Loading...
HomeMy WebLinkAboutBLOCK 23 MORNINGSTAR - PDP200006 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTSUBSURFACE EXPLORATION REPORT BLOCK 23 DEVELOPMENT NORTHWEST CORNER OF NORTH COLLEGE AVENUE AND MAPLE STREET FORT COLLINS, COLORADO EEC PROJECT NO. 1192054 Prepared for: Block 23, LLC c/o Jensen LaPlante Development 1603 Oakridge Drive, Suite 101 Fort Collins, Colorado 80525 Attn: Mr. Jeff Jensen (jeff@jensenlaplante.com) Prepared by: Earth Engineering Consultants, LLC 4396 Greenfield Drive Windsor, Colorado 80550 4396 GREENFIELD DRIVE WINDSOR, COLORADO 80550 (970) 545-3908 FAX (970) 663-0282 August 5, 2019 Block 23, LLC c/o Jensen LaPlante Development 1603 Oakridge Drive, Suite 101 Fort Collins, Colorado 80525 Attn: Mr. Jeff Jensen (jeff@jensenlaplante.com) Re: Subsurface Exploration Report Block 23 Development Northwest Corner of North College Avenue and Maple Street Fort Collins, Colorado EEC Project No. 1192054 Mr. Jensen: Enclosed herewith, are the results of the subsurface exploration completed by Earth Engineering Consultants, LLC (EEC) for the referenced project. For this exploration, a total of eleven (11) soil borings were completed across the site within the proposed Senior Living and Retail building footprint, the proposed 500-space parking garage structure, and within the planned on- site pavement improvement areas as presented herein. These site-specific borings were extended to depths of approximately 10 to 50 feet below existing site grades. This subsurface exploration was carried out in general accordance with our proposal dated March 18, 2019. We understand this project involves developing two parcels with a total of approximately 2.6 acres between Cherry Street and Maple Street, and between North College avenue and Mason Street in Fort Collins. The development is expected to include a 4-story, 195,000 gross square- foot (gsf) Senior Living and Retail building with interior courtyards, along with a 4-story, approximate 137,000 to 165,000 gsf, 350 to 500-space parking garage structure. The buildings are expected to be constructed as slab-on-grade (no basement) structures. We expect foundation loads for the proposed Senior Living Center building would be moderate (anticipated wall loads of 3 to 6 kips per linear foot and column loads on the order of 50 to 250 kips), with heavy loads (anticipated wall loads of 5 to 8 kips per linear foot and column loads on the order of 250 to 500 kips) expected for the parking garage. Floor loads are expected to be moderate to heavy. A Earth Engineering Consultants, LLC EEC Project No. 1192054 August 5, 2019 Page 2 portion of the site, as depicted by the enclosed Google Earth image of the site, is currently occupied by existing abandoned commercial buildings which will be razed/removed as part of the development of the project. In summary, a surficial of layer of gravel, asphaltic concrete and/or concrete pavement sections, or topsoil/landscape materials were observed throughout the site at the boring locations. An approximate 3 to 9-foot (±) layer of existing fill material was encountered immediately beneath the surface materials. Native cohesive to slightly cohesive sandy lean clay and clayey sand subsoils were encountered beneath the existing fill zone and extended to the fine to coarse granular strata below. Fine to coarse silty sand with gravel and intermittent cobbles strata was encountered below the upper overburden subsoils in most of the borings and extended to the depths explored and/or to the bedrock formation below. Siltstone/sandstone bedrock was encountered in borings B-1 through B-9 at depths of approximately 7 to 19 feet below present site grades and extended to maximum depths of exploration, approximately 50 feet. At the time of drilling, free water was observed in borings B-1 through B-5, B-7, and B-8 at depths of approximately 12 to 18-1/2-feet below site grades. Groundwater was not encountered in the remaining borings. The borings were backfilled with augers cuttings upon completion of the drilling operations, therefore subsequent groundwater measurements were not obtained. Based on the subsurface conditions encountered in the test borings, as well as the anticipated maximum loading conditions, we recommend the proposed 4-story residential/retail structure and the 4-story parking garage structure be supported on either a grade beam and straight shaft drilled pier foundation system extending into the underlying bedrock formation or on foundation footings supported on subgrades improved with rammed aggregate piers as described in the text of the attached report. We anticipate floor slabs, and exterior flatwork could be supported on newly placed and compacted fill soils or on ground modified in-place subsoils. SUBSURFACE EXPLORATION REPORT BLOCK 23 DEVELOPMENT NORTHWEST CORNER OF NORTH COLLEGE AVENUE AND MAPLE STREET FORT COLLINS, COLORADO EEC PROJECT NO. 1192054 August 5, 2019 INTRODUCTION The geotechnical subsurface exploration for the proposed 4-story Senior Living and Retail building, and the 4-story 350 to 500-space parking garage structure, planned as Phase II of the Block 23 redevelopment north of downtown Fort Collins, Colorado has been completed. The site for the proposed development is situated within the Northeast ¼ of Section 11, Township 7 North, Range 69 West of 6th PM, Larimer County, Colorado. To develop subsurface information in the proposed development area, eleven (11) soil borings were drilled within the proposed building footprints and planned site improvement areas to depths of approximately 10 to 50 feet below existing site grades. A site diagram indicating the approximate boring locations is included with this report. We understand this project involves developing two parcels with a total of approximately 2.6 acres between Cherry Street and Maple Street, and between North College Avenue and Mason Street in Fort Collins. The development is expected to include a 4-story, 195,000 gross square-foot (gsf) Senior Living and Retail building with interior courtyards, along with a 4-story, approximate 137,000 to 165,000 gsf, 350 to 500-space parking garage structure. The retail portion will include approximately 20,000 square feet (sf) on the ground level while the Senior Living portion will include approximately 90 independent living units, 25 memory care units, and 45 assisted living units on levels 1 through 4, along with approximately 20,950 sf of resident common space. The buildings are expected to be constructed as slab-on-grade (no basement) structures. We expect foundation loads for the proposed Senior Living Center building would be moderate (anticipated wall loads of 3 to 6 kips per linear foot and column loads on the order of 50 to 250 kips), with heavy loads (anticipated wall loads of 5 to 8 kips per linear foot and column loads on the order of 250 to 500 kips) expected for the parking garage. Floor loads are expected to be moderate to heavy. A portion of the site, as depicted by the enclosed Google Earth image of the site, is currently occupied by existing abandoned commercial buildings which will be razed/removed as part of the development of the project. Earth Engineering Consultants, LLC EEC Project No. 1192054 August 5, 2019 Page 2 The purpose of this report is to describe the subsurface conditions encountered in the test borings completed as part of the subsurface exploration, analyze and evaluate the test data and provide geotechnical recommendations concerning design and construction of foundations, support of floor slabs, on-site pavement improvements and other earth related features for the proposed site development. EXPLORATION AND TESTING PROCEDURES The boring locations were determined in the request for proposal and established in the field by a representative of Earth Engineering Consultants, LLC (EEC) by pacing and estimating angles from identifiable site features and by use of a hand-held GPS unit. Approximate ground surface elevations at each boring location were estimated based on linear interpolation between contours presented on the Fort Collins topographic quadrangle map, and Google Earth, and are recorded on the boring logs included with this report. The location for each boring and estimated ground surface elevations should be considered accurate only to the degree implied by the methods used for the field measurements. Photographs of the site, taken at the time of drilling, are provided with this report. 