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Home My WebLink AboutMONTAVA - PHASE E - TOWN CENTER RESIDENTIAL - BDR220003 - MONTAVA SUBMITTAL DOCUMENTS - ROUND 3 - GEOTECHNICAL (SOILS) REPORTFINAL SUBSURFACE EXPLORATION REPORT MONTAVA DEVELOPMENT - PHASE E APPROXIMATE 40-ACRE MIXED USE DEVELOPMENT SOUTH OF LARIMER COUNTY ROAD (LCR) 52 AND EAST OF LCR 50E FORT COLLINS, LARIMER COUNTY, COLORADO EEC PROJECT NO. 1172058 Prepared for: Montava Development, LLC 430 N College Avenue, Suite 410 Fort Collins, Colorado 80524 Attn: Mr. Max Moss (Max@hf2m.com), and Mr. Forrest Hancock (forrest@montava.com) Prepared by: Earth Engineering Consultants, LLC 4396 Greenfield Drive Windsor, Colorado 80550 4396 GREENFIELD D RIVE W INDSOR, CO LORADO 80550 (970) 545-3908 FAX (970) 663-0282 April 27, 2023 Montava Development, LLC 430 N College Avenue, Suite 410 Fort Collins, Colorado 80524 Attn: Mr. Max Moss (Max@hf2m.com), and Mr. Forrest Hancock (forrest@montava.com) Re: Final Subsurface Exploration Report Montava Development – Phase E - Approximate 40-Acre Mixed Use Development South of Larimer County Road (LCR) 52 and East of LCR 50E Fort Collins, Larimer County, Colorado EEC Project No. 1172058 Mr. Moss and Mr. Hancock: Enclosed, herewith, are the results of the supplemental preliminary (FINAL) subsurface exploration completed by Earth Engineering Consultants, LLC (EEC) personnel for the referenced project. For this preliminary supplemental subsurface exploration, a total of seventeen (17) soil borings were drilled on October 19 and 28, 2022, at the approximate locations as indicated on the enclosed Boring Location Diagrams included with this report. The supplemental borings were extended to depths of approximately 15 to 25 feet below existing site grades. It should be noted, that in 2017, EEC conducted a preliminary subsurface exploration for the overall site by drilling a series of thirty (30) test borings throughout the entire 80-acre property and preparing a preliminary report with our findings. For further information and preliminary recommendations based on the 2017 subsurface exploration, please refer to our Preliminary Subsurface Exploration Report dated October 2, 2017, EEC Project No. 1172058. On July 1, 2022, we were requested to perform a supplemental subsurface exploration for 40-acre Phase E portion. To develop supplemental subsurface information for the proposed development, as requested, EEC personnel advanced a total of seventeen (17) soil borings in the Phase E development area. Individual boring logs and results of laboratory testing are included as a part of the attached report. This supplemental exploration was completed in general accordance with our proposal dated July 11, 2022. In summary, the subsurface soils encountered in the seventeen (17) supplemental preliminary borings generally consisted of cohesive lean clay with varying amounts of sand subsoils, which extended to the underlying fine to course granular strata below and/or to the depths explored, approximately 15 to 25 Earth Engineering Consultants, LLC EEC Project No. 1172058 April 27, 2023 Page 3 cc: TST, Inc. – Consulting Engineers Don Taranto (dtaranto@tstinc.com) Jonathan Sweet (jsweet@tstinc.com) Martin/Martin Jeff A. White (JWHITE@martinmartin.com) Deborah Alvarado (DAlvarado@martinmartin.com) Stewart Environmental Consultants Dave Stewart (dave.stewart@stewartenv.com) FINAL SUBSURFACE EXPLORATION REPORT MONTAVA DEVELOPMENT- PHASE E APPROXIMATE 40-ACRE DEVELOPMENT SOUTH OF LARIMER COUNTY ROAD (LCR 52) AND EAST OF LCR 50E FORT COLLINS, COLORADO EEC PROJECT NO. 1172058 April 27, 2023 INTRODUCTION The supplemental preliminary (FINAL) subsurface exploration for the proposed 40-acre mixed use development located southeast of Larimer County Road (LCR) 52 and LCR 50E in Fort Collins, Colorado has been completed. For this supplemental subsurface exploration, a total of seventeen (17) soil borings were drilled on October 19, and 28, 2022, at the approximate locations as indicated on the enclosed Boring Location Diagrams included with this report. The supplemental borings were extended to depths of approximately 15 to 25 feet below existing site grades at pre-selected locations across the proposed development property to obtain information on existing subsurface conditions. The purpose of this supplemental preliminary report is to describe the subsurface conditions encountered in the boring locations, specifically within Phase E, analyze and evaluate the test data, and provide supplemental geotechnical recommendations concerning site development including foundations, floor slabs, pavement sections, and the possibility of an area underdrain system to support basement construction. EXPLORATION AND TESTING PROCEDURES The boring locations were established in the field by a representative of Earth Engineering Consultants, LLC (EEC) by pacing and estimating angles from identifiable site features. The boring locations and estimated ground surface elevations should be considered accurate only to the degree implied by the methods used to make the field measurements. Photographs of the site taken at the time of drilling are provided with this report. The borings were performed 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 Earth Engineering Consultants, LLC EEC Project No. 1172058 April 27, 2023 Page 2 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 driven into the ground by means of a 140-pound hammer falling a distance of 30 inches. The number of blows required to advance the 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 brass liners. All samples obtained in the field were sealed and returned to the laboratory for further examination, classification and testing. Laboratory moisture content tests were performed on each of the recovered samples. In addition, selected samples were tested for fines content and plasticity by washed sieve analysis and Atterberg limits tests. Swell/consolidation tests were completed on selected samples to evaluate the subgrade