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Home My WebLink AboutPOUDRE VALLEY PLAZA MIXED-USE - MJA210003 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTGEOTECHNICAL SUBSURFACE EXPLORATION REPORT LOT 7 POUDRE VALLEY PLAZA – 4-STORY APARTMENT BUILDING SOUTHEAST CORNER OF HORSETOOTH ROAD AND SHIELDS STREET FORT COLLINS, COLORADO EEC PROJECT NO. 1202075 Prepared for: Schuman Companies, Inc. 4630 Royal Vista Circle Suite 13 Windsor, Colorado 80550 Attn: Mr. Mark Morrison (markm@schumanco.com) Prepared by: Earth Engineering Consultants, LLC 4396 Greenfield Drive Windsor, Colorado 80550 4396 GREENFIELD DRIVE W INDSOR, COLORADO 80550 (970) 545-3908 FAX (970) 663-0282 November 3, 2020 Schuman Companies, Inc. 4630 Royal Vista Circle Suite 13 Windsor, Colorado 80550 Attn: Mr. Mark Morrison (markm@schumanco.com) Re: Geotechnical Subsurface Exploration Report Lot 7 Poudre Valley Plaza – 4-Story Apartment Building Southeast Corner of Horsetooth Road and Shields Street Fort Collins, Colorado EEC Project No. 1202075 Mr. Morrison: Enclosed, herewith, are the results of the subsurface exploration completed by Earth Engineering Consultants, LLC (EEC) for the referenced project. For this exploration, three (3) soil borings were extended to depths of approximately 20 to 35 feet below existing site grades. This subsurface exploration was carried out in general accordance with our proposal dated October 1, 2020. In summary, the subsurface conditions encountered beneath the surficial sparse vegetation layer in the test borings, generally consisted of soils classified as clayey sand/sandy lean clay extending to the underlying bedrock at depths of approximately 14 to 17 feet below the ground surface. The clayey sand/sandy lean clay was generally dry to moist nearing the groundwater table, very stiff, and exhibited moderate to high swell potential at current moisture and density conditions. Claystone/siltstone/sandstone bedrock was encountered below the clayey sand/sandy lean clay soils in a majority of the borings and extended to the depths explored, approximately 20 to 35 feet below the ground surface. The bedrock was generally moist in situ, highly weathered to moderately hard/poorly cemented and exhibited low swell potential at current moisture and density conditions. Groundwater was encountered at depths of approximately 14½ to 15 feet below the ground surface in borings B-1 and B-2. Groundwater was not encountered in boring B-3 which extended to a maximum depth of approximately 20 feet below the ground surface. GEOTECHNICAL SUBSURFACE EXPLORATION REPORT LOT 7 POUDRE VALLEY PLAZA – 4-STORY APARTMENT BUILDING SOUTHEAST CORNER OF HORSETOOTH ROAD AND SHIELDS STREET FORT COLLINS, COLORADO EEC PROJECT NO. 1202075 November 3, 2020 INTRODUCTION The geotechnical subsurface exploration for the proposed 4-story apartment building planned for construction on Lot 7 within the Poudre Valley Plaza development in Fort Collins, Colorado has been completed. To develop subsurface information for the proposed in-fill development lot, three (3) soil borings were drilled within the proposed building footprint to depths of approximately 20 to 35 feet below existing site grades. A site diagram indicating the approximate boring locations is included with this report. We understand the proposed development will consist of a 4-story slab-on-grade (no basement) apartment building. We anticipate maximum foundations loads will be relatively light to moderate with maximum wall and column loads less than 4 klf and 150 kips, respectively. If the actual loads vary significantly from the assumed loads, or if below grade construction is planned, we should be consulted to verify our recommendations are consistent for the actual loads and construction depths. Floor loads are expected to be light to moderate. Small grade changes are expected to develop site grades for the proposed improvements. Overall, cuts and fills are anticipated to be less than 3 feet (+/-) to develop finish site grades. The purpose of this report is to describe the subsurface conditions encountered in the test borings, analyze, and evaluate the field and laboratory test data and provide geotechnical recommendations concerning design and construction of foundations and floor slabs and support of flatwork. EXPLORATION AND TESTING PROCEDURES The test boring locations were selected and established in the field by EEC personnel by pacing and estimating angles from identifiable site features. Ground surface elevations at each boring location were estimated based on “Google Earth” and are presented on the boring logs. The approximate locations of the borings are shown on the attached boring location diagram and “Google Earth” image. The boring locations and estimate ground surface elevations should be considered accurate only to the degree implied by the methods used to make the field measurements. Earth Engineering Consultants, LLC EEC Project No. 1202075 November 3, 2020 Page 2 The test borings were advanced using a truck mounted CME-55 drill rig equipped with a hydraulic head employed in drilling and sampling operations. The boreholes were advanced using 4-inch nominal diameter continuous flight augers. Samples of the subsurface materials encountered were obtained using split-barrel and California barrel sampling procedures in general accordance with ASTM Specifications D1586 and D3550, respectively. In the split-barrel and California barrel sampling procedures, standard sampling spoons are advanced into the ground by means of a 140-pound hammer falling a distance of 30 inches. The number of blows required to advance the split-barrel and California barrel samplers is recorded and is used to estimate the in-situ relative density of cohesionless soils and, to a lesser degree of accuracy, the consistency of cohesive soils. In the California barrel sampling procedure, relatively intact samples are obtained in removable brass liners. All samples obtained in the field were sealed and returned to our laboratory for further examination, classification, and testing. Laboratory moisture content tests were completed on each of the recovered samples with unconfined compressive strength of appropriate samples estimated using a calibrated hand penetrometer. Atterberg limits and washed sieve analysis tests were completed on select samples to evaluate the quantity and plasticity of fines in the subgrades. Swell/consolidation testing was completed on select samples to evaluate the potential for the subgrade materials to change volume with variation in moisture content and load. Soluble sulfate tests were completed on selected samples to estimate the potential for sulfate attack on site cast concrete. Results of the outlined tests are indicated on the attached boring logs and summary sheets. As part of the testing program, all samples were examined in the laboratory and classified in general accordance with the attached General Notes and the Unified Soil Classification System, based on