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 a combination of 4-inch nominal diameter continuous flight augers and 4-1/4-inch inside diameter hollow stem 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. Earth Engineering Consultants, LLC EEC Project No. 1192054 August 5, 2019 Page 3 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 by an engineer and classified in accordance with the attached General Notes and the Unified Soil Classification System, based on the soil’s texture and plasticity. The estimated group symbol for the Unified Soil Classification System is indicated on the boring logs and a brief description of that classification system is included with this report. Classification of the bedrock was based on visual and tactual observation of disturbed samples and auger cuttings. Coring and/or petrographic analysis may reveal other rock types. SITE AND SUBSURFACE CONDITIONS The Block 23 parcel is located on the north side of Maple Street, west of North College Avenue, south of Cherry Street and east of Mason Street, north of downtown Fort Collins. As shown on the enclosed site plan and Google Earth image of the site, the BNSF railroad tracks run through the property near the northwest corner of the site and continues along the western boundary, parallel to North Mason Street. Existing single-story, slab-on-grade abandoned commercial buildings currently occupy portions of the east half of the Block 23 site. The buildings will be razed/removed as part of the site development. The ground surface was relatively flat and level, and aside from the existing structures and railroad, covered with sparse vegetation, gravels and pavements. A surficial of layer of gravel, asphaltic concrete, topsoil/landscape material, or concrete was observed at the boring locations. An approximate 3 to 9-foot (±) layer of existing fill material was encountered immediately beneath the surface materials. Native cohesive to slightly cohesive sandy lean clay and clayey sand subsoils were encountered beneath the existing fill zone and extended to the fine to coarse granular strata below. Fine to coarse silty sand with gravel and intermittent cobbles strata was encountered below the upper overburden subsoils in most of the borings and Earth Engineering Consultants, LLC EEC Project No. 1192054 August 5, 2019 Page 4 extended to the depths explored and/or to the bedrock formation below. Sandstone bedrock with interbedded siltstone lenses was encountered in borings B-1 through B-9 at depths of approximately 7 to 19 feet below present site grades and extended to maximum depths of exploration, approximately 50 feet. The stratification boundaries indicated on the boring logs represent the approximate locations of changes in soil and bedrock types. In-situ, the transition of materials may be gradual and indistinct. Well-cemented sandstone bedrock lenses were encountered at increased depths, as evident by the Standard Penetration Test (SPT) results presented on the boring logs. SPT results of the underlying bedrock formation with intermittent well-cemented sandstone lenses ranged from 50 blows per 6 inches to 50 blows per 1 inch at increased depths. Existing Fill Material Approximately 3 to 9 feet of fill material was encountered across the site, as indicated in the attached boring logs. The fill material generally consisted of silty sand with gravel, clayey sand with gravel and sandy lean clay with gravel. An occasional lens of cinders was encountered within the fill material. Based upon the limited field penetration resistance values recorded within the fill zone during our exploration, the in-situ moisture contents, and the in-situ dry densities, in general, the fill material is not uniform. Variations of depth, quality, and characteristics of the fill material may exist across the site and may not be revealed until time of construction. Additional field and laboratory testing as well as site observations will be required during construction phases to verify consistency across each building footprint. GROUNDWATER CONDITIONS Observations were made while drilling the borings to detect the presence and depth to hydrostatic groundwater. At the time of drilling, free water was observed in borings B-1 through B-5, B-7, and B-8 at depths of approximately 12 to 18-1/2 feet below site grades. Groundwater was not encountered in the remaining borings. The borings were backfilled with augers cuttings upon completion of the drilling operations, therefore subsequent groundwater measurements were not obtained. Earth Engineering Consultants, LLC EEC Project No. 1192054 August 5, 2019 Page 5 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 more accurately evaluate fluctuations 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. Zones of perched and/or trapped water can be encountered at times throughout the year in more permeable zones in the subgrade soils. Perched groundwater should be expected in the subgrade soils immediately above the less permeable bedrock strata. Based upon review of U.S. Geological Survey maps (Hillier, et al, 1983), regional groundwater is expected to be encountered in unconsolidated alluvial deposits on the site, at depths ranging from 10 to 20 feet below the existing ground surface. ANALYSIS AND RECOMMENDATIONS General Considerations The site appears suitable for the proposed development based on the subsurface conditions observed at the test boring locations; however, certain precautions will be required in the design and construction addressing the near surface variable fill, the groundwater conditions, the demolition of the existing structures on the east side of the property, the removal/excavation of cobbles at increased depths and penetration of the underlying well cemented sandstone bedrock lenses. We understand the existing buildings on the east side of the property along with any associated site improvements will be demolished/removed from the site prior to the construction of the new development. In addition, any uncontrolled fill material that may be encountered during the excavation phases, should be removed from improvement and/or fill areas on the site. Demolition of the existing structures, concrete sidewalks, pavement and other miscellaneous features should include complete removal of all concrete or debris within the proposed construction area. Site preparation should include removal of any loose backfill found adjacent to the existing site structures/improvements. All materials derived from the demolition of the existing buildings, pavements, sidewalks or other site improvements should be removed from the site and not be allowed for use in any on-site fills. Earth Engineering Consultants, LLC EEC Project No. 1192054 August 5, 2019 Page 6 Depending upon the depth of excavation (i.e. if lower level construction is being planned for elevator pits or mechanical areas), consideration should be given to installing an underdrain/underslab drainage system to intercept or control groundwater from impacting the lowest opening. Removal of large sized cobbles during excavation procedures should be implemented to reduce the potential for point loading conditions developing on the floor slabs. It is anticipated that excavations for the proposed construction can be accomplished with conventional earthmoving equipment. However, excavations penetrating the well-cemented sandstone bedrock may require the use of specialized heavy-duty equipment such as a rock hammer or core barrel to achieve final design elevations. Consideration should be given to obtaining a unit price for difficult excavation in the contract documents for the project. Depending upon the depth of any lower level construction, a shoring plan may be necessary to protect the adjacent sidewall slopes. EEC is available to provide supplemental design criteria or details such as but not limited to secant piles or piers, soldier piers, or a tie-back/bracing concept if requested. Although evidence of fill materials beyond the depths described herein, or underground facilities were not observed during the site exploration, such features could be encountered during construction. If unexpected fills or underground facilities are encountered, such features should be removed, and the excavation thoroughly cleaned prior to backfill placement and/or construction. Swell – Consolidation Test Results The swell-consolidation test is performed to evaluate the swell or collapse potential of soils or bedrock to help determine foundation, floor slab and pavement design criteria. In this test, relatively intact samples obtained directly from the California barrel 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 initial thickness. Samples obtained at approximate depths of 1 to 2 feet are generally pre-loaded at 150 psf to simulate the pavement loading conditions, while samples obtained at the 3 to 4-foot intervals are pre-loaded at 500 psf to simulate the overburden soil pressure. All samples are inundated with water and monitored for swell and consolidation. After the inundation period, additional incremental loads are applied to evaluate the swell pressure and consolidation response. Earth Engineering Consultants, LLC EEC Project No. 1192054 August 5, 2019 Page 7 Within the Phase II area of this site, we conducted eight (8) swell-consolidation tests at various intervals/depths. The swell index values for the samples analyzed revealed low swell characteristics of (+) 0.0 to (+) 0.1%. 