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HomeMy WebLinkAboutHANSEN FARM - PDP - PDP170036 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTPRELIMINARY GEOTECHNICAL SUBSURFACE EXPLORATION REPORT HANSEN FARM ANNEXATION APPROXIMATE 69 ACRE PARCEL PORTIONS OF THE E½ OF SECTION 7 AND THE NW¼ OF SECTION 8, T6N, R68W 6029 SOUTH TIMBERLINE ROAD, FORT COLLINS, COLORADO SOILOGIC # 16-1287 November 22, 2016 Soilogic, Inc. 3050 67th Avenue, Suite 200  Greeley, CO 80634  (970) 535-6144 P.O. Box 1121  Hayden, CO 81639  (970) 276-2087 November 22, 2016 The Landhuis Company 212 North Wahsatch Avenue, Suite 301 Colorado Springs, Colorado 80903 Attn: Mr. Jeff Mark Re: Preliminary Geotechnical Subsurface Exploration Report Hansen Farm Annexation (Approximate 69-Acre Parcel) Portions of Section 7 and 8, T6N, R68W 6029 South Timberline Road, Fort Collins, Colorado Soilogic Project # 16-1287 Mr. Mark: Soilogic, Inc. (Soilogic) personnel have completed the preliminary geotechnical subsurface exploration you requested for the Hansen Farm Annexation property, located at 6029 South Timberline Road in Fort Collins, Colorado. The results of our preliminary exploration are included with this report. The subsurface materials encountered in the completed test borings typically consisted of a thin mantle of vegetation and topsoil underlain by light brown/rust lean clay with varying amounts of sand. The lean clay varied from soft to very stiff in terms of consistency, exhibited no to low swell potential and low to high consolidation potential at current moisture and density conditions and extended to the bottom of all borings at a depth of approximately 15 feet below grade. When checked about two (2) days after completion of drilling, groundwater was measured in borings B-2 through B-6 at depths of approximately 15, 13, 12½, 9 and 13 feet below ground surface respectively. Borings B-1 and B-7 were observed to be dry to the approximate depths explored at that time. (Approximately 14 to 15 feet below ground surface.) Based on the subsurface conditions encountered in the completed site borings, results of laboratory testing and type of construction proposed, we expect lightly-loaded residential structures could be constructed with conventional footing foundations and floor slabs bearing on the site lean clay with no to low swell potential. Preliminary Geotechnical Subsurface Exploration Report Hansen Farm Annexation 6029 South Timberline Road, Fort Collins, Colorado Soilogic # 16-1287 2 Care will be needed in the area of boring B-5 where groundwater was measured at a depth of approximately 9 feet below grade in order to maintain adequate separation distances between footing foundations and the observed level of groundwater. Typically we recommend foundation excavations be established a minimum of three (3) feet above the observed groundwater level. Slightly raising site grades in this area could be considered to facilitate full-basement construction. Lowering site groundwater levels with an underdrain system could also be considered. Underdrain systems would require a suitable outfall. Soft, compressible lean clay soils were encountered with depth near current groundwater levels in the completed site borings such that care will be needed to ensure footing foundations are supported on soils with suitable strength. Overexcavation/backfill procedures or other approved stabilization measures, or alternative deep foundation systems could be considered in areas of very soft lean clay to reduce the potential for excessive post-construction settlement of the proposed residences. If raising the site through fill placement will be undertaken, areas of the site expected to receive fill depths greater than about 4 to 5 feet should be developed as early as possible during the development process and allowed to remain in place for several weeks in order to allow for consolidation of the underlying soft lean clay prior to construction of any overlying improvements. Based on the results of completed laboratory testing, the site lean clay appears suitable for use as low volume change (LVC) fill to develop the site. Depending on the in-place moisture content of the subgrade soils at the time of construction, stabilization of the pavement subgrade soils may become necessary prior to surfacing in order to develop a suitable paving platform. A final pavement exploration will be required for the development after streets have been graded to approximate finish subgrade elevation and deep utilities installed in accordance with the City of Fort Collins standards. Other preliminary opinions and recommendations concerning design criteria and construction details for the proposed site improvements are included with this report. Preliminary pavement section design estimates are also included. Preliminary Geotechnical Subsurface Exploration Report Hansen Farm Annexation 6029 South Timberline Road, Fort