mudulus of subgrade reaction of one hundred twenty (120) I-jounds per-equ.iro Inch per inch Lased on an "R" value of 15, a design life of tw..rity (20) years, and a concrete design with a modulus of rupture z f five hundred fifty (550) pounds per sriusre inch, the fullOwing pav,;ric�nt thicknesses are recomme:nclud: _llursetooth and Timberline koad•; Ptcnreinforeed Concrete - 51" -6- E t call Corarierclal Streets tionreinfurcod Concrete - 41" It is recommended that bll existing asphalt along Timberline fload be rcr.ioved. The suhdrade below propcsod roadways should be prepared in ac:c:irdonce with the recormendations discussed in tho "Site: Grading" suction of this report. The concrete pay. meat should be planed directly on the subgrada that has been uniformly and properly prepared in accrirdanco with the above recommendations. All concrete used In the pavc.r.tant Shall meet ASTiA specifications, and all aggregnte shall conform to ASTM, C-33 specifications. The concrete should be designed with a mililmum modulus of rupture of five hundred fifty (550) pounds per square inch In twenty-eight (28) days. It is recommended that laboratory mix designs be cinno to determine the proper proportions of aggregate, cement, and water necessary to meet the roquirements. It is essential thvt the concrete have a low water -cement ratio, an adequate: cement factor, and sufficient quantities of entrained air. Joints should be carefully designod and constructed in accordance with the City of Fart Collins "Design Criteria and Standards for Streets" to insure good perform,ince of the pavemant. It Is r,?eoimmurided th;ct all eoncrctta pavement. be: placed Iri accordance with City of Fort Collins specifications. if paving Is done during cold weather, acceptable cold weather procedures as outlined in the City specifications should he utilized. Tho concrete pavement should be properly cured and protected In accordance with the above: shr:clfic..tions. Concrota injur_,d by frost should be reimuved and replaced. It is recommended that the pavem?nt not be opened to traffic ut+tll a flexible strength of five hundred fifty (550) pounds Per square; inch Is nbtalr,cd ix ,i inliOrnimn of fourtac:n (14) (Jays after the concrete his b+:,n GENERAL COMMENTS This rcDort has bean prepared to old In the evaluation of the propt'.M! find to the engincer in the d-:sigri of this project. In -7- • 6 the event that any changes In the design of the pavement structure are planned, the conclusions and recommendations contained in this report Will Trot he considered valid unless sald changes are reviewed arid conclusions cf this report modified or :approved in writing by Empire 1_.rhoriAorle!i, Inc., the gootechnlcal eroglnerrr of record. Every effort was made to provide comprehensive sitc, coverige throu(.11) c.rref►rl 1,)c3tirns of the test borings, while Iceoping the site Investir;ition econc,micaily feasible. Variations In soil and groundwater cot,Altlons between test borings may be Encc►untered during construction. In order to purmlt correlation between the roported subsurface rondltions anti the actur.l conditlons encountered daring crnstruction and to aid In carrying out the plane and spcclfications as originally contemplated, It Is recomme-ndod that Entire Lahorotorles, Inc, be retained to perform coittl►,tiotis co ,►traction revlcw during the excavation and foundation phi�sc s of the wc,rk. Empire Laboratories, Inc, a ,sumes no responsibility for compliance with the; rcconriend3tions Ineludcd in this report unless they/ have been rosined to perform adequate on -site construction review durin(i the course of constructir,n. -8- APPENDIX A. I TEST BORING LOCATION PLAN GoLUrls bdsi�[.x rAfK .f�4T DAr, 1 t t ,jke-,4L ✓n,r 31 -7- 68 A-2 I KEY TO BORING LOGS TOPSOIL •••�` GRAVEL ® FILL SAND & GRAVEL SILT El SILTY SAND & GRAVEL /1 CLAYEY SILT r3--:9 • oA v v COBBLES i� SANDY SILT �.o� SAND, GRAVEL & COBBLES ® CLAY M WEATHERED BEDROCK i SILTY CLAY SILTSTONE BEDROCK SANDY CLAY ® CLAYSTONE BEDROCK ElSAND El SANDSTONE BEDROCK SILTY SAND ® LIMESTONE CLAYEY SAND x GRANITE V I LILASANDY SILTY CLAY F ' SHELBY TUBE SAMPLE STANDARD PENETRATION DRIVE SAMPLER WATER TABLE 7 Days AFTER DRILLING C HOLE CAVED 5/12 Indicates that 5 blows of a 140 pound hammer falling 30 inches was required to penetrate 12 inches. A-3 0 0 LOG OF BORINGS 10 15 omm !FAA: WA •® Nor NAM A-4 EMPIRE LABORATORIES, INC. • 0 m-- 10 LOG OF BORINGS ter, EMPIRE LABORATORIES, INC. APPENDIX B. -I F- J- E f P E '15 11 L- P-5. W L r) L I I'll S V EJ- I T U RE --- I -! , , I '. .-. r t -2: C! u I, L I " , . I r! '.. i I , - - - - - . -- - - - - - I -,, . .-! I . CJ,'. 'F I L! B-2 C , O C N rN- •N C\j N C\j N . N C\j m [d a 00 O r C71 r r %.D O r Cn LO ct S U 2 m = Q C O0 v D k-0 M r c r � j �L lD lD lD lD U Q U Q U Q U Q U Q a x d N LO co m N 1� r Z' x O ct r 00 (+M U oQ co r LO to �T N p E_ r r r r r O CO M O v E ae r� M in CM Irn CM M M J J— J N W � = a h- Lu I- LL m m O _ } N(_ Q d c� C LL m N a d r yC LL a .°a oN— U LL CM 1� r p y a. O M N lD r p ' CO CC) O r O r O r O f— M O 4c1 00 I.n In lD M N r N Ln C7l O lD N N 00 O dr r r � f 00 M lD r r N r r r r r r r r N N t_ O O O O O O O O O O O O O O m ti N M 00 N M, 00 N M 00 N M N M C� p— I I I I I 1 I I 1 1 I 1 1 I O O O O O O O O . O . O . O O O . O . . r . N . r� . r . N . I— . r N r� . . c O OZ r N M Ct LO m N oU O O r� LM Ln 00 r _J Ln r LD r cf' cf r U LD M N r CO r 1 d (S O ('M Ui co M L1 i CO J r r� r L1 CM r U LD M N r lD I Q O N (2) M co r- r LD N r I J M O Ll7 O Ll M N U LD >- (M N r DO r l (Y r d Lori C!3 LLJ m ^ L1' (2) O O LD K:r LD ct (M LU J M r r M U LD M N r 117 1 d Q O _ (21 M Co 00 O 1-, ct LD 1 J r L-� L71 00 N LD U LD • M r r Ll'J 1 r Q X 111 O Z F- Z O O m r-1 N X F- O r LLJ Q ED O U F- Z F- J /--1 Z Z F+ d U U LL LM S CD LLJ in 1 Ln 1-� W Z ► + F- F- Ln a (n .. N �--1 Ln Ln Q n Ln L.L tY cz O d d d O d Q I-y J J LY J Z m J d d o CD U � d APPENDIX C. noornmry r 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 Soils 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 s.ix inches, moistened as necessary, and compacted in a manner specified below for 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 fill. Each layer shall 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 shall as nearly as practical contain the amount of moisture required for optimum compaction 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 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. 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, It pneumatic -tired rollers, three -wheel power rollers, vibratory compactors, or other approved equipment well -suited to the soil being compacted. If a sheepfoot roller is 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 D 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.