materials’ tendency to change volume with variation in moisture content and load. The quantity of water soluble sulfates was determined on select samples to evaluate the risk of sulfate attack on site concrete. Results of the outlined tests are indicated on the attached boring logs and summary sheets. As a 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 sample's texture and plasticity. The estimated group symbol for the Unified Soil Classification System is shown on the boring logs and a brief description of that classification system is included with this report. SITE AND SUBSURFACE CONDITIONS The 40-acre development is southeast of Larimer County Road (LCR) 52 and LCR 50E in Fort Collins, Colorado. The project site is generally undeveloped farmland. Surface water drainage across the site is generally from northwest and to southeast. Estimated relief across the site from northwest to southeast is approximately 2 to 5 feet (±). An EEC field engineer was on-site during supplemental drilling services to direct the drilling activities and evaluate the subsurface materials encountered. Field descriptions of the materials encountered were based on visual and tactual observation of disturbed samples and auger cuttings. Earth Engineering Consultants, LLC EEC Project No. 1172058 April 27, 2023 Page 3 The boring logs included with this report may contain modifications to the field logs based on results of laboratory testing and engineering evaluation. Based on results of field and laboratory evaluation, subsurface conditions can be generalized as follows. In summary, the subsurface soils encountered in the seventeen (17) supplemental preliminary borings generally consisted of cohesive lean clay with varying amounts of sand subsoils, which extended to the underlying fine to course granular strata below and/or to the depths explored, approximately 15 to 25 feet below existing site grades, in the vicinity of supplemental borings B-2 through B-17. The cohesive soils were generally medium stiff to very stiff and exhibited low to high swell potential at current moisture and density conditions. The lean clay with variable amounts of sand subsoils were underlain by sand/gravel with varying amounts of silt subsoils at depths of approximately 22 feet below existing site grades in the vicinity of supplemental boring B-1. The sand/gravel subsoils extended to the depths explored, approximately 25 feet below existing site grades. Groundwater was observed at six (6) of the seventeen (17) supplemental borings at depths ranging from approximately 9½ to 22 feet below existing site grades. The stratification boundaries indicated on the boring logs represent the approximate locations of changes in soil and rock types; in-situ, the transition of materials may be gradual and indistinct. GROUNDWATER CONDITIONS Observations were made while drilling and after the completion of drilling to detect the presence and level of groundwater. Groundwater was observed in six (6) of the seventeen (17) supplemental test borings at depths ranging from approximately 9½ to 22 feet below existing site grades. Groundwater was not initially encountered in borings B-5, B-13, and B-17 to maximum depths of exploration, approximately 25 feet below site grades. A field/hand slotted 1-1/2-inch diameter PVC piezometer was installed in six (6) of our supplemental borings. Subsequent measurements on October 21, 2022 indicated groundwater in the six (6) borings at depths of approximately 9 ½ to 22 feet below site grades, respectively. The remaining supplemental borings were backfilled; therefore, subsequent groundwater measurements were not obtained. Groundwater measurements provided with this report are indicative of groundwater levels at the locations and at the time the borings/groundwater measurements were completed. Earth Engineering Consultants, LLC EEC Project No. 1172058 April 27, 2023 Page 4 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. Zones of perched and/or trapped groundwater may occur at times in more permeable zones in the subgrade soils. The location and amount of perched water is dependent upon several factors, including hydrologic conditions, type of site development, irrigation demands on or adjacent to the site, seasonal and weather conditions as well as when the canal is active. The observations provided in this report represent groundwater conditions at the time of the field exploration, and may not be indicative of other times, or at other locations. ANALYSIS AND RECOMMENDATIONS Swell – Consolidation Test Results The swell-consolidation test is performed to evaluate the swell, collapse, and consolidation potential of soils to assist in determining foundation, floor slab and pavement design criteria. In this test, relatively undisturbed/in-tact samples obtained directly from the ring 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, expressed as a percent of the sample’s initial/preload thickness. 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 characteristics. For this assessment, we conducted twenty-two (22) swell-consolidation tests on relatively intact soil samples obtained at various intervals/depths on the site. The swell index values for the in-situ soil samples analyzed revealed low to high swell characteristics as indicated on the attached swell test summaries. The (+) test results indicate the materials swell potential characteristics while the (-) test results indicate the 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. 