Collins, Colorado Soilogic # 16-1287 3 We appreciate the opportunity to be of service to you on this project. If you have any questions concerning the enclosed information or if we can be of further service to you in any way, please do not hesitate to contact us. Very Truly Yours, Soilogic, Inc. Reviewed by: Wolf von Carlowitz, P.E. Darrel DiCarlo, P.E. Principal Engineer Senior Project Engineer 36746 44271 PRELIMINARY GEOTECHNICAL SUBSURFACE EXPLORATION REPORT HANSEN FARM ANNEXATION APPROXIMATE 69 ACRE PARCEL PORTIONS OF THE E½ OF SECTION 7 AND THE NW¼ OF SECTION 8, T6N, R68W 6029 SOUTH TIMBERLINE ROAD, FORT COLLINS, COLORADO SOILOGIC # 16-1287 November 22, 2016 INTRODUCTION This report contains the results of the preliminary geotechnical subsurface exploration completed for the Hansen Farm Annexation property, located at 6029 South Timberline Road in Fort Collins, Larimer County, Colorado. The purpose of our exploration was to describe the subsurface conditions encountered in the completed site borings and develop preliminary recommendations concerning design and construction of residence foundations and support of floor slabs and site pavements. Recommendations concerning the installation of site utilities and preliminary pavement section estimates for interior site roadways are also included. The conclusions and recommendations outlined in this report are based on the results of the completed field and laboratory testing and our experience with subsurface conditions in this area. PROPOSED CONSTRUCTION The proposed development includes approximately 69 acres, we assume which will be developed as single-family residential. We expect the residential structures will be lightly-loaded one or two story wood frame structures which may include full basements, where feasible. Foundations loads for the structures are expected to be light, with continuous wall loads less than 3 to 4 kips per lineal foot and individual column loads less than 75 kips. Floor loads are expected to be light, less than 100 psf. Infrastructure improvements for the development will include utility installation and roadway construction. We expect the site roadways will be used by low volumes of passenger vehicles and light trucks, with occasional heavy truck traffic. Small grade changes are anticipated to develop finish site grades. Preliminary Geotechnical Subsurface Exploration Report Hansen Farm 6029 South Timberline Road, Fort Collins, Colorado Soilogic # 16-1287 2 SITE DESCRIPTION The development site includes a total of approximately 69 acres located in portions of Sections 7 and 8, Township 6 North, Range 68 West of the 6 th Principle Meridian, in Fort Collins, Colorado. At the time of our site exploration, the site contained a moderate growth of grass vegetation and a gentle overall slope downward to the east/northeast, with the maximum difference in ground surface elevation estimated to be approximately 10 to 15 feet based upon available USGS topographic maps of the area. A lower lying marshy area with approximate plan dimensions of 100 by 100 feet was observed in the central/southeast portion of the property. The Mail Creek Ditch, an earthen-lined irrigation ditch, forms the north property boundary and a smaller earthen-lined irrigation lateral forms the south and west property boundary. Timberline Road forms the east property line. Both irrigation ditches were observed to be dry at the time of our site exploration. An existing residence and associated site improvements currently occupies the south corner of the parcel. Evidence of prior building construction was not observed across a remainder of the site at the time of drilling. SITE EXPLORATION Field Exploration To develop subsurface information across the development parcel, a total of seven (7) soil borings were extended to a depth of approximately 15 feet below present site grades. The approximate boring locations were established in the field by Soilogic personnel by using a mechanical surveyor’s wheel and estimating angles from identifiable site references. A diagram indicating the approximate boring locations is included with this report. Graphic logs of each of the auger borings are also included. The test holes were advanced using 4-inch diameter continuous-flight auger powered by a truck-mounted CME-45 drill rig. Samples of the subsurface materials were obtained at regular intervals using California barrel sampling procedures in general accordance with ASTM specification D-1586. As part of the D-1586 sampling procedure, the standard sampling barrel is driven into the substrata using a 140-pound hammer falling a distance of 30 inches. The number of blows required to advance the sampler a distance of 12 Preliminary Geotechnical Subsurface Exploration Report Hansen Farm 6029 South Timberline Road, Fort Collins, Colorado Soilogic # 16-1287 3 inches is recorded and helpful in estimating the consistency or relative density of the soils