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Home My WebLink AboutMARS LANDING - FDP210024 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTSUBSURFACE EXPLORATION REPORT SKYWAY & MARS APARTMENTS SOUTHWEST CORNER OF SKYWAY DRIVE AND MARS AVENUE FORT COLLINS, COLORADO EEC PROJECT NO. 1192056 Prepared for: Goodwin Knight 8605 Explorer Drive, Suite 250 Colorado Springs, Colorado 80920 Attn: Mr. Mark Johnson, RLA (MJohnson@GoodwinKnight.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 www.earth-engineering.com July 17, 2019 Goodwin Knight 8605 Explorer Drive, Suite 250 Colorado Springs, Colorado 80920 Attn: Mr. Mark Johnson, RLA (MJohnson@GoodwinKnight.com) Re: Subsurface Exploration Report Skyway and Mars Apartments Southwest Corner of Skyway Drive and Mars Avenue Fort Collins, Colorado EEC Project No. 1192056 Mr. Johnson: Enclosed herewith, are the results of the subsurface exploration completed by Earth Engineering Consultants, LLC for the referenced project. For this exploration, a total of nine (9) soil borings were drilled within the proposed apartment buildings and surrounding pavement areas, (please refer to Boring Location Diagram for a proposed building layout). The borings were extended to depths of approximately 10 to 25 feet below site grades. This exploration was completed in general accordance with our proposal dated March 27, 2019. In summary, the subsurface conditions encountered beneath the surficial topsoil and vegetation and/or gravel layers in the test borings generally consisted of clayey sand/sandy lean clay and/or lean clay with sand subsoils, extending to the underlying bedrock at depths of approximately 2 to 6 feet below the ground surface. The overburden subsoils were generally dry in situ, loose to medium dense/stiff and exhibited low to high swell potential at current moisture and density conditions. Siltstone/sandstone bedrock was encountered underlying the surficial topsoil and vegetation and/or gravel in borings B-1 and B-6 and below the overburden soils in the remaining borings. The bedrock extended to the depths explored, approximately 10 to 25 feet below the existing ground surface. The bedrock was generally weathered near surface and became cemented with depth and exhibited low swell potential characteristics. Groundwater was observed at depths of approximately 14 to 17 feet below the ground surface in borings B-1 and B-5. Groundwater was not encountered in the remaining borings which extended to a maximum depth of approximately 15 feet below the ground surface. SUBSURFACE EXPLORATION REPORT SKYWAY & MARS APARTMENTS SOUTHWEST CORNER OF SKYWAY DRIVE AND MARS AVENUE FORT COLLINS, COLORADO EEC PROJECT NO. 1192056 July 17, 2019 INTRODUCTION The geotechnical subsurface exploration for the proposed apartment buildings has been completed. For this exploration, a total of nine (9) soil borings were drilled within the proposed apartment buildings and surrounding pavement areas, (please refer to the Boring Location Diagram for a proposed building and site development layout). The borings were extended to depths of approximately 10 to 25 feet below site grades. Individual boring logs and a site diagram indicating the approximate boring locations are provided with this report. Site photographs of the property at the time of our exploration are also provided with this report. Based on the information provided to us, we understand the development consists of two (2) approximately 13,870 square feet (SF) and approximately 15,700 SF in plan dimensions 3-story apartment buildings constructed as slab-on-grade, along with slab-on-grade garage buildings, a clubhouse building, and on-site pavement improvements. We anticipate maximum wall and column loads for the project would be light to moderate up to 4 kips per linear foot (klf) and 150 kips respectively. Paved drive and associated parking areas are also planned for the proposed development. Small grade changes of on the order of ±5 feet are expected