the soil’s texture and plasticity. The estimated group symbol for the Unified Soil Classification System is indicated on the boring logs and a brief description of that classification system is included with this report. Earth Engineering Consultants, LLC EEC Project No. 1202075 November 3, 2020 Page 3 SITE AND SUBSURFACE CONDITIONS The proposed 4-story apartment building is planned for construction on Lot 7 within the Poudre Valley Plaza, situated at the southeast corner of Horsetooth Road and Shields Street in Fort Collins, Colorado. Sparse vegetation was encountered at the surface of the borings. Ground surface in this area is relatively flat with approximately 2 feet ± of relief from west to east, based on our cursory review of the site on Google Earth. EEC field personnel were on site during drilling to evaluate the subsurface conditions encountered and direct the drilling activities. Field logs prepared by EEC site personnel were based on visual and tactual observation of disturbed samples and auger cuttings. The final boring logs included with this report may contain modifications to the field logs based on results of laboratory testing and evaluation. Based on results of the field borings and laboratory testing, subsurface conditions can be generalized as follows. From the ground surface, the subgrades underlying the vegetation layer consisted of soils classified as clayey sand/sandy lean clay extending to the underlying bedrock at depths of approximately 14 to 17 feet below the ground surface. The clayey sand/sandy lean clay was generally dry to moist nearing the groundwater table, very stiff, and exhibited moderate to high swell potential at current moisture and density conditions. Claystone/siltstone/sandstone bedrock was encountered below the clayey sand/sandy lean clay soils in a majority of the borings and extended to the depths explored, approximately 20 to 35 feet below the ground surface. The bedrock was generally moist in situ, highly weathered to moderately hard/poorly cemented and exhibited low swell potential at current moisture and density conditions. The stratification boundaries indicated on the boring logs represent the approximate location of changes in soil types; in-situ, the transition of materials may be gradual and indistinct. GROUNDWATER CONDITIONS Observations were made while drilling and after completion of the borings to detect the presence and depth to hydrostatic groundwater. At the time of drilling, groundwater was encountered at depths of approximately 14½ to 15 feet below the ground surface in borings B-1 and B-2. Groundwater was not encountered in boring B-3 which extended to a maximum depth of approximately 20 feet below Earth Engineering Consultants, LLC EEC Project No. 1202075 November 3, 2020 Page 4 the ground surface. The borings were backfilled upon completion of the drilling operations; therefore, subsequent groundwater measurements were not performed. Fluctuations in groundwater levels can occur over time depending on variations in hydrologic conditions and other conditions not apparent at the time of this report. Longer term monitoring of water levels in cased wells, which are sealed from the influence of surface water, would be required to evaluate fluctuations more accurately in groundwater levels at the site. We have typically noted deepest groundwater levels in late winter and shallowest groundwater levels in mid to late summer. ANALYSIS AND RECOMMENDATIONS Swell – Consolidation Test Results The swell-consolidation test is performed to evaluate the swell or collapse potential of soils to assist in determining foundation and floor slab design criteria. In this test, relatively undisturbed samples obtained directly from the California sampler are placed in a laboratory apparatus and inundated with water under a predetermined load. The swell-index is the resulting amount of swell or collapse after the inundation period expressed as a percent of the sample’s preload/initial thickness. After the inundation period, additional incremental loads are applied to evaluate the swell pressure and/or consolidation. For this assessment, we conducted eight (8) swell-consolidation tests on relatively undisturbed soil samples obtained at various intervals/depths on the site. The swell index values for the in-situ soil samples analyzed revealed low to moderate swell characteristics as indicated on the attached swell test summaries. The (+) test results indicate the soil materials swell potential characteristics while the (-) test results indicate the soils materials collapse/consolidation potential characteristics when inundated with water. The following table summarizes the swell-consolidation laboratory test results for samples obtained during our field explorations for the subject site. Earth Engineering Consultants, LLC EEC Project No. 1202075 November 3, 2020 Page 5 Table I – Laboratory Swell-Consolidation Test Results No of Samples Tested Pre-Load / Inundation Pressure, PSF Description of Material In-Situ Characteristics Range of Swell – Index Test Results Range of Moisture Contents, % Range of Dry Densities, PCF Low End, % High End, % Low End, PCF High End, PCF Low End (+/-) % High End, (+/-) % 1 150 Sandy Lean Clay (CL) 6.3 102.5 (+) 3.5 2 500 Clayey Sand/Sandy Lean Clay (SC/CL) 9.4 9.5 118.4 124.3 (+) 3.6 (+) 5.2 3 1000 Sandy Lean Clay (CL) or Claystone/Siltstone/Sandstone 10.7 15.9 103.3 128.3 (-) 0.1 (+) 4.0 Colorado Association of Geotechnical Engineers (CAGE) uses the following information to provide uniformity in terminology between geotechnical engineers to provide a relative correlation of slab performance risk to measured swell. “The representative percent swell values are not necessarily measured values; rather, they are a judgment of the swell of the soil and/or bedrock profile likely to influence slab performance.” Geotechnical engineers use this information to also evaluate the swell potential risks for foundation performance based on the risk categories. Table II - Recommended Representative Swell Potential Descriptions and Corresponding Slab Performance Risk Categories Slab Performance Risk Category Representative Percent Swell (500 psf Surcharge) Representative Percent Swell (1000 psf Surcharge) Low 0 to < 3 0 < 2 Moderate 3 to < 5 2 to < 4 High 5 to < 8 4 to < 6 Very High > 8 > 6 Based on the laboratory test results, the swell samples analyzed for this project at current moisture contents and dry density conditioned were within the low to high range. The upper cohesive soils were generally dry, very stiff/dense in-situ, and exhibited moderate to high swell potential characteristics; thus, a possible over-excavation and replacement concept could be considered provided the ownership group is willing to accept the risk of movement. Earth Engineering Consultants, LLC EEC Project No. 1202075 November 3, 2020 Page 6 General Considerations The overburden soils on these lots include approximately 14 to 17 feet of lean clay with varying amounts of