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HomeMy WebLinkAbout20042094.tiff PRELIMINARY SUBSURFACE EXPLORATION ANTELOPE ESTATES WELD COUNTY, COLORADO EEC PROJECT NO. 1012121 2004-2094 y EEC . EARTH ENGINEERING CONSULTANTS, Inc. June 22, 2001 ZWEST Development and Investments, Inc. P.O. Box 1365 Wellington, Colorado 80549 Attn: Mr. Fred Ziegler Re: Preliminary Geotechnical Subsurface Exploration Antelope Estates Development Weld County, Colorado EEC Project No. 1012121 Mr. Ziegler: Enclosed, herewith, are the results of the preliminary geotechnical subsurface exploration you requested for the Antelope Estates Development in Weld County, Colorado. In summary, the subsurface soils encountered in the test borings consisted of low plasticity sandy lean clay with varying amounts of sand underlain by granular and essentially granular soils. The granular soils were underlain at depths of approximately 2'/2 to 7 feet by poorly cemented sandstone bedrock. Free groundwater was not observed in the test borings at the time of drilling. Based on results of the field borings and laboratory testing, we believe lightly loaded residential structures could be supported on conventional footing foundations bearing on the near surface clayey sand or sandstone bedrock. The near surface cohesive or clayey sand soils could be used for direct support of floor slabs and for support of site pavements. The near surface sandy clay soils show percolation rates that would support the use of conventional absorption systems in accordance with Weld County standards. However, shallow bedrock encountered in the northeast portion of the site would mandate engineered systems. CENTRE FOR ADVANCED TECHNOLOGY 230 I RESEARCH BOULEVARD, SUITE 104 FORT COLLINS, COLORADO 80526 (970) 224-.1 522 (FAx) 224-4564 Earth Engineering Consultants,Inc. EEC Project No. 1012121 June 22, 2001 Page 2 Preliminary geotechnical recommendations concerning design and construction of foundations and support of floor slabs and pavements are presented in the text of the attached report. We appreciate the opportunity to be of service to you on this project. If you have any questions concerning the enclosed information, or if we can be of further service to you in any other way, please do not hesitate to contact us. Very truly yours, Earth Engineering Consultants, Inc. c,,,n,,, Reviewed by: (/ ON Q v' ca at Y � _ �SSaNALEN ' AL Wolfram von witz, E.I.T. Lester L. Litton, P.E. Project Engineer Principal Engineer cc: Land Images, Inc. PRELIMINARY SUBSURFACE EXPLORATION ANTELOPE ESTATES WELD COUNTY, COLORADO EEC PROJECT NO. 1012121 June 22, 2001 INTRODUCTION The preliminary subsurface exploration for the Antelope Estates Development in Weld County, Colorado, has been completed. Three soil borings extending to depths of approximately 15 feet below present site grades were advanced in the development area to obtain information on existing subsurface conditions. Individual boring logs and a diagram indicating the approximate boring locations are included with this report. The Antelope Estates Development includes approximately 120 acres of Section 29, T9N, R67W of the 6th P.M. in Weld County, Colorado. We understand the proposed development will include five single-family residential lots. It is anticipated the site residences will be one or two-story,wood frame structures constructed with full basements. Foundation loads for the residential structures are expected to be light with continuous wall loads less than 2.5 kips per lineal foot and column loads less than 30 kips. Small grade changes will be required to develop the final grades on this site. Site roadways will be constructed in the proposed development. It is anticipated the single-family residences will utilize individual sewage disposal systems (ISDS). The purpose of this report is to describe the subsurface conditions encountered in the borings, analyze and evaluate the test data and provide geotechnical recommendations concerning design and construction of the foundations and support of floor slabs and pavements. EXPLORATION AND TESTING PROCEDURES The boring locations were established in the field by representatives