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 I - 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 soil and bedrock samples analyzed for this project were within the low range. Site Preparation Although final site grades were not available at the time of this report, based on our understanding of the proposed development, we expect small cuts and/or fills, less than 2 feet, would be required to achieve pavement subgrade and finished floor elevations. After removal of all existing pavements, any existing fill material, and removal of any demolition debris from the razing/removal of existing structures on-site, an extensive/thorough evaluation of the exposed over excavation base material should be completed. Prior to placement of any fill or site improvements, we recommend the exposed soils be scarified to a minimum 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. If excavations extend to the underlying cemented sandstone bedrock, scarification and recompacting is not necessary. Earth Engineering Consultants, LLC EEC Project No. 1192054 August 5, 2019 Page 8 With the potential soft/compressible characteristics of native cohesive to slightly cohesive clay/clayey sand soils across the site, ground stabilization mechanism may be necessary to create a working platform for fill placement. Placement of a granular material, such as a 3-inch minus recycled concrete or equivalent, may be necessary as a subgrade enhancement layer embedded into the soft soils, prior to placement of additional fill material or operating heavy earth-moving equipment. Removal and replacement of the soft/compressible soils could also be considered. Supplemental recommendations can be provided upon request. Fill soils required for developing the building and site subgrades, after the initial zone has been stabilized, should consist of approved, low-volume-change materials, which are free from organic matter and debris. We recommend approved imported structural fill materials be placed and compacted within the building footprint(s) and consist of essentially granular soils with less than 20% material passing the No. 200 sieve. Beneath at-grade level floor slabs for the Retail and Senior Living building footprint areas, we recommend a minimum 2-foot layer of structural fill material be placed and compacted to reduce potential differential movement across the building footprint due to the variations of the on-site subsoils. Beneath at-grade level floor slabs for the 4-story parking garage building footprint area, we recommend a minimum 4-foot layer of structural fill material be placed and compacted due to anticipated floor loads and to reduce potential differential movement across the building footprint due to the variations of the on-site subsoils. In our opinion, with close observation/evaluation of the subgrades in the pavement areas, that imported structural fill zone could be eliminated as long as the in-place over-excavated and replaced on-site subsoils, replaced placed as engineered/controlled fill material appears stable. We recommend fill materials be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content to within ±2% of optimum moisture content, and compacted to at least 95% of the material’s maximum dry density as determined in accordance with ASTM Specification D698, the standard Proctor procedure. The moisture content of granular structural fill in the floor areas should be adjusted to within ±3% of optimum moisture content and compacted to at least 95% of standard Proctor maximum dry density. Care should be exercised after preparation of the subgrades to avoid disturbing the subgrade materials. Positive drainage should be developed away from the structures to avoid wetting of subgrade materials. Subgrade materials becoming wet subsequent to construction of the site structures can result in unacceptable performance. Earth Engineering Consultants, LLC EEC Project No. 1192054 August 5, 2019 Page 9 In areas where excavations will extend below existing groundwater table or the perched water surface level, placement of clean granular fill material would be desirable. Those materials should be placed in lifts and compacted to at least 70% relative density. Areas of deeper fills may experience settlement from underlying native soils and within the placed fill materials. Settlement on the order of 1-inch or more per each 10 feet of fill depth would be estimated. The rate of settlement will be dependent on the type of fill material placed and construction methods. Granular soils will consolidate essentially immediately upon placement of overlying loads. Cohesive soils will consolidate at a slower rate. 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 systems were evaluated for use on the site for the proposed buildings.  Straight shaft drilled piers bearing into the underlying bedrock formation  Ground modification by use of a Geo-pier system extending into the underlying dense sand and gravels or to bedrock and supporting the buildings of spread footings and/or a structural mat Other alternative foundation systems could be considered, and we would be pleased to provide additional alternatives upon request. Drilled Piers/Caissons Based on the maximum anticipated wall and columns loads, we recommend the two (2) proposed structures be supported by a grade beam and straight shaft drilled pier/caisson foundation system extending into the underlying bedrock formation. Particular attention will be required in the construction of drilled piers due to the presence of intermittent cobbles within the granular zone and groundwater or a perched surface water conditions. For axial compression loads, the drilled piers could be designed using a maximum end bearing pressure of 40,000 pounds per square foot (psf), along with a skin-friction of 4,000 psf for the portion of the pier Earth Engineering Consultants, LLC EEC Project No. 1192054 August 5, 2019 Page 10 extended into the underlying firm and/or harder bedrock formation. Straight shaft piers should be drilled a minimum of 10 feet into competent or harder bedrock. Required pier penetration should be balanced against potential uplift forces due to the potential for low expansive characteristics of the subsoils and underlying bedrock on 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 16-feet from ground surface and into the bearing strata. To satisfy forces in the horizontal direction, piers may be designed for lateral loads using a modulus of 50 tons per cubic foot (tcf) for the portion of the pier in native cohesive soils, 75 tcf for native granular materials or engineered fill, and 400 tcf in bedrock for a pier diameter of 12 inches. The coefficient of subgrade reaction for varying pier diameters is as follows: Table II - Lateral Load Coefficient of Subgrade Reaction Pier Diameter (inches) Coefficient of Subgrade Reaction (tons/ft3) Essentially Cohesive Soils Engineered Fill or Granular Soils Bedrock 18 33 50 267 24 25 38 200 30 20 30 160 36 17 25 133 When the lateral capacity of drilled piers is evaluated by the L-Pile 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 program: Earth Engineering Consultants, LLC EEC Project No. 1192054 August 5, 2019 Page 11 Table III - L-Pile Parameters Parameters Native Granular Soils or Structural Fill On-Site Overburden Essentially Cohesive Soils Bedrock Unit Weight of Soil (pcf) 130(1) 115(1) 125(1) Cohesion (psf) 0 200 5000 Angle of Internal Friction  (degrees) 35 20 20 Strain Corresponding to ½ Max. Principal Stress Difference 50 --- 0.02 0.015 *Notes: 1) Use of 64 PCF below the water table 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 sandstone bedrock lenses may be encountered throughout the site at various depths where specialized drilling equipment and/or rock excavating equipment may be required. Excavation penetrating the well-cemented sandstone bedrock may require the use of specialized heavy-duty equipment, together with rock augers and/or core barrels. Consideration should be given to obtaining