1172058 April 27, 2023 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, (+/-) % 3 150 Sandy Lean Clay (CL) 5.8 8.6 98.5 114.4 (+) 3.2 (+) 7.3 18 500 Sandy Silt (ML) / Sandy Lean Clay (CL) / Lean Clay with Sand (CL) 7.6 26.8 74.1 126.8 (-) 0.5 (+) 4.4 1 1000 Lean Clay (CL) 8.6 125.9 (+) 4.8 Colorado Association of Geotechnical Engineers (CAGE) uses the following information to provide uniformity in terminology between geotechnical engineers to provide a relative correlation of slab performance risk to measured swell. “The representative percent swell values are not necessarily measured values; rather, they are a judgment of the swell of the soil and/or bedrock profile likely to influence slab performance.” Geotechnical engineers use this information to also evaluate the swell potential risks for foundation performance based on the risk categories. TABLE II - Recommended Representative Swell Potential Descriptions and Corresponding Slab Performance Risk Categories Slab Performance Risk Category Representative Percent Swell (500 psf Surcharge) Representative Percent Swell (1000 psf Surcharge) Low 0 to < 3 0 < 2 Moderate 3 to < 5 2 to < 4 High 5 to < 8 4 to < 6 Very High > 8 > 6 Based on the laboratory test results, the in-situ samples analyzed for this project were within the low to high range, with an occasional sample indicating a slight tendency to hydro-compact when inundated with water and increased loads were applied. General Considerations If lower level construction or full-depth basements are being considered for the site, we would suggest that the lower level subgrade(s) be placed a minimum of 3 feet above the maximum anticipated rise in groundwater levels, or a combination exterior and interior perimeter drainage system(s) be installed in areas with shallow groundwater, as shown on the attached diagram. Also, Earth Engineering Consultants, LLC EEC Project No. 1172058 April 27, 2023 Page 6 consideration could be given to 1) either designing and installing an area underdrain system to lower the groundwater levels provided a gravity discharge point can be established. If a gravity outlet/system cannot be designed another consideration would be to design and install a mechanical sump pump system to discharge the collected groundwater within the underdrain system, or 2) elevate/raise the site grades to establish the minimum suggested 3-foot separation to the maximum anticipated rise in groundwater. Foundations for buildings that are constructed slab-on-grade (no basement) should also be placed a minimum of 3 feet above the maximum anticipated rise in groundwater levels. During our subsurface exploration groundwater was found at depths as shallow as 9 feet in some areas, as shown on the attached diagram. Consideration should be given to implementing a drainage or grading plan, as listed above, in these areas. Site Preparation All existing vegetation and/or topsoil should be removed from beneath site fills, roadways and building subgrade areas. Stripping depths should be expected to vary, depending, in part, on past agricultural activities. In addition, any soft/loose native soils or any existing fill materials without documentation of controlled fill placement should be removed from improvement and/or new improvement areas. After stripping and completing all cuts, any over excavation, and prior to placement of any fill, floor slabs or pavements, we recommend the exposed soils be scarified to a 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 with ASTM Specification D698, the standard Proctor procedure. The moisture content of the scarified materials should be adjusted to be within a range of ±2% of standard Proctor optimum moisture at the time of compaction. In general, fill materials required to develop the improvement areas should consist of approved, low- volume change materials which are free from organic matter and debris. The site lean clay soils with low swell potential and/or the underlying sand/gravel soils could be used as fill in these areas. The moderate to high swell potential cohesive subsoils will require reworking to a proper moisture content and recompacted as discussed. We recommend the fill soils be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content and compacted to at least 95% of the material’s Earth Engineering Consultants, LLC EEC Project No. 1172058 April 27, 2023 Page 7 maximum dry density as determined in accordance with the standard Proctor procedure. The moisture content of predominately clay soils should be adjusted to be within the range of ± 2% of optimum moisture content at the time of placement. Granular soil should be adjusted to a workable moisture content. Specific explorations should be completed for each building/individual residential lot to develop recommendations specific to the proposed structure and owner/builder and for specific pavement sections. Care should be taken after preparation of the subgrades to avoid disturbing the subgrade materials. Positive drainage should be developed away from structures and across and away from pavement edges to avoid wetting of subgrade materials. Subgrade materials allowed to become wetted subsequent to construction of the residences and/or pavements can result in unacceptable performance of those improvements. Areas of greater fills overlying areas with soft/compressible subsoils, especially within the deeper utility alignments, may experience settlement due to the soft/compressible subsoils below and within the zone of 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. Preloading and/or surcharging the fill areas could be considered to induce additional settlement in these areas prior to construction of improvements in or on the fills. Unless positive steps are taken to pre-consolidate the fill materials and/or underlying soft subgrades, special care will be needed for construction of improvements supported on or within these areas. Foundation Systems – General Considerations The cohesive subsoils will require particular attention in the design and construction to reduce the amount of movement due to low to high swell potential. Groundwater was also encountered at relatively shallow depths in a few areas which will require special attention in the overall design and construction of the project. As previously mentioned, consideration could be given to the installation of an area underdrain system. Earth Engineering Consultants, LLC EEC Project No. 1172058 April 27, 2023 Page 8 • Conventional spread footings bearing on a zone of either ground modified