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HomeMy WebLinkAboutARROWHEAD COTTAGES - MJA/FDP - FDP160004 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORT (5)August 7, 2009 Everitt Companies 3003 E. Harmony, Suite 400 Fort Collins, Colorado 80528 Attn: Mr. Stan Everitt Re: Subsurface Exploration Addendum Report Residential High Rise Condominium Project Centre for Advanced Technology P.U.D. - 7th Filing Fort Collins, Colorado EEC Project No. 1082101 Mr. Everitt: Earth Engineering Consultants, Inc. (EEC) personnel conducted a subsurface exploration study for -tile proposed residential high rise condominium project within the Centre for Advanced Technology P.U.D. — 7th Filing development in Fort Collins, Colorado in October of 2008, and prepared a report detailing our findings and geotechnical engineering design recommendations based on the subsurface conditions encountered. For further information, please refer to our "Subsurface Exploration Repart" dated October 13, 2008, and an Addendum Report dated April 21, 2009, EEC Project No. 1082101. We understand this project involves the construction of three (3) residential "high-rise" condominium structures and associated pavement areas, planned for construction at the northeast corner of Centre Avenue and Worthington Circle on Tracts A and C of the Centre for Advanced Technologies - 7th Filing. The residential buildings will be 4-story structures, including at-graiRe parking with 3 levels of residential units above. Foundation loads for the structures are expected to be moderate with continuous wall loads up to 5 kips per lineal foot and individual column loads up to about 250 kips. Floor loads are expected to be light to moderate. A detention pond is planned for development adjacent to the northwestern most building as shown on the enclosed site diagram. A design concept for the detention pond is to maximize the allotted space available versus deepening the pond to achieve the desired storage/detention necessary and use the building",s foundation as the limit/boundary of the pond. 4396 GREENFIELD DRIVE WINDSOR, COLORADO 80550 (970) 545-3908 FAX (970) 663-0282 Earth Engineering Consultants, I i Nc EEC Project No. 1082101 August 7, 2009 Page 2 EEC has been requested to provide supplemental geotechnical engineering recommendations to assist the structural engineer to design a combined foundation wall/pond edge system to allow for this type of construction. Critical issues with this type of concept include the possible development of hydrostatic pressures, the foundation wall, potentially saturated soils as the backfill zone a.nd infiltration of water impacting the underlying foundation bearing stratum increasing the possibility of differential movement across the building footprint. As a part of this supplemental evaluattua, EEC personnel explored the site with three (3) additional test borings drilled at the general locations as shown on the enclosed site diagram and performed additional laboratory testing services including direct shear testing to determine the internal friction angle of the site soils in drained and. saturated conditions. Enclosed herewith, are the results of our supplemental subsurface exploration for the referenced project. This supplemental exploration was completed in general accordance with our proposal dated July 7, 2009, SUPPLEMENTAL EXPLORATION AND TESTING PROCEDURES As part of this supplemental study, three (3) additional borings, identified as B-5, B-6, and B-7, were located around the perimeter of the northwestern most building within areas accessible to our drilling equipment. These supplemental borings were extended to approximate depths of 24 to 25-1/2­1'eet below existing site grades. The approximate drilling locations are shown on the enclosed. site diagram, Figure No. 1. Samples of the subsurface materials encountered were obtained using split barrel and California barrel sampling procedures. In the split barrel and California barrel sampling procedures, standard sampling spoons are advanced into the ground by means of a standard 140-pound hammer falling a distance of 30 inches, The number of blows (i.e., N-blows per foot as part of the Standard Penetration Testing protocol), required to advance the split barrel and California barrel samplers is recorded and is used to estimate the in -situ relative density of cohesionless soils and, to a lesser degree of accuracy, the consistency of cohesive soils and hardness of weathered bedrock. In the