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Home My WebLink AboutASPEN HEIGHTS STUDENT HOUSING - PDP - PDP110018 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTPRELIMINARY GEOTECHNICAL EXPLORATION REPORT ASPEN HEIGHTS FORT COLLINS, COLORADO SOILOGIC # 11-1074 October 24, 2011 SOILOGIC October 24, 2011 Owen Consulting Group, Inc. 3715 Shallow Pond Drive Fort Collins, Colorado 80528 Attn: Mr. Larry C. Owen, P.E. Re: Preliminary Subsurface Exploration Aspen Heights Fort Collins, Colorado Soilogic Project # 11-1074 Mr. Owen: Soilogic, Inc. (Soilogic) personnel have completed the preliminary geotechnical subsurface exploration for Aspen Heights located southeast of the intersection of Conifer Street and Blue Spruce Drive in Fort Collins, Colorado. The results of our preliminary exploration are included with this report. The subsurface materials encountered in the completed test borings consisted of a thin layer of topsoil and vegetation underlain by light brown to brown lean clay with varying amounts of silt and sand. The near surface lean clay was relatively stiff and dry at the time of drilling and showed moderate to high swell potential at current moisture and density conditions. Moist lean clay with low swell potential was encountered with depth in the completed site borings. The lean clay extended to depths ranging from approximately 5 to 8'/2 feet below ground surface and was underlain by reddish brown/grey sand and gravel. The sand and gravel was dense and would be subject to low swell potential at in situ moisture and density conditions. The sand and gravel extended to the bottom of borings B-1, B-2, B-4 and B-5 at a depth of approximately 15 feet below present site grades. Auger refusal was reached at a depth of approximately 11 feet below ground surface at boring location B-3 in what appeared to be larger cobble or possible boulder sized material. Groundwater level measurements were completed in the five (5) installed site piezometers approximately 19 days after the completion of drilling. A that time, groundwater was measured at depths of approximately 6.8, 6.3, 6.6, 10.0 and 6.4 feet below ground surface at boring locations B-1 through B-5 respectively. Soilogic, Inc. 4350 Highway 66 • Longmont, CO 80504 • (970) 674-3430 P.O. Box 1121 • Hayden, CO 81639 • (970) 276-2087 Aspen Heights Fort Collins, Colorado Soilogic # 11-1074 2 Based on the subsurface conditions encountered results of laboratory testing and type of construction proposed, we expect a majority of the proposed lightly loaded residential site structures could be constructed with conventional footing foundations and floor slabs bearing on a mat of properly placed and compacted overexcavation/backfill. Extending footing foundations deeper to bear on low swelling moist lean clay or sand and gravel could also be considered. The overexcavation/backfill procedures would develop a zone of low volume change potential soils beneath footing foundations and floor slabs reducing the potential for post construction heaving of those supported elements. The risk of some movement cannot be eliminated. Similar overexcavation/backfill procedures could be completed to develop low volume change potential exterior flatwork and pavement support. Other preliminary opinions and recommendations concerning design criteria and constriction details for the proposed site improvements are included with this report. Preliminary pavement section design estimates are also included. 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. po_REc' \1 o N c '� Wolf von CarVwitz, P.E. Principal Engineer PRELIMINARY GEOTECHNICAL EXPLORATION REPORT ASPEN HEIGHTS FORT COLLINS, COLORADO SOILOGIC # 11-1074 October 24, 2011 INTRODUCTION This report contains the results of the preliminary geotechnical subsurface exploration completed for Aspen Heights in Fort Collins, Colorado. The purpose of our investigation was to describe the subsurface conditions encountered in the completed site borings and develop preliminary recommendations concerning design and construction of lightly loaded foundations and support of floor slabs, exterior flatwork and site pavements. Recommendations concerning the installation of site utilities and