to develop final site grades. The purpose of this report is to describe the subsurface conditions encountered in the test borings, analyze and evaluate the test data and provide geotechnical recommendations concerning design and construction of foundations, support of floor slabs, exterior flatwork, and pavements and development of other earth related features for the proposed site improvements. EXPLORATION AND TESTING PROCEDURES The boring locations were selected and established in the field by Earth Engineering Consultants, LLC (EEC) personnel by pacing and estimating locations relative to observable site features. Earth Engineering Consultants, LLC EEC Project No. 1192056 July 17, 2019 Page 2 Photographs of the site at the time of drilling are included with this report. The approximate locations of the borings are indicated on the attached boring location diagram. The locations of those borings should be considered accurate only to the degree implied by the methods used to make the field measurements. The test borings were completed 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 Specification 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 and hardness of weathered bedrock. 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 Earth Engineering Consultants, LLC EEC Project No. 1192056 July 17, 2019 Page 3 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 proposed apartment development is planned for construction at the southwest corner of Skyway Drive and Mars Avenue in Fort Collins, Colorado. The borings were surfaced with gravel in the general vicinity of boring B-6. Ground surface in this area is relatively flat. 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 surficial vegetative and gravel layers consisted of clayey sand/sandy lean clay and/or lean clay with sand, extending to the underlying bedrock at depths of approximately 2 to 6 feet below the ground surface. The overburden subsoils were generally dry in-situ, loose to medium dense/stiff and exhibited low to high swell potential at current moisture and density conditions. Siltstone/sandstone bedrock was encountered underlying the surficial topsoil and vegetation and/or gravel in borings B-1 and B-6 and below the overburden soils in the remaining borings. The bedrock extended to the depths explored, approximately 10 to 25 feet below the existing ground surface. The bedrock was generally weathered near surface and became cemented with depth and exhibited low swell potential characteristics. 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 observed at depths of approximately 14 to 17 feet below the ground surface in borings B-1 and B-5. Groundwater was not Earth Engineering Consultants, LLC EEC Project No. 1192056 July 17, 2019 Page 4 encountered in the remaining borings which extended to a maximum depth of approximately 15 feet below the ground surface. The borings were backfilled upon completion of the drilling operations and subsequent groundwater measurements were not possible. 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. In addition, perched groundwater may be observed in the subgrade soils overlying lower permeability bedrock. 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. ANALYSIS AND RECOMMENDATIONS Swell – Consolidation Test Results The swell-consolidation test is performed to evaluate the swell or consolidation 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. Those samples are monitored for swell and consolidation. The swell-index is the resulting amount of swell or collapse after inundation, expressed as a percent of the sample’s initial thickness. After the inundation period, additional incremental loads are applied to evaluate the swell pressure and consolidation response. For this assessment, we conducted ten (10) 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. 