subsoils, which have been scarified a minimum depth of 12 inches, moisture conditioned to near optimum moisture content and recompacted to at least 95% of the material’s standard Proctor density (ASTM Specification D698) results, or on a zone of newly placed engineered fill material. Particular attention will be required during the supplemental site observations, such as “open-hole” or foundation excavation observations Footing Foundations We anticipate use of conventional footing foundations could be considered for lightly to moderately loaded structures at this site. We expect footing foundations would be supported either on 5 feet of moisture conditioned, recompacted native soils or on newly placed and compacted fills. A few soft zones were observed in the near surface clay soils; therefore, care should be taken to see that foundations are not supported directly on soft materials. Mitigation for swelling of the lean clay should be expected in the general areas shown on the attached diagram and mitigation for soft subgrade soils should be expected in a few areas. We suggest an over excavation and backfill procedure be considered in areas with moderate to high swell potential and/or soft/compressible subsoils to reduce the potential for post construction movement. Over excavation depths should be expected to vary across the site, based on builder/owner requirements and lot-specific conditions. After completing a site-specific/lot-specific geotechnical exploration study, a thorough “open-hole/foundation excavation” observation should be performed prior to foundation formwork placement to determine the extent of any over excavation and replacement procedure. Deeper over excavation depths may be necessary depending upon the observed subsoils at the time of the foundation excavation observation. In general, the over excavation area would extend 8 inches laterally beyond the building perimeter for every 12 inches of over-excavation depth. We anticipate backfill materials would consist of an approved native subsoils or approved imported granular structural fill material such as a CDOT Class 7 aggregate base course (ABC) either native and/or recycled concrete oriented and/or equivalent, which is placed in uniforms lifts, properly adjusted in moisture content and mechanically compacted to at least 95% of the material’s Standard Proctor Density (ASTM D698) results. Earth Engineering Consultants, LLC EEC Project No. 1172058 April 27, 2023 Page 9 For design of footing foundations bearing on approved native subsoils, or on properly placed and compacted fill materials as outlined above, maximum net allowable total load soil bearing pressures on the order of 1,500 to 2,500 psf could be considered depending upon the specific backfill material used. Footing foundations should maintain separation above maximum anticipated rise in groundwater elevation of at least 3 feet as indicated earlier. The net bearing pressure refers to the pressure at foundation bearing level in excess of the minimum surrounding overburden pressure. Total load would include full dead and live loads. Exterior foundations and foundations in unheated areas are typically located at least 30 inches below adjacent exterior grade to provide frost protection. Formed continuous footings would have minimum widths of 12 to 16 inches and isolated column foundations would have a minimum width of 24 to 30 inches. Trenched foundations could probably be used in the near surface soils. If used, trenched foundations would have a minimum width of 12 inches and formed continuous foundations a minimum width of 8 inches. Care should be taken to avoid placement of structures partly on native soils and partly on newly placed fill materials to avoid differential settlement. In these areas, mitigation approaches could include surcharging of the fill materials, over excavation of the native soils or use of alternative foundations, such as drilled piers, along with structural floors. Mitigation approaches may vary between structures depending, in part, on the extent and depth of new fill placement. Specific approaches could be established at the time of exploration for the individual structures. Care should be taken on the site to fully document the horizontal and vertical extent of fill placement on the site, including benching the fill into native slopes. Floor Slab/Exterior Flatwork Subgrades Slab-on-grade construction can be used on the site provided certain precautions are adhered to and some post-construction movement of the floor slabs is deemed acceptable. To reduce floor slab and/or exterior concrete flatwork movement, we recommend the proposed floor slab-on-grade, and exterior concrete flatwork bear on adequate moisture treated, recompacted native soils or engineered/controlled fill material properly placed and compacted as outlined under the “Site Preparation” section of this report. This procedure will not 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 Earth Engineering Consultants, LLC EEC Project No. 1172058 April 27, 2023 Page 10 less than 1 inch for the cohesive on-site subsoils. 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. • A minimum 3-inch void space should be constructed above, or below non-bearing partition walls placed on the floor slab. Special framing details should be provided at door jambs and frames within partition walls to avoid potential distortion. Partition walls should be isolated from suspended ceilings. • Interior trench backfills placed beneath slabs should be compacted in a similar manner as previously described for footing and floor slab fill. • In areas subjected to normal loading, a 6-inch layer of clean-graded gravel or aggregate base course should be placed beneath interior floor slabs. • 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. Basement Design and Construction Groundwater was encountered across the site within the supplementary soil borings at approximate depths of 9½ to 22 feet below existing site grades. If lower level construction