preliminary pavement section design estimates 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. PROPOSED CONSTRUCTION The Aspen Heights project involves the development of approximately 31 acres as student housing to include both single family and duplex units. We understand the proposed structures will be lightly loaded one or two story wood frame structures constructed as non -basement. Foundations loads for the structures are expected to be light with continuous wall loads less than 3 kips per lineal foot and individual column loads less than 50 kips. Infrastructure improvements for the development will include utility installation and interior drive and parking area construction. Small grade changes are anticipated to develop finish site grades. SITE DESCRIPTION The development parcel includes a total of approximately 31 acres located southeast of the intersection of Conifer Street and Blue Spruce Drive in Fort Collins, Colorado. At the time of our site exploration, the site was vegetated and gently sloping to the southeast with the maximum difference in ground surface elevation across the site estimated to be Aspen Heights Fort Collins. Colorado Soilogic # 11-1074 2 less than 10 feet. Evidence of prior building construction was not observed on the development parcel by Soilogic personnel at the time of our site exploration. SITE EXPLORATION Field Exploration To develop preliminary subsurface information across the development parcel, a total of five (5) soil borings were extended to depths ranging from approximately 11 to 15 feet below present site grades. The boring locations were established in the field by Soilogic personnel using a mechanical survey wheel and by estimating angles from identifiable site references. The boring locations should be considered accurate only to the degree implied by the methods used to make the field measurements. 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 trick -mounted CME-55 drill rig. Samples of the subsurface materials were obtained at regular intervals using California and split -barrel sampling procedures in general accordance with ASTM specification D-1586. As part of the D-1586 sampling procedure, standard sampling barrels are driven 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 or relative density of the soils encountered. In the California barrel sampling procedure, relatively undisturbed samples are obtained in removable brass liners. Samples of the subsurface materials obtained in the field were sealed and returned to the laboratory for further evaluation, classification and testing. To allow for longer term observation of site groundwater levels, field slotted PVC piezometers were installed in the open boreholes prior to backfilling. Groundwater level measurements were completed in the installed site piezometers on one (1) occasion after the completion of drilling. Groundwater level measurements are indicated in the upper right-hand corner of the attached boring logs. Aspen Heights Fort Collins, Colorado Soilo,,ic # 11-1074 Laboratory Testing 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. 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, 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 detennine 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. Results of the completed laboratory tests are outlined on the attached boring logs and swell/consolidation test summaries. SUBSURFACE CONDITIONS The subsurface materials encountered in the completed site borings can be summarized as follows. Approximately 3 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 varying amounts of silt and sand. The near surface lean clay was relatively stiff and dry at the time of drilling and showed moderate to high swell potential at current moisture and density conditions. Moist lean clay with low swell potential was encountered with depth in the completed site borings. The lean clay extended to depths ranging from approximately 5 to 8% feet below ground surface and was underlain by reddish brown/grey sand and gravel. The sand and gravel was dense and would be subject to low swell potential at in situ moisture and density conditions. The sand and gravel extended to the bottom of borings B-1, B-2, B-4 and