California barrel sampling procedure, relatively undisturbed samples are obtained in removable brass liners. All samples obtained in the field were sealed and returned to the laboratory for further examination, classification, and testing. Moisture content tests were completed on each of the recovered samples. Selected soil sainples were tested for in -situ dry density, unconfined compressive strength, swell -consolidation and/or Earth Engineering Consultants, hic. EEC Project No. 1082 101 August 7, 2009 Page 3 volume change characteristics, plasticity, and grain size distribution. A representative composite sample of the overburden soils was tested for moisture -density relationship/standard Proctor density (ASTM D698) and direct shear characteristics (ASTM D3080). Results of the outlined tests ary shown on the attached boring logs and presented on the laboratory summary sheets. As part of the testing program, all samples were examined in the laboratory by an enginee�ir md classified in accordance with the attached General Notes and the Unified Soil Classification System, based on the soil's texture and plasticity. The estimated group symbol for the Unified Soil Classification System is indicated on the boring logs and a brief description of that classificati011 system is included with this report. SUBSURFACE SOIL AND GROUNDWATER CONDITIONS The subsurface conditions generally consisted of the following. Native, essentially cohesive subsoils, classified as sandy lean clay, lean clay, and clayey sand were encountered beneath the surficial topsoil/vegetative layer, and extended to the depths explored or to the course granular stratum below. In soil borings B-6 and B-7 course clayey sand and/or silty sand with gravel strata, were encountered beneath the upper cohesive materials and extended to the depths explored, approximately 25-feet below site grades. At the time of drilling, free water was observed in -the supplemental soil borings .13-5 through B-7 �tt approximate depths of 9 to 11-feet below site grades. Hand slotted 1-1/2-inch diameter PVC casings/piezometers were installed in each of the supplemental borings to allow for subsequerit groundwater measurement. When checked several days after drilling, groundwater was measured. in borings B-5 through B-7 at approximate depths of 7-1/2 to 10- 1 /2-feet below site grades. Moisture Density Relationship -Standard Proctor Density EEC personnel completed a standard Proctor density (ASTM Specification D698) test on a composite overburden sample and also performed a soil classification (Atterberg Limits and MillUS No. 200 sieve analysis) evaluation on a representative portion of that sample. The results of tl,ie standard Proctor density tests, ASTM D698, for the representative overburden material are presented below and are also included at the conclusion of this report. Earth Engineering Consultants, Nc. EEC Project No. 1082101 August 7, 2009 Page 4 SUMMARY OF LABORATORY COMPACTION CHARACTERISITCS AND CLASSIFIATION OF SOILS Standard Proctor Density Soil Classification Sample ID Optimum Moisture Content, % Maximum Dry Density, PCF Liquid Limit Plastic Index % (-) No. 200 Sieve Description Overburden Subsoils 14.0 117.0 31 13 46.5 Clayey Sand —(C'L) Note: (1) The soil classification for the composite sample, which may have incorporated portions tu1.. the fine granular soils at increased depths, classified as a CLAYEY SAND due to the % (-) No.. 200 sieve of less than 50%. The majority of the overburden soils generally consisted of Sandy Lean Clay (CL) with an approximate % (-) No. 200 Sieve greater than 50%. Direct Shear Strength Tests Two direct shear tests, in general accordance with ASTM D3080, were performed on representativcc samples of the overburden soils by Advanced Terra Testing of Denver, Colorado. The first sample. was remolded to approximately 95% of the material's standard Proctor maximum dry density (ASTM D698) at approximately 4 to 5% above optimum moisture content to simulate essentially saturated conditions which could occur with the detention pond adjacent to the proposed northwestern most structure. The second sample was also remolded to approximately 95% of the material's standard Proctor maximum dry density (ASTM D698) however was adjusted in moisture content to at or near optimum moisture content to simulate "typical construction procedures" f(a)r placing and compacting earthen embankment material in a drained condition. Each direct shear test was conducted with three (3) passes at approximate loading schemes of Z/2 ton per square foot (tsf), 1-tsf, and 2-tsf to determine the internal friction angle and cohesion characteristics of the on -site; overburden soils. Laboratory test results are presented in the table below and graphs are included at the conclusion of this report. SUMMARY OF LABORATORY DIRECT SHEAR TEST RESULTS tl) Sample ID Internal Friction Angle Cohesion, PSF (2) Average Percent Compaction (3) Approxintattp. 