for either garden-level or full-depth basements is being considered for the site, we would suggest that the lower level subgrade(s) be placed a minimum of 3 feet above maximum anticipated rise in groundwater levels, or a combination exterior and interior perimeter drainage system(s) be installed in areas with shallow groundwater as indicated on the attached diagram. Consideration could be given to 1) either designing and installing an area underdrain system to lower the groundwater levels provided a gravity discharge point can be established. If a gravity Earth Engineering Consultants, LLC EEC Project No. 1172058 April 27, 2023 Page 11 outlet/system cannot be designed another consideration would be to design and install a mechanical sump pump system to discharge the collected groundwater within the underdrain system, or 2) elevate/raise the site grades to establish the minimum required 3-foot separation to the maximum anticipated rise in groundwater EEC is available to assist in the underdrain design if requested. For each individual building with a garden level or full-depth basement located less than 3 feet above maximum groundwater levels, the dewatering system should, at a minimum, include an under- slab gravel drainage layer sloped to an interior perimeter drainage system. Considerations for the supplementary design of the combination exterior and interior perimeter drainage system are as follows: The under-slab drainage system should consist of a properly sized perforated pipe, embedded in free- draining gravel, placed in a trench at least 12 inches in width. The trench should be inset from the interior edge of the nearest foundation a minimum of 12 inches. In addition, the trench should be located such that an imaginary line extending downward at a 45-degree angle from the foundation does not intersect the nearest edge of the trench. Gravel should extend a minimum of 3 inches beneath the bottom of the pipe. The underslab drainage system should be sloped at a minimum 1/8 inch per foot to a suitable outlet, such as a sump and pump system. The underslab drainage layer should consist of a minimum 6-inch thickness of free-draining gravel meeting the specifications of ASTM C33, Size No. 57 or 67 or equivalent. Cross-connecting drainage pipes should be provided beneath the slab at minimum 15-foot intervals and should discharge to the perimeter drainage system. Sizing of drainage pipe will be dependent upon groundwater flow into the dewatering system. Groundwater flow rates will fluctuate with permeability of the soils to be dewatered and the depth to which groundwater may rise in the future. Pump tests to determine groundwater flow rates are recommended in order to properly design the system. For preliminary design purposes, the drainage pipe, sump and pump system should be sized for a projected flow of 0.5 x 10-3 cubic feet per second (cfs) per lineal foot of drainage pipe. Additional recommendations can be provided upon request and should be presented in final subsurface exploration reports for each residential/commercial lot. The exterior drainage system should be constructed around the exterior perimeter of the lower level/below grade foundation system and sloped at a minimum 1/8-inch per foot to a suitable outlet, Earth Engineering Consultants, LLC EEC Project No. 1172058 April 27, 2023 Page 12 such as a sump and pump system. The exterior drainage system should consist of a properly sized perforated pipe, embedded in free- draining gravel, placed in a trench at least 12 inches in width. Gravel should extend a minimum of 3 inches beneath the bottom of the pipe, and at least 2 feet above the bottom of the foundation wall. The system should be underlain with a polyethylene moisture barrier, sealed to the foundation walls, and extended at least to the edge of the backfill zone. The gravel should be covered with drainage fabric prior to placement of foundation backfill. Lateral Earth Pressures For any portion of the proposed buildings constructed below grade, those portions will be subject to lateral earth pressures. Passive lateral earth pressures may help resist the driving forces for retaining walls 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 basements or 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 basements or 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 granular materials with a friction angle of 35 degrees or low volume change cohesive soils with a friction angle of 25. 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. Earth Engineering Consultants, LLC EEC Project No. 1172058 April 27, 2023 Page 13 TABLE III - Lateral Earth Pressures Soil Type On-Site Cohesive Soils Imported Medium Dense Granular Wet Unit Weight (pcf) 110 135 Saturated Unit Weight (pcf) 130 140 Friction Angle (φ) – (assumed) 25° 35° Active Pressure Coefficient 0.41 0.27 At-rest Pressure Coefficient 0.58 0.43 Passive Pressure Coefficient 2.46 3.69 The outlined values do not include factors of safety nor allowances for hydrostatic loads and are based on assumed friction angles and should be verified prior to construction. Care should be taken to develop appropriate systems in conjunction below grade walls to eliminate potential for hydrostatic loads developing on the walls and/or design the walls to accommodate hydrostatic load conditions. Pavements Due to the low to high swell subsoils found throughout the site, we recommend the pavement subgrade section consist of ground modified subsoils or newly placed and compacted engineered controlled fill material as recommended in the Site Preparation section of this report. If on-site subsoils are used, consideration could also be given to either a fly ash or Portland cement treatment of the top 12-inches of pavement subgrades for long-term stabilization purposes, if warranted. If fly ash treatment is chosen, we recommend the addition of at least 13% Class C fly ash to the in- place subgrade materials, based on dry weights. If cement treatment is selected, we suggest the addition of at