sand soils transitioning to more granular soils. Moderate to high swell potential was exhibited by the overburden soil samples, in our opinion this is likely due to the dry and stiff to very stiff conditions of the lean clay soils. In general, clay soils tend to swell when inundated with water when in-situ moisture contents are less than -2% dry of optimum moisture content. Typical optimum moisture contents for clay soils range from approximately 15 to 20%. The moisture contents observed in the borings were approximately 6 to 2% less than that range. Additionally, the soils appeared to be very stiff/dense, When moisture conditioned and re-compacted to near optimum moisture and density conditions, the swell potential of clay soils can be significantly reduced as shown by the lower swell potential exhibited by the near surface sample in boring B-3. The site preparation section of this report includes recommendations for an over excavation moisture treatment, and re-compaction procedure to reduce the risk of movement for the soils underlying the proposed site improvements. Although these methods reduce the overall risk of potential movement, that risk cannot be completely eliminated. The overburden clayey sand/sandy lean clay soils generally exhibited low to high potential when inundated with water. To mitigate for potential movement, we recommend either the use of a drilled pier foundation system with a structural floor slab and/or an extensive over excavation and replacement procedure for the use of a conventional slab-on-grade supported on a zone of engineered fill material as described herein. The purpose of these procedures is to reduce the potential for post-construction movement. It should be noted however, that the risk of potential movement cannot be completely eliminated, and the ownership group accepts that risk. Site Preparation Prior to placement of any fill and/or improvements, we recommend any existing topsoil, vegetation, and undocumented fill, and any unsuitable materials be removed from the planned development areas. Depending on the chosen foundation system, an over excavation procedure for the entire building footprint, below floor slabs should be completed to at least the minimum depths specified in the section titled Floor Slabs and Exterior Flatwork. Potholing and/or other observations should be completed prior to construction, to determine the depth to bedrock throughout the proposed building footprint. Due to the very high swell potential encountered in the near surface clay soils, Earth Engineering Consultants, LLC EEC Project No. 1202075 November 3, 2020 Page 7 consideration should be given to using drilled pier foundations and a structural floor system. Drilled piers are also recommended to minimize the impact to the surrounding pavement areas. If a 5-8 foot over excavation and replacement procedure were utilized to allow for spread footing foundations, the over excavation would extend well into the existing paved/developed areas adjacent to the infill lot. The use of drilled pier foundations would minimize the extensive limit beyond the building footprint. If elected as an alternative approach to a structural floor slab, and assuming a greater potential risk for movement, consideration could be given to over-excavating the site subsoils a minimum of 8 feet below existing ground surface or final floor slab elevation, whichever provides the greater overall depth, within the entire building footprint. Over excavations should be extended laterally beyond the edge of floor slabs, a minimum of 8-inches for every 12-inches of depth. Over excavations below the proposed floor slab could be confined to extending less than 5 feet laterally beyond the building footprint, to prevent them from extending into the adjacent pavement areas. After removal of all topsoil, vegetation, and removal of unacceptable or unsuitable subsoils, any overexcavation, and prior to placement of fill, the exposed soils should be scarified to a depth of 9 inches, adjusted in moisture content to within ±2% of standard Proctor optimum moisture content and compacted to at least 95% of the material's standard Proctor maximum dry density as determined in accordance with ASTM Specification D698. Fill materials to develop the subgrades should consist of approved, low-volume-change materials, which are free from organic matter and debris. It is our opinion, either granular structural fill or on- site moisture conditioned overburden soils could be used as fill in these areas, provided adequate moisture treatment and compaction procedures are followed. Bedrock should not be reused as engineered fill material. It should be noted that if the site lean clay soils are used as fill materials in lieu of a granular structural fill material, greater potential for movement should be expected. The imported granular materials should be graded similarly to a CDOT Class 5, 6 or 7 aggregate base. Fill materials should be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content to within ±2% of standard Proctor optimum moisture content and compacted to at least 95% of the material's standard Proctor maximum dry density as determined in accordance with ASTM Specification D698. If the site lean clay soils are used as fill material, care will be needed to maintain the recommended moisture content prior to and during construction of overlying improvements. Earth Engineering Consultants, LLC EEC Project No. 1202075 November 3, 2020 Page 8 Care should be exercised after preparation of the subgrades to avoid disturbing the subgrade materials. Materials which are loosened or disturbed should be reworked prior to placement of foundations/flatwork. Foundation Systems – General Considerations The site appears suitable for the proposed construction based on the results of our field exploration and our understanding of the proposed development plans. The following foundation system was evaluated for use on the site for the proposed building.  