1Yloistiire Different�i�aV Normal Stress vs. Peak Shear Stress Normal Stress vs. Ultimate Shear Stress Normal Stress vs. Peak Shear Stress Normal Stress vs. Ultimate Shear Stress 1 29.8 29.8 175.5 163.0 95 (+) 4.5% 2 32.5 32.4 72.5 72.5 95 (+) 0.6 (1) Sample ID No.1 — assumed a saturated state to simulate conditions which could occur with the adjacent detention pond. Sample ID No.2 — assumed typical earthwork construction protocol with the sample remolded to approximately 95% of the material's standard Proctor density value ai oar near optimum moisture content. Earth Engineering Consultants, lnc. EEC Project No. 1.082101 August 7, 2009 Page 5 (2) The percent compaction is based on the overburden material's standard Proctor density results of 117.0 PCF. (3) The approximate moisture percent differential is based on the overburden material's standard Proctor density results having an optimum moisture content of 14.0%. For purposes of evaluating the on -site soils and providing design parameters to the project°s structural engineer, we estimate an approximate internal friction angle of about 28 degrees for the in -place essentially saturated cohesive soils, and an internal friction angle of 32 degrees for the mi site cohesive soils placed to at least 95% standard Proctor maximum dry density and maintained in a drained state. Swell — Consolidation Test Results The swell -consolidation test is performed to evaluate the swell or collapse potential of soils for determining geotechnical engineering design criteria. For this project relatively undisturbed) overburden soil samples were placed in a laboratory apparatus and inundated with water under a dead load of 500 ps£ The sample was inundated with water and monitored for swell and consolidation, The swell -index is the resulting amount of swell or collapse as a percent of the sample's thickness after the inundation period. After the inundation period additional incremental loads are applied do evaluate the swell pressure and consolidation. For this assessment, we conducted one (1) swell -consolidation tests on a relatively undisturbed soil sample obtained from soil boring B-6 at an approximate depth of 4-feet below site grades. The swel I index value for the sample tested at approximately 500 psf inundation pressure was approximately (-) 1.0%, which indicated a slight potential to consolidated when inundated with water and increased. loads are applied. Colorado Association of Geotechnical Engineers (CAGE) uses the following information to provide uniformity in terminology between geotechnical engineers to provide a relative correlation of slab performance risk to measured swell. "The representative percent swell values are not necessarily measured values; rather, they are a judgment of the swell of the soil profile likely to influence slab performance." Geotechnical engineers use this information to also evaluate the swell potential risks for foundation performance based on the risk categories. Earth Engineering Consultants, Ine, EEC Project No. 1082101 August 7, 2009 Page 6 Recommended Representative Swell Potential Descriptions and Corresponding Slab Performance Risk Categories Slab Performance Risk Category Representative Percent Swell (500 psf Surcharge) Representative Percent Swell (1000 psf Surcharge) Low 0 < 3 0 < 2 Moderate 3 to < 5 2 to < 4 .... High 5 to < 8 ._ _...... 