a unit price for difficult caisson excavation in the contract documents for the project. Due to the depth of groundwater or the presence of groundwater via perched surface water conditions, as well as removal and/or drilling within large sized cobbles zones, maintaining shafts may be difficult without stabilizing measures. Groundwater was observed in borings B-1 through B-5, B-7, and B-8 at depths of approximately 12 to 18-1/2 feet below site grades; however, perched surface water may be encountered at the bedrock interface. Therefore, temporary casing may be required to adequately/properly drill and clean piers prior to concrete placement. Groundwater should be removed from each pier hole prior to concrete placement. Pier concrete should be placed immediately after completion of drilling and cleaning. A maximum 3-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. Pier concrete with slump in the range of 6 to 8 inches is recommended. Casing used for pier construction 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. Earth Engineering Consultants, LLC EEC Project No. 1192054 August 5, 2019 Page 12 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 significantly from those presented in this report, supplemental recommendations will be required. Ground Modifications – Rammed Aggregate Pier (RAP) Foundation System Based on the soils observed at the boring locations, it is our opinion the proposed buildings could be supported on spread footing foundations bearing on ground modified/improved subgrades. Without ground modifications/improvements, the natural site soils would not be suitable for direct support of spread footing foundations. To develop support for spread footing foundations, we recommend improving the subgrades using rammed aggregate piers. Recommendations for ground improvement using rammed aggregate piers are provided to develop adequate support capacity for the foundations and reduce the potential for post-construction settlement of the building’s foundations. Note that rammed aggregate piers are also recommended under heavy floor slabs and are included in the section titled Floor Slabs. Rammed aggregate piers generally consist of driving/placing aggregate into the supporting subgrades to develop aggregate piers or columns. The rammed aggregate piers would provide support for the overlying spread footings while also improving the stiffness of the adjacent subgrades. Common allowable bearing pressures of 3,000 to 5,000 psf or higher can be developed with this system; design bearing pressures should be provided by the installer/designer. To develop pier capacity, we recommend the rammed aggregate piers extend through the near surface cohesive soils and bear in the underlying dense sand and gravels and/or into the underlying bedrock formation. Pile load tests should be carried out to verify actual pile load and displacement characteristics. Rammed aggregate piers would likely be installed after completion of any site cuts and fills. A qualified and reputable rammed aggregate pier installer should provide the necessary design recommendations for the piers. We recommend formed continuous footings be a minimum of 16 inches wide and column foundations have minimum width of 30 inches. Exterior foundations and foundations in unheated areas should be located a minimum of 30 inches below adjacent exterior grades to provide frost protection. Trenched or grade beam foundations should not be used. Earth Engineering Consultants, LLC EEC Project No. 1192054 August 5, 2019 Page 13 Care should be taken at the time of construction to avoid disturbing the bearing soils. Bearing soils should be closely observed to see that aggregate piers are properly located beneath planned foundations. Soils which are loosened or disturbed by the construction activities or soils which become dry and desiccated or wet and softened should be removed and replaced with a material approved by the aggregate pier designer prior to construction of the footings. Foundation and Utility Backfill Backfill needed to develop site grades following installation of foundations and site utilities should consist of low volume change materials which are free of organic matter and debris. In our opinion the site sandy lean clay, clayey sand, or sand soils could be used. Those soils should be moisture conditioned and compacted as outlined for the fill soils in the section Site Preparation. Seismic The site soil conditions consist of approximately 7 to 19 feet of overburden soils overlying moderately hard/cemented bedrock. For those site conditions, the 2018 International Building Code indicates a Seismic Site Classification of C. Lateral Earth Pressures A portion of the structure(s) may be constructed “below grade” given the anticipated final site grades. Those structures will 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. 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 IV below. Equivalent fluid pressure is equal to the Earth Engineering Consultants, LLC EEC Project No. 1192054 August 5, 2019 Page 14 coefficient times the appropriate soil unit weight. Those coefficient values are based on horizontal backfill with backfill soils consisting of essentially granular materials with a friction angle of a 30 degrees or low volume change cohesive soils. For the at-rest and active earth pressures, slopes away from the structure would result in reduced driving forces with slopes up 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. Table IV - Lateral Earth Pressures Soil Type Low Plasticity Cohesive Medium Dense Granular Wet Unit Weight 115 135 Saturated Unit Weight 135 140 Friction Angle () 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. 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 Earth Engineering Consultants, LLC EEC Project No. 1192054 August 5, 2019 Page 15 the backfill. Where used, drain lines should be embedded in a uniformly graded filter material and provided with adequate clean-outs for periodic maintenance. A relatively impervious soil should be used in the upper layer of backfill to reduce the potential for surface 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. Floor Slabs Slab-on-grade construction is feasible for the site provided certain precautions are adhered to. Conventional slab-on-grade construction is feasible where slabs are placed a minimum of 4 feet above the groundwater levels. If lower level “floor” slabs encroach on the minimum 4-foot separation, consideration should be given to installing an underslab drainage system. Due to the type of construction and variability of the on-site subsoils and existing fill material encountered, and to reduce floor slab movement for the retail/senior living areas and the parking garage structures, as presented in the Site Preparation of this report, we recommend the proposed floor slabs on grade bear on a zone of properly placed and compacted imported structural fill material, such as CDOT Class 5, 6, or 7 aggregate base course material or recycled concrete. As indicated in the section Site Preparation, the zone of granular fill should be at 2 feet thick for the retail/living areas and at least 4 feet thick for the parking garage. The approved fill material should be placed in 9-inch loose lifts, moisture conditioned to within ±3% of optimum moisture content and compacted to at least 95% of standard Proctor maximum dry density (ASTM Specification D698). This procedure will not fully eliminate the possibilities of slab movement; but movements should be reduced and tend to be more uniform. We estimate the long-term movement of floor slabs with properly prepared subgrade subsoils as outlined above would be about one-inch or less. For structural design of concrete slabs-on-grade, a modulus of subgrade reaction of 200 pounds per cubic inch (pci) may be used for floors supported on non-expansive imported structural fill material as previously described. Additional floor slab design and construction recommendations are as follows:  Positive separations and/or isolation joints should be provided between slabs and all foundations, columns or utility lines to allow independent movement. Earth Engineering Consultants, LLC EEC Project No. 1192054 August 5, 2019 Page 16  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, Section 302.1R are recommended. Pavements Pavement subgrades should be prepared as outlined in the section Site Preparation. We anticipate the site pavements would include areas designated for low volumes of light weight automobiles (light duty) and areas of higher volumes for use with light weight trucks for delivery as well as the alley way between