Straight shaft drilled piers bearing into the underlying bedrock formation with either a structural floor slab or a minimum 8 feet of engineered/controlled fill materials placed and compacted below the floor slab Other alternative foundation systems could be considered, and we would be pleased to provide additional alternatives upon request. Drilled Piers/Caissons Foundations Due to the necessity to over-excavate, ground modify the existing moderately to highly expansive cohesive overburden soils, and reduce the over-excavation impact to the surrounding areas, consideration should be given to supporting the proposed building on a grade beam and straight shaft drilled pier/caisson foundation system extending into the underlying bedrock formation. For axial compression loads, the drilled piers could be designed using a maximum end bearing pressure of 30,000 pounds per square foot (psf), along with a skin-friction of 3,000 psf for the portion of the pier extended into the underlying firm and/or harder bedrock formation. The piers require sufficient dead-load and/or additional penetration into the bearing strata to resist the potential uplift of the expansive materials. All piers should be design for a minimum dead-load pressure of 5,000 psf, based upon pier end area. Straight shaft piers should be drilled a minimum of 15 feet into competent or harder bedrock with minimum pier length of at least 25 feet. Due to the weathered condition of the upper strata of bedrock, the top 3 feet should be neglected for final penetration depth. Lower values may be appropriate for pier “groupings” depending on the pier diameters and spacing. Pile groups should be evaluated individually. Earth Engineering Consultants, LLC EEC Project No. 1202075 November 3, 2020 Page 9 Required pier penetration should be balanced against potential uplift forces due to expansion of the subsoils and bedrock on the site. For design purposes, the uplift force on each pier can be determined on the basis of the following equation: Up = 20 x D Where: Up = the uplift force in kips, and D = the pier diameter in feet Uplift forces on piers should be resisted by a combination of dead-load and pier penetration below a depth of about 20 feet and into the bearing strata. To satisfy forces in the horizontal direction, piers may be designed for lateral loads using a coefficient of subgrade reaction for varying pier diameters is as follows: Table III – Lateral Load Coefficient of Subgrade Reaction Pier Diameter (inches) Coefficient of Subgrade Reaction (tons/ft3) Site Soils Bedrock 12 50 400 18 33 267 24 25 200 30 20 160 36 17 133 When the lateral capacity of drilled piers is evaluated by the L-Pile computer program, we recommend that internally generated load-deformation (P-Y) curves be used. The following parameters may be used for the design of laterally loaded piers, using the L-Pile computer program: Table IV – L-Pile Parameters Parameters On-Site Overburden Soils Bedrock Unit Weight of Soil (pcf) 120(1) 125(1) Cohesion (psf) 200 5000 Angle of Internal Friction () (degrees) 25 20 Strain Corresponding to ½ Max. Principal Stress Difference 50 0.02 0.015 *Notes: 1) Reduce by 62.4 pcf below the water table All piers should be reinforced full depth for the applied axial, lateral and uplift stresses imposed. The amount of reinforcing steel for expansion should be determined by the tensile force created by the Earth Engineering Consultants, LLC EEC Project No. 1202075 November 3, 2020 Page 10 uplift force on each pier, with allowance for dead load. Minimum reinforcement of at least one percent of the cross-sectional area of each pier should be specified. To reduce potential uplift forces on piers, use of long grade beam spans to increase individual pier loading, and small diameter piers are recommended. For this project, use of a minimum pier diameter of 18 inches is recommended. A minimum 6-inch void space should be provided beneath grade beams between piers. The void material should be of suitable strength to support the weight of fresh concrete used in grade beam construction and to avoid collapse when foundation backfill is placed. Drilling caissons to design depth should be possible with conventional heavy-duty single flight power augers equipped with rock teeth on the majority of the site. However, areas of well-cemented bedrock may be encountered throughout the site at various depths where specialized drilling equipment and/or rock excavating equipment may be required. Consideration should be given to obtaining a unit price for difficult caisson excavation in the contract documents for the project. To provide increased resistance to potential uplift forces, the sides of each pier should be mechanically roughened in the bearing strata. This should be accomplished by a roughening tooth placed on the auger. Pier bearing surfaces must be cleaned prior to concrete placement. A representative of the geotechnical engineer should inspect the bearing surface and pier configuration. Depending on the depth of groundwater encountered at the time of construction temporary casing may be required to maintain open boreholes. Concrete should be placed as soon as practical after drilling each shaft to reduce the potential for sloughing of sidewalls. Groundwater encountered should be removed from each pier hole prior to concrete placement. Pier concrete should be placed immediately after completion of drilling and cleaning. If a casing is used for pier construction, it should be withdrawn in a slow continuous manner maintaining a sufficient head of concrete to prevent infiltration of water or the creation of voids in pier concrete. Pier concrete should have relatively high fluidity when placed in cased pier holes or through a tremie. Pier concrete with slump in the range of 6 to 8 inches is recommended. Free-fall concrete placement in piers will only be acceptable if provisions are taken to avoid striking the concrete on the sides of the hole or reinforcing steel. The use of a bottom-dump hopper/tremie pipe or an elephant's trunk discharging near the bottom of the hole where concrete segregation will be minimized, is recommended. Earth Engineering Consultants, LLC EEC Project No. 1202075 November 3, 2020 Page 11 A maximum 6-inch depth of groundwater is acceptable in each pier prior to concrete placement. If pier concrete cannot be placed in dry conditions, a tremie should be used for concrete placement. Due to potential sloughing and raveling, foundation concrete quantities may exceed calculated geometric volumes. Foundation excavations should be observed by the geotechnical engineer. A representative of the geotechnical engineer should inspect the bearing surface and pier configuration. If the soil conditions encountered differ from those presented in this report, supplemental recommendations may be required. We estimate the long-term settlement of drilled pier foundations designed and constructed as outlined above would be less than 1-inch. Floor Slabs and Exterior Flatwork The variability of the existing soils at approximate slab subgrade elevation could result in differential movement of floor slab-on-grade should the underlying expansive subsoils become elevated in moisture content. Differential slab movement/heave on the order of 4 to 6 inches or more is possible. Use of a structural floor system structurally supported independent of the subgrade soils, is a positive means of eliminating the potentially detrimental effects of floor slab movement. Subgrades for floor slabs and exterior flatwork should be prepared as outlined in the section Site Preparation. If a conventional slab-on-grade is used, an over excavation extending a minimum of 8 feet below the bottom of the floor slab is recommended. A structural floor slab should strongly be considered; however, if the ownership group is willing to assume a greater potential risk of slab movement, an over excavation and replacement concept extending a minimum 8 feet below the floor slab could be considered. A common