4 to < 6 Very High > 8 > 6 Based on the laboratory test results, the remolded existing embankment cohesive material generally revealed low expansive potential. ANALYSIS AND RECOMMENDATIONS Foundations In our report of October 13, 2008, we provided recommendations for support of the proposed condominium structures on spread footing foundations bearing on a zone of approved engineered fill material. With this addendum report, we are providing additional recommendations for design of the foundations adjacent to the detention pond. At this time, believe the previously provided recommendations concerning support of footing foundations for the remainder of the structures are appropriate. Attached with this report is a schematic diagram of the anticipated section of the building foundation adjacent to the detention pond area illustrating our understanding and supplementall design concepts. The schematic indicates the support of this portion of the building on a footing foundation. We are providing with this report design criteria for support of the structure in this area on footing foundation being on a zone of structural fill. As outlined for the remainder of the buildings, we recommend the footing foundation in the area adjacent to the detention pond be supported on at least three (3) feet of newly placed and compacted structural fill. Overexcavation for placement of the structural fill should extend at least three (3) feet below foundation bearing and should extend at least eight (8) inches beyond the edges of the foundations for each 12 inches of structural fill placed beneath the footing. We recommend tl`le structural fill material consist of essentially granular material containing sufficient finds to prevent ponding of water in the backfill soils. The backfill materials should be placed in maximum nine (9) Earth Engineering Consultants, Inc. EEC Project No. 1082 101 August 7, 2009 Page 7 inch thick loose lifts, adjusted in moisture content to ± 3% of standard Proctor optimum moisture content and compacted to at least 98% of standard Proctor maximum dry density as determined in accordance with ASTM Specification D-698, the standard Proctor procedure. The outlined steps for preparation of the bearing materials will reduce but not eliminate potential liar some movement/settlement with consolidation of underlying soils. Overexcavation of a gre�ater depth of material could be considered to further reduce potential for post -construction settlement, Preloading or surcharge loading could also be used to reduce future settlement. Conventional footing foundations could be supported directly on the structural backfill solls, prepared as outlined above. For support of footing foundations bearing on at least three (3) feet of imported granular structural fill compacted to at least 98% of standard Proctor maximum dry density, we recommend using a net allowable total load soil bearing pressure not to exceed 2,500 psf. The net bearing pressure refers to the pressure at foundation bearing level in excess of the minimum surrounding overburden pressure. Total load should include fall dead and live loads, We recommend continuous wall footings have a minimum width of at least 16 inches and isolated pad foundations have minimum dimensions of at least 24 inches. Based on the structural loads provided, we anticipate larger footings sizes will be needed to accommodate actual foundation load requirements. Footings should be proportioned to reduce differential foundation movement. �Ve estimate total foundation settlements from the assumed structural loads to be on the order of one (1) inch. Differential movement could be on the order of 1/2 to 3/4of the total estimated movement. Foundation excavations should be observed by the geotechnical engineer. If soil conditions encountered differ significantly from those presented in this report, supplemental recommendations may be required. Lateral Earth Pressures The foundation walls adjacent to the detention pond will be subject to unbalanced lateral ealth pressures outward from the building. Those pressures may be resisted through passive earth, pressures, friction at the base of the footing and a tic back or counterfort system to reduce the potential for lateral deflection of the walls under the lateral loads. We recommend the walls, be designed for at -rest lateral earth pressures where rotation of the wall is restrained. Earth Engineering Consultants, hc. EEC Project No. 1082 101 August 7, 2009 Page 8 Coefficient values for backfill with at -rest and passive earth pressures are provided in Table 1, Horizontal pressures are equal to appropriate unit soil weight times the appropriate lateral '-.artli pressure coefficient. We have based the provided values on an internal friction angle of 28' assuming saturated conditions for the subgrade materials. We recommend use of buoyant unit weights in conjunction with the passive resistant values. Significant slopes on the detention pond away from the wall would reduce the passive resistance for the backfill, materials below the values provided in Table I. TABLE I — Recommended Soil Design Values Design Parameter Sandy Lean Clay/Clay