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Home My WebLink About20141589.tiff SO(LOGIC September 11, 2007 Mr. Pete Hyland 320 East Chestnut Street Windsor, Colorado 80550 Re: Geotechnical Subsurface Exploration Hyland Parcel Weld County, Colorado Soilogic Project# 07-1070 Mr. Hyland: Soilogic, Inc. (Soilogic) personnel have completed the geotechnical subsurface exploration you requested for the proposed residence to be constructed northeast of the intersection of County Roads 21 and 76.5 in Weld County, Colorado. The results of our subsurface exploration are included with this report. We understand the proposed residence will be a one or two-story wood frame structure constructed over a full basement. Foundation loads for the structure are expected to be light with continuous wall loads less than 3.5 kips per lineal foot and individual column loads less than 50 kips. Wastewater generated by the residence will be disposed of through an on-site individual sewage disposal system (ISDS). The purpose of our investigation was to describe the subsurface conditions encountered in the completed site boring and develop the test data necessary to provide recommendations concerning design and construction of the residence foundations and support of floor slabs and exterior flatwork. The results of a completed site percolation tests are also included. The conclusions and recommendations outlined in this report are based on results of the completed field and laboratory testing and our experience with subsurface conditions in this area. Soilogic, Inc. 1435 Hilltop Circle •Windsor, CO 80550 • (970) 674-3430 Hyland Parcel Soilogic#07-1070 2 SITE DESCRIPTION The proposed residence will be constructed northeast of the intersection of County Roads 21 and 76.5 in Weld County, Colorado. An irrigation canal forms the north property boundary. At the time of our site exploration, the lot was vegetated and gently sloping toward the south/southwest with a maximum difference in ground surface elevation across the approximate residence footprint estimated to be less than 3 feet. Evidence of prior building construction was not observed in the proposed construction area by Soilogic personnel at the time of our site exploration. EXPLORATION AND TESTING PROCEDURES To develop subsurface information in the area of the proposed residence, two (2) soil borings were extended to a depth of approximately 15 feet below present site grades within the approximate building footprint. The proposed residence location was established in the field by the client. The boring locations were established in the field by Soilogic personnel based on the proposed residence location. A diagram indicating the approximate boring locations is included with this report. A graphic log of each of the auger borings is also included. The test holes were advanced using 4-inch diameter continuous flight auger powered by a truck-mounted CME-55 drill rig. Samples of the subsurface materials were obtained at regular intervals using California barrel and split-barrel sampling procedures in general accordance with ASTM specification D-1586. Penetration resistance measurements were obtained by driving the standard sampling barrels into the substrata using a 140 pound hammer falling a distance of 30 inches. The number of blows required to advance the samplers a distance of 12 inches is recorded and helpful in estimating the consistency, relative density or hardness of the soils or bedrock encountered. In the California barrel sampling procedure, relatively undisturbed samples are obtained in removable brass sleeves. Samples of the subsurface materials obtained in the field were sealed and returned to the laboratory for further evaluation. As part of our site exploration, field slotted piezometers were installed at boring locations B-1 and B-2 prior to backfilling to allow for longer term observation of site groundwater Hyland Parcel Soilogic#07-1070 3 levels. Groundwater was measured in piezometers B-1 and B-2 on one occasion after the completion of drilling. Groundwater level measurements are indicated in the upper right hand corner of the attached boring logs. The samples collected were tested in the laboratory to measure natural moisture content and visually classified in accordance with the Unified Soil Classification System (USCS). The USCS group symbols are indicated on the attached boring logs. An outline of the USCS classification system is included with this report. Classification of bedrock was completed through visual observation of disturbed samples. Other bedrock types could be revealed through petrographic analysis. As part of the laboratory testing, a calibrated hand penetrometer (CHP) was used to estimate the unconfined compressive strength of essentially cohesive specimens. The CHP also provides a more consistent estimate of soil consistency than tactual observation alone. Dry density, Atterberg limits, -200 wash and swell/consolidation tests were completed on selected samples to help establish specific soil characteristics. Atterberg limits tests are used to determine soil plasticity. The percent passing the #200 size sieve (-200 wash) test is used to determine the percentage of fine grained soils (clay and silt) in a sample. Swell/consolidation tests are performed to evaluate soil volume change potential with variation in moisture content. The results of the completed laboratory tests are outlined on the attached boring logs and swell/consolidation test summaries. SUBSURFACE CONDITIONS The materials encountered in the completed site borings can be summarized as follows. Approximately 4 to 6 inches of topsoil and vegetation was encountered at the surface at the boring locations. The topsoil/vegetation was underlain by light brown to brown lean clay with sand. The lean clay was soft to medium stiff in consistency and extended to depths ranging from approximately 8 to 9 feet below ground surface. The medium stiff lean clay showed low swell potential at current moisture and density conditions. The soft lean clay encountered with depth showed high consolidation potential at in situ moisture and density conditions. At boring location B-2, the lean clay transitioned into silty sand at a depth of approximately 9 feet below ground surface. The silty sand extended to a depth of approximately 11 feet below present site grades at boring location B-2. The lean Hyland Parcel Soilogic#07-1070 4 clay and silty sand extended to depths ranging from approximately 8 to 11 feet below ground surface and were underlain by highly weathered sandstone with interbedded siltstone bedrock. The sandstone extended to the bottom of boring at a depth of approximately 15 feet below present site grades The stratigraphy indicated on the included boring logs represents the approximate location of changes in soil and rock types. Actual changes may be more gradual than those indicated. At the time of drilling, groundwater was encountered in the completed site borings at depths ranging from approximately 6 to 8 feet below present site grades. Groundwater was measured in piezometer B-1 and B-2 at depths of approximately 6.2 and 6.0 feet below ground surface respectively approximately 10 days after the completion of drilling. Groundwater levels will vary seasonally and over time based on weather conditions, site development, irrigation practices and other hydrologic conditions. Perched groundwater conditions may also be encountered at times throughout the year. Perched water is commonly encountered in soils overlying less permeable soil layers and/or