of Earth Engineering Consultants, Inc. (EEC)by pacing and estimating angles from identifiable site features. The locations Earth Engineering Consultants,Inc. EEC Project No. 1012121 June 22, 2001 Page 2 of the borings should be considerate accurate only to the degree implied by the methods used to make the field measurements. The borings were performed using a truck-mounted, CME-45 drill rig equipped with a hydraulic head employed in drilling and sampling operations. The boreholes were advanced using 4-inch nominal diameter continuous flight augers and samples of the subsurface materials encountered were obtained using split-barrel and California barrel sampling techniques in general accordance with ASTM Specification D-1586. In those sampling procedures, standard sampling spoons are driven into the ground by means of a 140-pound hammer falling a distance of 30 inches. The number of blows required to advance the 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 of the soils 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. Field percolation tests were completed at two of the boring locations. The percolation tests were completed in general accordance with Weld County standards. Results of the field percolation tests are provided with this report. Moisture content tests were completed on each of the recovered samples. Washed sieve analysis and Atterberg limits tests were performed on selected samples to evaluate the quantity and plasticity of the fines in the subgrade. Swell/consolidation tests were completed on selected samples to evaluate the soil's tendency to change volume with variation in moisture content. Results of the field borings and laboratory testing are indicated on the attached boring logs and summary sheets. As a part of the testing program, all samples were examined in the laboratory by an engineer and 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 shown on the boring logs and a brief description of that classification system is included with this report. Classification of the bedrock was based on visual and tactual Earth Engineering Consultants,Inc. EEC Project No. 1012121 June 22, 2001 Page 3 observation of disturbed samples and auger cuttings. Coring and/or petrographic analysis may reveal other rock types. SITE AND SUBSURFACE CONDITIONS The Antelope Estates Development will be located near the intersection of Weld County Roads 102 and 17. Weld County Road 17 forms the east property boundary. The site is relatively flat with drainage towards the east and a maximum difference in ground surface elevations across the site estimated to be approximately 5 to 10 feet. Evidence of prior building construction was not observed on the site by EEC field personnel. EEC personnel were on site during drilling to direct the drilling activities and evaluate the subsurface materials encountered. Field logs prepared by EEC site personnel were based on visual and tactual observation of disturbed samples and auger cuttings. The fmal boring logs included with this report may contain modifications to the field logs based on results of laboratory testing and engineering evaluation. Based on results of the field boring and laboratory testing, subsurface conditions can be generalized as follows. Approximately 3 to 6 inches of topsoil and/or vegetation was encountered at the surface at the boring locations. The topsoil/vegetation was underlain by stiff,brown sandy lean clay. The lean clay was relatively dry at the time of drilling, showed low to moderate swell potential at current moisture and density conditions, and extended to a depth of approximately 2%z to 4 feet below present site grades. The lean clay was underlain by clayey sand in borings B-2 and B3. The clayey sand was colored reddish brown and showed low swell potential at current moisture and density conditions. The clayey sand encountered in these borings extended to a depth of approximately 7 feet below ground surface. The sandy lean clay in boring B-1 and clayey sand in borings B-2 and B-3 were underlain by weathered sandstone bedrock. The sandstone was highly weathered, poorly cemented, and colored grey/brown. The sandstone