B-5 at a depth of approximately 15 feet below present site grades. Auger refusal was reached at boring location B-3 at a depth of approximately 1 1 feet below ground surface in what appeared to be larger cobble or possible boulder sized material. Aspen Heights Fort Collins. Colorado Soilogic # 11-1074 4 The stratigraphy indicated on the included boring logs represents the approximate location of changes in soil types. Actual changes may be more gradual than those indicated. At the time of drilling, groundwater was encountered at depths ranging from approximately 6 to 9 feet below ground surface in the completed site borings. Groundwater was measured in the installed site piezometers approximately 19 days after the completion of drilling. At that time groundwater was measured at depths of approximately 6.8, 6.3, 6.6, 10.0 and 6.4 feet below ground surface at boring locations B- 1 through B-5 respectively. Groundwater level measurements are indicated in the upper right-hand corner of the attached boring logs. Groundwater levels will vary seasonally and over time based on weather conditions, site development, irrigation practices and other hydrologic conditions. Perched and/or trapped 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. Trapped water is commonly encountered within more permeable zones of layered soil or bedrock systems. The location and amount of perched/trapped water can also vary over time. Longer -term observation of site groundwater levels in the installed site piezometers would be required to more accurately establish seasonal high groundwater levels and possible fluctuations in those groundwater levels over time. ANALYSIS AND RECOMMENDATIONS General The near surface light brown to brown lean clay encountered at this site was relatively dry and stiff at the time of drilling and showed moderate to high swell potential at in situ moisture and density conditions. Heaving of site improvements supported directly on or immediately above the expansive lean clay would be expected as the moisture content of those materials increases subsequent to construction. Based on results of the completed field and laboratory testing, we expect overexcavation/backfill procedures or other alternative foundation systems will be required to help reduce the potential for post construction heaving of site improvements placed directly on moderately expansive site Aspen Heights Fort Collins, Colorado SoiloQic # 1 1-1074 v 5 lean clay. In structural areas, overexcavation to moist lean clay or sand and gravel level should be anticipated. Moist lean clay soils were encountered at a depth of approximately four (4) feet below ground surface in the completed site borings. In exterior flatwork and pavement areas and since movement of exterior flatwork and site pavements is generally less consequential than structural movement, a minimum of two (2) to three (3) feet of overexcavation/backfill could be used for preliminary estimates in these areas. The specific depth of overexcavation/backfill may vary across the site based on the subgrade soils encountered and moisture content of those materials observed. Groundwater was measured at depths of approximately 6.8, 6.3, 6.6, 10.0 and 6.4 feet below ground surface at boring locations B-1 through B5 respectively approximately 19 days after the completion of drilling. Care will be required in establishing finish crawl space subgrade and floor slab levels above groundwater. Typically we recommend finish crawl space subgrade and floor slab levels be established a minimum of three (3) feet above observed groundwater level. Zones of soft clay were encountered with depth in the completed site borings. Depending on anticipated cuts, the site lean clay soils would be expected to become softer with depth near current groundwater levels. The soft clay encountered with depth would be easily disturbed by construction activities. Soils which are disturbed by the construction activities should be removed and replaced or reworked or stabilized in -place prior to placement of any overlying improvements. Dewatering of utility excavations extended below groundwater should be expected. Site Development All existing topsoil and vegetation should be removed