encountered. In the California barrel sampling procedure, lesser disturbed 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. Laboratory Testing The samples collected were tested in the laboratory to measure natural moisture content and visually and/or manually 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 determine the percentage of fine-grained materials (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 subsurface materials encountered in the completed test borings consisted of a thin mantle of vegetation and topsoil underlain by light brown/rust lean clay with varying amounts of sand. The lean clay varied from soft to very stiff in terms of consistency, exhibited no to low swell potential and low to high consolidation potential at current moisture and density conditions and extended to the bottom of all borings at a depth of approximately 15 feet below grade. Preliminary Geotechnical Subsurface Exploration Report Hansen Farm 6029 South Timberline Road, Fort Collins, Colorado Soilogic # 16-1287 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. Groundwater was encountered at the location of borings B-2, B-3, B-5 and B-6 at depths of approximately 15, 13, 9 and 13 feet below ground surface respectively at the time of drilling. Groundwater was not encountered at the location of borings B-1 B-4 and B-7 at that time. When checked about two (2) days after completion of drilling, groundwater was measured in borings B-2 through B-6 at depths of approximately 15, 13, 12½, 9 and 13 feet below ground surface. Borings B-1 and B-7 were observed to be dry to the approximate depths explored at that time. (Approximately 14 to 15 feet below ground surface.) Groundwater level information is 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 typically encountered within more permeable zones of layered soil and bedrock systems. The location and amount of perched/trapped water can also vary over time. ANALYSIS AND RECOMMENDATIONS General Groundwater was measured at the location of borings B-2 through B-6 at depths ranging from approximately 9 to 15 feet below ground surface about two (2) days after the completion of drilling. In general, the depth to groundwater observed is not expected to significantly impact full-basement construction across a majority of the site. In the area of boring B-5 where groundwater was measured at a depth of approximately 9 feet below ground surface, care will be needed to establish foundation bearing a minimum of three (3) feet above the level of water observed. Raising finish site grades in this area or Preliminary Geotechnical Subsurface Exploration Report Hansen Farm 6029 South Timberline Road, Fort Collins, Colorado Soilogic # 16-1287 5 lowering the groundwater table with an underdrain system could be considered to facilitate basement construction. Underdrain systems would require a suitable outfall. Irrigation ditches form the south, west and north property boundaries of this parcel. If the irrigation ditches will remain active after development, lining of the ditches could be considered to help limit the impact of ditch seepage waters. Soft, compressible lean clay soils were encountered with depth in a majority of the completed site borings. The lean clay soils would be expected to be soft near current groundwater levels. The soft lean clay would be subject to consolidation under additionally imposed fill loads. Areas of the site expected to receive fill depths greater than 4 to 5 feet should be developed as early as possible in the construction process. We recommend the fill materials in these areas be placed and allowed to remain in place for a minimum of six (6) weeks prior to the installation of site utilities and construction of any overlying improvements in order to allow for consolidation of underlying soils. Site Development All existing topsoil and vegetation should be removed from proposed fill and pavement areas. After stripping and completing all cuts and prior to placement of any overlying fill and/or improvements, 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 -1 to +3% of standard Proctor optimum moisture content at the time of compaction. Soft lean clay soils were encountered with depth in the completed site borings. Depending on the depth of site cuts, stabilization procedures may be required in some areas to develop a suitable working platform. Fill soils required to develop structural areas of the site should consist of approved low volume change (LVC) 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 could be used as fill to develop the site. Wet materials encountered near current groundwater levels would need to be dried out prior to placement as fill. If it is Preliminary Geotechnical Subsurface Exploration Report Hansen Farm 6029 South Timberline Road, Fort Collins, Colorado Soilogic # 16-1287 6 necessary to import fill material to the site, those materials should have low potential for