Sand Subgrade/backrill Wet Unit Weight (y,) 125 pcf Saturated Unit Weight (y,) 135 pcf Buoyant Unit Weight (7b) 72 pcf Angle of Internal Friction (y) 28' At -Rest Lateral Pressure Coefficient (ko) 0.53 Passive Lateral Pressure Coefficient (kp) 2.77 We recommend care be taken to prevent the development of unbalanced hydrostatic loads orl, the below grade wall. Use of a drainage blanket with an outfall could be considered for the interior of the wall to prevent development of unbalanced hydrostatic loads outward of the building. TlIat system would include placement of at least 12 inches of free draining granular fill behind the foundation wall for the full height between the top of the footing and the bottom of the interior floor. A drain system to allow free drainage of water from behind the wall would be required. A, filter fabric should be placed between the subgrade soil and the granular fill. Use of preformed drain material could also be considered. The outlined lateral earth pressure values do not include a factor safety nor an allowance for hydrostatic loads. Surcharge loads placed in the backfill including floor loads or point loads placed in the backfill can create additional loads on below grade walls. Backfill adjacent to the walls should be compacted to densities as recommended in the previmtsly provided geotechnical engineering report. The existing cohesive soils are slightly to mediw-n plastic. Compaction of the materials should be accomplished with hand operated tampers or other light weight compactors. Over compaction of materials may cause excessive lateral earth pressures which could result in wall movement. Earth Engineering Consultants, Inc, EEC Project No. 1082101 August 7, 2009 Page 9 GENERAL COMMENTS The analysis and recommendations presented in this report are based upon the data obtained frorn ffie soil borings performed at the indicated locations and from any other information discussed in this report. This report does not reflect any variations which may occur between borings or across the site. The nature and extent of such variations may not become evident until further exploration or construction I"r variations appear evident, it will be necessary to re-evaluate the recommendations of this report. It is recommended that the geotechnical engineer be retained to review the plans and specifications so comments can be made regarding the interpretation and implementation of our geotechrrlical recommendations in the design and specifications. It is further recommended that the geotechnical engineer be retained for testing and observations during earthwork construction phases to help determine that the design requirements are fulfilled. This report has been prepared for the exclusive use of Everitt Companies for specific application to the project discussed and has been prepared in accordance with generally accepted geotechnical engineev'ing practices. No warranty, express or implied, is made. In the event that any changes in the nature, design, or location of the project as outlined in this report are planned, the conclusions and recommendations contained in this report shall not be considered valid unless the changes are reviewed and the conclusions of this report are modified or verified in writing by the geotechnical engineer. We appreciate the opportunity to be of service to you on this project. If you have any .questions concerning this report, or if we can be of further service to you in any other way, please do not he°spate to contact us. Very truly yours, Earth Engineering Consultants, Inc. Lester L. Litton, P.E. Principal Engineer Reviewed by: David A. Richer, P.E. Senior Project Engineer DRILLING AND EXPLORATION DRILLING & SAMPLING SYMBOLS: SS: Split Spoon - 13/8" I.D., 2" O.D., unless otherwise noted PS: Piston Sample ST: Thin -Walled Tube - 2" O.D., unless otherwise noted WS: Wash Sample R: Ring Barrel Sampler - 2.42" I..D., 3" O.D. unless otherwise noted PA: Power Auger FT: Fish Tail Bit HA: Hand Auger RB: Rock Bit DB: Diamond Bit = 4", N, B BS: Bulk Sample AS: Auger Sample PM: Pressure Meter HS: Hollow Stem Auger WB: Wash Bore Standard "N" Penetration: Blows per foot of a 140 pound hammer failing 30 inches on a 2-inch O.D. split spoon, except where r ot:ed, WATER LEVEL MEASUREMENT SYMBOLS: WL : Water Level WS : While Sampling WCI: Wet Cave .in WD : While Drilling DCI: Dry Cave in BCR: Before Casing Removal AB : After Baring ACR: After Casting Removal Water levels indicated on the boring logs are the