from proposed fill, building, exterior flatwork and pavement areas. After stripping and completing all cuts and any overexcavation and prior to placement of any overlying fill, overexcavation/backfill or site improvements, we recommend the exposed subgrade soils be scarified to a depth of 9 inches, adjusted in moisture content and compacted to within the range of 94 to 98% 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 -1 to +3% of standard Proctor optimum moisture content at the time of compaction. Depending on the Aspen Heights Fort Collins. Colorado Soilogic # 11-1074 6 depth of site cuts, stabilization procedures may be required in some areas to develop a suitable working platform. Fill and overexcavation/backfill soils required to develop structural areas of 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 and underlying sand and gravel could be used as fill and overexcavation/backfill. Some drying of the wetter soils encountered with depth would be required prior to placement as fill. If it is necessary to import fill material to the site, those materials should consist of approved low -volume change potential soils. We recommend the site lean clay or similar soils be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content and compacted as recommended for the scarified materials above. Imported low volume change fill soils and the site sand and gravel should be placed in loose lifts not to exceed 9 inches thick, adjusted to within ±2% of standard Proctor optimum moisture content and compacted to at least 95% of standard Proctor maximum dry density. Conventional Footings and Floor Slabs Based on the materials encountered in the completed site borings and results of laboratory testing, we believe lightly loaded site structures could be constructed with conventional spread footing foundations and floor slabs bearing on a zone of moisture conditioned and compacted overexcavation backfill. Extending footing foundations to bear on moist lean clay or sand and gravel with low swell potential could also be considered. Overexcavation/backfill procedures will reduce the swell potential of the relatively dry near surface clay reducing the amount of post construction heaving of the supported improvements. The risk of some movement cannot be eliminated. In general, the overexcavation area would extend 8 inches laterally past the edges of the footings and floor slabs for every 12 inches of overexcavation depth. A four (4) foot depth of overexcavation could be used for preliminary estimates. Site specific subsurface explorations would be required to better define the swell potential and depth of expansive near surface lean clay in the proposed construction areas and specific overexcavation/backfill recommendations. Aspen Heights Fort Collins. Colorado Soilogic # 11-1074 7 The reconditioned soil zone can be developed through any combination of overexcavation/backfill and/or fill placement procedures. It would be possible to undercut the stricture, pavement and exterior flatwork areas of the site as part of the initial grading and backfill those soils as moisture conditioned and compacted low - volume change fill. For design of footing foundations bearing on properly placed and compacted overexcavation/backfill soils developed as outlined above or natural site soils with low swell potential, maximum net allowable total load soil bearing pressures in the range of 1000 to 2000 psf appear usable. The net bearing pressure refers to the pressure at foundation bearing level in excess of the minimum surrounding overburden pressure. Total load would include full dead and live loads. Lightly loaded floor slabs could be supported directly on the controlled and compacted overexcavation/backfill soils developed as outlined above. Care should be taken in overexcavation/backfill areas to insure the proper moisture contents are maintained in the reconditioned soils prior to concrete placement. Floor slab subgrades which become dry and desiccated or wet and softened would require removal and replacement or reworking in -place prior to floor slab construction. Post Tensioned Slab -on -Grade Foundations Post tension slab -on -grade foundation systems could be considered for non basement