volume change and should be approved prior to use. We recommend suitable fill materials be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content and compacted as recommended for the scarified materials above. The soft lean clay soils encountered with depth in the completed site borings would be subject to consolidation under additionally-imposed loads. Areas of the site expected to receive fill depths greater than 4 to 5 feet should be evaluated closely for consolidation potential. Fill soils required to develop the site should be placed and allowed to remain in place for a minimum of 6 weeks prior to construction of any overlying improvements in order to allow for consolidation of the underlying soft/loose soils. The soft clay soils encountered with depth would be easily disturbed by the construction activities. Disturbed soils should be removed and replaced or reworked in place prior to placement of any overlying improvements Footing Foundations Based on the materials encountered in the completed site borings and the results of laboratory testing, we expect a majority, if not all relatively lightly-loaded site structures could be supported on conventional footing foundations bearing on the natural site lean clay with suitable strength or suitable fill or overexcavation/backfill soils placed and compacted as outlined above a minimum of three (3) feet above observed groundwater. The foundations for the individual structures should bear on like materials. For design of footing foundations bearing on the natural site lean clay and/or properly placed and compacted fill or overexcavation/backfill, maximum net allowable soil bearing pressures in the range of 1,000 to 2,000 psf appear usable. Soft/compressible clay soils with insufficient strength were encountered with depth in several of the site borings. Settlement of improvements placed directly on soft clay would be expected. Individual site explorations and careful observation of all foundation bearing soils should be completed for each of the proposed structures to ensure those improvements will be supported on soils with suitable strength. Overexcavation/backfill Preliminary Geotechnical Subsurface Exploration Report Hansen Farm 6029 South Timberline Road, Fort Collins, Colorado Soilogic # 16-1287 7 procedures or other approved stabilization measures, or alternative deep foundation systems could be considered in areas of soft clay to reduce the potential for post- construction settlement of the supported structures. Floor Slabs Based on the results of the completed laboratory testing, we expect lightly-loaded floor slabs could be supported on reconditioned natural site sols and/or properly placed and compacted fill. Care should be taken to avoid disturbing floor slab subgrades prior to concrete placement. Subgrade soils expected to receive flatwork concrete should be evaluated closely prior to surfacing. If areas of disturbed, wet and softened, or dry subgrade soils develop during construction, those materials should be removed and replaced or reworked in place prior to placement of the overlying improvements. Basement Construction We recommend perimeter drain systems 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 areas A perimeter drain system should consist of a 4-inch diameter 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 areas and run to a sump pit and pump system, free outfall or project underdrain system with a minimum slope of ⅛-inch per foot to facilitate efficient water removal. If free outfalls will be considered, measures to help reduce the potential for reverse flow and animal access into the systems should be considered. Backfill placed adjacent to the below-grade walls should consist of LVC potential and relatively impervious soils which are free from organic matter, debris and other objectionable materials. The site lean clay could be used as fill in these areas. The Preliminary Geotechnical Subsurface Exploration Report Hansen Farm 6029 South Timberline Road, Fort Collins, Colorado Soilogic # 16-1287 8 backfill soils should be placed in loose lifts not to exceed 9 inches thick, adjusted to be within -1 to +3% of standard Proctor optimum moisture content and compacted to at least 95% of the materials standard Proctor maximum dry density. Excessive lateral stress can be imposed on below-grade walls when using heavier mechanical compaction equipment. We recommend compaction of unbalanced basement wall backfill be completed using light mechanical or hand compaction equipment. 