1192056 July 17, 2019 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, (+/-) % 2 150 Lean Clay with Sand (CL) 8.8 9.4 112.8 118.5 (+) 9.7 (+) 13.6 7 500 Lean Clay with Sand (CL) or Siltstone / Sandstone 7.6 14.1 91.6 126.0 (-) 0.4 (+) 3.1 1 1000 Siltstone / Sandstone 9.9 112.1 (-) 0.3 Colorado Association of Geotechnical Engineers (CAGE) uses the following information presented below in Table II, to provide uniformity in terminology between geotechnical engineers to provide a relative correlation of 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 samples analyzed for this project were within the low to high range. The higher swell results were within the overburden cohesive subsoils; while the underlying bedrock formation reveal minimum to low swell potential characteristics. The swells analyzed for the building were generally low to moderate, and the swell indices for the pavement borings were above the maximum allowable 2% criteria to determine whether a swell mitigation plan is necessary. Based on these results, a swell mitigation procedure should be implemented for the interior floor slabs and on-site pavement areas. Earth Engineering Consultants, LLC EEC Project No. 1192056 July 17, 2019 Page 6 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 in order to establish a uniform bearing and penetration of the underlying cemented sandstone bedrock lenses. 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. Although evidence of fill materials beyond the depths described herein, or underground facilities were not observed during the site reconnaissance, such features could be encountered during construction and/or demolition of the existing on-site buildings. 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. Site Preparation Prior to placement of any fill and/or improvements, we recommend any existing vegetation/topsoil and any undocumented fill material be removed from the planned improvement areas. Care should be taken to ensure the buildings are bearing on uniform materials at the time of construction. If spread footing excavations do not extend to the siltstone/sandstone bedrock in some areas, an overexcavation to the bedrock and placement of fill material to develop building subgrades within the entire building envelope should be completed. In the pavement areas, a swell mitigation plan consisting of a minimum 3-foot overexcavation with fly ash treatment of the top 12 inches of subgrade should be completed. Over excavations would extend 8 inches laterally for every 12 inches of depth. Those conditions can best be evaluated in open excavations at the time of construction. After stripping, completing all cuts, removing any existing fill, and prior to placement of any new fill, the in-place soils should be scarified a minimum depth of 9 inches, adjusted in moisture content and compacted to at least 95% of the material’s maximum dry density as determined in accordance Earth Engineering Consultants, LLC EEC Project No. 1192056 July 17, 2019 Page 7 with ASTM Specification D698, the standard Proctor procedure. The moisture content of the scarified soils should be adjusted within the range of ±2% of standard Proctor optimum moisture content. Fill materials should consist of approved, low-volume change materials which are free from organic matter and debris. Soils similar to the site sandy lean clay /clayey sand and sandy lean clay could be used as fill in these areas. Siltstone/sandstone bedrock found on site could also be used as a fill material provided it is pulverized to a maximum particle size of 2 inches or less. Any bedrock composed of primarily claystone or siltstone is not recommended for use as fill. Fill and/or backfill materials should be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content and compacted as recommended for the scarified soils. Care should be taken after preparation of the subgrades to avoid disturbing the subgrade materials. Materials which are loosened or disturbed by the construction activities or materials which become dry and desiccated or wet and softened should be removed and replaced prior to placement of the