least 4% Portland cement to the in-place subgrade materials, based on dry weight. The Class C fly ash and/or cement should be thoroughly blended with the in-place soils to a depth of 12 inches below the top of subgrade. The blended materials should be adjusted to be within ±2% of standard Proctor optimum moisture and compacted to at least 95% of the materials maximum dry density as determined in accordance with the standard Proctor procedure for stabilized materials (ASTM Specification D558). We expect the site pavements will include areas designated for light-duty automobile traffic as well as some areas for heavier automobile and heavy-duty truck traffic. For design purposes, an assumed Earth Engineering Consultants, LLC EEC Project No. 1172058 April 27, 2023 Page 14 equivalent daily load axle (EDLA) rating of 7 is used in the light-duty pavement areas and an EDLA of 15 is used in the heavy-duty pavement areas. An assumed R-Value of 10 is being used for the pavement design, based off the observed subsurface conditions and soil classification. Hot mix asphalt (HMA) underlain by aggregate base course, or a non-reinforced concrete pavement may be feasible options for the proposed on-site paved sections. HMA pavements may show rutting and distress in areas of heavy truck traffic or in truck loading and turning areas. Concrete pavements should be considered in those areas. Suggested pavement sections are provided in the table below. The outlined pavement sections are minimums and thus, periodic maintenance should be expected. Table VII - Minimum Pavement Thickness Recommendations Light Duty Areas Heavy Duty Areas 18-kip EDLA 18-kip ESAL Reliability Resilient Modulus (Based on R-Value=10) PSI Loss 7 51,100 75% 3562 2.5 15 109,500 80% 3562 2.2 Design Structure Number 2.47 2.88 Composite Section – Option A (assume Stable Subgrade) Hot Mix Asphalt Aggregate Base Course Structure Number 4" 7" (2.53) 5" 7" (2.97) Composite Section with Fly Ash Treated Subgrade Hot Mix Asphalt Aggregate Base Course Fly Ash or Cement Treated Subgrade (assume half-credit) Structure Number 3-1/2" 6" 12" (2.80) 4" 6" 12" (3.02) PCC (Non-reinforced) – placed on a stable subgrade 5½" 6" We recommend aggregate base be graded to meet a Class 5 or Class 6 aggregate base. Aggregate base should be adjusted to a workable moisture content and compacted to achieve a minimum of 95% of standard Proctor maximum dry density. HMA should be graded to meet a S (75) or SX (75) with PG 58-28 binder. HMA should be compacted to achieve 92 to 96% of the mix's theoretical maximum specific gravity (Rice Value). Portland cement concrete should be an acceptable exterior pavement mix with a minimum 28-day compressive strength of 4,500 psi and should be air entrained. Earth Engineering Consultants, LLC EEC Project No. 1172058 April 27, 2023 Page 15 The recommended pavement sections are minimums; thus, periodic maintenance should be expected. Longitudinal and transverse joints should be provided as needed in concrete pavements for expansion/contraction and isolation. The location and extent of joints should be based upon the final pavement geometry. Sawed joints should be cut in accordance with ACI recommendations. All joints should be sealed to prevent entry of foreign material and dowelled where necessary for load transfer. 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., garden centers, wash racks). • 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. • Place and compact 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. If during or after placement of the 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 methods of stabilization, or a change in the pavement section. Water Soluble Sulfates – (SO4) The water soluble sulfate (SO4) testing of the on-site subsoil materials taken during our subsurface exploration at an approximate depth of 4-feet to 9-feet below site grades is provided below. Based on the reported sulfate contents test results, this report includes a recommendation for the CLASS or TYPE of cement for use for contact in association with the on-site subsoils. Earth Engineering Consultants, LLC EEC Project No. 1172058 April 27, 2023 Page 16 TABLE IV - Water Soluble Sulfate Test Results Sample Location Description Soluble Sulfate Content (mg/kg) Soluble Sulfate Content (%) B-1, S-2 at 9’ Sandy Silt (ML) 2,960 0.30 B-4, S-1 at 4’ Sandy Lean Clay (CL) 14,750 1.48 B-14, S-1 at 4’ Sandy Lean Clay (CL) 16,000 1.60 B-17, S-3 at 9’ Sandy Lean Clay (CL) 15,250 1.53 Based on the results as presented above, ACI 318, Section 4.2 indicates the site soils have a low to severe risk of sulfate attack on Portland cement concrete. Therefore Class 2 cement with the use of fly ash should be used for concrete on and below site grades within the overburden soils. Foundation concrete should be designed in accordance with the provisions of the ACI Design Manual, Section 318, Chapter 4. These results are being compared to the following table. TABLE V- Requirements to Protect Against Damage to Concrete by Sulfate Attack from External Sources of Sulfate Severity of Sulfate exposure Water-soluble sulfate (SO4) in dry soil, percent Water-cement ratio, maximum Cementitious material Requirements Class 0 0.00 to 0.10% 0.45 Class 0 Class 1 0.11 to 0.20% 0.45 Class 1 Class 2 0.21 to 2.00% 0.45 Class 2 Class 3 2.01 of greater 0.45 Class 3 Underground Utility Systems All piping should be adequately bedded for proper load distribution. It is suggested that clean, graded gravel compacted to 75 percent of Relative Density ASTM D4253 be used as bedding. Where utilities and/or if the various structures are excavated below groundwater, temporary dewatering will be required during excavation, pipe placement, foundation placement, and backfilling operations for proper construction. Utility trenches should be excavated on safe and stable slopes in accordance with OSHA regulations as discussed above. Backfill should consist of the on-site soils or approved materials. The pipe backfill should be compacted to a