construction. In general, post -tensioned slab foundations consist of a combined floor slab and foundation system joined together with post -tensioning tendons. The post -tensioned system moves as a single unit to reduce differential movement between floor slab and foundation elements. Use of post -tensioned slab foundations will not eliminate overall movement of the structures, but would significantly reduce the potential for differential movement across the building footprints. Care should be taken during design of the post - tensioned structures to allow for flexible connections for all utilities where those services enter the building. In addition, care should be taken at entryways to allow for some differential movement between the structures and adjacent flatwork, steps, or other immediately adjacent site improvements. Aspen Heights Fort Collins, Colorado Soilogic # 11-1074 8 Post tensioned slab -on -grade foundations are most applicable with a uniform floor level and a minimum amount of required floor penetrations. If stepped floor levels or extensive areas of floor penetrations are required, the post -tensioned system may not be possible. Deep Foundations Drilled pier or driven pile foundations could also be considered for support of the proposed site structures. Drilled piers and driven piles would develop support capacity through end bearing and skin friction in the overburden soils and bedrock underlying the site. Design parameters for the drilled pier and driven pile foundations would need to be developed through more extensive subsurface exploration. For preliminary estimates, minimum pier/pile lengths on the order of approximately 25 feet should be anticipated. Casing of drilled shafts would most likely be required to prevent soil and groundwater from entering the shaft excavations prior to concrete placement. Specialized rock auger or coring equipment may be required to penetrate larger cobble and possible boulder sized material. Similarly, driving shoes may be required to facilitate advancing piles through cobbles and boulders. If drilled pier or driven pile foundation systems are constructed, overexcavation/backfill procedures or structural flooring systems should be employed to reduce the potential for movement of the building floors. Exterior Flatwork Subgrades Movement of exterior flatwork placed directly on the expansive near surface soils would be expected subsequent to construction. Overexcavation/backfill procedures could be completed to reduce the potential for post construction movement of those improvements with increases in subgrade moisture content. The risk of some movement cannot be eliminated. A minimum of two (2) to three (3) feet of overexcavation/backfill could be used for preliminary estimates for exterior flatwork areas. Care should be taken in design of building entryway concrete to insure that when those improvements move, the integrity of the adjacent structure and usability of building doors Aspen Heights Fort Collins, Colorado Soilogic # 11-1074 9 and entryways is not compromised. Care should also be taken to insure that when exterior flatwork moves, positive drainage will be maintained away from the buildings. Pavements With the expansive nature of the near surface site lean clay, overexcavation/backfill procedures could be considered to reduce the potential for movement of site pavements. A minimum of two (2) to three (3) feet of overexcavation/backfill could be used for preliminary estimates in pavement areas. Overexcavation of the pavement subgrades will not necessarily preclude the need for subgrade stabilization. The site lean clay would be susceptible to instability with a tendency to pump when elevated in moisture content. If construction occurs during wet periods of the year or if the moisture content of the subgrade soils is adjusted to the high end of the allowable moisture range, stabilization may still be required. As an alternative to overexcavation/backfill procedures, it is our opinion fly ash stabilization of the pavement subgrades could be considered to reduce the swell potential of the lean clay subgrade soils and increase support strength. If subgrade stabilization is planned, a reduction in the thickness