overlying improvements. Care should be taken to maintain proper moisture contents in the subgrade soils prior to placement of any overlying improvements. Foundation System- Conventional Spread Footings Based on the materials observed in the test borings, we expect conventional type spread footings could be used to support the apartment buildings, provided the footings are placed on natural undisturbed bedrock or a uniform zone of properly placed fill materials prepared as outlined under “Site Preparation”. To minimize the potential for differential movement of dissimilar foundation bearing type materials, we recommend all footings be placed on siltstone/sandstone bedrock or a uniform zone of properly placed fill. Footings bearing natural undisturbed bedrock or engineered fill material could be designed for a maximum net allowable total load bearing pressure of 3,500 psf or 2,000 psf, respectively. The net bearing pressure refers to the pressure at foundation bearing level in excess of the minimum surrounding overburden pressure. Total load should include full dead and live loads. Earth Engineering Consultants, LLC EEC Project No. 1192056 July 17, 2019 Page 8 Footings should be proportioned to reduce differential foundation movement. We estimate the total long term settlement of footings designed as outlined above would be less than one inch. Greater settlements could occur if foundations are supported on soft or loose fill soils. The backfill soils adjacent to the foundations should be placed in loose lifts not to exceed 9 inches in thickness, moisture conditioned to ±2% of the material’s standard Proctor optimum moisture content, and mechanically compacted to be at least 95% of standard Proctor maximum dry density, ASTM D698. After placement of the fill materials, care should be taken to avoid wetting or drying of those materials. Bearing materials, which are loosened or disturbed by the construction activities, or materials which become dry and desiccated or wet and softened, should be removed and replaced or reworked in place prior to construction of the overlying improvements. Exterior foundations and foundations in unheated areas should be located at least 30 inches below adjacent exterior grade to provide frost protection. We recommend formed continuous footings have a minimum width of 12 inches and isolated column foundations have a minimum width of 24 inches. Seismic The site soil conditions consist of approximately 0 to 6 feet of overburden cohesive soils overlying weathered to poorly cemented siltstone/sandstone bedrock. For those site conditions, the International Building Code indicates a Seismic Site Classification of C. Lateral Earth Pressures For any area of the proposed development having below grade construction, such as retaining walls, etc., those portions 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 Earth Engineering Consultants, LLC EEC Project No. 1192056 July 17, 2019 Page 9 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 the table 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 essentially on-site cohesive subsoils or approved imported granular materials with friction angles of 25 and 35 degrees respectively. For the 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. Table III – Lateral Earth Pressure Design Values Soil Type On-Site Low Plasticity Cohesive Imported Medium Dense Granular Wet Unit Weight 115 135 Saturated Unit Weight 135 140 Friction Angle () – (assumed) 25° 35° Active Pressure Coefficient 0.40 0.27 At-rest Pressure Coefficient 0.58 0.43 Passive Pressure Coefficient 2.46 3.70 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. 