minimum of 98 % of Standard Proctor Density ASTM D698 below a depth of 10 feet or great and to 95% of Standard Proctor Density for the upper 10-foot zone. Earth Engineering Consultants, LLC EEC Project No. 1172058 April 27, 2023 Page 17 All underground piping within or near the proposed structure should be designed with flexible couplings, so minor deviations in alignment do not result in breakage or distress. Utility knockouts in grade beams and/or foundation should be oversized to accommodate differential movements. Other Considerations and Recommendations Groundwater was observed at depths of approximately 9½ to 22 feet below present site grades. Excavations extending to the wetter soils could create difficulties for backfilling of the structures and utility trenches with drying of the subgrade soils required to use those materials as backfill. In general, the subgrade soils could be used as backfill soils although care will be necessary to maintain sufficient moisture to reduce potential for post-construction movement. Although evidence of fills or underground facilities such as septic tanks, cesspools, basements, and utilities was not observed during the site reconnaissance, 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. Excavations into the on-site soils will encounter a variety of conditions. Excavations into the cohesive soils can be expected to stand on relatively steep temporary slopes during construction; however, caving soils may also be encountered especially in close proximity to the groundwater table. Groundwater seepage should also be anticipated for utility excavations. Pumping from sumps may be utilized to control water within the excavations. Well points may be required for significant groundwater flow, or where excavations penetrate groundwater to a significant depth. 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. 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 buildings to avoid features which would pond water adjacent to the foundations or stemwalls. Placement of plants which require irrigation systems or could result in fluctuations of the moisture content of the subgrade material should be avoided adjacent to site improvements. Irrigation systems should not be Earth Engineering Consultants, LLC EEC Project No. 1172058 April 27, 2023 Page 18 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. 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. Site specific explorations will be necessary for the proposed site buildings. It is recommended that the geotechnical engineer be retained to review the plans and specifications so that comments can be made regarding the interpretation and implementation of our geotechnical recommendations in the design and specifications. It is further recommended that the geotechnical engineer be retained for testing and observations during earthwork and foundation construction phases to help determine that the design requirements are fulfilled. This report has been prepared for the exclusive use of Montava Development 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. Site safety, excavation support, and dewatering requirements are the responsibility of others. 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 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 MONTAVA DEVELOPMENT - PHASE E FORT COLLINS, COLORADO EEC PROJECT NO. 1172058 OCTOBER 2022 MONTAVA DEVELOPMENT - PHASE E FORT COLLINS, COLORADO EEC PROJECT NO. 1172058 OCTOBER 2022 B-1 B-2 B-3 B-4 B-5 B-6 B-7 B-8 B-9 B-10 B-11 B-12 B-13 B-14 B-15 B-16 B-17 Proposed Boring Location Diagram Montava - Phase E Supplemental Exploration Fort Collins, Colorado EEC Project #: 1172058 Date: July 2022 Approximate Locations Ior 17 Preliminary Borings, 15 - 25 EARTH ENGINEERING CONSULTANTS, LLC Legend 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 CORN STUBBLE _ _ 1 SANDY LEAN CLAY (CL) _ _ brown / gray / rust, moist 2 soft to very stiff _ _ 3 _ _ 4 _ _ CS 5 3 1000 19.7 94.0 67.0 <500 PSF None _ _ 6 _ _ 7 _ _ 8 _ _ 9 _ _water soluble sulfates = 0.3% SS 10 5 4000 25.6 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ CS 15 15 3000 14.7 119.7 _ _ 16 _ _ 17 _ _ 18 _ _ SAND WITH GRAVEL (SW) 19 brown/red _ _ medium dense SS 20 22 9.6 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ CS 25 26 12.0 122.6 BOTTOM OF BORING DEPTH 25' _ _ Earth Engineering Consultants, LLC A-LIMITS SWELL SURFACE ELEV N/A FINISH DATE 10/19/2022 AFTER DRILLING 9'6" SHEET 1 OF 1 WATER DEPTH START DATE 10/19/2022 WHILE DRILLING 16' MONTAVA DEVELOPMENT - PHASE E LOG OF BORING B-1PROJECT NO: 1172058 DECEMBER 2022 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 CORN STUBBLE _ _ 1 SANDY LEAN CLAY (CL) _ _ brown, moist 2 medium stiff to very stiff _ _ with gypsum crystals CS 3 7 6000 15.8 109.6 28 13 55.0 <500 PSF None _ _ 4 _ _ SS 5 5 1000 14.4 _ _ 6 _ _ 7 _ _ 8 _ _ 9 _ _ CS 10 9 1000 19.3 107.1 55.0 <500 PSF None _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ SS 15 17 4000 18.7 _ _ BOTTOM OF BORING DEPTH 15.5' 16 _ _ 17 _ _ 18 _ _ 19 _ _ 20 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ 25 _ _ Earth Engineering Consultants, LLC MONTAVA DEVELOPMENT - PHASE E PROJECT NO: 1172058 LOG OF BORING B-2 DECEMBER 2022 FORT COLLINS, COLORADO SHEET 1 OF 1 WATER DEPTH START DATE 10/19/2022 WHILE DRILLING None SURFACE ELEV N/A FINISH DATE 10/19/2022 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 SPARSE VEGETATION _ _ 1 SANDY LEAN CLAY (CL) _ _ brown, dry 2 very stiff to stiff _ _% @ 150 PSF with calcareous deposits and gypsum crystals CS 3 18 6500 5.8 104.6 950 PSF 4.5% _ _ 4 _ _ SS 5 17 8000 9.4 _ _ 6 _ _ 7 _ _ 8 _ _ 9 _ _ CS 10 11 8000 15.4 110.7 <500 PSF None _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ SS 15 11 5000 19.1 _ _ BOTTOM OF BORING DEPTH 15.5' 16 _ _ 17 _ _ 18 _ _ 19 _ _ 20 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ 25 _ _ Earth Engineering Consultants, LLC MONTAVA DEVELOPMENT - PHASE E PROJECT NO: 1172058 LOG OF BORING B-3 DECEMBER 2022 FORT COLLINS, COLORADO SHEET 1 OF 1 WATER DEPTH