of the supported pavement section may be allowed with the higher strength subgrade soils developed through the stabilization procedures. Some movement of lightly loaded site pavements where the depth of reconditioning/subgrade stabilization is limited should be expected. We anticipate a majority of the site drive and parking areas will be used by low to moderate volumes of automobiles and light trucks and occasional trash truck traffic. A Hveem R-value of 5 was estimated for the site sandy lean clay and used for preliminary pavement section design estimates. At this time and based on the subgrade soils encountered in the completed site borings, a composite pavement section consisting of approximately 4 to 5 inches of asphaltic concrete overlying 6 to 8 inches of aggregate base course could be used for preliminary estimates for the project. If subgrade stabilization will be completed, a pavement section consisting of 3 to 4 inches of asphaltic concrete overlying 4 to 6 inches of aggregate base course overlying 12 inches of fly ash treated subgrade could be used for preliminary estimates. Pavement areas Aspen Heights Fort Collins. Colorado Soilogic # l 1-1074 10 expected to receive heavier trucks or higher traffic volumes may require thicker pavement sections. Other Considerations Positive drainage should be developed away from site structures and away from the pavement edges with a minimum slope of 1 inch per foot for the first 10 feet away from those improvements. Developing proper and efficient control of drainage waters is essential for long-term performance of all site improvements. Utility Installation Bedding around utility pipelines should be placed in accordance with recommendations from the pipeline designer. Backfill soils placed above pipelines should consist of approved materials which are free from organic matter, debris and other objectionable materials. The on -site lean clay and sand and gravel could be used as pipeline backfill. Lean clay pipeline backfill should be placed in maximum 9-inch loose lifts, adjusted to within -1 to +3% of standard Proctor optimum moisture content and compacted to within the range of 94 to 98% of the materials standard Proctor maximum dry density. Sand and gravel backfill soils should be placed in maximum 9-inch loose lifts, adjusted to within +2% of standard Proctor optimum moisture content and compacted to at least 95% of the materials standard Proctor maximum dry density. Wet soils encountered with depth would need to be dried prior to placement as utility backfill. Depending on site cuts and the depth of site utilities, dewatering of trench excavations extended below site groundwater levels should be expected. Care will be needed to develop stable side slopes in pipeline trenches excavated through soft clay and essentially granular overburden soils. LIMITATIONS This report was prepared based upon the data obtained from the completed site exploration, laboratory testing, engineering analysis and any other information discussed. Aspen Heights Fort Collins, Colorado Soilogic # 1 1-1074 11 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 and supplemental recommendations can be 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 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. r' CD Q 0 Z O F— Q U O J 0 Z FY O m O � N C W m Z�lz O U U O w D O ry C REDWOOD STREET M I o] 1 i I w I w � I V 0 z m o c.� I I BLUE SPRUCE DRIVE I I L— — — — — — — — — — — — — — — -- — — — — W J a U = �— rO O Z O Z cn C� w Z W n in Q ASPEN HEIGHTS LOG OF BORING B-1 FORT COLLINS, COLORADO Project# 11-1074 SOv,LOG'C October 2011 Sheet 1/1 Drilling Rig: CME 55 Water Depth Information Start Date 10/5/2011 Auger Type 4" CFA During Drilling 6.5' Finish Date 10/5/2011 Hammer Type: Manual After Drilling 6.5' Surface Elev. - Field Personnel: KSK 19 Days After Drilling 6.8' rn m Estd. % Passing SOIL DESCRIPTION Depth E "N" MC DD (pcf) q (psf) % Swell @ 500 psf Swell Pressure Atterberg Limits ILL PI # 200 Sieve I ) 6" TOPSOIL AND VEGETATION - 1 CL LEAN CLAY WITH SAND 2 brown/light brown - medium stiff to stiff 3 4 5 Cs 5 24.9 104.1 1000 None <500psf 30 16 75.5% 6 7 8 9 - SP-GP SAND AND GRAVEL SS 34 9.8 - N/A - - - brown/red/grey 10 dense - 11 12 13 14 