practice to reduce potential slab heave involves overexcavation of the expansive soils and replacing these materials with either moisture conditioned engineered fill of with non-expansive imported structural fill material. This alternative over-excavation and replacement concept will not eliminate the possibility of slab heave; but movements should be reduced and tend to be more uniform. Constructing improvements (i.e. buildings, flatwork, pavements, floor slabs, etc.) on a site which exhibits potential for swelling is inherently at high risk for post construction heaving, causing distress of site improvements. The following recommendations provided herein are to reduce the risk of post construction heaving; however, that risk cannot be eliminated. If the owner does not accept that risk, we would be pleased to provide more stringent recommendations. Earth Engineering Consultants, LLC EEC Project No. 1202075 November 3, 2020 Page 12 As an alternative to a preferred structural floor system as previously recommended in this subsurface exploration report and assuming the owners are willing to accept total and differential movements of the floor as outlined below the use of moisture conditioned engineered fill material and/or approved imported structural fill material could be placed and compacted in an over-excavation zone beneath the floor slab. An underslab gravel layer or thin leveling course could be used underneath the concrete floor slabs to provide a capillary break mechanism, a load distribution layer, and as a leveling course for the concrete placement. Failure to limit the intrusion of water from any source, (i.e., surface water infiltration, seepage from detention ponds and/or adjacent utility trenches bedding zone, run-off, etc.); into the expansive subgrades materials could results in movement greater than those outlined below. The following table provides estimates for the total and differential amounts of movement which could be expected for a range of overexcavation depths, replaced with either non-expansive imported structural/granular fill material or moisture conditioned on-site cohesive materials, should the underlying subsoils or the bedrock formation below the over-excavated zone become elevated in moisture content to a reasonable depth. Table V - Calculated Heave Potential Depth of Removal of Expansive Soil and Replacement with Low to Non Expansive Fill Materials (ft) Calculated Heave Potential, Inches Imported Structural/Granular Fill Material Reuse of on-site moisture conditioned Subsoils 0 > 5+ > 5+ 4 < 3-1/2 < 4 6 < 2 < 3 8 < 3/4 < 1-1/2 It should be noted that the heave potential is the heave that could occur if subsurface moisture increases sufficiently subsequent to construction. When subsurface moisture does not increase, or increases only nominally, the full heave potential may not be realized. For this reason, and assuming some surface water run-off will be controlled with grading contours, drainage swales, etc., we provided surface slope and drainage recommendations in our report to reduce the potential for surface water infiltration. With appropriate surface features to limit the amount infiltration, we would not expect the full amount of potential heave to occur. In general, we believe the on-site cohesive subsoils and/or an approved imported, essentially granular structural fill material with a sufficient amount of fines to prevent the ponding of water Earth Engineering Consultants, LLC EEC Project No. 1202075 November 3, 2020 Page 13 within the fill, could be used for supporting the interior floor slab. Particular care will be needed with the use of cohesive subgrade soils to establish and maintain sufficient moisture in the fill material to maintain a low swell potential in the fill zone. However, as illustrated above the slabs post-construction total and differential movement cannot be completely eliminated. The cohesive soil materials may also be subject to strength loss and instability when wetted. Any over excavations should be completed, and fill materials should be placed as described in the section Site Preparation. For structural design of concrete slabs-on-grade, a modulus of subgrade reaction of 100 pounds per cubic inch (pci) or 200 pci could be used for floors supported on controlled/engineered fill materials or imported structural fill materials, respectively. Additional floor slab design and construction recommendations are as follows:  Interior partition walls should be separated/floated from floor slabs to allow for independent movement.  Positive separations and/or isolation joints should be provided between slabs and all foundations, columns, and utility lines to allow for independent movement.  Control joints should be provided in slabs to control the location and extent of cracking.  Interior trench backfill placed beneath slabs should be compacted in a similar manner as previously described for imported structural fill material.  Floor slabs should not be constructed on frozen subgrade.  Other design and construction considerations as outlined in the ACI Design Manual should be followed. For interior floor slabs, depending on the type of floor covering and adhesive used, those material manufacturers may require that specific subgrade, capillary break, and/or vapor barrier requirements be met. The project architect and/or material manufacturers should be consulted with for specific under slab requirements. We estimate the long-term movement of conventional floor slabs-on-grade designed and constructed as outlined above would be about 1 inch. It should be noted that if the lean clay soils are used as compacted fill materials below floor slabs, greater potential for movement could be expected. Earth Engineering Consultants, LLC EEC Project No. 1202075 November 3, 2020 Page 14 Care should be exercised after development of the floor slab and exterior flatwork subgrades to prevent disturbance of the in-place materials. Subgrade soils which are loosened or disturbed by construction activities or soils which become wet and softened or dry and desiccated should be removed and replaced or reworked in place prior to placement of the overlying slabs. Lateral Earth Pressures Portions of the new structure or site improvements which are constructed below grade may be subject to lateral earth pressures. Passive lateral earth pressures may help resist the driving forces for retaining wall or other similar site structures. Active lateral earth pressures could be used for design of structures where some movement of the structure is anticipated, such as retaining walls. The total deflection of structures for design with active earth pressure is estimated to be on the order of one half of one percent of the height of the down slope side of the structure. We recommend at- rest pressures be used for design of structures where rotation of the walls is restrained, such as below grade walls for a building. Passive pressures and friction between the footing and bearing