the retail/senior living building and parking garage (heavy duty). An equivalent daily load application (EDLA) value of 7 was assumed for light duty areas, and an EDLA of 15 was assumed for heavy duty areas. Based on the subsurface conditions encountered at the site, an assumed R-value of 10 was used in design of the pavement sections. Recommended minimum pavement sections are provided below in Table V. Hot Bituminous Pavement (HBP) sections may show rutting/distress in truck loading and drive areas; therefore, concrete pavements should be considered in these areas. The recommended pavement sections are considered minimum; thus, periodic maintenance should be expected. Table V - Recommended Minimum Pavement Sections Automobile Parking Heavy Duty Areas 18-kip EDLA 18-kip ESAL’s Reliability Resilient Modulus (R = 10) PSI Loss 7 51,100 75% 3562 psi 2.5 15 109,500 85% 3562 psi 2.2 Design Structure Number 2.47 2.96 (A) Composite Hot Bituminous Pavement Aggregate Base (Design Structural Number) 4" 7" (2.53) 5" 7" (2.98) (B) Composite with Fly Ash Treated Subgrade Hot Bituminous Pavement Aggregate Base Fly Ash Treated Subgrade (Design Structure Number) 3½" 6" 12" (2.70) Earth Engineering Consultants, LLC EEC Project No. 1192054 August 5, 2019 Page 17 Proofrolling and recompacting the subgrade is recommended immediately prior to placement of the aggregate road base section. Soft or weak areas delineated by the proofrolling operations should be undercut or stabilized in-place to achieve the appropriate subgrade support. We recommend aggregate base meet a CDOT Class 5 or Class 6 aggregate base. Aggregate base should be adjusted in moisture content and compacted to achieve a minimum of 95% of standard Proctor maximum dry density. HBP should be graded as SX or S and be prepared with 75 gyrations using a Superpave gyratory compactor in accordance with CDOT standards. The HBP should consist of PG 58-28 or PG 64-22 asphalt binder. HBP should be compacted to achieve 92 to 96% of the mix’s theoretical maximum specific gravity (Rice Value). Portland cement concrete should be an approved exterior pavement mix with a minimum 28-day compressive strength of 4,500 psi and should be air entrained. Wire mesh or fiber could be considered to reduce shrinkage cracking. Long-term pavement performance will be dependent upon several factors, including maintaining subgrade moisture levels and providing for preventive maintenance. The following recommendations should be considered the minimum:  The subgrade and the pavement surface should be adequately sloped to promote proper surface drainage.  Install pavement drainage surrounding areas anticipated for frequent wetting (e.g. landscaped and irrigated islands, etc.),  Install joint sealant and seal cracks immediately,  Seal all landscaped areas in, or adjacent to pavements to minimize or prevent moisture migration to subgrade soils;  Placing compacted, low permeability backfill against the exterior side of curb and gutter; and,  Placing curb, gutter, and/or sidewalk directly on approved proof rolled subgrade soils without the use of base course materials. Earth Engineering Consultants, LLC EEC Project No. 1192054 August 5, 2019 Page 18 Please note that if during or after placement of the stabilization or initial lift of pavement, the area is observed to be yielding under vehicle traffic or construction equipment, it is recommended that EEC be contacted for additional alternative methods of stabilization, or a change in the pavement section. Water Soluble Sulfates (SO4) The water-soluble sulfate (SO4) content of the on-site overburden subsoils, 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 is provided in this report. Table VI - Water Soluble Sulfate Test Results Sample Location Description Soluble Sulfate Content (%) B-1, S-4, at 19’ Sandstone Bedrock 0.02 B-3, S-2, at 4’ Clayey Sand (SC) 0.01 Based on the results as presented above, ACI 318, Section 4.2 indicates the overburden subsoils and underlying sandstone bedrock materials have a low risk of sulfate attack on Portland cement concrete, therefore, ACI 318 indicates site concrete should be designed with a sulfate exposure of S0 or higher. 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 structure and pavement 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 building 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 placed within 5 feet of the perimeter of the building and parking areas. Spray heads should be designed not to spray water on or immediately adjacent to the structure or site pavements. Roof drains should be designed to discharge at least 5 feet away from the structure and away from the pavement areas. Earth Engineering Consultants, LLC EEC Project No. 1192054 August 5, 2019 Page 19 Excavations into the on-site soils may encounter a variety of conditions. Excavations into the on- site clays can be expected to stand on relatively steep temporary slopes during construction. However, if excavations extend into the underlying granular strata, caving soils may be encountered. 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 Block 23, LLC, 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. Group Symbol Group Name Cu≥4 and 1<Cc≤3 E GW Well-graded gravel F Cu<4 and/or 1>Cc>3 E 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≤3 E SW Well-graded sand I Cu<6 and/or 1>Cc>3 E 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 BLOCK 23 DEVELOPMENT FORT COLLINS, COLORADO EEC PROJECT NO. 1192054 JULY 2019 1 2 1 2 11 1 Figure 1: Boring Location Diagram Preston Center II - Block 23 Development - Fort Collins, Colorado EEC Project #: 1192054 July 2019 Approimate Boring Locations 1 EARTH ENGINEERING CONSULTANTS, LLC Legend Site Potos Potos taken in approimate location, in direction o arro B-5 B-4 B-11 B-1 B-3 B-2 B-10 B-9 B-8 B-7 B-6 1 2 Approximate Boring Locations 1 A SLAS LL Legend igre Boring Location iagram Preston enter Boc eeopment ort oins oorado Proect Site Photos Photos taen in approximate ocation in direction o arro 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 GRAVEL _ _ 1 FILL MATERIAL: Silty, Clayey Sand with Gravel _ _ black, trace cinders 2 _ _ 3 _ _ 4 _ _ SILTY SAND (SM) CS 5 8 1000 11.1 105.8 17 2 33.7 700 psf 0.1% brown _ _ medium dense to very dense 6 _ _ 7 _ _ 8 *increase GRAVEL with depth _ _ 9 _ _ SS 10 50/9" -- 3.0 8.6 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ CS 15 50/11" -- 6.0 108.8 < 500 psf None SANDSTONE _ _ tan, gray, dry to moist 16 poorly cemented to cemented _ _ 17 _ _ 18 _ _ 19 _ _ SS 20 50/4.5" 4000 23.5 _ _ 21 _ _ 22 *interbedded cemented to well cemented lenses with depth _ _ 23 _ _ 24 grey _ _ CS 25 50/3" 9000+ 17.9 112.6 Continued on Sheet 2 of 2 _ _ Earth Engineering Consultants, LLC PRESTON CENTER II - BLOCK 23 DEVELOPMENT 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 _ _ SANDSTONE 27 grey _ _ cemented 28 _ _ 29 _ _ SS 30 50/5" -- 15.6 _ _ 31 _ _ 32 _ _ 33 _ _ 34 _ _ CS 35 50/2" 9000+ 14.1 110.1 _ _ 36 _ _ 37 _ _ 38 _ _ 39 _ _ SS 40 50/3" 5000 14.4 _ _ BOTTOM OF BORING DEPTH 40.5' 41 _ _ 42 _ _ 43 _ _ 44 _ _ 45 _ _ 46 _ _ 47 _ _ 48 _ _ 49 _ _ 50 _ _ Earth Engineering Consultants, LLC PRESTON CENTER II - BLOCK 23 DEVELOPMENT FORT COLLINS, COLORADO 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 WEEDS with GRAVEL _ _ 1 FILL MATERIAL: Clayey Sand / Sandy Lean Clay _ _ trace gravel, brown, black, moist 2 _ _ 3 _ _ 4 _ _ SANDY LEAN CLAY (CL) CS 5 4 1000 15.3 77.6 brown, _ _ soft/medium stiff to stiff 6 _ _ 7 _ _ 8 _ _ 9 _ _ SS 10 18 6500 15.9 33 19 62.6 _ _ 11 _ _ 12 _ _ SAND & GRAVEL (SP/GP) 13 brown / gray / rust _ _ medium dense 14 _ _ CS 15 24 -- 13.5 110.8 _ _ 16 _ _ 17 _ _ 18 _ _ 19 _ _ SANDSTONE / SILTSTONE SS 20 50/2" 9000+ 13.9 grey _ _ poorly cemented to cemented 21 _ _ 22 _ _ 23 *interbedded cemented to well cemented lenses with depth _ _ 24 _ _ SS 25 50/4" 5000 14.9 Continued on Sheet 2 of 2 _ _ Earth Engineering Consultants, LLC PRESTON CENTER II - BLOCK 23 DEVELOPMENT 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 _ _ SANDSTONE / SILTSTONE 27 grey _ _ cemented 28 _ _ 29 _ _ CS 30 50/3.5" 9000+ 14.6 123.9 _ _ 31 _ _ 32 _ _ 33 _ _ 34 _ _ SS 35 50/4" 4000 17.6 _ _ 36 _ _ 37 _ _ 38 _ _ 39 _ _ CS 40 50/1.5" -- 15.4 BOTTOM OF BORING DEPTH 40.0' _ _ 41 _ _ 42 _ _ 43 _ _ 44 _ _ 45 _ _ 46 _ _ 47 _ _ 48 _ _ 49 _ _ 50 _ _ Earth Engineering Consultants, LLC PRESTON CENTER II - BLOCK 23 DEVELOPMENT FORT COLLINS, COLORADO 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 WEEDS with GRAVEL _ _ 1 FILL MATERIAL: Silty, Clayey Sand _ _ trace gravel, loose to medium dense 2 _ _ % @ 150 psf CS 3 4 2000 10.5 110.5 18 1 31.1 < 150 psf None _ _ 4 _ _ CLAYEY SAND (SC) SS 5 5 -- 9.3 brown _ _ loose 6 _ _ 7 _ _ 8 _ _ 9 _ _ SAND & GRAVEL (SP/GP) CS 10 50/7.5" 2000 6.7 112.2 brown / gray / rust _ _ very dense 11 _ _ 12 _ _ 13 _ _ 14 _ _ SANDSTONE SS 15 50/8" -- 17.0 brown / rust _ _ poorly cemented to cemented 16 _ _ 17 _ _ 18 *interbedded cemented to well cemented lenses with depth _ _ 19 _ _ CS 20 50/2.5" 5500 21.8 104.0 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ SS 25 50/3" -- 24.5 Continued on Sheet 2 of 2 _ _ Earth Engineering Consultants, LLC PRESTON CENTER II - BLOCK 23 DEVELOPMENT 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 _ _ SANDSTONE 27 grey / rust _ _ cemented 28 _ _ 29 _ _ CS 30 50/3" 4500 20.5 113.8 _ _ 31 _ _ 32 _ _ 33 _ _ 34 _ _ SS 35 50/3" -- 20.8 _ _ 36 _ _ 37 _ _ 38 _ _ 39 _ _ CS 40 50/3" 9000+ 14.6 114.7 _ _ 41 _ _ 42 _ _ 43 _ _ 44 _ _ 45 _ _ 46 _ _ 47 _ _ 48 _ _ 49 SANDSTONE / CLAYSTONE / SILTSTONE _ _ grey / rust SS 50 50/3" 8500 14.8 BOTTOM OF BORING DEPTH 50.5' _ _ Earth Engineering Consultants, LLC PRESTON CENTER II - BLOCK 23 DEVELOPMENT FORT COLLINS, COLORADO 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 ASPHALT - 2" _ _ Aggregate Base Course (ABC) - 7" 1 _ _ FILL MATERIAL: - Sandy Lean Clay 2 brown _ _ medium stiff to soft CS 3 10 2500 12.2 109.4 with gravel _ _ 4 _ _ SS 5 5 -- 18.3 _ _ 6 _ _ 7 _ _ SILTY SAND with GRAVEL (SM) 8 brown _ _ very dense 9 _ _ CS 10 50/11" 1500 4.3 122.8 13.1 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ SANDSTONE SS 15 50/8" -- 20.0 brown / rust _ _ poorly cemented to cemented 16 _ _ 17 _ _ 18 _ _ 19 _ _ CS 20 50/3" 9000+ 19.2 100.9 _ _ 21 _ _ 22 *interbedded cemented to well cemented lenses with depth _ _ 23 _ _ 24 _ _ SS 25 50/4" -- 17.1 Continued on Sheet 2 of 2 _ _ Earth Engineering Consultants, LLC PRESTON CENTER II - BLOCK 23 DEVELOPMENT 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 _ _ SANDSTONE 27 grey _ _ cemented 28 _ _ 29 _ _ CS 30 50/3" -- 17.2 97.7 _ _ *interbedded cemented to well cemented lenses with depth 31 _ _ 32 _ _ 33 _ _ 34 brown / rust _ _ SS 35 50/1" -- 20.3 _ _ BOTTOM OF BORING DEPTH 35.5' 36 _ _ 37 _ _ 38 _ _ 39 _ _ 40 _ _ 41 _ _ 42 _ _ 43 _ _ 44 _ _ 45 _ _ 46 _ _ 47 _ _ 48 _ _ 49 _ _ 50 _ _ Earth Engineering Consultants, LLC PRESTON CENTER II - BLOCK 23 DEVELOPMENT FORT COLLINS, COLORADO 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 ASPHALT - 3" _ _ Aggregate Base Course (ABC) - 4" 1 _ _ FILL MATERIAL: Silty Sand with Gravel 2 brown _ _ 3 _ _ 4 _ _ CS 5 5 -- 4.7 109.0 13.7 _ _ 6 _ _ 7 _ _ 8 _ _ 9 _ _ SAND & GRAVEL (SP/GP) SS 10 50 -- 3.3 brown / gray / rust _ _ dense 11 _ _ 12 _ _ 13 _ _ 14 _ _ CS 15 50/11" -- 17.0 111.2 NL NP 12.4 < 500 psf None SANDSTONE _ _ brown / rust 16 poorly cemented to cemented _ _ 17 _ _ 18 _ _ 19 _ _ SS 20 50/5" 1500 20.7 _ _ 21 _ _ 22 *interbedded cemented to well cemented lenses with depth _ _ 23 _ _ 24 _ _ CS 25 50/3" 9000 19.4 104.1 Continued on Sheet 2 of 2 _ _ Earth Engineering Consultants, LLC PRESTON CENTER II - BLOCK 23 DEVELOPMENT 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 _ _ SANDSTONE 27 brown / rust _ _ cemented 28 _ _ 29 _ _ SS 30 50/2.5" -- 23.8 _ _ 31 _ _ *interbedded cemented to well cemented lenses with depth 32 _ _ 33 _ _ 34 _ _ 35 _ _ SS 36 50/5" -- 23.9 _ _ 37 _ _ 38 _ _ 39 _ _ CS 40 50/1" _ _ 41 _ _ 42 _ _ 43 _ _ 44 _ _ SS 45 50/1" -- 26.8 _ _ BOTTOM OF BORING DEPTH 45.5' 46 _ _ 47 _ _ 48 _ _ 49 _ _ 50 _ _ Earth Engineering Consultants, LLC PRESTON CENTER II - BLOCK 23 DEVELOPMENT FORT COLLINS, COLORADO 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 ASPHALT - 2.5" _ _ Aggregate Base Course (ABC) - 6" 1 _ _ FILL MATERIAL: Clayey Sand with Gravel 2 brown _ _ CS 3 5 -- 7.0 116.9 _ _ 4 _ _ CLAYEY SAND (SC) SS 5 4 500 14.6 brown, _ _ loose to medium dense 6 _ _ 7 _ _ WELL GRADED GRAVEL with SAND (GW) 8 brown / gray / rust _ _ very dense 9 _ _ CS 10 50/6" -- 1.8 121.1 4.9 _ _ 11 _ _ 12 _ _ SANDSTONE 13 brown / rust / grey _ _ poorly cemented to cemented 14 _ _ SS 15 50/3.5" -- 15.3 _ _ 16 _ _ 17 _ _ 18 _ _ 19 _ _ with trace claystone lenses CS 20 50/3" -- 15.5 89.2 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ SS 25 50/3.5" -- 14.0 Continued on Sheet 2 of 2 _ _ Earth Engineering Consultants, LLC PRESTON CENTER II - BLOCK 23 DEVELOPMENT 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 _ _ SANDSTONE 27 brown / rust / grey _ _ 28 *interbedded cemented to well cemented lenses with depth _ _ 29 _ _ CS 30 50/1" -- 11.9 _ _ 31 _ _ 32 _ _ 33 _ _ 34 _ _ SS 35 50/0.5" -- 14.5 _ _ BOTTOM OF BORING DEPTH 35.5' 36 _ _ 37 _ _ 38 _ _ 39 _ _ 40 _ _ 41 _ _ 42 _ _ 43 _ _ 44 _ _ 45 _ _ 46 _ _ 47 _ _ 48 _ _ 49 _ _ 50 _ _ Earth Engineering Consultants, LLC PRESTON CENTER II - BLOCK 23 DEVELOPMENT FORT COLLINS, COLORADO 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 CONCRETE - 6" _ _ 1 FILL MATERIAL: Silty Sand _ _ black / brown with trace gravel 2 _ _ 3 _ _ 4 _ _ % @ 150 psf *cinders and coal noted within fill zone CS 5 3 -- 41.3 51.3 NL NP 14.9 < 150 psf None _ _ 6 _ _ SANDY LEAN CLAY (CL) 7 brown _ _ medium stiff 8 with trace gravel _ _ 9 _ _ SS 10 32 1500 13.9 _ _ WELL GRADED GRAVEL with SILT (GW) 11 brown / gray / rust _ _ with sand 12 _ _ 13 _ _ 14 _ _ CS 15 50/11" -- 8.0 136.5 7.4 _ _ SANDSTONE 16 brown / grey / rust _ _ poorly cemented to cemented 17 _ _ 18 _ _ 19 _ _ SS 20 50/4" 2500 20.8 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ CS 25 50/4" 9000+ 18.8 119.5 Continued on Sheet 2 of 2 _ _ Earth Engineering Consultants, LLC PRESTON CENTER II - BLOCK 23 DEVELOPMENT 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 _ _ SANDSTONE 27 brown / grey / rust _ _ cemented 28 _ _ 29 _ _ SS 30 50/5" 1000 21.0 _ _ 31 _ _ 32 _ _ 33 _ _ 34 _ _ CS 35 50/4" 1000 20.7 95.7 BOTTOM OF BORING DEPTH 35.0' _ _ 36 _ _ 37 _ _ 38 _ _ 39 _ _ 40 _ _ 41 _ _ 42 _ _ 43 _ _ 44 _ _ 45 _ _ 46 _ _ 47 _ _ 48 _ _ 49 _ _ 50 _ _ Earth Engineering Consultants, LLC PRESTON CENTER II - BLOCK 23 DEVELOPMENT FORT COLLINS, COLORADO 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 CONCRETE - 6.5" _ _ 1 FILL MATERIAL: - Clayey Sand with Gravel _ _ brown, loose 2 _ _ CS 3 3 2000 12.7 109.4 _ _ 4 _ _ SS 5 2 1500 12.2 _ _ SILTY CLAYEY SAND (SM/SC) 6 brown _ _ loose to medium dense 7 _ _ 8 _ _ 9 with gravel _ _ CS 10 24 2500 13.4 102.0 _ _ 11 _ _ 12 _ _ SANDSTONE 13 brown / rust _ _ poorly cemented to cemented 14 _ _ SS 15 50/5" -- 21.4 _ _ 16 _ _ 17 _ _ *interbedded cemented to well cemented lenses with depth 18 _ _ 19 _ _ CS 20 50/3" 6000 18.3 99.3 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ SS 25 50/5" -- 21.2 Continued on Sheet 2 of 2 _ _ Earth Engineering Consultants, LLC PRESTON CENTER II - BLOCK 23 DEVELOPMENT 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 _ _ SANDSTONE 27 brown / rust _ _ cemented 28 _ _ 29 _ _ CS 30 50/3.5" 7500 17.7 120.6 _ _ 31 _ _ 32 _ _ 33 _ _ 34 _ _ SS 35 50/4" 1000 20.6 _ _ BOTTOM OF BORING DEPTH 35.5 36 _ _ 37 _ _ 38 _ _ 39 _ _ 40 _ _ 41 _ _ 42 _ _ 43 _ _ 44 _ _ 45 _ _ 46 _ _ 47 _ _ 48 _ _ 49 _ _ 50 _ _ Earth Engineering Consultants, LLC PRESTON CENTER II - BLOCK 23 DEVELOPMENT FORT COLLINS, COLORADO 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 FILL MATRIAL: Clayey Sand with trace Gravel _ _ brown, moist, medium dense 2 _ _ 3 _ _ CLAYEY SAND (SC) 4 brown _ _ medium dense CS 5 20 3000 10.2 103.8 22 10 32.5 < 500 psf None with gravel _ _ 6 _ _ 7 _ _ SANDSTONE 8 brown / rust _ _ poorly cemented to cemented 9 _ _ SS 10 50/11" 1000 13.7 20.8 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ CS 15 50/3" -- 13.9 105.9 _ _ 16 *interbedded cemented to well cemented lenses with depth _ _ 17 _ _ 18 _ _ 19 _ _ SS 20 50/2" -- 16.6 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ CS 25 50/2.5" -- 17.9 94.5 Continued on Sheet 2 of 2 _ _ Earth Engineering Consultants, LLC PRESTON CENTER II - BLOCK 23 DEVELOPMENT 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 _ _ SANDSTONE 27 grey _ _ cemented 28 _ _ 29 _ _ SS 30 50/2" -- 16.7 _ _ BOTTOM OF BORING DEPTH 30.5' 31 _ _ 32 _ _ 33 _ _ 34 _ _ 35 _ _ 36 _ _ 37 _ _ 38 _ _ 39 _ _ 40 _ _ 41 _ _ 42 _ _ 43 _ _ 44 _ _ 45 _ _ 46 _ _ 47 _ _ 48 _ _ 49 _ _ 50 _ _ Earth Engineering Consultants, LLC PRESTON CENTER II - BLOCK 23 DEVELOPMENT FORT COLLINS, COLORADO 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 ASPHALT - 5.25" _ _ Aggregate Base Course (ABC) - 15" 1 _ _ FILL MATERIAL: Silty Sand 2 brown / black _ _ % @ 150 psf medium dense CS 3 11 -- 17.3 70.0 30 NP 18.0 < 150 psf None _ _ 4 _ _ SS 5 13 500 10.9 CLAYEY SAND (SC) _ _ brown / black 6 medium dense _ _ 7 _ _ 8 _ _ 9 SANDY LEAN CLAY (CL) _ _ brown / black SS 10 17 5000 15.7 very stiff _ _ BOTTOM OF BORING DEPTH 10.5' 11 _ _ 12 _ _ 13 _ _ 14 _ _ 15 _ _ 