encountered in boring B-3 was underlain by grey claystone bedrock at a depth of approximately 14 feet below present site grades. The claystone showed moderate swell Earth Engineering Consultants,Inc. EEC Project No. 1012121 June 22,2001 Page 4 potential at current in-situ moisture and density conditions. The sandstone in borings B-1 and B-2, and the claystone in boring B-3 extended to the bottom of boring at depths of approximately 15 feet below ground surface at the boring locations. The stratification boundaries indicated on the boring logs represent the approximate location of changes in soil and rock types; in-situ, the transition of materials may be gradual and indistinct. GROUNDWATER CONDITIONS Observations were made while drilling and after completion of the borings to detect the presence and depth to hydrostatic groundwater. At the time of drilling, free water was not observed in any of the completed borings. Fluctuations in groundwater levels can occur over time depending on variations in hydrologic conditions and other conditions not apparent at the time of this report. Zones of perched and/or trapped water may be encountered in more permeable zones within the subgrade soils. Perched water is commonly encountered in soils overlying less permeable highly weathered bedrock. The location and amount of perched water can also vary over time depending on variations in hydrologic conditions and other conditions not apparent at the time of this report. ANALYSIS AND RECOMMENDATIONS Site Preparation All existing vegetation and/or topsoil should be removed from beneath fill, roadway or building subgrade areas. After stripping and completing all cuts and prior to placement of any fill, floor slabs or pavements, we recommend the exposed soils be scarified to a minimum depth of 9 inches, adjusted in moisture content and compacted to at least 95% of the material's maximum dry density as determined in accordance with ASTM Specification D-698, the standard Proctor procedure. The moisture content of the scarified materials should be adjusted to be within the range of±2% of standard Proctor optimum moisture at the time of compaction. Earth Engineering Consultants,Inc. EEC Project No. 1012121 June 22,2001 Page 5 Fill soils required to develop the building areas or pavement subgrades should consist of approved, low-volume change materials which are free from organic matter and debris. The near surface lean clay or clayey sand soils could be used as fill in these areas. We recommend the fill soils be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content as recommended for the scarified materials and compacted to at least 95% of the material's standard Proctor maximum dry density. Care should taken after preparation of the subgrades to avoid disturbing the subgrade materials. Positive drainage should be developed away from the structures and across and away from the pavement edges to avoid wetting of subgrade materials. Subgrade materials allowed to become wetted subsequent to construction of the residences and/or pavements can result in unacceptable performance of those improvements. Foundations Based on the materials observed at the boring locations, it is our opinion lightly loaded structures could be supported on conventional footing foundations bearing on the near surface natural site soils. For design of footing foundations bearing in the natural, medium dense clayey sand or poorly cemented sandstone bedrock, we anticipate using net allowable total load soil bearing pressures in the range of 1,500 to 3,000 psf. The net bearing pressure refers to the pressure at foundation bearing level in excess of the minimum surrounding overburden pressure. Total load includes full dead and live loads. No unusual problems are anticipated in completing the excavations required for construction of the footing foundations. Care should be taken to avoid disturbing the foundation bearing materials. materials loosened or disturbed by the construction activities or materials which become wet and softened or dry and desiccated should be removed and replaced with acceptable soils prior to construction of the footing foundations. Earth