bedrock. The location and amount of perched water can also vary over time. An irrigation canal forms the north boundary of the referenced development lot. With the proximity of the residence to the irrigation ditch, we expect site groundwater levels would be impacted by water levels in the canal. Longer term observation of site groundwater levels would be required in wells which are cased and isolated from the influence of surface water to help better define fluctuations in site groundwater levels over time. ANALYSIS AND RECOMMENDATIONS General Groundwater was measured at depths of approximately 6.2 and 6.0 feet below ground surface at boring locations B-1 and B-2 respectively approximately 10 days after the completion of drilling. As a precaution, we recommend finish basement floor slab levels Hyland Parcel Soilogic#07-1070 5 be established a minimum of three (3) feet above observed groundwater. Lesser separation distances may be possible with longer term groundwater level observations. Soft lean clay soils were observed with depth in the completed site borings. The lean clay would be expected to be soft near current groundwater levels. Based on the subsurface conditions encountered, we do not expect overexcavation/backfill procedures would be required to redevelop suitable strength foundation bearing if the minimum recommended separation distance of three (3) feet is maintained between observed groundwater and finish floor slab levels. If lesser separation distances will be considered, overexcavation/backfill procedures to redevelop suitable foundation bearing would become more likely. For full basement construction and in order to maintain the recommended separation distances outlined above, approximately 6 feet of fill will be required to develop finish site grades. Soft lean clay soils with high consolidation potential were encountered with depth in the completed site borings. With the amount of fill required to develop the site, some movement of the placed fill soils would be expected over time as the underlying soft clay layer consolidates under the additionally imposed fill loads. With the essentially cohesive nature of the site lean clay, we recommend the proposed fill soils be placed on the development lot as early as possible in the construction process and allowed to remain in place for an extended period of time to allow for consolidation of the soft clay. We estimate the fill soils would need to remain in place for a minimum of eight (8) weeks prior to commencing construction of the residence. As an alternative, consideration could be given to use of a deep foundation system. Drilled piers would extend structural loads to sandstone bedrock underlying the site significantly reducing the potential for post construction movement of the supported residence. We estimate drilled piers on the order of approximately 25 feet in length with minimum bedrock penetrations of approximately 15 feet would be required for the residence. We expect casing of the drilled piers would be required during construction to prevent saturated clay from entering the drilled shafts prior to concrete placement. Drilled pier design parameters can be provided at your request. Hyland Parcel Soilogic li 07-1070 6 Site Development All existing topsoil and vegetation should be removed from the proposed fill and flatwork areas. After stripping and completing all cuts and prior to placement of any overlying fill or flatwork concrete, we recommend the exposed subgrade soils be scarified to a depth of 9 inches, adjusted in moisture content and compacted to at least 95% of the materials standard Proctor maximum dry density. The moisture content of the reconditioned subgrade soils should be adjusted to be within the range of ±2% of standard Proctor optimum moisture content at the time of compaction. Fill soils required to develop the site should consist of approved low volume change soils free from organic matter, debris and other objectionable materials. Based on the results of the completed laboratory testing, it is our opinion the site lean clay or processed sandstone/siltstone bedrock could be used as fill to develop the site. Wet materials encountered with depth would need to be dried out prior to placement as fill. If it is necessary to import fill material to the site, those materials should have low potential for volume change and be relatively impervious. Fill soils should be approved prior to use. We recommend fill soils similar to the site lean clay be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content and compacted as recommended for the scarified materials above. Foundations After a majority of the anticipated soft clay consolidation has occurred, we expect the proposed lightly loaded residence could be supported by continuous spread footing and isolated pad foundations bearing on the site lean clay. In order to help reduce the potential for differential movement of the residence, we recommend all footing foundations be extended to bear on natural undisturbed lean clay. Some extending of garage stemwall foundations may be required to develop consistent foundation bearing. For design of footing foundations bearing on medium stiff lean clay, we recommend using a maximum net allowable soil bearing pressure of 1500 psf. • For design of footing foundations and foundation walls to resist lateral movement, a passive equivalent fluid pressure value of 200 pcf could be used. The top 30 inches of Hyland Parcel Soilogic#07-1070 7 subgrade could be considered a surcharge load but should not be used in the passive resistance calculations. A coefficient of friction of 0.25 could be used between foundation and floor slab concrete and the bearing soils to resist sliding. The recommended passive equivalent fluid pressure value and coefficient of friction do not include a factor of safety. Exterior footings should be placed a minimum of 30 inches below finished adjacent exterior grade to provide frost protection. We recommend formed strip footings have a minimum width of 12 inches and isolated pad foundations have a minimum width of 24 inches in order to facilitate construction and reduce the potential for development of eccentrically loaded footings. Actual footing widths should be designed by a structural engineer. Softer lean clay was encountered with depth in the completed site borings. Careful observation of the exposed foundation bearing materials should be completed at the time of excavation to insure structure footing foundations will be supported on like materials with suitable strength. If more extensive areas of soft clay with insufficient strength are encountered at that time, overexcavation/backfill procedures to develop suitable foundation support would be required. The site lean clay would be easily disturbed by the construction activities. Soils which are disturbed or allowed to become wetted or dried prior to foundation construction should be removed and replaced or reworked in place prior to concrete placement. We estimate settlement of footing foundations designed and constructed as outlined above would be less than 1 inch. Differential settlement could approach the amount of total settlement estimated above. Floor Slabs and Exterior Flatwork In the basement area of the residence, the floor slab could be supported directly on natural undisturbed lean clay. A thin sand leveling course could be considered to facilitate finish grading. Depending on the type of floor covering and floor covering adhesive used in the basement area, a vapor barrier may be required immediately