16 _ _ 17 _ _ 18 _ _ 19 _ _ 20 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ 25 _ _ Earth Engineering Consultants, LLC PRESTON CENTER II - BLOCK 23 DEVELOPMENT 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 ASPHALT - 5" _ _ Aggregate Base Course (ABC) - 6" 1 SILTY SAND (SM) - FILL _ _ % @ 150 psf brown CS 2 10 -- 8.4 96.2 28 NP 14.3 < 150 psf None BOTTOM OF BORING DEPTH 2.0' _ _ 3 NOTE: Boring terminated at 2 feet due to presence of _ _ existing utilities 4 _ _ 5 _ _ 6 _ _ 7 _ _ 8 _ _ 9 _ _ 10 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ 15 _ _ 16 _ _ 17 _ _ 18 _ _ 19 _ _ 20 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ 25 Continued on Sheet 2 of 2 _ _ Earth Engineering Consultants, LLC PRESTON CENTER II - BLOCK 23 DEVELOPMENT Project: Location: Project #: Date: Preston Center II - Block 23 Development Fort Collins, Colorado 1192054 July 2019 Beginning Moisture: 11.1% Dry Density: 120.2 pcf Ending Moisture: 15.0% Swell Pressure: 700 psf % Swell @ 500: 0.1% Sample Location: Boring 1, Sample 1, Depth 4' Liquid Limit: 17 Plasticity Index: 2 % Passing #200: 33.7% SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown Silty Sand (SM) -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 10 Percent Movement Load (TSF) Consolidatio Swell Water Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: rust, gray Sandstone Bedrock - classified as Silty Sand (SM) Sample Location: Boring 1, Sample 3, Depth 14' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - Beginning Moisture: 6.0% Dry Density: 108.8 pcf Ending Moisture: 16.2% Swell Pressure: < 500 psf % Swell @ 500: None Preston Center II - Block 23 Development Fort Collins, Colorado 1192054 July 2019 -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 10 Percent Movement Load (TSF) Consolidatio Swell Water Added Project: Location: Project #: Date: Preston Center II - Block 23 Development Fort Collins, Colorado 1192054 July 2019 Beginning Moisture: 10.5% Dry Density: 119.6 pcf Ending Moisture: 14.7% Swell Pressure: < 150 psf % Swell @ 150: None Sample Location: Boring 3, Sample 1, Depth 2' Liquid Limit: 18 Plasticity Index: 1 % Passing #200: 31.1% SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown Silty Sand (SM) -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 10 Percent Movement Load (TSF) Consolidatio Swell Water Added Project: Location: Project #: Date: Preston Center II - Block 23 Development Fort Collins, Colorado 1192054 July 2019 Beginning Moisture: 17.0% Dry Density: 111 pcf Ending Moisture: 20.1% Swell Pressure: < 500 psf % Swell @ 500: None Sample Location: Boring 5, Sample 3, Depth 14' Liquid Limit: NL Plasticity Index: NP % Passing #200: 12.4% SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown / Rust Sandstone Bedrock - classified as Silty Sand (SM) -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 10 Percent Movement Load (TSF) Consolidatio Swell Water Added Project: Location: Project #: Date: Preston Center II - Block 23 Development Fort Collins, Colorado 1192054 July 2019 Beginning Moisture: 41.3% Dry Density: 58.6 pcf Ending Moisture: 41.9% Swell Pressure: < 150 psf % Swell @ 150: None Sample Location: Boring 7, Sample 1, Depth 4' Liquid Limit: NL Plasticity Index: NP % Passing #200: 14.9% SWELL / CONSOLIDATION TEST RESULTS Material Description: FILL MATERIAL black Coal / Cinders - classified as Silty Sand (SM) -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 10 Percent Movement Load (TSF) Consolidatio Swell Water Added Project: Location: Project #: Date: Preston Center II - Block 23 Development Fort Collins, Colorado 1192054 July 2019 Beginning Moisture: 10.2% Dry Density: 106.8 pcf Ending Moisture: 16.5% Swell Pressure: < 500 psf % Swell @ 500: None Sample Location: Boring 9, Sample 1, Depth 4' Liquid Limit: 22 Plasticity Index: 10 % Passing #200: 32.5% SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown 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 10 Percent Movement Load (TSF) Consolidatio Swell Water Added Project: Location: Project #: Date: Preston Center II - Block 23 Development Fort Collins, Colorado 1192054 July 2019 Beginning Moisture: 17.3% Dry Density: 72.9 pcf Ending Moisture: 37.9% Swell Pressure: < 150 psf % Swell @ 150: None Sample Location: Boring 10, Sample 1, Depth 2' Liquid Limit: 30 Plasticity Index: NP % Passing #200: 18.0% SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown / Black Silty Sand (SM) - Fill -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 10 Percent Movement Load (TSF) Consolidatio Swell Water Added Project: Location: Project #: Date: Preston Center II - Block 23 Development Fort Collins, Colorado 1192054 July 2019 Beginning Moisture: 8.4% Dry Density: 104 pcf Ending Moisture: 19.1% Swell Pressure: < 150 psf % Swell @ 150: None Sample Location: Boring 11, Sample 1, Depth 2' Liquid Limit: 28 Plasticity Index: NP % Passing #200: 14.3% SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown Silty Sand (SM) - Fill -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 10 Percent Movement Load (TSF) Consolidatio Swell Water Added 2 1/2" (63 mm) 2" (50 mm) 1 1/2" (37.5 mm) 1" (25 mm) 3/4" (19 mm) 1/2" (12.5 mm) 3/8" (9.5 mm) No. 4 (4.75 mm) No. 8 (2.36 mm) No. 10 (2 mm) No. 16 (1.18 mm) No. 30 (0.6 mm) No. 40 (0.425 mm) No. 50 (0.3 mm) No. 100 (0.15 mm) No. 200 (0.075 mm) Project: Preston Center II - Block 23 Development Location: Fort Collins, Colorado Project No: 1192054 Sample ID: B-1, S-2, 9' Sample Desc.: Well Graded Sand with Silt (SW - SM) Date: July 2019 EARTH ENGINEERING CONSULTANTS, LLC SUMMARY OF LABORATORY TEST RESULTS Sieve Analysis (AASHTO T 11 & T 27 / ASTM C 117 & C 136) 100 Sieve Size Percent Passing 100 100 100 100 99 97 89 76 13 8.6 71 53 32 27 22 0.52 0.10 Fine 15.29 1.91 D30 D 10 Cu CC July 2019 19.00 1.49 1.09 Preston Center II - Block 23 Development Fort Collins, Colorado 1192054 B-1, S-2, 9' Well Graded Sand with Silt (SW - SM) D100 D 60 D50 EARTH ENGINEERING CONSULTANTS, LLC Summary of Washed Sieve Analysis Tests (ASTM C117 & C136) Date: Project: Location: Project No: Sample ID: Sample Desc.: Cobble Silt or Clay Gravel Coarse Fine Sand Coarse Medium 6" 5" 4" 3" 2.5" 2" 1.5" 1" 3/4" 1/2" 3/8" No. 4 No. 8 No. 10 No. 16 No. 30 No. 40 No. 50 No. 100 No. 200 0 10 20 30 40 50 60 70 80 90 100 1000 100 10 1 0.1 0.01 2 1/2" (63 mm) 2" (50 mm) 1 1/2" (37.5 mm) 1" (25 mm) 3/4" (19 mm) 1/2" (12.5 mm) 3/8" (9.5 mm) No. 4 (4.75 mm) No. 8 (2.36 mm) No. 10 (2 mm) No. 16 (1.18 mm) No. 30 (0.6 mm) No. 40 (0.425 mm) No. 50 (0.3 mm) No. 100 (0.15 mm) No. 200 (0.075 mm) Project: Preston Center II - Block 23 Development Location: Fort Collins, Colorado Project No: 1192054 Sample ID: B-4, S-3, 9' Sample Desc.: Silty Sand with Gravel (SM) Date: July 2019 EARTH ENGINEERING CONSULTANTS, LLC SUMMARY OF LABORATORY TEST RESULTS Sieve Analysis (AASHTO T 11 & T 27 / ASTM C 117 & C 136) 100 Sieve Size Percent Passing 100 100 100 100 85 81 68 55 16 13.1 51 40 27 23 20 0.72 ‐‐‐ Fine ‐‐‐ ‐‐‐ D30 D 10 Cu CC July 2019 19.00 3.32 1.89 Preston Center II - Block 23 Development Fort Collins, Colorado 1192054 B-4, S-3, 9' Silty Sand with Gravel (SM) D100 D 60 D50 EARTH ENGINEERING CONSULTANTS, LLC Summary of Washed Sieve Analysis Tests (ASTM C117 & C136) Date: Project: Location: Project No: Sample ID: Sample Desc.: Cobble Silt or Clay Gravel Coarse Fine Sand Coarse Medium 6" 5" 4" 3" 2.5" 2" 1.5" 1" 3/4" 1/2" 3/8" No. 4 No. 8 No. 10 No. 16 No. 30 No. 40 No. 50 No. 100 No. 200 0 10 20 30 40 50 60 70 80 90 100 1000 100 10 1 0.1 0.01 2 1/2" (63 mm) 2" (50 mm) 1 1/2" (37.5 mm) 1" (25 mm) 3/4" (19 mm) 1/2" (12.5 mm) 3/8" (9.5 mm) No. 4 (4.75 mm) No. 8 (2.36 mm) No. 10 (2 mm) No. 16 (1.18 mm) No. 30 (0.6 mm) No. 40 (0.425 mm) No. 50 (0.3 mm) No. 100 (0.15 mm) No. 200 (0.075 mm) Project: Preston Center II - Block 23 Development Location: Fort Collins, Colorado Project No: 1192054 Sample ID: B-5, S-1, 4' Sample Desc.: Silty Sand with Gravel (SM) Date: July 2019 EARTH ENGINEERING CONSULTANTS, LLC SUMMARY OF LABORATORY TEST RESULTS Sieve Analysis (AASHTO T 11 & T 27 / ASTM C 117 & C 136) 100 Sieve Size Percent Passing 100 100 100 97 91 86 70 55 23 13.7 51 44 35 31 29 0.36 ‐‐‐ Fine ‐‐‐ ‐‐‐ D30 D 10 Cu CC July 2019 25.00 3.18 1.85 Preston Center II - Block 23 Development Fort Collins, Colorado 1192054 B-5, S-1, 4' Silty Sand with Gravel (SM) D100 D 60 D50 EARTH ENGINEERING CONSULTANTS, LLC Summary of Washed Sieve Analysis Tests (ASTM C117 & C136) Date: Project: Location: Project No: Sample ID: Sample Desc.: Cobble Silt or Clay Gravel Coarse Fine Sand Coarse Medium 6" 5" 4" 3" 2.5" 2" 1.5" 1" 3/4" 1/2" 3/8" No. 4 No. 8 No. 10 No. 16 No. 30 No. 40 No. 50 No. 100 No. 