levels measured in the borings at the time indicated. In pervious soils, tile u2dicaaied levels may reflect the location of ground water. In low permeability soils, the accurate determination of ground water levels is no, possible with only short term observations. DESCRIPTIVE SOIL CLASSIFICATION Soil Classification is based on the Unified Soil Classification system and the ASTM Designations D-2488. Coarse Grained Soils have move than 50% of their dry weight retained on a 9200 sieve; they are described as: boulders, cobbles, gravel or sand. Fine Grained Soils have less than 50% of their dry weight retained on a #200 sieve; they are described as : clays, if they are plastic, and silts if they are slightly plastic or non -plastic. Major constituents may be added as modifiers and minor constituents may be added according to the relative proportions based on grain size. In addition to gradation, coarse grained soils are defined on the basis of their relative in -place density and fine grained soils on the basis of their consistency. Example: Lean clay with sand, trace gravel, stiff (CL); silty sand, trace gravel, medium dense (SM). CONSISTENCY OF FINE-GRAINED SOILS Unconfined Compressive Strength, Qu, psf Consistency 500 Very Soft 500 - 1,000 Soft 1,001 - 2,000 Medium 2,001 - 4,000 Stiff 4,001 - 8,000 Very Stiff 8,001 - 16,000 Very Hard RELATIVE DENSITY OF COARSE -GRAINED SOILS: N-Blows/ft Relative Density 0-3 Very Loose 4-9 Loose 10-29 Medium Dense 30-49 Dense 50-80 Very Dense 80 + Extremely Dense PHYSICAL PROPERTIES OF BEDROCK. DEGREE OF WEATHERING: Slight Slight decomposition of parent material on joints. May be color change. Moderate Some decomposition and t:,olor change throughout. High Rock highly decomposed, may be extreme.i,y broken. HARDNESS AND DEGREE OF CEMENTATUON: Limestone and Dolomite: Hard Difficult to scratch with knife. Moderately Can be scratched easily with knife. Hard Cannot be scratched with fingernail. Soft Can be scratched with fingernail. Shale, Siltstone and Claystone: Hard Can be scratched easily with knife, cannot be scratched with fingernail. Moderately Can be scratched with fingernail. Hard Soft Can be easily dented but not molded a�rftla fingers. Sandstone and Conglomerate: Well Capable of scratching a knife blade. Cemented Cemented Can be scratched with knife. Poorly Can be broken apart easily with fingers, Cemented U�,RFITED ��OIL ----- -- -- - CFj Group Nom,S CriIsrio fur 4,iqning Group Symbols and Group nomes Using LcIporotory Tests Colirse-Grained Gravels more than Ciatin Grovels Less Sails more than !30% of coarse than 5% fines Cu>4 and WPM -tjccidt,�d qr,ovcT 500 retained on fraction retained — - . .. .... . . ..... -- No. 200 sieve on No. 4 sieve Cu <4 and/or 1>Cc>3£ CP Pocfly-grodcH qnr l'a,Cl — ----- --- - - Gravels with Fines Fines classify as ML or MH GM Silly grovI more than 12% fines Fines classify as CL. or CH GC C'Iayey C�Vel --- --- . .. . . ............... Sands 50% or Clean Sands Loss Cu:?-6 rind 1<C-c:53E SIN Wr'! I (I a d ,,, d s 1,( I MOM coarse then 5% fines fr'action posses Cu<6 and/or 1>Cr>3' sond, No. 4 sieve Sands with Fines Fines classify as ML or VH Sp, SRY more than 12% - - - - - - ------------------- - ............... SCI I-Ine-Grolned 'Ats and Clays inorganic PI>7 and plots an or above *A"Line' CL Leon cloy fines Fines, classify as Cl- or CH Soils % or Liquid Limit less - — - - - --------- ----- more pLii;ieq the than A PI<4 or plots below ML Sit t 04 LN Nor 200 sieve ......... . ... ot genic Liquid Limit riven dried ci,,JYUAK Liquid Limit not dried Organic silt, 111JA"D Sills and Clays inorganic PI plots on or above "A Lane,._,...._, GI Fat ckly`o Liquid Limit 50 or more Fit plots below "A'Une organic Liquid Unnit oven dried Oigurlic cloy'"" Liquid Limit not dried Oigank:: siftuW,O Highly organic soils Primarily organic rnott,--r, dark in color, and organic odor P IPro" — ----- - ---- . ...... . .. Ab--scA on the a,itertol p,,,,,tjing the 3-i., (75- X ptn� 200, odil frim) Cu-0,s/D, Cc= tanil -)rtu�n% 29pkAur 91 "with send' �Vr ")lQN6" NhbAewr N f rlu-ld ampie c.ItoinPd -bblLs or boulders, tirdominoril- w both. add %,itln w,wbbftox Ku' boulders, or both* elf sad C.nto'OS o :50' pi,I& tv o. 200 to group n e- rif sail contains 215% sand, add'wIth sond'Lo woo-ni.=,11y sward, arld ',uwly in: gru,,P 191U. 5 to 12X Irq.ired dual nr-e. Sr group ric'na. I T sA �aotoiris -�- 30,'� plus 200 GM .61 graded �ith �4illt ©p Rnes classify cis CL-ML, u%�, duol syrnbal predonlinantly "Ild "yuvf,�Y` r, 9-up CAI X-CM, or SC-$M. GC WrJI-4,Ude4 qm,ct wql, Cloy "If F."