soils could be used for design of resistance to movement of retaining walls. Coefficient values for backfill with anticipated types of soils for calculation of active, at-rest and passive earth pressures are provided in Table V below. Equivalent fluid pressure is equal to the coefficient times the appropriate soil unit weight. Those coefficient values are based on horizontal backfill with backfill soils consisting of on-site essentially cohesive subsoils. For at-rest and active earth pressures, slopes down and away from the structure would result in reduced driving forces with slopes up and away from the structures resulting in greater forces on the walls. The passive resistance would be reduced with slopes away from the wall. The top 30 inches of soil on the passive resistance side of walls could be used as a surcharge load; however, should not be used as a part of the passive resistance value. Frictional resistance is equal to the tangent of the friction angle times the normal force. Surcharge loads or point loads placed in the backfill can also create additional loads on below grade walls. Those situations should be designed on an individual basis. Earth Engineering Consultants, LLC EEC Project No. 1202075 November 3, 2020 Page 15 Table V - Lateral Earth Pressures Soil Type On-Site Overburden Lean Clay Soils Imported Medium Dense Granular Material Wet Unit Weight (psf) 105 135 Saturated Unit Weight (psf) 115 140 Friction Angle () – (assumed) 20° 35° Active Pressure Coefficient 0.49 0.27 At-rest Pressure Coefficient 0.66 0.43 Passive Pressure Coefficient 2.04 3.70 Coefficient of Friction at Base 0.20 0.35 The outlined values do not include factors of safety nor allowances for hydrostatic loads and are based on assumed friction angles, which should be verified after potential material sources have been identified. Care should be taken to develop appropriate drainage systems behind below grade walls to eliminate potential for hydrostatic loads developing on the walls. Those systems would likely include perimeter drain systems extending to sump areas or free outfall where reverse flow cannot occur into the system. Where necessary, appropriate hydrostatic load values should be used for design. To reduce hydrostatic loading on retaining walls, a subsurface drain system should be placed behind the wall. The drain system should consist of free-draining granular soils containing less than five percent fines (by weight) passing a No. 200 sieve placed adjacent to the wall. The free-draining granular material should be graded to prevent the intrusion of fines or encapsulated in a suitable filter fabric. A drainage system consisting of either weep holes or perforated drain lines (placed near the base of the wall) should be used to intercept and discharge water which would tend to saturate the backfill. Where used, drain lines should be embedded in a uniformly graded filter material and provided with adequate clean-outs for periodic maintenance. An impervious soil should be used in the upper layer of backfill to reduce the potential for water infiltration. As an alternative, a prefabricated drainage structure, such as geo-composite product, may be used as a substitute for the granular backfill adjacent to the wall. Earth Engineering Consultants, LLC EEC Project No. 1202075 November 3, 2020 Page 16 Seismic The site soil conditions generally consist of clayey sand /sandy lean clay which extended to the underlying bedrock at depths of 14 to 17 feet. For those site conditions, the International Building Code indicates a Seismic Site Classification of C. Drilling to a greater depth could reveal a different site classification. Water Soluble Sulfates (SO4) The water-soluble sulfate (SO4) content of the on-site overburden subsoils and underlying bedrock taken during our subsurface exploration at random locations and intervals are provided below. Based on reported sulfate content test results, the Class/severity of sulfate exposure for concrete in contact with the on-site subsoils and bedrock is provided in this report. Table VII - Water Soluble Sulfate Test Results Sample Location Description Soluble Sulfate Content (%) B-2, S-2, at 4’ Sandy Lean Clay (CL) 0.03 B-3, S-3 at 14’ Claystone / Siltstone / Sandstone 0.02 Based on the results of completed soluble sulfate tests of the overburden soils and bedrock formation, ACI 318, Section 4.2 indicates a low risk of sulfate attack on Portland cement concrete, therefore, ACI Class S0 requirements should be followed for concrete placed in the overburden soils and underlying bedrock. Foundation concrete should be designed in accordance with the provisions of the ACI Design Manual, Section 318, Chapter 4. Other Considerations Positive drainage should be developed away from the structures and exterior flatwork areas with a minimum slope of 1 inch per foot for the first 10 feet away from the improvements in landscape areas. Care should be taken in planning of landscaping (if required) adjacent to the buildings to avoid features which would pond water adjacent to the foundations or stemwalls. Placement of plants which require irrigation systems or could result in fluctuations of the moisture content of the subgrade material should be avoided adjacent to site improvements. Irrigation systems should not be Earth Engineering Consultants, LLC EEC Project No. 1202075 November 3, 2020 Page 17 placed within 5 feet of the perimeter of the buildings and parking areas. Spray heads should be designed not to spray water on or immediately adjacent to the structures or site flatwork. Roof drains should be designed to discharge at least 5 feet away from the structures and away from the flatwork areas. Excavations into the on-site clayey sand/sandy lean clay soils and underlying bedrock can be expected to stand on relatively steep, temporary slopes during construction. The individual contractor(s) should be made responsible for designing and constructing stable, temporary excavations as required to maintain stability of both the excavation sides and bottom. All excavations should be sloped or shored in the interest of safety following local and federal regulations, including current OSHA excavation and trench safety standards. GENERAL COMMENTS The analysis and recommendations presented in this report are based upon the data obtained from the soil borings performed at the indicated locations and from any other information discussed in this report. This report does not reflect any variations, which may occur between borings or across the site. The nature and extent of such variations may not become evident until construction. If variations appear evident, it will be necessary to re-evaluate the recommendations of this report. It is recommended that the geotechnical engineer be retained to review the plans and specifications, so comments can be made regarding the interpretation and implementation of our geotechnical recommendations in the design and specifications. It is further recommended that