200 0 10 20 30 40 50 60 70 80 90 100 1000 100 10 1 0.1 0.01 2 1/2" (63 mm) 2" (50 mm) 1 1/2" (37.5 mm) 1" (25 mm) 3/4" (19 mm) 1/2" (12.5 mm) 3/8" (9.5 mm) No. 4 (4.75 mm) No. 8 (2.36 mm) No. 10 (2 mm) No. 16 (1.18 mm) No. 30 (0.6 mm) No. 40 (0.425 mm) No. 50 (0.3 mm) No. 100 (0.15 mm) No. 200 (0.075 mm) Project: Preston Center II - Block 23 Development Location: Fort Collins, Colorado Project No: 1192054 Sample ID: B-6, S-3, 9' Sample Desc.: Well Graded Gravel with Sand (GW) Date: July 2019 EARTH ENGINEERING CONSULTANTS, LLC SUMMARY OF LABORATORY TEST RESULTS Sieve Analysis (AASHTO T 11 & T 27 / ASTM C 117 & C 136) 100 Sieve Size Percent Passing 100 100 93 70 55 51 40 31 8 4.9 30 24 17 14 12 2.08 0.23 Fine 63.34 1.26 D30 D 10 Cu CC July 2019 37.50 14.76 9.02 Preston Center II - Block 23 Development Fort Collins, Colorado 1192054 B-6, S-3, 9' Well Graded Gravel with Sand (GW) D100 D 60 D50 EARTH ENGINEERING CONSULTANTS, LLC Summary of Washed Sieve Analysis Tests (ASTM C117 & C136) Date: Project: Location: Project No: Sample ID: Sample Desc.: Cobble Silt or Clay Gravel Coarse Fine Sand Coarse Medium 6" 5" 4" 3" 2.5" 2" 1.5" 1" 3/4" 1/2" 3/8" No. 4 No. 8 No. 10 No. 16 No. 30 No. 40 No. 50 No. 100 No. 200 0 10 20 30 40 50 60 70 80 90 100 1000 100 10 1 0.1 0.01 2 1/2" (63 mm) 2" (50 mm) 1 1/2" (37.5 mm) 1" (25 mm) 3/4" (19 mm) 1/2" (12.5 mm) 3/8" (9.5 mm) No. 4 (4.75 mm) No. 8 (2.36 mm) No. 10 (2 mm) No. 16 (1.18 mm) No. 30 (0.6 mm) No. 40 (0.425 mm) No. 50 (0.3 mm) No. 100 (0.15 mm) No. 200 (0.075 mm) Project: Preston Center II - Block 23 Development Location: Fort Collins, Colorado Project No: 1192054 Sample ID: B-7, S-3, 14' Sample Desc.: Well Graded Gravel with Silt and Sand (GW - GM) Date: July 2019 EARTH ENGINEERING CONSULTANTS, LLC SUMMARY OF LABORATORY TEST RESULTS Sieve Analysis (AASHTO T 11 & T 27 / ASTM C 117 & C 136) 100 Sieve Size Percent Passing 100 91 76 68 60 56 46 37 10 7.4 35 28 21 17 15 1.41 0.14 Fine 88.84 1.17 D30 D 10 Cu CC July 2019 50.00 12.30 6.73 Preston Center II - Block 23 Development Fort Collins, Colorado 1192054 B-7, S-3, 14' Well Graded Gravel with Silt and Sand (GW - GM) D100 D 60 D50 EARTH ENGINEERING CONSULTANTS, LLC Summary of Washed Sieve Analysis Tests (ASTM C117 & C136) Date: Project: Location: Project No: Sample ID: Sample Desc.: Cobble Silt or Clay Gravel Coarse Fine Sand Coarse Medium 6" 5" 4" 3" 2.5" 2" 1.5" 1" 3/4" 1/2" 3/8" No. 4 No. 8 No. 10 No. 16 No. 30 No. 40 No. 50 No. 100 No. 200 0 10 20 30 40 50 60 70 80 90 100 1000 100 10 1 0.1 0.01 2 1/2" (63 mm) 2" (50 mm) 1 1/2" (37.5 mm) 1" (25 mm) 3/4" (19 mm) 1/2" (12.5 mm) 3/8" (9.5 mm) No. 4 (4.75 mm) No. 8 (2.36 mm) No. 10 (2 mm) No. 16 (1.18 mm) No. 30 (0.6 mm) No. 40 (0.425 mm) No. 50 (0.3 mm) No. 100 (0.15 mm) No. 200 (0.075 mm) Project: Preston Center II - Block 23 Development Location: Fort Collins, Colorado Project No: 1192054 Sample ID: B-9, S-2, 9' Sample Desc.: Silty Sand (SM) Date: July 2019 EARTH ENGINEERING CONSULTANTS, LLC SUMMARY OF LABORATORY TEST RESULTS Sieve Analysis (AASHTO T 11 & T 27 / ASTM C 117 & C 136) 100 Sieve Size Percent Passing 100 100 100 100 97 97 95 92 41 20.8 91 89 86 83 80 0.11 ‐‐‐ Fine ‐‐‐ ‐‐‐ D30 D 10 Cu CC July 2019 19.00 0.22 0.18 Preston Center II - Block 23 Development Fort Collins, Colorado 1192054 B-9, S-2, 9' Silty Sand (SM) D100 D 60 D50 EARTH ENGINEERING CONSULTANTS, LLC Summary of Washed Sieve Analysis Tests (ASTM C117 & C136) Date: Project: Location: Project No: Sample ID: Sample Desc.: Cobble Silt or Clay Gravel Coarse Fine Sand Coarse Medium 6" 5" 4" 3" 2.5" 2" 1.5" 1" 3/4" 1/2" 3/8" No. 4 No. 8 No. 10 No. 16 No. 30 No. 40 No. 50 No. 100 No. 200 0 10 20 30 40 50 60 70 80 90 100 1000 100 10 1 0.1 0.01 Finer by Weight (%) Grain Size (mm) Standard Sieve Size Finer by Weight (%) Grain Size (mm) Standard Sieve Size Finer by Weight (%) Grain Size (mm) Standard Sieve Size Finer by Weight (%) Grain Size (mm) Standard Sieve Size Finer by Weight (%) Grain Size (mm) Standard Sieve Size Finer by Weight (%) Grain Size (mm) Standard Sieve Size FORT COLLINS, COLORADO PROJECT NO: 1192054 LOG OF BORING B-11 JULY 2019 SHEET 1 OF 2 WATER DEPTH START DATE 7/18/2019 WHILE DRILLING None APPROX. SURFACE ELEV 4985 24 HOUR N/A FINISH DATE 7/18/2019 AFTER DRILLING N/A A-LIMITS SWELL FORT COLLINS, COLORADO PROJECT NO: 1192054 LOG OF BORING B-10 JULY 2019 SHEET 1 OF 1 WATER DEPTH START DATE 7/18/2019 WHILE DRILLING None APPROX. SURFACE ELEV 4984 24 HOUR N/A FINISH DATE 7/18/2019 AFTER DRILLING N/A A-LIMITS SWELL PROJECT NO: 1192054 LOG OF BORING B-9 JULY 2019 SHEET 2 OF 2 WATER DEPTH START DATE 7/18/2019 WHILE DRILLING None 7/18/2019 AFTER DRILLING N/A APPROX. SURFACE ELEV 24 HOUR N/A FINISH DATE A-LIMITS SWELL 4986 FORT COLLINS, COLORADO PROJECT NO: 1192054 LOG OF BORING B-9 JULY 2019 SHEET 1 OF 2 WATER DEPTH START DATE 7/18/2019 WHILE DRILLING None APPROX. SURFACE ELEV 4986 24 HOUR N/A FINISH DATE 7/18/2019 AFTER DRILLING N/A A-LIMITS SWELL PROJECT NO: 1192054 LOG OF BORING B-8 JULY 2019 SHEET 2 OF 2 WATER DEPTH START DATE 7/17/2019 WHILE DRILLING 13' 7/17/2019 AFTER DRILLING N/A APPROX. SURFACE ELEV 24 HOUR N/A FINISH DATE A-LIMITS SWELL 4982 FORT COLLINS, COLORADO PROJECT NO: 1192054 LOG OF BORING B-8 JULY 2019 SHEET 1 OF 2 WATER DEPTH START DATE 7/17/2019 WHILE DRILLING 13' APPROX. SURFACE ELEV 4982 24 HOUR N/A FINISH DATE 7/17/2019 AFTER DRILLING N/A A-LIMITS SWELL PROJECT NO: 1192054 LOG OF BORING B-7 JULY 2019 SHEET 2 OF 2 WATER DEPTH START DATE 7/18/2019 WHILE DRILLING 12' 7/18/2019 AFTER DRILLING N/A APPROX. SURFACE ELEV 24 HOUR N/A FINISH DATE A-LIMITS SWELL 4983 FORT COLLINS, COLORADO PROJECT NO: 1192054 LOG OF BORING B-7 JULY 2019 SHEET 1 OF 2 WATER DEPTH START DATE 7/18/2019 WHILE DRILLING 12' APPROX. SURFACE ELEV 4983 24 HOUR N/A FINISH DATE 7/18/2019 AFTER DRILLING N/A A-LIMITS SWELL PROJECT NO: 1192054 LOG OF BORING B-6 JULY 2019 SHEET 2 OF 2 WATER DEPTH START DATE 7/17/2019 WHILE DRILLING None 7/17/2019 AFTER DRILLING N/A APPROX. SURFACE ELEV 24 HOUR N/A FINISH DATE A-LIMITS SWELL 4983 FORT COLLINS, COLORADO PROJECT NO: 1192054 LOG OF BORING B-6 JULY 2019 SHEET 1 OF 2 WATER DEPTH START DATE 7/17/2019 WHILE DRILLING None APPROX. SURFACE ELEV 4983 24 HOUR N/A FINISH DATE 7/17/2019 AFTER DRILLING N/A A-LIMITS SWELL PROJECT NO: 1192054 LOG OF BORING B-5 JULY 2019 SHEET 2 OF 2 WATER DEPTH START DATE 7/17/2019 WHILE DRILLING 16' 7/17/2019 AFTER DRILLING N/A APPROX. SURFACE ELEV 24 HOUR N/A FINISH DATE A-LIMITS SWELL 4982 FORT COLLINS, COLORADO PROJECT NO: 1192054 LOG OF BORING B-5 JULY 2019 SHEET 1 OF 2 WATER DEPTH START DATE 7/17/2019 WHILE DRILLING 16' APPROX. SURFACE ELEV 4982 24 HOUR N/A FINISH DATE 7/17/2019 AFTER DRILLING N/A A-LIMITS SWELL PROJECT NO: 1192054 LOG OF BORING B-4 JULY 2019 SHEET 2 OF 2 WATER DEPTH START DATE 7/17/2019 WHILE DRILLING 18.5' 7/18/2019 AFTER DRILLING N/A APPROX. SURFACE ELEV 24 HOUR N/A FINISH DATE A-LIMITS SWELL 4984 FORT COLLINS, COLORADO PROJECT NO: 1192054 LOG OF BORING B-4 JULY 2019 SHEET 1 OF 2 WATER DEPTH START DATE 7/17/2019 WHILE DRILLING 18.5' APPROX. SURFACE ELEV 4984 24 HOUR N/A FINISH DATE 7/18/2019 AFTER DRILLING N/A A-LIMITS SWELL PROJECT NO: 1192054 LOG OF BORING B-3 JULY 2019 SHEET 2 OF 2 WATER DEPTH START DATE 7/17/2019 WHILE DRILLING 17.5' 7/17/2019 AFTER DRILLING N/A APPROX. SURFACE ELEV 24 HOUR N/A FINISH DATE A-LIMITS SWELL 4986 FORT COLLINS, COLORADO PROJECT NO: 1192054 LOG OF BORING B-3 JULY 2019 SHEET 1 OF 2 WATER DEPTH START DATE 7/17/2019 WHILE DRILLING 17.5' APPROX. SURFACE ELEV 4986 24 HOUR N/A FINISH DATE 7/17/2019 AFTER DRILLING N/A A-LIMITS SWELL PROJECT NO: 1192054 LOG OF BORING B-2 JULY 2019 SHEET 2 OF 2 WATER DEPTH START DATE 7/17/2019 WHILE DRILLING 13.5' 7/17/2019 AFTER DRILLING N/A APPROX. SURFACE ELEV 24 HOUR N/A FINISH DATE A-LIMITS SWELL 4987 FORT COLLINS, COLORADO PROJECT NO: 1192054 LOG OF BORING B-2 JULY 2019 SHEET 1 OF 2 WATER DEPTH START DATE 7/17/2019 WHILE DRILLING 13.5' APPROX. SURFACE ELEV 4987 24 HOUR N/A FINISH DATE 7/17/2019 AFTER DRILLING N/A A-LIMITS SWELL PROJECT NO: 1192054 LOG OF BORING B-1 JULY 2019 SHEET 2 OF 2 WATER DEPTH START DATE 7/17/2019 WHILE DRILLING 14' 7/17/2019 AFTER DRILLING N/A APPROX. SURFACE ELEV 24 HOUR N/A FINISH DATE A-LIMITS SWELL 4985 FORT COLLINS, COLORADO PROJECT NO: 1192054 LOG OF BORING B-1 JULY 2019 SHEET 1 OF 2 WATER DEPTH START DATE 7/17/2019 WHILE DRILLING 14' APPROX. SURFACE ELEV 4985 24 HOUR N/A FINISH DATE 7/17/2019 AFTER DRILLING N/A A-LIMITS SWELL 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 90 100 110 PLASTICITY 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 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 4" 7" 12" (3.03) (C) PCC (Non-reinforced) 5" 6"