� bm organic, add'with organic Knes-to nerna. GP -GM psiorly-grod,d qru-A with ulit "PI;,4 and pla�% o. r 'A' �kAl- with cloy 'if =A contains >L5%grn,ef, odd"wiLh gravel' ;C poorly-qmded gro" group name 'PI<4 or iflo", Urhjw 'A* lino, 0��arids with .5 to 127 ti�,,,I% require dual Pi plots on or otwre 'A" bare.-.. to group nam N., aPI plots heluoi "A- lim, 'if Atterb-9 limits plots shaded are., soO is S,W-Sm ell-grnocci sv.xnj with silt GL-ML, cilty clay. -Sr well-gi-nded -nd with cloy SM Poorly qrod-1 nord with silt poorly graded sand with cloy I L "I auaslr-tlua 0 d fl—q,uiucd lt-ti- of so FX.1k, .1 11- ttarr:ontor of U- PI 73 (LL-20) f 'u'-11- Q31 Ve,Lkml al LL.15 is PI.7 to " Ll✓- U) - < 20MH aR OH 1L qa 0 L LL 7, LIQUID LIMIT (LQ 20 to g to 2, � 10 Cl) cu mac .O u CO C) (114 0 rh� n.- V) 6 z D < Lu 6:5 to LL > U-i Cl 0. 0 LU IUJ ly F - z I. CAT 7TH FILING - CONDO DEVELOPMENT FORT COLLINS, COLORADO PROJECT NO: 1082101 DATE: JULY 2009 LOG OF BORING B-5 (PIEZOMETER) RIG TYPE: CME45 SHEET 1 OF I WATER DEPTH FOREMAN: DG START DATE 7/20/2009 WHILE DRILLING 91 AUGER TYPE: 4"CFA FINISH DATE 7120/2009 7/22/2009 ........... 8.2' SPT HAMMER: MANUAL SURFACE ELEV NIA 124 HOUR WA SOIL DESCRIPTION TYPE D N (FEET) (BLOWSIFT) ou (PSF) MG Do (PCF) A -LIMITS -200 SWELL ----F F- LL P1 PRESSURE %@ SOD PSF VEGETATION AND TOPSOIL SANDY CLAY (CL) brown, red stiff with scattered gravel CS SS SS with intermittent send and gravel seams CS 1SS SS Ess SS 1 2 3 4 5 14 6 8 7 3 8 9 3 10 1 — 11 — 3 12 13 14 -- 15 -- 10 16 17 18 19 -- 20 — 7 21 22 23 24 25 8 26 3000 20.3 107.8 10.2 17.2 21.1 23.4 21.7 24.7 BOTTOM OF BORING DEPTH 25.5' Earth Engineering Consultants CAT 7TH FILING - CONDO DEVELOPMENT FORT COLLINS, COLORADO PROJECT NO: 1082101 DATE: JULY 2009 LOG OF BORING B-6 PIEZOMETER RIG TYPE: CME45 SHEET 1 OF 1 WATER DEPTH FOREMAN: DG START DATE 7/2012009 WHILE DRILLING AUGER TYPE: 4" CFA FINISH DATE 7/20/2009 7/22/2009 7,7' SPT HAMMER: MANUAL SURFACE ELEV N/A 124 HOUR i SOIL DESCRIPTION D N Qu MC DD A -LIMITS -200 SWELL LL PI PRESSURE' %@ 600 P8I NPE (FEET) (RLOWSlFT) (PSF) 1,A) {PCF) (°!<) VEGETATION AND TOPSOIL 1 SANDY CLAY (CL) 2 brown, red _ very stiff 3 4 CS 5 8 5600 20.3 103.4 <500 sf Nti3t7o with scattered gravel _ 7 4500 16.5 SS 6 SS 7 10 13 11.8 8 9 with intermittent sand and gravel seams CS brown, red, gray _ .W. 5 loose to to medium dense SS 10 SS 11 4 ._...... __..___....w-._. 12 13 14 Ess -_ 15 8 18.9 16 17 18 19 with clay seams _ 14 20.2 Es, 20 21 22 23 24 BOTTOM OF BORING DEPTH 24' 25 26 Earth Engineering Consultants CAT 7TH FILING - CONDO DEVELOPMENT FORT COLLINS, COLORADO PROJECT NO: 1082101 DATE: JULY 2009 LOG OF BORING B-7 (PIEZOMETER) RIG TYPE: CME45 SHEET 1 OF 1 WATER DEPTH FOREMAN: DG START DATE 7120/2009 WHILE DRILLING AUGER TYPE: 4" CFA FINISH DATE 7/20/2009 7/2212009 SPT HAMMER: MANUAL SURFACE ELEV NIA 24HOUR N/A SOIL DESCRIPTION D N Qu MC DD A -LIMITS 2011 SWELL LL PI PRESSURE &0psf Edl (FEET) WSIFT) (BLOWS/FT) i (%I VEGETATION AND TOPSOIL SANDY CLAY (CL) 2 brown stiff to very stiff 3 dry 4 CS 5 6 21 9001 11.1 100.7 SAND AND GRAVEL SS 501111, 3.8 brown, red, gray very dense to loose 7 8 with intermittent sand and gravel seams CS 9 60181, 9000+ 2.3 117.5 SS 10 50/10" 4.2 1 12 with clay seams 13 14 SS — 15 7 21.1 16 17 18 19 ss 20 6 23.4 21 22 23 24 SS 25 26 9 4.6 EL E BOTTOM OF BORING DEPTH 25.5' Earth Engineering Consuitants SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown / Red Sandy Lean Clay (CL) Sample Location: Boring 6, Sample 1, Depth 4' Liquid Limit: Plasticity Index: -- 1% Passing #200: Beginning Moisture: 19.7% 1Dry Density: 106.6 psf JEnding Moisture: '119.2% .Swell Pressure: <500 psf 1% Swell @ 500: None Project: Cat 7th Filing Condo Development Fort Collins, Colorado Project 1082101 Date: July 2009 EARTH ENGINEERING CONSULTANTS, INC. 11 GRADATION OF AGGREGATE (ASTM C-136) 11 11 SIEVE SIZE 11 PERCENT PASSING 11 6" -------------------------------------------- r ---------------------------- -- ---------- 5" 1 100% -------------------------------------------- ------------------------------ I ----------- 4" I 100% -------------------- --------------------- L -------------------------------- 3" 100% -------------------- ---------------------I------------------------------------ _... -_ 2" 100% -------------------------------------------- r ---------------------------------------------- 1 1/2" 100% ------------------------------------------ -- -------------------------------------------- V 100% -------------------------------------------- ---------------------------- - ------------------ 3/4" 100% -------------------------------------------- r ------------------------------------------- 1/2" I 99% -------------------------------------------- ------------------------------ 3/8" 99% - ------------------------------------------ L ------------------------------------------- No. 4 94% -------------------------------------------- r ------------------------------------------ No. 8 1 85% -------------------------------------------- ------------------------------------------- No. 16 i 67% --------------------------------------------- L --------------------------------------------- i No. 30 46% -------------------------------------------- r --------------------------------------------- No. 40 37% --------------------------------------------- ----------------------------------------------- No. 50 29% --------------------------------------------- --------------------------------------___..-. No. 100 19,6% --------------------------------------------- r --------------------------------------- No. 200 1 14.7% Project: CAT 7th Filing Fort Collins, Colorado EEC Project Number: 1082101 Date: July 2009 Sample Number: B-7, S-3, 8' I 7 C) a .-I -I I.R O -R 0-1 O -.1 -1 -1 -Q C) 001 ) C) 0 0(0 0 0 0 CD 0 00 rl- lq6pM Aq JGUIJ IUDOAd A LL r (m E .1 m 0 0 Q) .C: LL is O E2 m 0 EARTH ENGINEERING CONSULTANTS, INC. SUMMARY OFGRADATION TEST RESULTS Project: CAT 7th Filing Fort Collins, Colorado EEC Project Number: 1OO21O1 Date: July 2009 E 4.i cli 0 z 75 0 c 0 z cu .9 LO- _a cu z -j c 0 ci m LU E = E LL, bA O cn 0 (D C) C)00 CD C) U-) 0 0 0 0) 1- Cl) CN ;q6iaAA Aq jaui� juawad 7 0 E N _0 0 0 7, CU 04 0 LL, c O LL 2, dJ —ID M Earth Engineering Consultants, Inc. Summary of Laboratory Classification/ Moisture -Density Relationship 145 Material Designation: 1082101.A r ^, Sample Location: Comp. Sample of Cohesive Soils, Borings B-5 - B-7 . �4 Clayey Sand SC 140 P Y Y ( ? "� �� _Desch Description: �..� Limits {ASTM D 4318) j �, Liquid Limit: 31 fti 135 Plastic Limit: 18 lasticity Index: 13 i 41...�, �� `P ercent Passing No. 200 Sieve (ASTM C 117): 18.5010 130 t Y ��� + a _ _ � — :�J1 i TStandard Proctor {ASTM D-698ximum Dry Density: 117.0 pcf' ptimum Moisture Content: 14-0% u- 125 r� Client: Everitt Companies Project: Centre for Advanced Technology - 7th Filing - High Rise Condominium Fort Collins, Colorado Project No: 1082101 Date July 2009 �)Yff 01rr' q Earth Engineering Consultants, Inc. Summary of Laboratory Gradation Test 100 10 1 0.1 0.01 13.0011 Grain Size in Millimeters Sieve Size Percent Passing No. 4 93% No. 10 85% No. 40 66% No. 200 46.5% Material Designation: 1082101.A Sample Location: Comp. Sample of Cohesive Soils, Borings B-5 - B-7 Material Description: Clayey Sand (SC) AASHTO Classification: A-6 Project: Centre for Advanced Technology - 7th Filing - High Rise Condominium Fort Collins, Colorado Project No: 1082101 Date July 2009 CLIENT: PROJECT: PROJECT NO. SAMPLE LOCATION: SOIL CLASSIFICATION: DIRECT SHEAR TEST REPORT Everitt Companies C.A.T. 7th Filing - High Rise Condominium 1082101 Composite Sample of Cohesive Soils (Boring Nos. B'5 through 13'7) Clayey Sand (8C) Sample remolded boapproximately A596Standard Proctor Density (ASTN1DSQ8)adapproximately 4percent above Optimum Moisture Content bosimulate saturated conditions. NORMAL ULTIMATE SHEAR PEAK SHEAR MOISTURE DRY SAMPLE NO. STRESS STRESS STRESS CONTENT DEN!YTY' TANGENT INTERNAL FRICTION ANGLE COHESION PSF Normal Stress vs. Peak Shear Stress 3000 o 1000 ,000 3000 4000 NORMAL STRESS 'poF Normal Stress vs. Ultimate Shear Stress 1000 zuoo oono 4000 '11RECT SHEAR TEST REPORT ASTIVI D 3080 CLIENT: Everitt Companies PROJECT: C.A.T. 7th Filing - High Rise Condominium PROJECT NO. 1082101 SAMPLE LOCATION: Composite Sample of Cohesive Soils (Boring Nos. B-5through B-7) SOIL CLASSIFICATION: Clayey Sand (SC) Sample remolded to approximately 95% of Standard Proctor Density (ASTM D698) at 1/2 to 1-percent above Optimum Moisture Content. NORMAL ULTIMATE SHEAR PEAK SHEAR MOISTURE DRY SAMPLE NO. STRESS STRESS STRESS CONTENT DENSITY (PSF) (PSF) (PSF) M ipu) 1 1000 748 748 14.0 2 2000 1278 1290 14.6 111,3 3 4000 2629 2641 15.1 110.8 TANGENT INTERNAL FRICTION ANGLE . . . ........ COHESION - P'SF PEAK 0.637 32.5 72.5 ULTIMATE 0.634 32.4 72.5 Normal Stress vs. Ultimaie Shear Stress 4000 —3000 LL 0) IL (n U) LU 2000 1000 N 0 1000 2000 3000 4000 NORMAL STRESS-PSF