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 could be used as pipeline backfill. Pipeline backfill 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 out prior to placement as utility backfill. Care will be needed to ensure utilities are not placed on or above disturbed or sloughed materials. Utility excavations will likely expose the overburden lean clay. Care will also be needed to develop stable side slopes in pipeline trenches excavated through some of the soft lean clay soils. As such, we expect temporary shoring, bracing, or cutting of shallow slopes may be necessary in deeper excavations. Excavations should be sloped or shored in the interest of safety following local and federal regulations, including current OSHA excavation and trench safety standards. As a safety measure, it is recommended that vehicles and soil stockpiles be kept to a minimum lateral distance from the crest of the slope equal to no less than the slope height. Cuts below groundwater elevation will require dewatering to facilitate proper construction. We expect a majority of the dewatering procedures could be completed through open pumping procedures in sumps fed from ditches or sloped trench excavations. Preliminary Geotechnical Subsurface Exploration Report Hansen Farm 6029 South Timberline Road, Fort Collins, Colorado Soilogic # 16-1287 9 Site Roadways We expect the pavement subgrades will consist of the site lean clay with low swell potential. Pavement subgrades should be developed as outlined in the “Site Development” section of this report. A final subgrade evaluation and pavement section design report will be required once roadways are developed to approximate finish grade in accordance with City of Fort Collins standards. For preliminary design estimates, a pavement section consisting of 4 inches of asphaltic concrete overlying 6 inches of aggregate base course could be used for local residential roadways. A pavement section consisting of approximately 5 inches of asphaltic concrete overlying 8 inches of aggregate base course could be used for preliminary estimates for collector roadways. The site lean clay would be particularly susceptible to strength loss and instability when elevated in moisture content, with a tendency to rut and pump when subjected to vehicle traffic. Depending on the in-place moisture content of the subgrade soils, time of year when construction occurs and other hydrologic conditions, stabilization of site pavement subgrades may become necessary to develop a suitable paving platform. If required, we recommend consideration be given to stabilization of the pavement subgrades with Class C fly ash. Fly ash stabilization can also eliminate some of the uncertainty associated with attempting to pave during periods of inclement weather. Drainage Positive drainage is imperative for satisfactory long-term performance of the proposed site structures and associated site improvements. We recommend positive drainage be developed away from all site structures and pavement areas to reduce the potential for wetting of the subgrade and bearing materials. Water which is allowed to pond adjacent to the site improvements can result in unacceptable performance of those improvements over time. LIMITATIONS This report was prepared based upon the data obtained from the completed site exploration, laboratory testing, engineering analysis and any other information discussed. Preliminary Geotechnical Subsurface Exploration Report Hansen Farm 6029 South Timberline Road, Fort Collins, Colorado Soilogic # 16-1287 10 The completed borings provide an indication of subsurface conditions at the boring locations only. Variations in subsurface conditions can occur in relatively short distances 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. LOG OF BORING B-1 1/1 CME 45 4" CFA Automatic BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 6" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - rust/brown 3 CS 19 9.3 114.9 9000+ 0.8% 1250 - - - medium stiff to very stiff - 4 - 5 CS 22 12.2 113.4 9000+ - - - - - - 6 - 7 - 8 - 9 - 10 CS 17 14.5 109.3 9000+ 0.1% 600 - - - - 11 - 12 - 13 - 14 - 15 CS 8 19.5 96.9 3000 - - - - - BOTTOM OF BORING 15' - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - LOG OF BORING B-2 1/1 CME 45 4" CFA Automatic BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 6" VEGETATION & TOPSOIL - 1 - 2 CL LEAN CLAY WITH SAND - rust/brown 3 soft to very stiff - 4 - 5 CS 29 9.4 116.5 9000+ 2.2% 2250 38 22 80.1% - 6 - 7 - 8 - 9 - 10 CS 5 13.4 112.2 9000+ - - - - - - 11 - 12 - 13 - 14 - 15 CS 5 21.3 99.7 2000 - - - - - BOTTOM OF BORING 15' - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 HANSEN FARM PRELIMINARY EXPLORATION 6029 SOUTH TIMBERLINE ROAD, FORT COLLINS, COLORADO LOG OF BORING B-3 1/1 CME 45 4" CFA Automatic BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 5" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - rust/brown 3 CS 18 10.8 117.6 9000+ 2.5% 5000 - - - medium stiff to stiff - 4 - 5 CS 7 13.3 102.3 9000+ - - - - - - 6 - 7 - 8 - 9 - Scattered Gravel with Depth 10 CS 9 31.9 87.9 2000 None <500 - - - - 11 - 12 - 13 - 14 - 15 CS 6 20.3 102.8 3000 - - - - - BOTTOM OF BORING 15' - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 HANSEN FARM PRELIMINARY EXPLORATION Atterberg Limits LOG OF BORING B-4 1/1 CME 45 4" CFA Automatic BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 4" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - rust/brown 3 medium stiff to stiff - 4 - 5 CS 12 9.7 120.4 9000 2.7% 10,000 - - - - 6 - 7 - 8 - 9 - 10 CS 6 21.9 103.2 3000 None <500 - - - - 11 - 12 - 13 - 14 - 15 CS 9 20.1 104.6 4000 - - - - - BOTTOM OF BORING 15' - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 HANSEN FARM PRELIMINARY EXPLORATION 6029 SOUTH TIMBERLINE ROAD, FORT COLLINS, COLORADO LOG OF BORING B-5 1/1 CME 45 4" CFA Automatic BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 7" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - light brown/rust 3 CS 14 12.4 117.3 9000+ 1.1% 2500 - - - soft to stiff - 4 With Scattered Gravel - 5 CS 9 24.0 96.6 4000 - - - - - - 6 - 7 - 8 - 9 - 10 CS 3 37.1 81.3 2000 None <500 - - - - 11 - 12 - 13 - 14 - 15 SS 10 20.9 107.0 5000 - - - - - BOTTOM OF BORING 15' - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - LOG OF BORING B-6 1/1 CME 45 4" CFA Automatic BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 5" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - rust/brown 3 soft to stiff - 4 - 5 CS 17 10.6 118.1 9000+ 2.5% 3900 - - - - 6 - 7 - 8 - 9 - 10 CS 5 15.9 99.5 7000 - - - - - - 11 - 12 - 13 - 14 - 15 CS 3 2.1 98.5 2000 - - - - - BOTTOM OF BORING 15' - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 HANSEN FARM PRELIMINARY EXPLORATION 6029 SOUTH TIMBERLINE ROAD, FORT COLLINS, COLORADO LOG OF BORING B-7 1/1 CME 45 4" CFA Automatic BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 6" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - rust/brown 3 CS 26 7.6 - 9000+ - - - - - stiff to very stiff - 4 - 5 CS 16 13.1 116.1 9000+ - - 34 19 69.3% - 6 - 7 - 8 - 9 - 10 CS 11 14.0 115.6 9000 0.9% 1900 - - - - 11 - 12 - 13 - 14 - 15 CS 15 16.0 112.5 9000+ - - - - - BOTTOM OF BORING 15' - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 HANSEN FARM PRELIMINARY EXPLORATION 6029 SOUTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Liquid Limit - Plasticity Index - % Passing #200 - Dry Density (pcf) 114.9 Final Moisture 21.2% % Swell @ 500 psf 0.8% Swell Pressure (psf) 1,250 Sample ID: B-1 @ 2' Sample Description: Rust/Brown Sandy Lean Clay (CL) Initial Moisture 9.3% HANSEN FARM PRELIMINARY EXPLORATION 6029 SOUTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 16-1287 November 2016 SWELL/CONSOLIDATION TEST SUMMARY -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density (pcf) 109.3 HANSEN FARM PRELIMINARY EXPLORATION 6029 SOUTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 16-1287 November 2016 SWELL/CONSOLIDATION TEST SUMMARY Sample ID: B-1 @ 9' Sample Description: Rust/Brown Sandy Lean Clay (CL) Initial Moisture 14.5% Final Moisture 18.7% % Swell @ 500 psf 0.1% Swell Pressure (psf) 600 -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit 38 Plasticity Index 22 % Passing #200 80.1% Dry Density (pcf) 116.5 Final Moisture 19.4% % Swell @ 500 psf 2.2% Swell Pressure (psf) 2,250 Sample ID: B-2 @ 4' Sample Description: Rust/Brown Lean Clay with Sand (CL) Initial Moisture 9.4% HANSEN FARM PRELIMINARY EXPLORATION 6029 SOUTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 16-1287 November 2016 SWELL/CONSOLIDATION TEST SUMMARY -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density (pcf) 117.6 Final Moisture 17.1% % Swell @ 500 psf 2.5% Swell Pressure (psf) 5,000 Sample ID: B-3 @ 2' Sample Description: Rust/Brown Sandy Lean Clay (CL) Initial Moisture 10.8% HANSEN FARM PRELIMINARY EXPLORATION 6029 SOUTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 16-1287 November 2016 SWELL/CONSOLIDATION TEST SUMMARY -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density (pcf) 87.9 Final Moisture 31.9% % Swell @ 500 psf None Swell Pressure (psf) <500 Sample ID: B-3 @ 9' Sample Description: Light Brown Sandy Lean Clay with Scattered Gravel (CL) Initial Moisture 31.9% HANSEN FARM PRELIMINARY EXPLORATION 6029 SOUTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 16-1287 November 2016 SWELL/CONSOLIDATION TEST SUMMARY -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density (pcf) 120.4 Final Moisture 16.2% % Swell @ 500 psf 2.7% Swell Pressure (psf) 10,000 Sample ID: B-4 @ 4' Sample Description: Rust/Brown Sandy Lean Clay (CL) Initial Moisture 9.7% HANSEN FARM PRELIMINARY EXPLORATION 6029 SOUTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 16-1287 November 2016 SWELL/CONSOLIDATION TEST SUMMARY -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density (pcf) 103.2 Final Moisture 20.7% % Swell @ 500 psf None Swell Pressure (psf) <500 Sample ID: B-4 @ 9' Sample Description: Rust/Brown Sandy Lean Clay (CL) Initial Moisture 21.9% HANSEN FARM PRELIMINARY EXPLORATION 6029 SOUTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 16-1287 November 2016 SWELL/CONSOLIDATION TEST SUMMARY -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density (pcf) 117.3 Final Moisture 16.9% % Swell @ 500 psf 