Engineering Consultants, Inc. EEC Project No. 1012121 June 22,2001 Page 6 Floor Slab Subgrades We expect floor slabs could be supported on the natural site cohesive or essentially granular soils. All existing vegetation and/or topsoil should be removed from beneath the floor areas. Fill soils required to develop the floor slab subgrades should consist of approved, low-volume change materials which are free from organic matter and debris. Based on testing completed as a part of this project, it is our opinion the near surface cohesive and/or essentially granular soils could be used as fill beneath the floor slabs. The near surface lean clay soils encountered were relatively dry at the time of drilling. Those materials could show swell potential from dry to moist conditions. Care should be taken with these materials to develop proper moisture contents prior to placement as fill. Care should be taken after preparation of the subgrades to avoid disturbing the subgrade materials. • Materials which are loosened or disturbed by the construction activities or materials which become dry and desiccated or wet and softened should be removed and replaced prior to placement of the overlying floor slabs. Positive drainage should be developed away from the proposed structures to avoid wetting the subgrades and bearing materials. Subgrades and bearing soils allowed to become wetted subsequent to construction can result in unacceptable performance. Below Grade Areas If basement construction is anticipated, we recommend an exterior perimeter drain system be constructed around the below grade areas of the structures to avoid the development of hydrostatic loads on the below grade walls and/or seepage of surface infiltration water into the basements. Backfill placed adjacent to below grade walls above the perimeter drain system should consist of approved, low-volume change materials which are free from organic matter and debris. If free draining granular fills are used in this area, we recommend the top 2 feet of soil contain sufficient Earth Engineering Consultants,Inc. EEC Project No. 1012121 June 22,2001 Page 7 fines to prevent a direct influx of water into the perimeter drain system. The near surface cohesive or clayey sand soils could be used as backfill adjacent to the structures. Pavement Subgrades All existing vegetation and/or topsoil should be removed from pavement areas. After stripping and completing all cuts and prior to placement of any fill or pavements, we recommend the exposed soils be scarified to a minimum depth of 9 inches, adjusted in moisture content and compacted to at least 95% of the material's maximum dry density as determined in accordance with the standard Proctor procedure. The moisture content of the scarified soils should be adjusted to be within the range of ±2% of standard Proctor optimum moisture. Fill materials required to develop the pavement subgrades should consist of approved, low-volume change materials, free from organic matter and debris. The near surface lean clay or clayey sand soils could be used for fill in these areas. We recommend those fill soils be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content and compacted to at least 95%of the material's standard Proctor maximum dry density. After completion of the pavement subgrades, care should be taken to prevent disturbance of those materials prior to placement of the overlying pavements. Soils which are disturbed by construction activities should be reworked in-place or, if necessary, removed and replaced prior to placement of overlying fill or pavements. Pavements We estimate the R-value of the cohesive subgrade soils would be approximately 10; the granular soils would have a higher R-value. We anticipate traffic on the site roadways would consist of low volumes of light vehicles including automobiles and light trucks. Based on anticipated subgrade and traffic conditions, we expect the minimum pavement section would consist of 3'/ inches of hot bituminous pavement overlying 6 inches of aggregate base. Earth Engineering Consultants,Inc. EEC Project No. 1012121 June 22,2001 Page 8 The hot bituminous pavement should be compatible