the geotechnical engineer be retained for testing and observations during earthwork phases to help determine that the design requirements are fulfilled. This report has been prepared for the exclusive use of Schuman Companies for specific application to the project discussed and has been prepared in accordance with generally accepted geotechnical engineering practices. No warranty, express or implied, is made. In the event that any changes in the nature, design, or location of the project as outlined in this report are planned, the conclusions and recommendations contained in this report shall not be considered valid unless the changes are reviewed, and the conclusions of this report are modified or verified in writing by the geotechnical engineer. Earth Engineering Consultants, LLC DRILLING AND EXPLORATION DRILLING & SAMPLING SYMBOLS: SS: Split Spoon ‐ 13/8" I.D., 2" O.D., unless otherwise noted PS: Piston Sample ST: Thin‐Walled Tube ‐ 2" O.D., unless otherwise noted WS: Wash Sample R: Ring Barrel Sampler ‐ 2.42" I.D., 3" O.D. unless otherwise noted PA: Power Auger FT: Fish Tail Bit HA: Hand Auger RB: Rock Bit DB: Diamond Bit = 4", N, B BS: Bulk Sample AS: Auger Sample PM: Pressure Meter HS: Hollow Stem Auger WB: Wash Bore Standard "N" Penetration: Blows per foot of a 140 pound hammer falling 30 inches on a 2‐inch O.D. split spoon, except where noted. WATER LEVEL MEASUREMENT SYMBOLS: WL : Water Level WS : While Sampling WCI: Wet Cave in WD : While Drilling DCI: Dry Cave in BCR: Before Casing Removal AB : After Boring ACR: After Casting Removal Water levels indicated on the boring logs are the levels measured in the borings at the time indicated. In pervious soils, the indicated levels may reflect the location of ground water. In low permeability soils, the accurate determination of ground water levels is not possible with only short term observations. DESCRIPTIVE SOIL CLASSIFICATION Soil Classification is based on the Unified Soil Classification system and the ASTM Designations D‐2488. Coarse Grained Soils have move than 50% of their dry weight retained on a #200 sieve; they are described as: boulders, cobbles, gravel or sand. Fine Grained Soils have less than 50% of their dry weight retained on a #200 sieve; they are described as : clays, if they are plastic, and silts if they are slightly plastic or non‐plastic. Major constituents may be added as modifiers and minor constituents may be added according to the relative proportions based on grain size. In addition to gradation, coarse grained soils are defined on the basis of their relative in‐ place density and fine grained soils on the basis of their consistency. Example: Lean clay with sand, trace gravel, stiff (CL); silty sand, trace gravel, medium dense (SM). CONSISTENCY OF FINE‐GRAINED SOILS Unconfined Compressive Strength, Qu, psf Consistency < 500 Very Soft 500 ‐ 1,000 Soft 1,001 ‐ 2,000 Medium 2,001 ‐ 4,000 Stiff 4,001 ‐ 8,000 Very Stiff 8,001 ‐ 16,000 Very Hard RELATIVE DENSITY OF COARSE‐GRAINED SOILS: N‐Blows/ft Relative Density 0‐3 Very Loose 4‐9 Loose 10‐29 Medium Dense 30‐49 Dense 50‐80 Very Dense 80 + Extremely Dense PHYSICAL PROPERTIES OF BEDROCK DEGREE OF WEATHERING: Slight Slight decomposition of parent material on joints. May be color change. Moderate Some decomposition and color change throughout. High Rock highly decomposed, may be extremely broken. HARDNESS AND DEGREE OF CEMENTATION: Limestone and Dolomite: Hard Difficult to scratch with knife. Moderately Can be scratched easily with knife. Hard Cannot be scratched with fingernail. Soft Can be scratched with fingernail. Shale, Siltstone and Claystone: Hard Can be scratched easily with knife, cannot be scratched with fingernail. Moderately Can be scratched with fingernail. Hard Soft Can be easily dented but not molded with fingers. Sandstone and Conglomerate: Well Capable of scratching a knife blade. Cemented Cemented Can be scratched with knife. Poorly Can be broken apart easily with fingers. Cemented Group Symbol Group Name Cu≥4 and 1<Cc≤3E GW Well-graded gravel F Cu<4 and/or 1>Cc>3E GP Poorly-graded gravel F Fines classify as ML or MH GM Silty gravel G,H Fines Classify as CL or CH GC Clayey Gravel F,G,H Cu≥6 and 1<Cc≤3E SW Well-graded sand I Cu<6 and/or 1>Cc>3E SP Poorly-graded sand I Fines classify as ML or MH SM Silty sand G,H,I Fines classify as CL or CH SC Clayey sand G,H,I inorganic PI>7 and plots on or above "A" Line CL Lean clay K,L,M PI<4 or plots below "A" Line ML Silt K,L,M organic Liquid Limit - oven dried Organic clay K,L,M,N Liquid Limit - not dried Organic silt K,L,M,O inorganic PI plots on or above "A" Line CH Fat clay K,L,M PI plots below "A" Line MH Elastic Silt K,L,M organic Liquid Limit - oven dried Organic clay K,L,M,P Liquid Limit - not dried Organic silt K,L,M,O Highly organic soils PT Peat (D30)2 D10 x D60 GW-GM well graded gravel with silt NPI≥4 and plots on or above "A" line. GW-GC well-graded gravel with clay OPI≤4 or plots below "A" line. GP-GM poorly-graded gravel with silt PPI plots on or above "A" line. GP-GC poorly-graded gravel with clay QPI plots below "A" line. 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 Earth Engineering Consultants, LLC IIf soil contains >15% gravel, add "with gravel" to group name JIf Atterberg limits plots shaded area, soil is a CL- ML, Silty clay Unified Soil Classification System Soil Classification Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests Sands 50% or more coarse fraction passes No. 4 sieve Fine-Grained Soils 50% or more passes the No. 200 sieve <0.75 OL Gravels with Fines more than 12% fines Clean Sands Less than 5% fines Sands with Fines more than 12% fines Clean Gravels Less than 5% fines Gravels more than 50% of coarse fraction retained on No. 4 sieve Coarse - Grained Soils more than 50% retained on No. 200 sieve CGravels with 5 to 12% fines required dual symbols: Kif soil contains 15 to 29% plus No. 200, add "with sand" or "with gravel", whichever is predominant. <0.75 OH Primarily organic matter, dark in color, and organic odor ABased on the material passing the 3-in. (75-mm) sieve ECu=D60/D10 Cc= HIf fines are organic, add "with organic fines" to group name LIf soil contains ≥ 30% plus No. 200 predominantly sand, add "sandy" to group name. MIf soil contains ≥30% plus No. 200 predominantly gravel, add "gravelly" to group name. DSands with 5 to 12% fines require dual symbols: BIf field sample contained cobbles or boulders, or both, add "with cobbles or boulders, or both" to group name.FIf soil contains ≥15% sand, add "with sand" to GIf fines classify as CL-ML, use dual symbol GC- CM, or SC-SM. Silts and Clays Liquid Limit less than 50 Silts and Clays Liquid Limit 50 or more 0 10 20 30 40 50 60 0 10 20 30 40 50 60 70 80 90 100 110PLASTICITY INDEX (PI) LIQUID LIMIT (LL) ML OR OL MH OR OH For Classification of fine-grained soils and fine-grained fraction of coarse-grained soils. Equation of "A"-line Horizontal at PI=4 to LL=25.5 then PI-0.73 (LL-20) Equation of "U"-line Vertical at LL=16 to