beneath Hyland Parcel Soilogic#07-1070 8 the basement floor slab. A vapor barrier would help reduce the transmission of moisture through the basement floor slab, however, the unilateral moisture release caused by placing concrete on an impermeable surface can increase slab curl. The amount of slab curl can be reduced by careful selection of an appropriate concrete mix. Slab curl cannot be eliminated. We recommend the owner, architect and flooring contractor consider the performance of the slab in conjunction with the proposed flooring products to help determine if a vapor barrier will be required and where best to position the vapor barrier in relation to the floor slab. Additional guidance and recommendations concerning slab on grade design can be found in American Concrete Institute (ACI) section 302. In slab-on-grade and exterior flatwork areas, those slabs could be supported on reconditioned natural site soils or suitable fill soils placed and compacted as outlined above. Subgrade soils expected to receive flatwork concrete should be evaluated closely immediately prior to concrete placement. If areas of disturbed, wet and softened, or dry subgrade soils are encountered at that time, those materials should be removed and replaced or reworked in place prior to concrete placement. As a precaution, we recommend all residence and garage partition walls be constructed as floating walls to help reduce the potential for slab or foundation movement causing distress in upper sections of the residence. Special attention to door framing, drywall, and trim carpentry should be taken to isolate those elements from the floor slabs allowing for some movement of the floor slabs or foundations to occur without transmitting stresses to the overlying structure. Basement Construction We recommend a perimeter drain system be installed around all below grade areas to help reduce the potential for development of hydrostatic pressures behind the below grade walls and water infiltration into the basement area. A perimeter drain system should consist of a perforated drain pipe surrounded by a minimum of six (6) inches of free draining gravel. A filter fabric should be considered around the free draining gravel or perforated pipe to reduce the potential for an influx of fine grained soils into the system. The drain pipe should be placed at approximate foundation bearing level around the exterior perimeter of the below grade area and run to a sump pit or free outfall with a minimum slope of 1/8 inch per foot to facilitate efficient water removal. If a free outfall Hyland Parcel Soilogic#07-1070 9 will be considered, measures to help reduce the potential for reverse flow and animal access into the system should be considered. Backfill placed adjacent to the below grade walls should consist of low volume change potential and relatively impervious soils which are free from organic matter, debris and other objectionable materials. The site lean clay could be used as backfill in this area. Site lean clay or similar backfill soils should be placed in loose lifts not to exceed 9 inches thick, adjusted to be within ±2% of standard Proctor optimum moisture content and compacted to at least 95% of the materials standard Proctor maximum dry density. Excessive lateral stresses can be imposed on below grade walls when using heavier mechanical compaction equipment. We recommend compaction of unbalanced foundation wall backfill soils be completed using light mechanical or hand compaction equipment. Lateral Earth Pressures For design of below grade walls where preventative measures have been taken to reduce the potential for development of hydrostatic pressures on the walls, we recommend using an active equivalent fluid pressure of 40 pounds per cubic foot. Some rotation of the basement wall must occur to develop the active earth pressure state. That rotation can result in cracking of the basement walls typically in between corners and other restrained points. The amount of deflection of the top of the wall can be estimated at 0.5% times the height of the wall. An equivalent fluid pressure of 60 pounds per cubic foot could be used for restrained wall conditions. Variables that affect lateral earth pressures include but are not limited to the swell potential of the backfill soils, backfill compaction and geometry, wetting of the backfill soils, surcharge loads and point loads developed in the backfill materials. The recommended equivalent fluid pressure values do not include a factor of safety or an allowance for hydrostatic loads. Use of expansive soil backfill, excessive compaction of wall backfill or surcharge loads placed adjacent to the basement walls can add to the lateral earth pressures causing the equivalent fluid pressure values used in design to be exceeded. Hyland Parcel Soilogic#07-1070 10 Drainage Positive drainage is imperative for long term performance of the proposed residence and associated site improvements. We recommend positive drainage be developed away from the structure with twelve (12) inches of fall in the first 10 feet away from the building during construction and throughout the life of the site improvements. Shallower slopes could be considered in hardscape areas. In the event that some settlement of the backfill soils occurs adjacent to the residence, the original grade and associated positive drainage outlined above should be immediately restored. Care should be taken in the planning of landscaping to avoid features which could result in the fluctuation of the moisture content of the foundation bearing and/or flatwork subgrade soils. We recommend watering systems be placed a minimum of 5 feet away from the perimeter of the site structure and be designed to discharge away from all site improvements. Gutter systems should be considered to help reduce the potential for water ponding adjacent to the structure with the gutter downspouts, roof drains or scuppers extended to discharge a minimum of 5 feet away from structural, flatwork and pavement elements. Water which is allowed to pond adjacent to site improvements can result in unsatisfactory performance of those improvements over time. Site Percolation Test Six (6) six-inch diameter percolation test holes and one 8-foot deep profile boring were completed in the approximate area of the proposed wastewater absorption field. The materials encountered in the profile boring consisted of approximately 4 to 6 inches of topsoil and vegetation underlain by brown lean clay with sand. The lean clay extended to the bottom of boring at a depth of approximately 8 feet below ground surface. At the time of drilling, groundwater was not encountered in the completed profile boring to the depth explored. Groundwater was not observed in the open profile boring approximately 10 days after the completion of drilling. A log of the profile test hole is included with this report. An average percolation rate of 180 minutes per inch was established in the percolation test borings after presoaking for approximately 24 hours. Weld County guidelines Hyland Parcel Soilogic#07-1070 11 require a percolation rate in the range of 5 to 60 minutes per inch for use of a non- engineered conventional septic absorption field. The measured percolation rate does not meet that criterion. In addition, Weld County guidelines require that neither groundwater nor bedrock be encountered within 4 feet of the bottom of the proposed absorption field. The test boring completed indicates the thickness of the near surface site soils is sufficient enough to develop adequate