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 Earth Engineering Consultants, LLC EEC Project No. 1192056 July 17, 2019 Page 10 cannot occur into the system. Where necessary, appropriate hydrostatic load values should be used for design. Floor Slabs Depending upon final site grades the slab-on-grade could be placed directly on the undisturbed bedrock formation with an underslab gravel zone or on a uniform zone of engineered/controlled fill material properly placed and compacted as outlined under the “Site Preparation” section of this report. It is our opinion the on-site cohesive soils could be used as fill in these areas, provided adequate moisture treatment and compaction procedures are followed. We estimate the long-term movement of floor slabs with properly prepared subgrade subsoils as outlined above would be less than 1 inch. For structural design of concrete slabs-on-grade, a modulus of subgrade reaction of 100 pounds per cubic inch (pci) may be used for floors supported on reconditioned and compacted on-site soils. 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.  Control joints should be provided in slabs to control the location and extent of cracking.  Interior trench backfills placed beneath slabs should be compacted in a similar manner as previously described for imported structural fill material.  In areas subjected to normal loading, a minimum 4-inch layer of clean-graded gravel, aggregate base course should be placed beneath interior slabs. For heavy loading, reevaluation of slab and/or base course thickness may be required.  A minimum 6-inch layer of free-draining gravel should be placed beneath garden level floor slab in conjunction with the underslab drainage system.  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. Earth Engineering Consultants, LLC EEC Project No. 1192056 July 17, 2019 Page 11 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 of light weight automobiles and low volumes of trucks (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. 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. Based on the subsurface conditions encountered at the site, an assumed R-value of 10 was used in design of the pavement sections. As a part of the swell mitigation procedure, we recommend a fly ash treatment of the subgrades. The fly ash treatment process would involve incorporating Class C fly ash within the upper 12-inches of the interior roadways subgrade sections from back of curb to back of curb, (in essence the full roadway width), prior to construction of the overlying pavement structure. Stabilization would consist of blending 13% by dry weight of Class C fly ash in the top 12 inches of the subgrades. The blended materials should be adjusted in moisture content to slightly dry of standard Proctor optimum moisture content and compacted to at least 95% of the materials maximum dry density as determined in accordance with the standard Proctor procedure. Compaction of the subgrade should be completed within two hours after initial blending of the Class C fly ash. Recommended minimum pavement sections are provided below in Table IV. 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. Earth Engineering Consultants, LLC EEC Project No. 1192056 July 17, 2019 Page 12 Table IV - 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" (2.97) (B) Composite with Fly Ash Treated Subgrade Hot Bituminous Pavement Aggregate Base Fly Ash Treated Subgrade (Design Structure Number) 3-1/2" 6" 12" (2.80) 4" 6" 12" (3.02) (C) PCC (Non-reinforced) 5-1/2" 6-1/2" 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. Earth Engineering Consultants, LLC EEC Project No. 1192056 July 17, 2019 Page 13  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. 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 V - Water Soluble Sulfate Test Results Sample Location Description Soluble Sulfate Content (%) B-1, S-1, at 4’ Siltstone/Sandstone 0.08 B-5, S-1, at 2’ Siltstone/Sandstone 0.06 B-9, S-1, at 2’ Siltstone/Sandstone 0.25 Based on the results as presented above, ACI 318, Section 4.2 indicates the clayey/silty sand soils have a low to severe risk of sulfate attack on Portland cement concrete, therefore, ACI Class S2 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. Earth Engineering Consultants, LLC EEC Project No. 1192056 July 17, 2019 Page 14 