1.1% Swell Pressure (psf) 2,500 Sample ID: B-5 @ 2' Sample Description: Rust/Brown Sandy Lean Clay with Scattered Gravel (CL) Initial Moisture 12.4% HANSEN FARM PRELIMINARY EXPLORATION 6029 SOUTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 16-1287 November 2016 SWELL/CONSOLIDATION TEST SUMMARY -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density (pcf) 81.3 Final Moisture 34.3% % Swell @ 500 psf None Swell Pressure (psf) <500 Sample ID: B-5 @ 9' Sample Description: Light Brown Sandy Lean Clay (CL) Initial Moisture 37.1% HANSEN FARM PRELIMINARY EXPLORATION 6029 SOUTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 16-1287 November 2016 SWELL/CONSOLIDATION TEST SUMMARY -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density (pcf) 118.1 Final Moisture 16.2% % Swell @ 500 psf 2.5% Swell Pressure (psf) 3,900 Sample ID: B-6 @ 4' Sample Description: Rust/Brown Sandy Lean Clay (CL) Initial Moisture 10.6% HANSEN FARM PRELIMINARY EXPLORATION 6029 SOUTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 16-1287 November 2016 SWELL/CONSOLIDATION TEST SUMMARY -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density (pcf) 115.6 Final Moisture 17.1% % Swell @ 500 psf 0.9% Swell Pressure (psf) 1,900 Sample ID: B-7 @ 9' Sample Description: Rust/Brown Sandy Lean Clay (CL) Initial Moisture 14.0% HANSEN FARM PRELIMINARY EXPLORATION 6029 SOUTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 16-1287 November 2016 SWELL/CONSOLIDATION TEST SUMMARY -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) UNIFIED SOIL CLASSIFICATION SYSTEM Criteria for Assigning Group Symbols and Group Names Using Laboratory TestsA Soil Classification Group Symbol Group NameB Clean Gravels Cu ! 4 and 1 " Cc " 3E GW Well graded gravelF Less than 5% finesC Cu < 4 and/or 1 > Cc > 3E GP Poorly graded gravelF Fines classify as ML or MH GM Silty gravelF,G, H Coarse Grained Soils More than 50% retained on No. 200 sieve Gravels More than 50% of coarse fraction retained on No. 4 sieve Gravels with Fines More than 12% finesC Fines classify as CL or CH GC Clayey gravelF,G,H Clean Sands Cu ! 6 and 1 " Cc " 3E SW Well graded sandI Less than 5% finesD Cu < 6 and/or 1 > Cc > 3E SP Poorly graded sandI Fines classify as ML or MH SM Silty sandG,H,I Sands 50% or more of coarse fraction passes No. 4 sieve Sands with Fines More than 12% finesD Fines classify as CL or CH SC Clayey sandG,H,I Silts and Clays PI > 7 and plots on or above “A” lineJ CL Lean clayK,L,M Liquid limit less than 50 Inorganic PI < 4 or plots below “A” lineJ ML SiltK,L,M Liquid limit - oven dried Organic clayK,L,M,N Fine-Grained Soils 50% or more passes the No. 200 sieve Organic Liquid limit - not dried < 0.75 OL Organic siltK,L,M,O Inorganic PI plots on or above “A” line CH Fat clayK,L,M Silts and Clays Liquid limit 50 or more PI plots below “A” line MH Elastic siltK,L,M Organic Liquid limit - oven dried Organic clayK,L,M,P Liquid limit - not dried < 0.75 OH Organic siltK,L,M,Q Highly organic soils Primarily organic matter, dark in color, and organic odor PT Peat A Based on the material passing the 3-in. (75-mm) sieve B If field sample contained cobbles or boulders, or both, add “with cobbles or boulders, or both” to group name. C Gravels with 5 to 12% fines require dual symbols: GW-GM well graded gravel with silt, GW-GC well graded gravel with clay, GP-GM poorly graded gravel with silt, GP-GC poorly graded gravel with clay. D Sands with 5 to 12% fines require dual symbols: SW-SM well graded sand with silt, SW-SC well graded sand with clay, SP-SM poorly graded sand with silt, SP-SC poorly graded sand with clay E Cu = D60/D10 Cc = GENERAL NOTES DRILLING & SAMPLING SYMBOLS: SS: Split Spoon - 1⅜" I.D., 2" O.D., unless otherwise noted HS: Hollow Stem Auger ST: Thin-Walled Tube – 2.5" O.D., unless otherwise noted PA: Power Auger RS: Ring Sampler - 2.42" I.D., 3" O.D., unless otherwise noted HA: Hand Auger CS: California Barrel - 1.92" I.D., 2.5" O.D., unless otherwise noted RB: Rock Bit BS: Bulk Sample or Auger Sample WB: Wash Boring or Mud Rotary The number of blows required to advance a standard 2-inch O.D. split-spoon sampler (SS) the last 12 inches of the total 18-inch penetration with a 140-pound hammer falling 30 inches is considered the “Standard Penetration” or “N-value”. For 2.5” O.D. California Barrel samplers (CB) the penetration value is reported as the number of blows required to advance the sampler 12 inches using a 140-pound hammer falling 30 inches, reported as “blows per inch,” and is not considered equivalent to the “Standard Penetration” or “N-value”. WATER LEVEL MEASUREMENT SYMBOLS: WL: Water Level WS: While Sampling WCI: Wet Cave in WD: While Drilling DCI: Dry Cave in BCR: Before Casing Removal AB: After Boring ACR: After Casing Removal Water levels indicated on the boring logs are the levels measured in the borings at the times indicated. Groundwater levels at other times and other locations across the site