separation from groundwater and bedrock. An engineered septic system design will need to be completed for this residence. A combination absorption/evapotranspiration system could be considered for this site. Importing silty sand would be required to develop the ET bed. We would be happy to complete an engineered septic system design at your request. Weld County requirements concerning the proximity of system components to site features and amenities should be addressed at the time of system installation. GENERAL COMMENTS This report was prepared based upon the data obtained from the completed site exploration, laboratory testing, engineering analysis and any other information discussed. The completed borings provide an indication of subsurface conditions at the boring locations only. Variations in subsurface conditions can occur in relatively short distanced away from the borings. This report does not reflect any variations which may occur across the site or away from the borings. If variations in the subsurface conditions anticipated become evident, the geotechnical engineer should be notified immediately so that further evaluation can be completed and when warranted, alternative recommendations provided. The scope of services for this project does not include either specifically or by implication any biological or environmental assessment of the site or identification or prevention of pollutants or hazardous materials or conditions. Other studies should be completed if concerns over the potential of such contamination or pollution exist. The geotechnical engineer should 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. The geotechnical Hyland Parcel Soilogic#07-1070 12 engineer should also be retained to provide testing and observation services during construction to help determine that the design requirements are fulfilled. This report has been prepared for the exclusive use of our client for specific application to the project discussed and has been prepared in accordance with the generally accepted standard of care for the profession. No warranties express or implied, are made. The conclusions and recommendations contained in this report should not be considered valid in the event that any changes in the nature, design or location of the project as outlined in this report are planned, unless those changes are reviewed and the conclusions of this report modified and verified in writing by the geotechnical engineer. We appreciate the opportunity to be of service to you on this project. If we can be of further service to in any way or if you have any questions concerning the enclosed information, please do not hesitate to contact us. Very Truly Yours, Soilogic, Inc. OO REG/ �v cy :QS' �':LL • re • ASS/ONA Wolf von Carlowi , P.E. Principal Enginee SEPTEMBER 2007 BORING LOCATION DIAGRAM SOILOGICI PROJECT # 07-1070 Percolation Test Results 1 = 180 min/inch 2 = 180 min/inch 3 = 180 min/inch 4 = 180 min/inch — — 5 = 180 min/inch 6 = 180 min/inch Average = 180 min/inch • N — ' \ NOT TO SCALE — ' B-2 \ o -- / \ o G VC'\\ / B-1 \ -C z z \ -1 ' Approximate Residence Location -< 1 O i 6O4O \ D i p --- 5 8-3 O i --- / 4 / / / Percolation Test Area/ WELD COUNTY ROAD 76.5 HYLAND PARCEL WELD COUNTY, COLORADO HYLAND PARCEL LOG OF BORING B-1 WELD COUNTY, COLORADO SOP-LOGIC Project# 07-1070 September 2007 Sheet 1/1 Drilling Rig: CME 55 Water Depth Information Start Date 8/31/2007 Auger Type: 4"CFA During Drilling 8' Finish Date 8/31/2007 Hammer Type: Manual After Drilling Surface Elev. - Field Personnel: DP 10 Days After Drilling 6.2' N %Passing SOIL DESCRIPTION Depth d "N" MC DD qs %Swell @ Swell Atterberg Limits #200 Sieve o Iro Ix) Ipcf lest) 500 psf Pressure LL PI (%) TOPSOIL AND VEGETATION - 1 2 CL LEAN CLAY WITH SAND - light brown to brown 3 CS 10 20.5 110.1 3500 Nano 400 psf soft to medium star - 4 5 Ss 10 37.7 - 1000 - - • Gravel Zone C2 6' 6 7 8 9 SANDSTONE 10 CS 50/6 28.9 - 2500 • Ugh'brown poorly cemented 11 With Inlerbeaded Slltslone 12 13 10 15 SS 50/6 27.4 - 1500 - - • _ - BOTTOM OF BORING 15.5' 16 17 18 19 20 21 22 23 24 25 HYLAND PARCEL LOG OF BORING B-2 WELD COUNTY,COLORADO SO;LOGIC Project Si 07-1070 September 2007 Sheet 1/1 Drilling Rig: CME 55 Water Depth Information Start Date 8/31/2007 Auger Type: 4"CFA During Drilling 6' Finish Date 8/31/2007 Hammer Type: Manual After Drilling Surface Elev. - Field Personnel: DP 10 Days After Drilling 6.0' '^ %Passing SOIL DESCRIPTION Depth a "N" MC DD q„ %Swell l Swell Atterberg Limits #200 Steve (ft) of (%1 (pc0 lest) 500 psf Pressure LL PI 1x1 TOPSOIL AND VEGETATION - 1 2 CL LEAN CLAY WITH SAND - ligbtbrownto brown 3 soft to medium stiff 4 5 CS 12 26.7 97.2 1000 None <500 psi 40 23 662% 6 7 9 SILTY SAND light brown 10 CS 13 29.0 - 2000 - - - • 462% loose to medium dense - 11 12 SANDSTONE - tight brown 13 poorly cemented 14 With Interbedded Sillstone 15 SS 50/7 27.5 • 3000 • - - BOTTOM OF BORING 15.5' 16 17 18 19 20 21 22 23 24 25 HYLAND PARCEL LOG OF BORING B-3 WELD COUNTY, COLORADO SO'.LOGIC Project# 07-1070 September 2007 Sheet 1/1 Drilling Rig: CME 55 Water Depth informalion Start Date 8/31/2007 Auger Type: 4'CFA During Drilling None Finish Date 8/31/2007 Hammer Type: Manual After Drilling Surface Elev. - Field Personnel: DP 10 Days After Drilling None SOIL DESCRIPTION Depth a "N" MC DD % %00ssing P - q° Swell @ Swell Atterberg Limits #200 Sieve (II) (X) (Pea (PM1) 500 psf Pressure LL PI (x) TOPSOIL AND VEGETATION • 1 CL LEAN CLAY WITH SAND 2 Tight brown to brown soft to medium stiff 3 4 5 6 7 B BOTTOM OF BORING 8' • 9 10 11 12 13 14 15 16 17 15 19 20 21 22 23 24 25 HYLAND PARCEL WELD COUNTY, COLORADO Project# 07-1070 September 2007 SWELL/CONSOLIDATION TEST SUMMARY 12 , To CO r 10 -Ii i 2I I _2 - -a1 . . - . . . ... 5 -81 ''' o 4 -8 .ae -to I -12 I : 'I 10 100 1000 10000 100000 Applied Load (psf) Sample ID: B-1,S-1 @ 2' Sample Description: Brown Lean Clay with Sand Initial Moisture 18.5% - Liquid Limit - Final Moisture 19.3% Plasticity Index _ % Swell @ 500 psf _ None I % Passing#200 - Swell Pressure <500 psf I Dry Density 110.1 pcf s SaLOGIC HYLAND PARCEL WELD COUNTY, COLORADO Project# 07-1070 September 2007 SWELL/CONSOLIDATION TEST SUMMARY 12 I I i 1oJ 8 . . . . . . . . . . . . .. . . . ac 4 . . . . . . . .. __ . 2J Water Added s -s : Go oo . t 4 12 10 100 1000 10000 100000 Applied Load (psf) Sample ID: B-2, 5-1 @ 4' Sample Description: Brown Lean Clay with Sand Initial Moisture 26.9% j Liquid Limit _ _ 40 Final Moisture 24.1% I Plasticity Index 23 %Swell @ 500 psf _ None ! % Passing#200 86.2% Swell Pressure <500 psf I Dry Density 97.2 pcf Y SCIILOGIC UNIFIED SOIL CLASSIFICATION SYSTEM (U5C5) Coorso-Grained Grovels more Nan Clean Grovels Less Soils more than 50% of coarse than 5% lines Cu>4 end cCc<3' GW Well-graded grovel` 50% retained on fraction retained Na. 200 sieve on No. 4 sieve CuC4 and/or 1>CO3' CP Poorly-graded grovel Grovels with Fines Fines Glossily os ML or MN GM Silly gravel, GH more than 12% lines Fines classify as CL or CH GC Clayey Gravel"" Sands 50% or Clean Sands Less Cu≥S and IcccSS` SW Well-graded sand' mare coarse than 5% fines fraction posses Cu<6 and/or I>Cc>3` SP Pearly-graded sand' No. 4 sieve Sands with Fines Fines dassily as ML er MH SM Silty send"" more Irian 12% fines ' Pmes Glossily os CL or CH Sc Clayey send"' Fine-Grained Sills and Cloys inorganic P1>7 and plots on or above 'Aline CL Leon clay"' Sails 50% or Liquid Limit less more passes the than 50 PI<4 or plots boles •A-Line ML Silt's No. 200 sieve organic Liquid Limit - oven dried Organic clay ti-5. <OJ5 OL Liquid Limit - not dried Organic sill'sr' Sills and Clays .n organic Ps plots an or stay -A-Lne CH Fat clay" Liquid Limit 50 or mare PI plots below -A'Line MU Elustic Si 1.0 organic Liquid Limit - oven dried Organic cloy's'. <0.75 OH Liquid Limit - not dried Organic silt Highly organic soils P.Lmarly organic molter. dark in color. and organic odor PT Peat %and um ute reels, oozing Ins l-... Ivs- 1 CU.OdOt Ce" (0x) •a eo&twitch,IS to stHYs No.ECG.odd 511=mole owl deco e D e D predominant 111soa or with Toni'.whichever-n n both. odd 'el l0•`bade`v boulders.as boii. 