Other Considerations Positive drainage should be developed away from the structures 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 buildings and parking areas. Spray heads should be designed not to spray water on or immediately adjacent to the structures or site pavements. Roof drains should be designed to discharge at least 5 feet away from the structures and away from the pavement areas. Excavations into the on-site clays 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. Site-specific explorations should be completed to develop site- specific recommendations for each of the site buildings. Earth Engineering Consultants, LLC EEC Project No. 1192056 July 17, 2019 Page 15 This report has been prepared for the exclusive use of Goodwin Knight 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 1 2 %1 %2 % % % % % % 6N\ZD\0DUV% Boring Location Diagram Skyway & Mars Apartments - Fort Collins, Colorado EEC Project Number: 1192056 July 2019 EARTH ENGINEERING CONSULTANTS, LLC Appro[imate Boring Locations 1 Legend Site PKotos PKotos taken in appro[imate location, in direction oI arrow SKYWAY & MARS APARTMENTS FORT COLLINS, COLORADO EEC PROJECT NO. 1192056 JULY 2019 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 VEGETATION & TOPSOIL _ _ 1 SILTSTONE / SANDSTONE _ _ brown / rust 2 poorly cemented to cemented _ _ CS 3 50/6" 3500 7.6 115.1 23 2 33.3 3000 PSF 2.1% cemented lense from 3.5' to 4' _ _ 4 *bedrock classified as SILTY SAND (SM) _ _ SS 5 50/9" 1000 11.5 _ _ 6 _ _ 7 _ _ 8 _ _ 9 _ _% @ 1000 PSF CS 10 50/4" 9000 14.1 108.7 < 500 PSF None _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ SS 15 50/4" 11.7 _ _ 16 _ _ 17 _ _ 18 _ _ 19 _ _ CS 20 50/2" 9000 10.9 107.5 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ SS 25 50/3" 15.1 BOTTOM OF BORING DEPTH 25.5' _ _ Earth Engineering Consultants, LLC SKYWAY & MARS APARTMENTS FORT COLLINS, COLORADO LOG OF BORING B-1PROJECT NO: 1192056 JULY 2019 SHEET 1 OF 1 WATER DEPTH START DATE 7/3/2019 WHILE DRILLING 14.0' SURFACE ELEV N/A 24 HOUR N/A FINISH DATE 7/3/2019 AFTER DRILLING N/A 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 VEGETATION & TOPSOIL _ _ 1 LEAN CLAY WITH SAND (CL) _ _ brown 2 medium stiff to stiff _ _ 3 _ _ 4 _ _ SILTSTONE / SANDSTONE CS 5 50/10" 9000 9.3 123.3 26 8 33.7 < 500 PSF None brown / rust _ _ poorly cemented to cemented 6 _ _ *bedrock classified as CLAYEY SAND (SC) 7 _ _ 8 _ _ 9 _ _ SS 10 50/4" 13.9 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ CS 15 50/2" 12.9 115.7 BOTTOM OF BORING DEPTH 15.0' _ _ 16 _ _ 17 _ _ 18 _ _ 19 _ _ 20 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ 25 _ _ Earth Engineering Consultants, LLC SKYWAY & MARS APARTMENTS FORT COLLINS, COLORADO PROJECT NO: 1192056 LOG OF BORING B-2 JULY 2019 SHEET 1 OF 1 WATER DEPTH START DATE 7/3/2019 WHILE DRILLING None SURFACE ELEV N/A 24 HOUR N/A FINISH DATE 7/3/2019 AFTER DRILLING N/A 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 VEGETATION & TOPSOIL _ _ 1 LEAN CLAY WITH SAND (CL) _ _ brown 2 medium stiff to stiff _ _ 3 _ _ SILTSTONE / SANDSTONE 4 brown / rust _ _ poorly cemented to well cemented CS 5 50/7" 9000+ 9.4 114.5 < 500 PSF None _ _ 6 _ _ 7 _ _ 8 _ _ 9 _ _ SS 10 50/3" 13.0 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ CS 15 50/0.25" 8.5 BOTTOM OF BORING DEPTH 15.0' _ _ 16 _ _ 17 _ _ 18 _ _ 19 _ _ 20 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ 25 _ _ Earth Engineering Consultants, LLC SKYWAY & MARS APARTMENTS FORT COLLINS, COLORADO PROJECT NO: 1192056 LOG OF BORING B-3 JULY 2019 SHEET 1 OF 1 WATER DEPTH START DATE 7/3/2019 WHILE DRILLING None SURFACE ELEV N/A 24 HOUR N/A FINISH DATE 7/3/2019 AFTER DRILLING N/A 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 _ _ LEAN CLAY WITH SAND (CL) 1 brown _ _ very stiff to medium stiff 2 with calcareous deposits _ _ CS 3 20 8.2 36 21 74.5 900 PSF 1.5% _ _ 4 _ _ SS 5 9 9000+ 9.4 _ _ 6 _ _ SILTSTONE / SANDSTONE 7 brown / rust _ _ poorly cemented to cemented 8 _ _ 9 _ _ CS 10 50/4" 10.9 111.4 