with Colorado Department of Transportation (CDOT) requirements for grading S or Sx. Aggregate base should be consistent with CDOT requirements for Class 5 or Class 6 base. Roadways with heavier traffic volumes or use by heavier vehicles may require thicker pavement sections. Positive drainage should be developed across the pavements and away from the pavement edges to avoid wetting the pavement subgrades. Subgrades allowed to become wetted subsequent to construction can result in premature failure of the pavement section. On-Site Wastewater Disposal We understand on-site septic systems will be used for wastewater disposal. Percolation tests were completed at two locations on the site to evaluate the percolation rate of the on-site materials. Percolation rates for area 1 and 2 were found to be 48 and 54 minutes per inch respectively. Weld county standards require a percolation rate in the range of 5 to 60 minutes per inch for the use of conventional absorption systems. The measured percolation rates meet that criterion. However, areas with percolation rates greater than 60 minutes per inch should be expected. Weld County standards also require at least 6 feet of soil overlying bedrock to use a conventional absorption field system. Bedrock was encountered in percolation area 1 at a depth of approximately 2 feet below ground surface precluding the use of a conventional system. Based on the measured percolation rates and subsurface conditions encountered,we anticipate some engineered systems may be required. Additional testing should be completed on a lot by lot basis to further evaluate the percolation rate and location of bedrock. GENERAL COMMENTS The preliminary analysis and recommendations presented in this report are based upon the data obtained from the 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 Earth Engineering Consultants,Inc. EEC Project No. 1012121 June 22,2001 Page 9 exploration or construction. If 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 that comments can be made regarding the interpretation and implementation of our geotechnical recommendations in the design and specifications. It is further recommended that the geotechnical engineer be retained for testing and observations during earthwork and foundation construction phases to help determine that the design requirements are fulfilled. This report has been prepared for the exclusive use of Fred Ziegler for specific application to the project discussed and has been prepared in accordance with generally accepted geotechnical engineering 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 modified or verified in writing by the geotechnical engineer. WELD COUNTY ROAD 102 n N 0 a 0 NOT TO SCALE r I- z 0 U 0 J W Perc Area 1 ° {Y4iF B-1 B-3 B-2 ° ° ° ° ° Perc Area 2 ° ANTELOPE ESTATES BORING LOCATION DIAGRAM WELD COUNTY, COLORADO PROJECT NO: 1012121 DATE: JUNE 2001 __ __ P.ARTH PNaTNP.PRTNa MNCTTT TANTC DRILLING AND EXPLORATIP 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 falling 30 inches on a 2-inch O.D. split spoon,except where noted. 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 Boring 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, the indicated levels may reflect the location of ground water. In low permeability soils, the accurate determination of ground water levels is not possible with only short term observations. DESCRIPTIVE SOIL CLASSIFICATION PHYSICAL PROPERTIES OF BEDROCK Soil Classification is based on the Unified Soil Classification DEGREE OF WEATHERING: system and the ASTM Designations D-2488. Coarse Grained Slight Slight decomposition of parent material on Soils have move than 50% of their dry weight retained on a joints. May be color change. #200 sieve;they are described as: boulders, cobbles,gravel or Moderate Some decomposition and color change sand. Fine Grained Soils have less than 50%of their dry weight throughout. retained on a#200 sieve;they are described as : clays, if they High Rock highly decomposed,may be extremely are plastic, and silts if they are slightly plastic or non-plastic. broken. Major constituents may be added as modifiers and minor HARDNESS AND DEGREE OF CEMENTATION: constituents may be added according to the relative proportions Limestone and Dolomite: based on grain size. In addition to gradation, coarse grained Hard Difficult to scratch with knife. soils are defined on the basis of their relative in-place density Moderately Can be scratched easily with knife. and fine grained soils on the basis of their consistency. Example: Lean clay with sand, trace gravel, stiff(CL); silty Hard Cannot be scratched with fingernail. sand, trace gravel,medium dense(SM). Soft Can be scratched with fingernail. CONSISTENCY OF FINE-GRAINED SOILS Shale, Siltstone and Claystone: Hard Can be scratched easily with knife,cannot be scratched with fingernail. Unconfined Compressive Strength,Qu,psf Consistency Moderately Can be scratched with fingernail. Hard < 500 Very Soft Soft Can be easily dented but not molded with 500 - 1,000 Soft fingers. 1,001 - 2,000 Medium Sandstone and Conglomerate: 2,001 - 4,000 Stiff Well Capable or scratching a knife blade. 4,001 - 8,000 Very Stiff Cemented 8,001 - 16,000 Very Hard Cemented Can be scratched with knife. RELATIVE DENSITY OF COARSE-GRAINED SOILS: Poorly Can be broken apart easily with fingers. Cemented 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 UNIFIED SOIL CLASSIFICATION SYSTEM ,- Soil Classification Criteria for Assigning Group Symbols and Group names Using Laboratory Tests Group Group Name 9 9 YTn Y Symbol roue Coarse—Grained Gravels more than Clean Gravels Less Soils more than 50% of coarse than 5% fines Cu>4 and <Cc≤3` OW Well—graded grovel` 50% retained on fraction retained No. 200 sieve on No. 4 sieve Cu<4 and/or 1>Cc>3L GP Poorly—graded gravel` Gravels with Fines Fines classify as ML or MH GM Silty grovel, G,H more than 12% fines Fines classify as CL or CH GC Clayey Gravel ra" Sands 50% or Clean Sands Less Cu»§ and 1<Cc<3r gyy Well—graded sand' more coarse than 5% fines fraction passes Cu<6 and/or 1>Cc>3` SP Poorly—graded sand' No. 4 sieve Sands with Fines Fines classify as ML or MH SM Silty sand°^' more than 12% fines Fines classify as CL or CH SC Clayey sands" Fine—Grained Silts and Clays inorganic PI>7 and plots on or above "Aline' CL Lean clay'LL" Soils 50% or Liquid Limit less more passes the than 50 PI<4 or plots below "Aline' ML Silt"I.' No. 200 sieve organic Liquid Limit — oven dried Organic clay".L".e <0.75 OL Liquid Limit — not dried Organic silt"L"° Silts and Clays inorganic PI plots on or above "A"Line CH Fat cloy"'L" Liquid Limit 50 or more PI plots below "A"Line MH Elastic Silt"" organic Liquid Limit — oven dried Organic cloy`'"' <0.75 OH Liquid Limit — not dried Organic silt' Highly organic soils Primarily organic matter, dark in color, and organic odor PT Peat "Based on the material passing the 3—in. (75— a (0se) "If soil contains 15 to 29Rplus No. 200, add mm) sieve CU=D,p/D,CC= D x 0 "with sand or 'with gravel', whichever is slf field sample contained cobbles or boulders, predominant. or both, add 'with cobbles or boulders, or both' 4f soil contains 2 30' plus No. 200 to group name. 'If soil contains 215% sand. add"with sand"to predominantly sand, odd "sandy to group °Gravels with 5 to 12% fines required dual group name, name. symbols: @f fines classify as CL—ML, use dual symbol "0 soil contains 2 30% plus No. 200 GW—GM well graded gravel with silt GC—CM, or SC—SM. predominantly gravel, add gravely to group GW—GC well—graded grovel with clay If fines ore organic, add"with organic fines'to Nome. GP-GM poorly-graded gravel with silt group name PI24 and plots an or above "A" line. GP-GC poorly-graded gravel with clay Of sail contains >15%grovel, add-with grovel' "PI54 or plots below "A" line. °Sands with 5 to 12% tines require dual to group name, POI i plots an or above A' line. symbols: +If Atterberg limits plots shaded area, soil is a PI plots below A" line. SW-SM well-graded sand with silt CL-ML, cilty cloy. SW-SC well-graded sand with clay SP-SM poorly graded sand with silt SP-SC poorly graded sand with cloy 60 For Clasallkatbn of Me-grained soh and line-groins M1aclen of coarse i. - grs =tile 5O- Boeotian of'A-ene / Horizenld at PI-4 to LLe25.5, ¢ then P1-0.73(LL-20) �.