'n.55 (Ionia:,a 50'plus Ga. ZOO to group mane 'l m e 115x zone.am.n0• tuna t, reeom mur sane,odd ssndr le y:n ar vtlt m 5 le nx Oro,env m era Poorm,n:onions ame. h ° pnoar. l 10 eve closely go a-uL..rr duo' sPnbw a .a1 emmns x Ylz pW,No. 1W ev-w oeo"od a v°•er. a: ee for. p'mam.nanar Sear°,.Odd-eo.O: a G U-01 poorly-graded grovel r a.a 1 m orpmk.ado'-Lin apa•< r ea b NP:1.4 one l'NG -eC pvmlrgltdea grass) ...an day II° r a l oPlae u PI"Pe.-*A�''- sonde .:l0•s m nz lints rtdo,d a group ea l..1,1.os ee ...n yvoq rP1 a 1br. SW-SM SMo.td-9meed s with 'n t e 5n, ise pals 10•01100 era,.spr a e °PI plots bet. w wt Sri-sr. . -gradvd tons wits eLse CL-GL.[Illy e°1 5P-SM poser g'v°m SP-5C pea+,p'sdea eo-n .n0• a r 1OIhe Vern,-wtma rams" .w.0 rw. - lawny.r v... .-- _— ___ _ ___ __..•z s� :K:i" GPI' • I ft rpY --,4---7"-- IMH w OHS T-'f'._� I —i'l DJla LI.IIt 1i-LI9 ra Fine Grained Soils Coarse Grained Soils Bedrock Qu(psf) Consistency Blows/ft Relative Density Blows/ft Weathering e500 Very Soft 0.4 Very Loose 0-50 Weathered 500-1000 Soft 5-8 Loose 50. Competent 1001-2000 Medium Stiff 9-12 Slightly Dense Degree of Weathering 2001-4000 Stiff 7330 Medium Dense Slight: Slight decomposition,possible color change 4001-8000 Very Stiff 31-50 Dense Moderate: Some decomposition and color change throughout 8001-16000 Very Hard 50. Very Dense High: Rock highly decomposed,may be extremely broken GEOLOGY / SOILS INFORMATION to SCIjLCIGIC August 29, 2008 Mr. Pete Hyland 320 East Chestnut Street Windsor, Colorado 80550 Re: Geotechnical Subsurface Exploration Hyland Parcel II Weld County, Colorado Soilogic Project # 08-1047 Mr. Hyland: Soilogic, Inc. (Soilogic) personnel have completed the geotechnical subsurface exploration you requested for the proposed residence to be constructed northeast of the intersection of County Roads 21 and 76.5 in Weld County, Colorado. The results of our subsurface exploration are included with this report. We understand the proposed residence will be a one or two-story wood frame structure constructed over a full basement. Foundation loads for the structure are expected to be light with continuous wall loads less than 3.5 kips per lineal foot and individual column loads less than 50 kips. Wastewater generated by the residence will be disposed of through an on-site individual sewage disposal system (ISDS). The purpose of our investigation was to describe the subsurface conditions encountered in the completed site boring and develop the test data necessary to provide recommendations concerning design and construction of the residence foundations and support of floor slabs and exterior flatwork. The results of a completed site percolation tests are also included. The conclusions and recommendations outlined in this report are based on results of the completed field and laboratory testing and our experience with subsurface conditions in this area. Soilogic, Inc. 1435 Hilltop Circle •Windsor, CO 80550 • (970) 674-3430 Hyland Parcel II Weld County,Colorado Soilogic#08-1047 2 SITE DESCRIPTION The proposed residence will be constructed northeast of the intersection of County Roads 21 and 76.5 in Weld County, Colorado. An irrigation canal forms the north property boundary. At the time of our site exploration, the proposed construction area was vegetated and gently sloping to the northeast with a maximum difference in ground surface elevation across the residence footprint estimated to be less than 2 feet. Evidence of prior building construction was not observed in the proposed construction area by Soilogic personnel at the time of our site exploration. EXPLORATION AND TESTING PROCEDURES To develop subsurface information in the area of the proposed residence, two (2) soil borings were extended to a depth of approximately 15 feet below present site grades within the approximate building footprint. The proposed residence location was established in the field by the client. The boring locations were established in the field by Soilogic personnel based on the proposed residence location. A diagram indicating the approximate boring locations is included with this report. A graphic log of each of the auger borings is also included. The test holes were advanced using 4-inch diameter continuous flight auger powered by a truck-mounted CME-55 drill rig. Samples of the subsurface materials were obtained at regular intervals using California barrel and split-barrel sampling procedures in genera] accordance with ASTM specification D-1586. Penetration resistance measurements were obtained by driving the standard sampling barrels into the substrata using a 140 pound hammer falling a distance of 30 inches. The number of blows required to advance the samplers a distance of 12 inches is recorded and helpful in estimating the consistency, relative density or hardness of the soils or bedrock encountered. In the California barrel sampling procedure, relatively undisturbed samples are obtained in removable brass sleeves. Samples of the subsurface materials obtained in the field were sealed and returned to the laboratory for further evaluation, classification and testing. Hyland Parcel II Weld County,Colorado Soilogic#08-1047 3 As part of our site exploration, one (1) field slotted piezometer was installed at boring location B-1 prior to backfilling to allow for longer term observation of site groundwater levels. Groundwater was measured in piezometer B-1 and open borehole B-2 on one (I) occasion after the completion of drilling. Groundwater level measurements are indicated in the upper right hand corner of the attached boring logs. The samples collected were tested in the laboratory to measure natural moisture content and visually classified in accordance with the Unified Soil Classification System (USCS). The USCS group symbols are indicated on the attached boring logs. An outline of the USCS classification system is included with this report. Classification of bedrock was completed through visual and tactual observation of disturbed samples. Other bedrock types could be revealed through petrographic analysis. As part of the laboratory testing, a calibrated hand penetrometer (CHP) was used to estimate the unconfined compressive strength of essentially cohesive specimens. The CHP also provides a more reliable estimate of soil consistency than tactual observation alone. Dry density, Atterbcrg limits, -200 wash and swell/consolidation tests were completed on selected samples to help establish specific soil characteristics. Atterberg limits tests are used to determine soil plasticity. The percent passing the #200 size sieve (-200 wash) test is used to determine the percentage of fine grained soils (clay and silt) in a sample. Swell/consolidation tests are performed to evaluate soil volume change potential with variation in moisture content. The results of the completed laboratory tests are outlined on the attached boring logs and swelUconsolidation test summaries. SUBSURFACE CONDITIONS The materials encountered in the completed site borings can be summarized