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ SS 15 50/1" _ _ BOTTOM OF BORING DEPTH 15.5' 16 _ _ 17 _ _ 18 _ _ 19 _ _ 20 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ 25 _ _ Earth Engineering Consultants, LLC SKYWAY & MARS APARTMENTS FORT COLLINS, COLORADO PROJECT NO: 1192056 LOG OF BORING B-4 JULY 2019 SHEET 1 OF 1 WATER DEPTH START DATE 7/3/2019 WHILE DRILLING None SURFACE ELEV N/A 24 HOUR N/A FINISH DATE 7/3/2019 AFTER DRILLING N/A 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 _ _ LEAN CLAY WITH SAND (CL) 1 brown _ _ medium stiff to stiff 2 _ _ 3 SILTSTONE / SANDSTONE _ _ brown / olive 4 poorly cemented to cemented _ _ CS 5 50/5" 9000+ 8.8 118.2 _ _ 6 _ _ 7 _ _ 8 _ _ 9 _ _ SS 10 50/4" 12.2 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ CS 15 50/2" 10.9 107.9 _ _ 16 _ _ 17 _ _ 18 _ _ 19 _ _ SS 20 50/4" 20.8 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ CS 25 50/2" 14.1 120.5 BOTTOM OF BORING DEPTH 25.0' _ _ Earth Engineering Consultants, LLC SKYWAY & MARS APARTMENTS FORT COLLINS, COLORADO PROJECT NO: 1192056 LOG OF BORING B-5 JULY 2019 SHEET 1 OF 1 WATER DEPTH START DATE 7/3/2019 WHILE DRILLING 17.0' SURFACE ELEV N/A 24 HOUR N/A FINISH DATE 7/3/2019 AFTER DRILLING N/A 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 GRAVEL - 1' _ _ 1 _ _ SILTSTONE / SANDSTONE 2 brown / rust / gray / olive _ _ poorly cemented to cemented 3 _ _ 4 _ _ CS 5 50/4" 11.6 123.1 < 500 PSF None _ _ 6 _ _ 7 _ _ 8 _ _ 9 _ _ SS 10 50/1" 5.1 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _% @ 1000 PSF CS 15 50/3" 9.9 111.4 < 500 PSF None BOTTOM OF BORING DEPTH 15.0' _ _ 16 _ _ 17 _ _ 18 _ _ 19 _ _ 20 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ 25 _ _ Earth Engineering Consultants, LLC SKYWAY & MARS APARTMENTS FORT COLLINS, COLORADO PROJECT NO: 1192056 LOG OF BORING B-6 JULY 2019 SHEET 1 OF 1 WATER DEPTH START DATE 7/3/2019 WHILE DRILLING None SURFACE ELEV N/A 24 HOUR N/A FINISH DATE 7/3/2019 AFTER DRILLING N/A 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 VEGETATION & TOPSOIL _ _ 1 SANDY LEAN CLAY (CL) _ _ brown 2 medium stiff _ _ 3 _ _ 4 _ _ CS 5 7 8.9 24 10 69.3 1600 psf 3.1% _ _ 6 _ _ 7 SILTSTONE / SANDSTONE _ _ brown / rust / gray 8 poorly cemented _ _ 9 _ _ SS 10 50/9" 14.7 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ CS 15 50/2" 13.5 93.9 BOTTOM OF BORING DEPTH 15.0' _ _ 16 _ _ 17 _ _ 18 _ _ 19 _ _ 20 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ 25 _ _ Earth Engineering Consultants, LLC SKYWAY & MARS APARTMENTS FORT COLLINS, COLORADO PROJECT NO: 1192056 LOG OF BORING B-7 JULY 2019 SHEET 1 OF 1 WATER DEPTH START DATE 7/3/2019 WHILE DRILLING None SURFACE ELEV N/A 24 HOUR N/A FINISH DATE 7/3/2019 AFTER DRILLING N/A 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 VEGETATION & TOPSOIL _ _ 1 LEAN CLAY WITH SAND (CL) _ _ brown 2 very stiff _ _% @ 150 PSF CS 3 21 9000+ 9.4 103.7 38 23 76.8 6500 PSF 13.6% _ _ 4 _ _ SILTSTONE / SANDSTONE SS 5 31 13.7 brown / rust / olive _ _ highly weathered to poorly cemented 6 _ _ 7 _ _ 8 _ _ 9 _ _ SS 10 50/4" 14.7 _ _ 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 SKYWAY & MARS APARTMENTS FORT COLLINS, COLORADO PROJECT NO: 1192056 LOG OF BORING B-8 JULY 2019 SHEET 1 OF 1 WATER DEPTH START DATE 7/3/2019 WHILE DRILLING None SURFACE ELEV N/A 24 HOUR N/A FINISH DATE 7/3/2019 AFTER DRILLING N/A 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 VEGETATION & TOPSOIL _ _ 1 LEAN CLAY WITH SAND (CL) _ _ brown 2 with calcareous deposits _ _% @ 150 PSF CS 3 20 8.8 108.7 6000 PSF 9.7% _ _ SILTSTONE / SANDSTONE 4 brown / rust _ _ highly weathered to poorly cemented SS 5 50/8" 8.6 _ _ 6 _ _ 7 _ _ 8 _ _ 9 _ _ SS 10 50/6" 11.3 _ _ 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 SKYWAY & MARS APARTMENTS FORT COLLINS, COLORADO PROJECT NO: 1192056 LOG OF BORING B-9 JULY 2019 SHEET 1 OF 1 WATER DEPTH START DATE 7/3/2019 WHILE DRILLING None SURFACE ELEV N/A 24 HOUR N/A FINISH DATE 7/3/2019 AFTER DRILLING N/A A-LIMITS