15 SS 50/9" 13.0 - N/A - - - BOTTOM OF BORING 15.5' 16 17 18 19 20 21 22 23 24 25 ASPEN HEIGHTS LOG OF BORING B-2 FORT COLLINS, COLORADO Project# 11-1074 SOvILOGIC October 2011 Sheet 111 Drilling Rig: CME 55 Water Depth Information Start Date 10/5/2011 Auger Type: 4" CFA During Drilling 6' Finish Date 10/5/2011 Hammer Type: Manual After Drilling 6' Surface Elev. Field Personnel: KSK 19 Days After Drilling 6.3' to Estd. % Passing N SOIL DESCRIPTION Depth tet E in "N" MC (i I DD (pcf) q (pst7 % Swell @ 500 psf Swell Pressure Atterberg Limits LL PI # 200 Sieve (i I 6" TOPSOIL AND VEGETATION - 1 CL LEAN CLAY WITH SAND 2 - brown/light brown CS 25 18.5 110.5 9000+ 6.9 % - - medium stiff to stiff 3 4 5 CS 4 23.5 - 1000 - - - 6 7 8 9 - SP-GP SAND AND GRAVEL SS 23 7.5 - N/A - - - - brown/red/grey 10 dense - 11 12 13 14 15 SS 50/11" 13.2 - N/A - BOTTOM OF BORING 15.5' 16 17 18 19 20 21 22 23 24 25 ASPEN HEIGHTS LOG OF BORING B-3 FORT COLLINS, COLORADO Project# 11-1074 SO -LOGIC October 2011 Sheet 1/1 IlDrilling Rig: CME 55 Water Depth Information Start Date 10/5/2011 Auger Type: 4" CFA During Drilling 7' Finish Date 10/5/2011 Hammer T e: Manual After Drilling 7' Surface Elev. Field Personnel: KSK 19 Days After Drilling 6.6' N N SOIL DESCRIPTION Depth tfft in "N" MC 1 �) DD (Pcf) Estd. q (Psf) % Swell @ 500 psf Swell Pressure Atterberg Limits LL PI % Passing # 200 Sieve (i ) 6" TOPSOIL AND VEGETATION - 1 CL LEAN CLAY WITH SAND 2 - brown/light brown CS 27 18.8 9000+ - medium stiff to stiff 3 4 5 CS 5 21.9 100.4 1000 1.3 % 1500 PSf - - 6 7 8 9 - SP-GP SAND AND GRAVEL SS 50/10" 7.6 - N/A - - - brown/red/grey 10 dense - 11 - Posslble Boulder @ 11 AUGER REFUSAL @ 11' 12 13 14 15 16 17 18 19 20 21 22 23 24 25 ASPEN HEIGHTS LOG OF BORING B-4 FORT COLLINS, COLORADO Project # 11-1074 SO,-„ LOGIC October 2011 Sheet 1/1 Drilling Rig: CME 55 Water Depth Information Start Date 10/5/2011 Auger Type: 4" CFA During Drilling 9' Finish Date 10/5/2011 Hammer Type: Manual After Drilling 9' Surface Elev. - Field Personnel: KSK 19 Days After Drilling 10.0' N Estd. % Passing N SOIL DESCRIPTION Depth (n) E rn "N" MC (%) DIDq" (pcf) (psf) % Swell @ 500 psf Swell Pressure Atterberg Limits LL PI # 200 Sieve (i) 6" TOPSOIL AND VEGETATION - 1 CL LEAN CLAY WITH SAND 2 - brown/light brown CS 28 15.1 1 115.3 9000+ 2.7 % 4000 psf 42 26 87.7 % medium stiff to stiff 3 4 5 CS 10 18.0 1000 - - - - 6 7 8 9 - SP-GP SAND AND GRAVEL SS 38 9.5 - N/A - - - brown/red/grey 10 dense - 11 12 13 14 15 SS 5018" 15.1 - N/A - - BOTTOM OF BORING 15.5' 16 17 18 19 20 21 22 23 24 25 ASPEN HEIGHTS LOG OF BORING B-5 FORT COLLINS, COLORADO Project# 11-1074 SOLOGIC October 2011 Sheet 1/1 Drilling Rig: CME 55 Water Depth Information Start Date 10/5/2011 Auger Type: 4" CFA During Drillin 7' Finish Date 10/5/2011 Hammer Type: Manual After Drilling 7' Surface Elev. - Field Personnel: KSK 19 Days After Drilling 6.4' In N SOIL DESCRIPTION Depth d E "N" MC DD (pcf) Estd. q (psf) %Swell @ 500 psf Swell Pressure Atterberg Limits LL PI % Passing # 200 Sieve (i ) 6" TOPSOIL AND VEGETATION - 1 CL LEAN CLAY WITH SAND 2 - brown/light brown CS 14 10.3 - 9000+ - - - medium stiff to stiff 3 4 5 r6 CS 6 11.7 110.3 2000 0.1 % 800 psf - - - 7 8 9 - SP-GP SAND AND GRAVEL SS 34 7.4 N/A - - - brown/red/grey 10 dense 11 12 13 14 15 SS 50/10" 6.8 N/A - - - BOTTOM OF BORING 15.5' 16 17 18 19 20 21 22 23 24 25 ASPEN HEIGHTS FORT COLLINS, COLORADO Project # 11-1074 October 2011 SWELL/CONSOLIDATION TEST SUMMARY Applied Load (psf) Sample ID: B-1, S-1 @ 4' Sample Description: Brown Sandy Lean Clay (CL) Initial Moisture 20.3% Liquid Limit 30 Final Moisture 21.9% Plasticity Index 16 % Swell @ 500 psf None % Passing #200 75.5% Swell Pressure <500 psf Dry Density 104.1 pcf SOLOGIC ASPEN HEIGHTS FORT COLLINS, COLORADO Project # 11-1074 October 2011 SWELL/CONSOLIDATION TEST SUMMARY 12 10 - - 8 - --- m 6 3 - -- — W � I � 4 - -- — I o -4 cc .o -O -10 4 - -- -12 -- -- r - - -; 10 100 1000 10000 100000 Applied Load (psf) Sample ID: B-2, S-1 @ 2' Sample Description: Brown Sandy Lean Clay (CL) Initial Moisture 16.1 % Liquid Limit - Final Moisture 24.0% Plasticity Index - % Swell @ 500 psf 6.9% % Passing #200 - Swell Pressure >8000 psf Dry Density 110.5 pcf SO�LOGIC ASPEN HEIGHTS