as follows. Approximately 4 to 6 inches of topsoil and vegetation was encountered at the surface at the boring locations. The topsoil/vegetation was underlain by light brown to brown sandy lean clay. The lean clay was soft to medium stiff in consistency and showed low swell potential at in situ moisture and density conditions. The softer lean clay encountered with depth would be subject to moderate to high consolidation potential at current moisture and density conditions. The lean clay extended to depths ranging from approximately 10 to 11 feet below ground surface and was underlain by highly weathered Hyland Parcel II Weld County,Colorado Soilogic#08-1047 4 sandstone bedrock. The sandstone was poorly cemented and extended to the bottom of boring at a depth of approximately 15 feet below present site grades. The stratigraphy indicated on the included boring logs represents the approximate location of changes in soil and rock types. Actual changes may be more gradual than those indicated. At the time of drilling, groundwater was encountered in the completed site borings at depths ranging from approximately 9% to 10 feet below present site grades. Groundwater was measured in piezometer B-1 and borehole B-2 at depths of approximately 9.8 and 9.5 feet below ground surface respectively two (2) days after the completion of drilling. Groundwater levels will vary seasonally and over time based on weather conditions, site development, irrigation practices and other hydrologic conditions. Perched groundwater conditions may also be encountered at times throughout the year. Perched water is commonly encountered in soils overlying less permeable soil layers and/or bedrock. The location and amount of perched water can also vary over time. An irrigation canal forms the north boundary of the referenced development lot. The irrigation ditch was observed to be running water at the time of our site exploration. We expect site groundwater levels would be directly impacted by water levels in the irrigation ditch. Longer term observation of site groundwater levels would be required in wells which arc cased and isolated from the influence of surface water to help better define static groundwater levels and possible fluctuations in those groundwater levels over time. ANALYSIS AND RECOMMENDATIONS General Groundwater was measured at depths of approximately 9.8 and 9.5 feet below ground surface at boring locations B-1 and B-2 respectively two (2) days after the completion of drilling. As a precaution, we recommend finish basement floor slab levels be established a minimum of three (3) feet above observed groundwater. Hyland Parcel II Weld County,Colorado Soilogic#08-1047 5 Soft lean clay soils were observed with depth in the completed site borings. The lean clay would be expected to be soft near current groundwater levels. Careful observation of the proposed foundation bearing materials should be completed at the time of construction. If more extensive zones of soft clay arc encountered at or immediately below proposed foundation bearing, some overexcavation/backfill procedures may be required. For full basement construction and in order to maintain the recommended separation distances outlined above, approximately 4 feet of fill will be required to develop finish site grades. Soft lean clay soils with high consolidation potential were encountered with depth in the completed site borings. With the amount of fill required to develop the site, some movement of the placed fill soils would be expected over time as the underlying soft clay layer consolidates under the additionally imposed loads. With the essentially cohesive nature of the site lean clay, we recommend the proposed fill soils be placed on the development lot as early as possible in the construction process and allowed to remain in place for an extended period of time to allow for consolidation of the soft clay. We estimate fill soils would need to remain in place for a minimum of eight (8) weeks prior to commencing construction of the residence. As an alternative, consideration could be given to use of a deep foundation system. Drilled piers would extend structural loads to sandstone bedrock underlying the site significantly reducing the potential for post construction movement of the supported residence. We estimate drilled piers on the order of approximately 20 feet in length with minimum bedrock penetrations of approximately 15 feet would be required for the residence. We expect casing of the drilled piers would be required during construction to prevent sloughing soils from entering the drilled shafts prior to concrete placement. We would be happy to provide drilled pier design parameters at your request. Site Development All existing topsoil and vegetation should be removed from proposed fill and flatwork areas. After stripping and completing all cuts and prior to placement of any overlying fill or flatwork concrete, we recommend the exposed subgrade soils be scarified to a depth of Hyland Parcel II Weld County,Colorado Soilogic#08-1047 6 9 inches, adjusted in moisture content and compacted to at least 95% of the materials standard Proctor maximum dry density. The moisture content of the reconditioned subgrade soils should be adjusted to be within the range of ±2% of standard Proctor optimum moisture content at the time of compaction. Fill soils required to develop the site should consist of approved low volume change soils free from organic matter, debris and other objectionable materials. Based on the results of the completed laboratory testing, it is our opinion the site lean clay or processed sandstone bedrock could be used as fill to develop the site. Wet materials encountered with depth would need to be dried out prior to placement as fill. If it is necessary to import fill material to the site, those materials should have low potential for volume change and be relatively impervious. Fill soils should be approved prior to use. We recommend fill soils similar to the site lean clay be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content and compacted as recommended for the scarified materials above. Foundations After a majority of the anticipated soft clay consolidation has occurred, we expect the proposed lightly loaded residence could be supported by continuous spread footing and isolated pad foundations bearing on the site lean clay. In order to help reduce the potential for differential movement of the residence, we recommend all footing foundations be extended to bear on natural undisturbed lean clay. Some extending of garage stemwall foundations may be required to develop consistent foundation bearing. For design of footing foundations bearing on medium stiff lean clay, we recommend using a maximum net allowable soil bearing pressure of 1500 psf. For design of footing foundations and foundation walls to resist lateral movement, a passive equivalent fluid pressure value of 200 pcf could be used. The top 30 inches of subgrade could be considered a surcharge load but should not be uscd in the passive resistance calculations. A coefficient of friction of 0.25 could be used between foundation and floor slab concrete and the bearing soils to resist sliding. The recommended passive equivalent fluid pressure value and coefficient of friction do not include a factor of safety. Hyland Parcel II Weld County,Colorado Soilogic#08-1047 7 Exterior footings should be placed a minimum of 30 inches below finished adjacent exterior grade to provide frost protection. We recommend formed strip footings have a minimum width of 