could vary. In pervious soils, the indicated levels may reflect the location of groundwater. In low permeability soils, the accurate determination of groundwater levels may not be possible with only short-term observations. DESCRIPTIVE SOIL CLASSIFICATION: Soil classification is based on the Unified Classification System. Coarse Grained Soils have more than 50% of their dry weight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand. Fine Grained Soils have less than 50% of their dry weight retained on a #200 sieve; they are principally described as clays if they are plastic, and silts if they are slightly plastic or non-plastic. Major constituents may be added as modifiers and minor constituents may be added according to the relative proportions based on grain size. In addition to gradation, coarse-grained soils are defined on the basis of their in-place relative density and fine-grained soils on the basis of their consistency. FINE-GRAINED SOILS COARSE-GRAINED SOILS BEDROCK (CB) Blows/Ft. (SS) Blows/Ft. Consistency (CB) Blows/Ft. (SS) Blows/Ft. Relative Density (CB) Blows/Ft. (SS) Blows/Ft. Consistency < 3 0-2 Very Soft 0-5 < 3 Very Loose < 24 < 20 Weathered 3-5 3-4 Soft 6-14 4-9 Loose 24-35 20-29 Firm 6-10 5-8 Medium Stiff 15-46 10-29 Medium Dense 36-60 30-49 Medium Hard 11-18 9-15 Stiff 47-79 30-50 Dense 61-96 50-79 Hard 19-36 16-30 Very Stiff > 79 > 50 Very Dense > 96 > 79 Very Hard > 36 > 30 Hard RELATIVE PROPORTIONS OF SAND AND GRAVEL GRAIN SIZE TERMINOLOGY Descriptive Terms of Other Constituents Percent of Dry Weight Major Component of Sample Particle Size Trace < 15 Boulders Over 12 in. (300mm) With 15 – 29 Cobbles 12 in. to 3 in. (300mm to 75 mm) Modifier > 30 Gravel 3 in. to #4 sieve (75mm to 4.75 mm) Sand Silt or Clay #4 to #200 sieve (4.75mm to 0.075mm) Passing #200 Sieve (0.075mm) RELATIVE PROPORTIONS OF FINES PLASTICITY DESCRIPTION Descriptive Terms of Other Constituents Percent of Dry Weight Term Plasticity Index Trace With Modifiers < 5 5 – 12 > 12 Non-plastic Low Medium High 0 1-10 11-30 30+ F If soil contains ! 15% sand, add “with sand” to group name. G If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM. HIf fines are organic, add “with organic fines” to group name. I If soil contains ! 15% gravel, add “with gravel” to group name. J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay. K If soil contains 15 to 29% plus No. 200, add “with sand” or “with gravel,” whichever is predominant. L If soil contains ! 30% plus No. 200 predominantly sand, add “sandy” to group name. M If soil contains ! 30% plus No. 200, predominantly gravel, add “gravelly” to group name. N PI ! 4 and plots on or above “A” line. O PI < 4 or plots below “A” line. P PI plots on or above “A” line. Q PI plots below “A” line. Project # 16-1287 November 2016 Sheet Drilling Rig: Water Depth Information Start Date 11/2/2016 Auger Type: During Drilling None Finish Date 11/2/2016 Hammer Type: After Drilling None Surface Elev. - Field Personnel: 2 Days After Drilling Dry to 14' USCS Sampler Atterberg Limits Project # 16-1287 November 2016 Sheet Drilling Rig: Water Depth Information Start Date 11/2/2016 Auger Type: During Drilling 13' Finish Date 11/2/2016 Hammer Type: After Drilling 13' Surface Elev. - Field Personnel: 2 Days After Drilling 13' USCS Sampler Atterberg Limits 26 - 27 - 28 - 29 - 30 HANSEN FARM PRELIMINARY EXPLORATION 6029 SOUTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 16-1287 November 2016 Sheet Drilling Rig: Water Depth Information Start Date 11/2/2016 Auger Type: During Drilling 9' Finish Date 11/2/2016 Hammer Type: After Drilling 9' Surface Elev. - Field Personnel: 2 Days After Drilling 9' USCS Sampler Atterberg Limits Project # 16-1287 November 2016 Sheet Drilling Rig: Water Depth Information Start Date 11/2/2016 Auger Type: During Drilling None Finish Date 11/2/2016 Hammer Type: After Drilling None Surface Elev. - Field Personnel: 2 Days After Drilling 12 1/2' USCS Sampler Atterberg Limits 13' During Drilling After Drilling Sheet Start Date Finish Date 2 Days After Drilling Water Depth Information 11/2/2016 13' 6029 SOUTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 16-1287 November 2016 Sampler USCS Surface Elev. 13' Auger Type: Drilling Rig: Hammer Type: Field Personnel: 11/2/2016 - Project # 16-1287 November 2016 Sheet Drilling Rig: Water Depth Information Start Date 11/2/2016 Auger Type: During Drilling 15' Finish Date 11/2/2016 Hammer Type: After Drilling 15' Surface Elev. - Field Personnel: 2 Days After Drilling 15' USCS Sampler Atterberg Limits 26 - 27 - 28 - 29 - 30 HANSEN FARM PRELIMINARY EXPLORATION 6029 SOUTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 16-1287 November 2016 Sheet Drilling Rig: Water Depth Information Start Date 11/2/2016 Auger Type: During Drilling None Finish Date 11/2/2016 Hammer Type: After Drilling None Surface Elev. - Field Personnel: 2 Days After Drilling Dry to 15' USCS Sampler Atterberg Limits