PI-7, then PI=0.9 (LL-8) CL-ML LOT 7 POUDRE VALLEY PLAZA FORT COLLINS, COLORADO EEC PROJECT NO. 1202075 OCTOBER 2020 Lot 7 - Poud re Valley Plaza - In -Fill Lo t for 4-Story Apartment Build i ng Approxim ate locations for three (3) tes t borings with building footprint 300 ft N➤➤N B-1B-2B-312Boring Location DiagramLot 7 Poudre Valley Plaza - Fort Collins, ColoradoEEC Project #: 1202075October 2020EARTH ENGINEERING CONSULTANTS, LLCASSro[imate BoringLocations1LegendSite PKotosPKotos taNen in aSSro[imatelocation, in direction oI arroZ DATE: RIG TYPE: CME55 FOREMAN: DG AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC SOIL DESCRIPTION D N QU MC DD -200 TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF SPARSE VEGETATION _ _ 1 CLAYEY SAND (SC) _ _ red / brown / tan 2 dense to medium dense _ _ 3 _ _ 4 _ _ CS 5 32 9000+ 9.4 123.4 33 19 46.2 7500 psf 5.2% _ _ 6 _ _ 7 _ _ 8 _ _ 9 _ _ SS 10 10 8000 16.4 _ _ 11 _ _ 12 _ _ 13 _ _ with organics 14 _ _ CS 15 28 9.9 117.8 _ _ 16 _ _ 17 _ _ CLAYSTONE / SILTSTONE / SANDSTONE 18 brown / gray / rust _ _ weathered to moderately hard / poorly cemented 19 _ _ SS 20 50/11" 16.3 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ CS 25 50/5" 5500 15.9 112.5 29 4 20.3 < 1000 psf None Continued on Sheet 2 of 2 _ _ Earth Engineering Consultants, LLC POUDRE VALLEY PLAZA - LOT 7 FORT COLLINS, COLORADO LOG OF BORING B-1PROJECT NO: 1202075 OCTOBER 2020 SHEET 1 OF 2 WATER DEPTH START DATE 10/21/2020 WHILE DRILLING 15' APPROX. SURFACE ELEV. 5086 FINISH DATE 10/21/2020 A-LIMITS SWELL DATE: RIG TYPE: CME55 FOREMAN: DG AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC SOIL DESCRIPTION D N QU MC DD -200 TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF Continued from Sheet 1 of 2 26 _ _ CLAYSTONE / SILTSTONE / SANDSTONE 27 brown / gray / rust _ _ moderately hard to hard / poorly cemented 28 _ _ 29 _ _ SS 30 50 16.2 _ _ 31 _ _ 32 _ _ 33 _ _ 34 _ _ CS 35 50/4" 9000+ 16.6 117.0 BOTTOM OF BORING DEPTH 35' _ _ 36 _ _ 37 _ _ 38 _ _ 39 _ _ 40 _ _ 41 _ _ 42 _ _ 43 _ _ 44 _ _ 45 _ _ 46 _ _ 47 _ _ 48 _ _ 49 _ _ 50 _ _ Earth Engineering Consultants POUDRE VALLEY PLAZA - LOT 7 FORT COLLINS, COLORADO LOG OF BORING B-1 OCTOBER 2020PROJECT NO: 1202075 SHEET 2 OF 2 WATER DEPTH START DATE 10/21/2020 WHILE DRILLING 15' 10/21/2020 AFTER DRILLING APPROX. SURFACE ELEV. 24 HOUR FINISH DATE A-LIMITS SWELL N/A DATE: RIG TYPE: CME55 FOREMAN: DG AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC SOIL DESCRIPTION D N QU MC DD -200 TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF SPARSE VEGETATION _ _ 1 SANDY LEAN CLAY (CL) _ _ red / brown 2 very stiff _ _% @150 psf CS 3 30 6.3 99.7 33 17 50.6 800 psf 3.5% _ _ 4 _ _ SS 5 24 9000+ 11.9 _ _ 6 _ _ 7 _ _ 8 _ _ 9 with calcareous deposits _ _% @1000 psf CS 10 28 9000+ 10.7 128.0 38 24 51.2 7500 psf 4.0% _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ SS 15 18 1500 23.8 _ _ CLAYSTONE / SILTSTONE / SANDSTONE 16 brown / gray / rust _ _ weathered to moderately hard / poorly cemented 17 _ _ 18 _ _ 19 _ _ CS 20 50/5" 9000+ 15.6 117.4 BOTTOM OF BORING DEPTH 20' _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ 25 _ _ Earth Engineering Consultants, LLC POUDRE VALLEY PLAZA - LOT 7 FORT COLLINS, COLORADO PROJECT NO: 1202075 LOG OF BORING B-2 OCTOBER 2020 SHEET 1 OF 2 WATER DEPTH 14.5'START DATE 10/21/2020 WHILE DRILLING FINISH DATE 10/21/2020 APPROX. SURFACE ELEV. 5086 A-LIMITS SWELL DATE: RIG TYPE: CME55 FOREMAN: DG AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC SOIL DESCRIPTION D N QU MC DD -200 TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF SPARSE VEGETATION _ _ 1 CLAYEY SAND / SANDY LEAN CLAY (SC / CL) _ _ red 2 dense to medium dense / very stiff to stiff _ _ 3 _ _ 4 _ _ CS 5 35 9000+ 9.5 123.4 3500 psf 3.6% _ _ 6 _ _ 7 _ _ 8 _ _ 9 with trace gravel _ _ SS 10 12 9000+ 13.6 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _% @1000 psf CLAYSTONE / SILTSTONE / SANDSTONE CS 15 34 9000+ 15.4 118.8 1400 psf 0.3% brown / gray / rust _ _ weathered to moderately hard / poorly cemented 16 _ _ 17 _ _ 18 _ _ 19 _ _ SS 20 50/11" 9000+ 14.3 _ _ BOTTOM OF BORING DEPTH 20.5' 21 _ _ 22 _ _ 23 _ _ 24 _ _ 25 _ _ Earth Engineering Consultants, LLC POUDRE VALLEY PLAZA - LOT 7 FORT COLLINS, COLORADO PROJECT NO: 1202075 LOG OF BORING B-3 OCTOBER 2020 SHEET 1 OF 2 WATER DEPTH NoneSTART DATE 10/21/2020 WHILE DRILLING FINISH DATE 10/21/2020 APPROX. SURFACE ELEV. 5087 A-LIMITS SWELL Project: Location: Project #: Date: Poudre Valley Plaza - Lot 7 Fort Collins, Colorado 1202075 October 2020 Beginning Moisture: 9.4% Dry Density: 124.3 pcf Ending Moisture: 13.6% Swell Pressure: 7500 psf % Swell @ 500: 5.2% Sample Location: Boring 1, Sample 1, Depth 4' Liquid Limit: 33 Plasticity Index: 19 % Passing #200: 46.2% SWELL / CONSOLIDATION TEST RESULTS Material Description: Red / Brown / Tan Clayey Sand (SC) -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Poudre Valley Plaza - Lot 7 Fort Collins, Colorado 1202075 October 2020 Beginning Moisture: 15.9% Dry Density: 113.6 pcf Ending Moisture: 20.2% Swell Pressure: < 1000 psf % Swell @ 1000: None Sample Location: Boring 1, Sample 5, Depth 24' Liquid Limit: 29 Plasticity Index: 4 % Passing #200: 20.3% SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown / Gray / Rust Claystone / Siltstone / Sandstone -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Poudre Valley Plaza - Lot 7 Fort Collins, Colorado 1202075 October 2020 Beginning Moisture: 6.3% Dry Density: 102.5 pcf Ending Moisture: 20.7% Swell Pressure: 800 psf % Swell @ 150: 3.5% Sample Location: Boring 2, Sample 1, Depth 2' Liquid Limit: 33 Plasticity Index: 17 % Passing #200: 50.6% SWELL / CONSOLIDATION TEST RESULTS Material Description: Red / Brown Sandy Lean Clay (CL) -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Poudre Valley Plaza - Lot 7 Fort Collins, Colorado 1202075 October 2020 Beginning Moisture: 10.7% Dry Density: 128.3 pcf Ending Moisture: 12.2% Swell Pressure: 7500 psf % Swell @ 1000: 4.0% Sample Location: Boring 2, Sample 3, Depth 9' Liquid Limit: 38 Plasticity Index: 24 % Passing #200: 51.2% SWELL / CONSOLIDATION TEST RESULTS Material Description: Red / Brown Sandy Lean Clay (CL) -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: Red Clayey Sand / Sandy Lean Clay (SC / CL) Sample Location: Boring 3, Sample 1, Depth 4' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - Beginning Moisture: 9.5% Dry Density: 118.4 pcf Ending Moisture: 18.0% Swell Pressure: 3500 psf % Swell @ 500: 3.6% Poudre Valley Plaza - Lot 7 Fort Collins, Colorado 1202075 October 2020 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Poudre Valley Plaza - Lot 7 Fort Collins, Colorado 1202075 October 2020 Beginning Moisture: 15.4% Dry Density: 118.8 pcf Ending Moisture: 17.4% Swell Pressure: 1400 psf % Swell @ 1000: 0.3% Sample Location: Boring 3, Sample 3, Depth 14' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown / Gray / Rust Claystone / Siltstone / Sandstone -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added