12 inches and isolated pad foundations have a minimum width of 24 inches in order to facilitate construction and reduce the potential for development of eccentrically loaded footings. Actual footing widths should be designed by a structural engineer. The site lean clay would be easily disturbed by the construction activities. Soils which are disturbed or allowed to become wetted or dried prior to foundation construction should be removed and replaced or reworked in place prior to concrete placement. We estimate settlement of footing foundations designed and constructed as outlined above would be less than 1 inch. Differential settlement could approach the amount of total settlement estimated above. Floor Slabs and Exterior Flatwork In the basement area of the residence, the floor slab could be supported directly on natural undisturbed lean clay. A thin sand leveling course could be considered to facilitate finish grading. Depending on the type of floor covering and floor covering adhesive used in the basement area, a vapor barrier may be required immediately beneath the basement floor slab. A vapor barrier would help reduce the transmission of moisture through the basement floor slab. However, the unilateral moisture release caused by placing concrete on an impermeable surface can increase slab curl. The amount of slab curl can be reduced by careful selection of an appropriate concrete mix. Slab curl cannot be eliminated. We recommend the owner, architect and flooring contractor consider the performance of the slab in conjunction with the proposed flooring products to help determine if a vapor barrier will be required and where best to position the vapor barrier in relation to the floor slab. Additional guidance and recommendations concerning slab on grade design can be found in American Concrete Institute (ACI) section 302. Hyland Parcel II Weld County,Colorado Soilogic#08-1047 8 In slab-on-grade and exterior flatwork areas, those slabs could be supported on reconditioned natural site soils or suitable fill soils placed and compacted as outlined above. Subgrade soils expected to receive flatwork concrete should be evaluated closely immediately prior to concrete placement. If areas of disturbed, wet and softened, or dry subgrade soils are encountered at that time, those materials should be removed and replaced or reworked in place prior to concrete placement. As a precaution, we recommend all residence and garage partition walls be constructed as floating walls to help reduce the potential for differential slab to foundation movement causing distress in upper sections of the residence. Special attention to door framing, drywall, and trim carpentry should be taken to isolate those elements from the floor slabs allowing for some differential floor slab to foundation movement to occur without transmitting stresses to the overlying structure. Basement Construction We recommend a perimeter drain system be installed around all below grade areas to help reduce the potential for development of hydrostatic pressures behind the below grade walls and water infiltration into the basement area. A perimeter drain system should consist of a perforated drain pipe surrounded by a minimum of six (6) inches of free draining gravel. A filter fabric should be considered around the free draining gravel or perforated pipe to reduce the potential for an influx of fine grained soils into the system. The drain pipe should be placed at approximate foundation bearing level around the exterior perimeter of the below grade area and run to a sump pit or free outfall with a minimum slope of 1/8 inch per foot to facilitate efficient water removal. If a free outfall will be considered, measures to help reduce the potential for reverse flow and animal access into the system should be considered. Backfill placed adjacent to the below grade walls should consist of low volume change potential and relatively impervious soils free from organic matter, debris and other objectionable materials. The site lean clay or thoroughly processed sandstone bedrock could be used as backfill in this area. Hyland Parcel II Weld County,Colorado Soilogic#08-1047 9 Site lean clay or similar backfill soils should be placed in loose lifts not to exceed 9 inches thick, adjusted to be within ±2% of standard Proctor optimum moisture content and compacted to at least 95% of the materials standard Proctor maximum dry density. Excessive lateral stresses can be imposed on below grade walls when using heavier mechanical compaction equipment. We recommend compaction of unbalanced foundation wall backfill soils be completed using light mechanical or hand compaction equipment. Lateral Earth Pressures For design of below grade walls where preventative measures have been taken to reduce the potential for development of hydrostatic pressures on the walls, we recommend using an active equivalent fluid pressure of 40 pounds per cubic foot. Some rotation of the basement wall must occur to develop the active earth pressure state. That rotation can result in cracking of the basement walls typically in between corners and other restrained points. The amount of deflection of the top of the wall can be estimated at 0.5% times the height of the wall. An equivalent fluid pressure of 60 pounds per cubic foot could be used for restrained wall conditions. Variables that affect lateral earth pressures include but are not limited to the swell potential of the backfill soils, backfill compaction and geometry, wetting of the backfill soils, surcharge loads and point loads developed in the backfill materials. The recommended equivalent fluid pressure values do not include a factor of safety or an allowance for hydrostatic loads. Use of expansive soil backfill, excessive compaction of wall backfill or surcharge loads placed adjacent to the basement walls can add to the lateral earth pressures causing the equivalent fluid pressure values used in design to be exceeded. Drainage Positive drainage is imperative for long term performance of the proposed residence and associated site improvements. We recommend positive drainage be developed away from the structure with twelve (12) inches of fall in the first 10 feet away from the Hyland Parcel II Weld County,Colorado Soilogic#08-1047 10 building during construction and throughout the life of the site improvements. Shallower slopes could be considered in hardscape areas. In the event that some settlement of the backfill soils occurs adjacent to the residence, the original grade and associated positive drainage outlined above should be immediately restored. Care should be taken in the planning of landscaping to avoid features which could result in the fluctuation of the moisture content of the foundation bearing and/or flatwork subgrade soils. We recommend watering systems be placed a minimum of 5 feet away from the perimeter of the site structure and be designed to discharge away from all site improvements. Gutter systems should be considered to help reduce the potential for water ponding adjacent to the structure with the gutter downspouts, roof drains or scuppers extended to discharge a minimum of 5 feet away from structural, flatwork and pavement elements. Water which is allowed to pond adjacent to site improvements can result in unsatisfactory performance of those improvements over time. Site Percolation Test Six (6) six-inch diameter percolation test holes and one 8-foot deep profile boring were completed in the approximate area of the proposed wastewater absorption field. The materials encountered in the