FORT COLLINS, COLORADO Project # 11-1074 October 2011 SWELL/CONSOLIDATION TEST SUMMARY 10 12 _ --- -- 10 100 I i 1000 10000 Applied Load (psf) Sample ID: B-3, S-2 @ 4' Sample Description: Brown Sandy Lean Clay (CL) 100000 Initial Moisture 14.4% Liquid Limit - Final Moisture 23.8% Plasticity Index - % Swell @ 500 psf 1.3% % Passing #200 - Swell Pressure 1500 psf Dry Density 100.4 pcf SO'LOGIC ASPEN HEIGHTS FORT COLLINS, COLORADO Project # 11-1074 October 2011 SWELL/CONSOLIDATION TEST SUMMARY 2 1 - - -6 II, - --- -- -10 - - - - -12�- 10 100 1000 Applied Load (psf) Sample ID: B-4, S-1 @ 2' Sample Description: Brown Sandy Lean Clay (CL) Initial Moisture 13.9% Liquid Limit 42 Final Moisture 18.6% Plasticity Index 26 % Swell @ 500 psf 2.7% % Passing #200 87.7% Swell Pressure 4000 psf Dry Density 115.3 pcf SO' LOGIC ASPEN HEIGHTS 0 0 N U FORT COLLINS, COLORADO Project # 11-1074 October 2011 SWELL/CONSOLIDATION TEST SUMMARY -a - - - -s $. -10 -12 - ---�- -- - 10 100 1000 Applied Load (psf) 10000 Sample ID: B-5, S-2 @ 4' Sample Description: Brown Sandy Lean Clay (CL) 100000 Initial Moisture 15.7% Liquid Limit - Final Moisture 19.7% Plasticity Index - % Swell @ 500 psf 0.1 % % Passing #200 - Swell Pressure 800 psf Dry Density 110.3 pcf SO LOGIC UNIFIED SOIL CLASSIFICATION SYSTEM (USCS) Coarse-Croined Grovels more than Clean Grovels Less Soils more than 50% of coorse than 5% lines Cu>4 and <Cc<3' CW Well grovel' 50% retained on Iraclion retained No. 200 sieve on No. 4 sieve Cu<a and/ar 1>Cc>3r CP Poorly -graded grovel' Gravels with Fines Fines classify as Mt. or MH GM Silly gravel, G,H more than 127.— fines Fines Classify as CL or CH GC Clayey Gravel"'" Sands 50➢L or Clean Sands Less Cu>_F and 1<C.c<!' Syr Well-groded sond' more coarse. frbction classes than 5% fines — Cu<G and/or 1>Cc>3r SP Poorly-groded sand' No. A sieve Sands with Fines Fines classify as ML or MH SM Silly send" more than 12% fines Rnes clossity as CL or CH SC Clayey sond— Fine-Grained Sills and Cloys inorgan,c PI>7 and plots on or above "A"Line' CL Leon clay'" Soils 50% or Liquid Limit less -- - more posses the than 50 PI<A or plots below 'A'Lore' ML Silt No. 200 sieve a`- organic Liquid Limit oven dried Organic cloy ��•• <0.75 OL Liquid Limit - not dried Organic silt-" Silts and Cloys inorganic PI plots on or above "A"Line Ci Fol cloy Liquid Limit 50 or more PI plots aelow -A-Line MH Elastic Sill' — organic Liquid Limit - oven dried Organic clay'.'"'" <0.75 014 Liquid Limit - not dried organic silt" Highly organic soils Primarily organic molter, dark in color, and organic odor PT Peat `bated on the Material posing the 3-:n. (75- 'Cu-0D�Cc- D� w/ (rR-� ill fall cdnlorts 15 Id 29il i h. odd a -.�lh fond or 'eiln grmel-..nkne+rr s If field "ample canla'erel coboal or boulder%, 'll ocedornndnt. 'll soi conlanf ! 30- putt No. 200 br bath, add cobbles or baAl a both' to lralp npmt. ril sou contain% 215x .and, %ontl-la %and, odd sandy to group tGdveit .ilh 5 la 12x rnes roavlred dud, symbalt: gsroup name nomemfnonlly `l: sal can la in% 2 30x pals Na. 200 GM -cm wen graded grovel •tin s!t a rnes clossn s CL-uL. �.. a„m bat ae-Qt. or SC rSN. .pr predomnondy gra.ei, add -groat. la qr arp Gll well-groded grovel liln cloy It rnes 'at orgon�c, and -win wgo�c li a *l. D11'O "PIZa ontl plat% an or oboe •�-inc I:P-GM pally-lratla0 grovel .11n sri qr pup n °Plie ur plot% polo• GP-Ga pearly-graet0 gravel ran clay "Sands 5 la 12. Ines rtau're ad -il %as cool o�s aLS zqr o.ei. add•+•In yromi• plots on or bo.a with symOds: to groan ncm c. "I '•. Zit • opt plats help. - rme. W-Sw %and with f0 Alterberg lit—, plots shdaca orco. %oil n CL-uL, :en-groded SW -SC wee-gmd,d sand .itn cloy cony clay SP-SM poorly graded an •:1h %ill Slil Pearly lidded %ontl eith cloy ao rw eb[[ln[elbn t � n,e-ryv�w .Wa r - __._ - l no.Yen t..l¢t'lLLia"; �7i5. • � F � �� T_ x sd dt — .._ �, vv` w 0 I a � --'---i----- - — i--..� G� iMH aIH ,o ciluL ML on—�---- a 1 a to 1d -- 1- — — ------ a n 1. +o eo m - ra+ "o LIOUID LIA11 r�(LL) Fine Grained Soils Qu (sf) Consistency Coarse Grained Soils Blows/ft Relative Density Bedrock Blovil Weathering t500 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 13-30 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