� `\/� 4' Equation of'u'-line '5'd ,0 _ Vertical 01 LL"16 to P1=7, 09.O '{`� W 4° then P1-0.9(LL-8) Z Cr 30- I- to U_ F ZMH a OR OH 10- }r'' /CL,ML ML OR OL I I 0 10 20 30 e0 50 60 70 Bo 90 100 110 LIQUID LIMIT (LL) • ANTELOPE ESTATES WELD COUNTY,COLORADO PROJECT NO:1012121 DATE: JUNE 2001 LOG OF BORING B-I RIG TYPE: CME 45 SHEET I OF 1 WATER DEPTH FOREMAN:SG START DATE 6/14/01 WHILE DRILLING None AUGER TYPE: 4"CFA FINISH DATE 6/14/01 AFTER DRILLING None SPT HAMMER: Manual SURFACE ELEV N/A 24 HOUR N/A U N OU MC 00 A-LIMITS -200 SWELL SOIL DESCRIPTION TYPE (FEET( (BLOWS/FT) (PSF) (%) (PCF), LL Pt F (%) PRESSURE %@ 500PSF TOPSOIL AND VEGETATION _ _ SANDY LEAN CLAY(CL) _ _ brown 2 stiff CS 3 25 5000 8.3 90.4 _ 30 13 59.7 600 psf 0.3% SANDSTONE light brown/grey 4 poorly cemented _ _ 55 5 50/5 - 8.4 —6 8 _9_ CS 1-0 5017 - 10.7 101.0 _ _ • 11 12 '-3 14 5S 15 50/4 - 9.1 BOTTOM OF BORING 15.5' 1-6 1-] 1-6 1-9 2-0 2-1 22 23 2-4 25 Earth Engineering Consultants ANTELOPE ESTATES WELD COUNTY,COLORADO PROJECT NO:1012121 DATE: JUNE 2001 LOG OF BORING B-2 RIG TYPE: CME45 SHEET OFI WATER DEPTH FOREMAN:SG START DATE 6114101 WHILE DRILLING None AUGER TYPE: 4"CFA FINISH DATE 6114101 AFTER DRILLING None SPT HAMMER: Manual SURFACEELEV NIA 24 HOUR NIA 0 N DU MC DO A-LIMBS .200 SWELL SOIL DESCRIPTION TYPE (FEET) IRLOWSIFT) (PSF) IX) IPCF) LL PI (%) _ PRESSURE %@ 500 PSF TOPSOIL AND VEGETATION _ — 1 SANDY LEAN CLAY(CL) — — brown 2 stilt — _ SS 3 22 9000+ 11.9 4 CLAYEY SAND(SC) CS 5 8 - 8.7 98.3 27 12 32.8 <500 pa/ None reddish brown _ _ loose to medium dense 6 _7_ SANDSTONE -8 light brown/grey _ _ poorly cemented 9 55 10- 5018 - 11.2 _ _11 1-2 1-3 1-4 SS 1-5- 50/5 - 12.0 BOTTOM OF BORING 15 5' 16 17 1-8 1-9 20 2-1 22 2-3 _ _ 24 25 Earth Engineering Consultants ANTELOPE ESTATES WELD COUNTY,COLORADO PROJECT NO:1012121 DATE: JUNE 2001 LOG OF BORING 6-3 RIG TYPE: CME45 SHEETI OFI WATER DEPTH FOREMAN:SG START DATE 6/14/01 WHILE DRILLING None AUGER TYPE: 4-CFA FINISH DATE 6114/01 AFTER DRILLING None SPT HAMMER: Manual SURFACE ELEV N/A 24 HOUR WA 0 N OU MC DO A-LIMITS -200 SWELL SOIL DESCRIPTION TTPE (FEET) (BLOWSIFT) (PSn L%) IPCFI LL PI (%) PRESSURE%S SOD PDF TOPSOIL AND VEGETATION - - SANDY LEAN CLAY(CL) 1 brown _ _ stiff 2 5S -3 14 9000+ 10.4 CLAYEY SAND(SC) — — reddish brown 4 medium dense — _ SS 5 58 - 10.1 6 _7 SANDSTONE -8 light brown/grey — — poorly cemented 9 SS 10 50/3 - - - — 1 1-2 1-3 1-4 CLAYSTONE-grey,soft CS 15 32 4000 24.8 98.8 58 31 94.3 2600 psi 1.9% BOTTOM OF BORING 15.0' - - 16 1-7 1-8 1-9 20 21 22 2-3 24 2-5 Earth Engineering Consultants SWELL / CONSOLIDATION TEST RESULTS Material Description: Light Brown Sandy Lean Clay Sample Location: B-1, S-1 @ 2.0' _ Liquid Limit: 30 'Plasticity Index: 13 1 % Passing #200: 59.7 Beginning Moisture: 7.8% Dry Density: 90.4 pcf 'Ending Moisture: 24.0% Swell Pressure: 600 psf % Swell @ 500 psf: 0.3% 10 I , i I 8 i I I d co 6 - - i I 4 - . _ _ . _ . c 2 _ . m E 0 > g 0 r C d u N_ Water Added 2 -4 . 0 O v c 0 o -8 I I -10 - 0.01 0.1 1 10 Load (TSF) Project: Antelope Estates Weld County, Colorado Project No.: 1012121 • Date: June 2001 SWELL / CONSOLIDATION TEST RESULTS Material Description: Reddish Brown Clayey Sand Sample Location: B-2, S-2 @ 4.0' Liquid Limit: 27 [Plasticity Index: 12 I % Passing #200: 32.8 Beginning Moisture: 6.3% Dry Density: 98.3 pcf "Ending Moisture: 15.7% Swell Pressure: <500 psf % Swell @ 500 psf: None I , 8 I- co 6 4 - d E C) 2 0 •----_� m a Water Ac ded —14%.%%.**N\ 2 -4 0 -6 0 0 -8 I I I I -10 0.01 0.1 1 10 Load (TSF) Project: Antelope Estates Weld County, Colorado Project No.: 1012121 • Date: June 2001 .- SWELI_ / CONSOLIDATION TEST RESULTS Material Description: Grey Claystone Sample Location: 6-3, S-4 @ 14.0' Liquid Limit: 56 'Plasticity Index: 31 I °/0 Passing #200: 94.3 , Beginning Moisture: 23.6% Dry Density: 98.6 pcf 'Ending Moisture: 25.6% Swell Pressure: 2600 psf % Swell @ 500 psf: 1.9% 10 I I 8 1 - . _ . , - . I I .. i 4 — - c 2 . . d g d O — 2 0 •—...._L____=-------IIL-%%%.XNN. , . +r C N 2 Water Added -2 I -.4 . . . . . c 0 0 70 0 -6 O - C 0 U i -8 - - . I I I I - -10 { 0.01 0.1 1 10 Load (TSF) Project: Antelope Estates Weld County, Colorado Project No.: 1012121 Date: June 2001 • Hello