profile boring consisted of approximately 4 to 6 inches of topsoil and vegetation underlain by brown sandy lean clay. The lean clay extended to the bottom of boring at a depth of approximately 8 feet below ground surface. At the time of drilling, groundwater was not encountered in the completed profile boring to the depth explored. Groundwater was not observed in the open profile boring two (2) days after the completion of drilling. A log of the profile test hole is included with this report. An average percolation rate of 140 minutes per inch was established in the percolation test borings after presoaking for approximately 24 hours. Weld County guidelines require a percolation rate in the range of 5 to 60 minutes per inch for use of a non- engineered conventional septic absorption field. The measured percolation rate does not meet that criterion. In addition, Weld County guidelines require that neither groundwater nor bedrock be encountered within 4 feet of the bottom of the proposed absorption field. The test boring completed indicates the near surface site soils meet the groundwater and bedrock separation criteria. An engineered septic system design will need to be Hyland Parcel II Weld County,Colorado Soilogic#08-1047 1I completed for this residence due to the relatively slow percolation rates measured in the field. A combination absorption/evapotranspiration or low application drip system could be considered for this site. Importing silty sand would be required to develop an ET bed if that type of system is preferred. We would be happy to complete an engineered septic system design at your request. Weld County requirements concerning the proximity of system components to site features and amenities should be addressed at the time of system installation. GENERAL COMMENTS This report was prepared based upon the data obtained from the completed site exploration, laboratory testing, engineering analysis and any other information discussed. The completed borings provide an indication of subsurface conditions at the boring locations only. Variations in subsurface conditions can occur in relatively short distanced away from the borings. This report does not reflect any variations which may occur across the site or away from the borings. If variations in the subsurface conditions anticipated become evident, the geotechnical engineer should be notified immediately so that further evaluation can be completed and when warranted, alternative recommendations provided. The scope of services for this project does not include either specifically or by implication any biological or environmental assessment of the site or identification or prevention of pollutants or hazardous materials or conditions. Other studies should be completed if concerns over the potential of such contamination or pollution exist. The geotechnical engineer should 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. The geotechnical engineer should also be retained to provide testing and observation services during construction to help determine that the design requirements are fulfilled. This report has been prepared for the exclusive use of our client for specific application to the project discussed and has been prepared in accordance with the generally accepted standard of care for the profession. No warranties express or implied, are made. The Hyland Parcel II Weld County, Colorado Soilogic#08-1047 12 conclusions and recommendations contained in this report should not be considered valid in the event that any changes in the nature, design or location of the project as outlined in this report are planned, unless those changes are reviewed and the conclusions of this report modified and verified in writing by the geotechnical engineer. We appreciate the opportunity to be of service to you on this project. If we can be of further service to in any way or if you have any questions concerning the enclosed information,please do not hesitate to contact us. Very Truly Yours, Soilogic, Inc,...•.'^ •N c,SrF• • (L.•N. ECG,.. Wolf von Carlow" z, P.E. Principal Engineer a AUGUST 2008 BORING LOCATION DIAGRAM SOLOG'C PROJECT # 08-1047 Percolation Test Results 1 = 120 min/inch A 2 = 120 min/inch .1 3 = 120 min/inch 4 = 120 min/inch 5 = 180 min/inch — — \ 6 = 180 min/inch — N Average = 140 min/inch T \ N � � NOT TO SCALE — ' 1 \ \ \ m p op 1 1 \ o I ZC o� 1 \ Z --- 5 ea 3 — — O O I 1 \ A Percolation Test Area-./-------- 6 O 2 1 1 \ o i1> -- I \ \ 0 - r, I \ I \ ..- B-1t e-z I \ N I I Approximate Residence Location I 1 \ WELD COUNTY ROAD 76.5 H HYLAND PARCEL II WELD COUNTY, COLORADO HYLAND PARCEL II LOG OF BORING B-1 WELD COUNTY, COLORADO SCI,LCIGIC Project# 08.1047 August 2008 Sheet 1/1 Drilling Rig: CME 55 Water Depth Information Start Date 8/25/2008 Auger Type: 4"CFA During Drilling 10' Finish Date 8/25/2008 Hammer Type: Manual After Drilling Surface Elev. - Field Personnel: WvC 2 Days After Drilling 9.8' n cc e/Passing SOIL DESCRIPTION Depth c. "N" MC DD q„ %Swell @ Swell Atterberg Limits #200 Sieve lel s 1%) loch irs0 500 psf Pressure LL PI (1:) TOPSOIL AND VEGETATION 1 2 CL SANDY LEAN CLAY - VI brown to brown 3 CS 5 15.2 100.2 6500 None COO pet soft to medium stilt - 4 5 55 6 16.2 6500 5 8 9 10 CS 5 22.e 4500 11 12 SANDSTONE light brown 13 poorly cemented . 14 15 SS 50/10 25.3 3000 - BOTTOM OF BORING 15.5' 16 17 18 19 20 21 22 23 24 25 HYLAND PARCEL II LOG OF BORING 8-2 WELD COUNTY, COLORADO SO(LOGIC Project# 08.1047 -� August 2008 Sheet 1/1 Drilling Rig: CME 55 Water Depth Information Start Date 8/26/2008 Auger Type: 4"CFA During Drilling 9.5' Finish Date 8/26/2008 Hammer Type: Manual After Drilling Surface Elev. - Field Personnel: WvC 2 Days After Drilling 9.5' %Passing SOIL DESCRIPTION Depth a "N" MC DD qv %Swell @ Swell Atterberg Limits #200 Sieve Iro H 1%) (pot) Ipso 500 psf Pressure LL PI t%1 TOPSOIL AND VEGETATION - 1 2 CL SANDY LEAN CLAY - light brown to brown 3 soil to nwdium stiff - 4 5 CS 6 18.8 101.9 4500 None <500 psf 29 14 62.3% 6 7 B 9 Very Soft©V 10 SS 6 24.9 <500 11 12 SANDSTONE light brown 13 poorly cemented 14 15 SS 50/10 27.9 9000+ BOTTOM OF BORING 15.5' 16 17 18 19 20 21 22 23 24 25 HYLAND PARCEL II LOG OF BORING B-3 WELD COUNTY,COLORADO SOilLOGIC Project if 08.1047 August 2008 Sheet 1/1 Drilling Rig: CME 55 Water Depth Information Start Date 8/26/2008 Auger Type: 4"CFA During Drilling None Finish Date 8/26/2008 Hammer Type: Manual After Drilling Surface Elev. - Field Personnel: WvC 2 Days After Drilling None ut V.Passing SOIL DESCRIPTION Depth ii "N" MC DD q„ %Swell @ Swell Atterberg Limits #200 Sieve IFit ..51 1st Ipp0 , 0350 500 psf Pressure LL PI Ixt TOPSOIL AND VEGETATION - 1 CL SANDY LEAN CLAY 2 light Drown to brown soft to medium Of 3 4 5 6 B BOTTOM OF BORING 8' - 9 • 10 11 12 • 13 14 • 15 16 17 18 19 20 • 21 22 • 23 24 25 HYLAND PARCEL II WELD COUNTY, COLORADO Project# 08-1047 August 2008 SWELUCONSOLIDATION TEST SUMMARY 12 ------,---7 IiII II I i l III : II 10 I I ll ICI I Il I ' ll 9 I : il : I 1 1 , l I ' I L I! 'l 111 ( ' "I I w e iii ! I I ! I ae I II ; I , Iii- 2 II 0 .� I 1111 Iii I I I I , _2 I I I ' I , ' I ; 1 I,1 I I II I I I w } I ; I I I I ; I I i i I II Ii I I co ! I IIII to 1 I 1 I I i 1 C 1 II II I I iI am _g I I ', I 11IIII• i �1 :' 'I • I I ; I I it i I III -12 10 100 1000 10000 100000 Applied Load (psf) Sample ID: 8-2,S-1 @ 4' Sample Description: Brown Sandy Lean Clay Initial Moisture 20.3% I Liquid Limit 29 Final Moisture _ 20.4% I Plasticity Index 14 %Swell @ 500 psf None ' % Passing#200 62.3% Swell Pressure <500 psf I Dry Density 101.9 pcf s SOLCIGIC Hello