SWELL Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown / Rust Siltstone / Sandstone Sample Location: Boring 1, Sample 1, Depth 2' Liquid Limit: 23 Plasticity Index: 2 % Passing #200: 33.3% Beginning Moisture: 7.6% Dry Density: 118.8 pcf Ending Moisture: 17.3% Swell Pressure: 3000 psf % Swell @ 500: 2.1% Skyway & Mars Apartments Fort Collins, Colorado 1192056 Jul-19 -14.0 -12.0 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Skyway & Mars Apartments Fort Collins, Colorado 1192056 Jul-19 Beginning Moisture: 14.1% Dry Density: 109.1 pcf Ending Moisture: 19.4% Swell Pressure: < 500 psf % Swell @ 500: None Sample Location: Boring 1, Sample 3, Depth 9' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown / Rust Siltstone / Sandstone -14.0 -12.0 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Skyway & Mars Apartments Fort Collins, Colorado 1192056 Jul-19 Beginning Moisture: 9.3% Dry Density: 126 pcf Ending Moisture: 14.8% Swell Pressure: < 500 psf % Swell @ 500: None Sample Location: Boring 2, Sample 1, Depth 4' Liquid Limit: 26 Plasticity Index: 8 % Passing #200: 33.7% SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown / Rust Siltstone / Sandstone -14.0 -12.0 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Skyway & Mars Apartments Fort Collins, Colorado 1192056 Jul-19 Beginning Moisture: 9.4% Dry Density: 110.7 pcf Ending Moisture: 20.0% Swell Pressure: < 500 psf % Swell @ 500: None Sample Location: Boring 3, Sample 1, Depth 4' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown / Rust Siltstone / Sandstone -14.0 -12.0 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Skyway & Mars Apartments Fort Collins, Colorado 1192056 Jul-19 Beginning Moisture: 8.2% Dry Density: 91.6 pcf Ending Moisture: 26.8% Swell Pressure: 900 psf % Swell @ 500: 1.5% Sample Location: Boring 4, Sample 1, Depth 2' Liquid Limit: 36 Plasticity Index: 21 % Passing #200: 74.5% SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown Lean Clay with Sand (CL) -14.0 -12.0 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Skyway & Mars Apartments Fort Collins, Colorado 1192056 Jul-19 Beginning Moisture: 11.6% Dry Density: 116.1 pcf Ending Moisture: 17.2% Swell Pressure: < 500 psf % Swell @ 500: None Sample Location: Boring 6, Sample 1, Depth 4' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown / Rust Sandstone -14.0 -12.0 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Skyway & Mars Apartments Fort Collins, Colorado 1192056 Jul-19 Beginning Moisture: 9.9% Dry Density: 112.1 pcf Ending Moisture: 17.8% Swell Pressure: < 500 psf % Swell @ 500: None Sample Location: Boring 6, Sample 3, Depth 14' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown, Gray, Rust Sandstone -14.0 -12.0 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Skyway & Mars Apartments Fort Collins, Colorado 1192056 Jul-19 Beginning Moisture: 8.9% Dry Density: 97.8 pcf Ending Moisture: 23.7% Swell Pressure: 1600 psf % Swell @ 500: 3.1% Sample Location: Boring 7, Sample 1, Depth 4' Liquid Limit: 24 Plasticity Index: 10 % Passing #200: 69.3% SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown Sandy Lean Clay (CL) -14.0 -12.0 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Skyway & Mars Apartments Fort Collins, Colorado 1192056 Jul-19 Beginning Moisture: 9.4% Dry Density: 118.5 pcf Ending Moisture: 17.1% Swell Pressure: 6500 psf % Swell @ 150: 13.6% Sample Location: Boring 8, Sample 1, Depth 2' Liquid Limit: 38 Plasticity Index: 23 % Passing #200: 76.8% SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown Lean Clay with Sand (CL) -14.0 -12.0 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Skyway & Mars Apartments Fort Collins, Colorado 1192056 Jul-19 Beginning Moisture: 8.8% Dry Density: 112.8 pcf Ending Moisture: 17.0% Swell Pressure: 6000 psf % Swell @ 150: 9.7% Sample Location: Boring 9, Sample 1, Depth 2' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown Lean Clay with Sand (CL) -14.0 -12.0 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added