START DATE 10/19/2022 WHILE DRILLING None SURFACE ELEV N/A FINISH DATE 10/19/2022 AFTER DRILLING N/A A-LIMITS SWELL Project: Location: Project #: Date: Montava Development - Phase E Fort Collins, Colorado 1172058 December 2022 Beginning Moisture: 19.7% Dry Density: 94.2 pcf Ending Moisture: 21.1% Swell Pressure: <500 psf % Swell @ 500: None Sample Location: Boring 1, Sample 1, Depth 4' Liquid Limit: NL Plasticity Index: NP % Passing #200: 67.0% SWELL / CONSOLIDATION TEST RESULTS Material Description: Sandy Lean Clay (CL) -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: Sandy Lean Clay (CL) Sample Location: Boring 2, Sample 1, Depth 2' Liquid Limit: 28 Plasticity Index: 13 % Passing #200: 55.0% Beginning Moisture: 15.8% Dry Density: 109.9 pcf Ending Moisture: 17.3% Swell Pressure: <500 psf % Swell @ 500: None Montava Development - Phase E Fort Collins, Colorado 1172058 December 2022 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: Sandy Lean Clay (CL) Sample Location: Boring 2, Sample 3, Depth 9' Liquid Limit: NL Plasticity Index: NP % Passing #200: 55.0% Beginning Moisture: 19.3% Dry Density: 106.6 pcf Ending Moisture: 18.0% Swell Pressure: <500 psf % Swell @ 500: None Montava Development - Phase E Fort Collins, Colorado 1172058 December 2022 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: Sandy Lean Clay (CL) Sample Location: Boring 3, Sample 1, Depth 2' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - Beginning Moisture: 5.8% Dry Density: 101.4 pcf Ending Moisture: 23.0% Swell Pressure: 950 psf % Swell @ 150: 4.5% Montava Development - Phase E Fort Collins, Colorado 1172058 December 2022 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: Sandy Lean Clay (CL) Sample Location: Boring 3, Sample 3, Depth 9' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - Beginning Moisture: 15.4% Dry Density: 112.7 pcf Ending Moisture: 18.2% Swell Pressure: <500 psf % Swell @ 500: None Montava Development - Phase E Fort Collins, Colorado 1172058 December 2022 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: Sandy Lean Clay (CL) Sample Location: Boring 4, Sample 1, Depth 4' Liquid Limit: Plasticity Index: % Passing #200: Beginning Moisture: 19.9% Dry Density: 107.5 pcf Ending Moisture: 19.0% Swell Pressure: <500 psf % Swell @ 500: None Montava Development - Phase E Fort Collins, Colorado 1172058 December 2022 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: Lean Clay With Sand (CL) Sample Location: Boring 5, Sample 1, Depth 4' Liquid Limit: 36 Plasticity Index: 18 % Passing #200: 73.8% Beginning Moisture: 11.2% Dry Density: 120 pcf Ending Moisture: 16.1% Swell Pressure: 5000 psf % Swell @ 500: 4.4% Montava Development - Phase E Fort Collins, Colorado 1172058 December 2022 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: Lean Clay With Sand (CL) Sample Location: Boring 6, Sample 1, Depth 4' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - Beginning Moisture: 18.1% Dry Density: 109.1 pcf Ending Moisture: 16.6% Swell Pressure: <500 psf % Swell @ 500: None Montava Development - Phase E Fort Collins, Colorado 1172058 December 2022 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Montava Development - Phase E Fort Collins, Colorado 1172058 December 2022 Beginning Moisture: 22.8% Dry Density: 100.6 pcf Ending Moisture: 28.0% Swell Pressure: 1450 psf % Swell @ 500: 0.9% Sample Location: Boring 7, Sample 3, Depth 9' Liquid Limit: 54 Plasticity Index: 32 % Passing #200: 81.2% SWELL / CONSOLIDATION TEST RESULTS Material Description: Sandy Lean Clay (CL) -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: Lean Clay With Sand (CL) Sample Location: Boring 8, Sample 3, Depth 9' Liquid Limit: 43 Plasticity Index: 28 % Passing #200: 82.1% Beginning Moisture: 26.8% Dry Density: 95.9 pcf Ending Moisture: 26.0% Swell Pressure: 650 psf % Swell @ 500: 0.3% Montava Development - Phase E Fort Collins, Colorado 1172058 December 2022 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: Sandy Lean Clay (CL) Sample Location: Boring 9, Sample 1, Depth 2' Liquid Limit: 27 Plasticity Index: 13 % Passing #200: 61.9% Beginning Moisture: 17.1% Dry Density: 105.9 pcf Ending Moisture: 17.2% Swell Pressure: <500 psf % Swell @ 500: None Montava Development - Phase E Fort Collins, Colorado 1172058 December 2022 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: Sandy Lean Clay (CL) Sample Location: Boring 10, Sample 3, Depth 9' Liquid Limit: 33 Plasticity Index: 22 % Passing #200: 53.6% Beginning Moisture: 23.0% Dry Density: 107.4 pcf Ending Moisture: 16.3% Swell Pressure: <500 psf % Swell @ 500: None Montava Development - Phase E Fort Collins, Colorado 1172058 December 2022 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Montava Development - Phase E Fort Collins, Colorado 1172058 December 2022 Beginning Moisture: 7.6% Dry Density: 103.5 pcf Ending Moisture: 22.2% Swell Pressure: 1300 psf % Swell @ 500: 1.9% Sample Location: Boring 11, Sample 1, Depth 4' Liquid Limit: 34 Plasticity Index: 20 % Passing #200: 73.3% SWELL / CONSOLIDATION TEST RESULTS Material Description: Lean Clay With Sand (CL) -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: Sandy Lean Clay (CL) Sample Location: Boring 12, Sample 1, Depth 2' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - Beginning Moisture: 5.9% Dry Density: 98.5 pcf Ending Moisture: 22.8% Swell Pressure: 870 psf % Swell @ 150: 3.2% Montava Development - Phase E Fort Collins, Colorado 1172058 December 2022 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: Sandy Lean Clay (CL) Sample Location: Boring 12, Sample 3, Depth 9' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - Beginning Moisture: 15.9% Dry Density: 112.4 pcf Ending Moisture: 15.0% Swell Pressure: <500 psf % Swell @ 500: None Montava Development - Phase E Fort Collins, Colorado 1172058 December 2022 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: Lean Clay With Sand (CL) Sample Location: Boring 13, Sample 1, Depth 4' Liquid Limit: 31 Plasticity Index: 19 % Passing #200: 71.2% Beginning Moisture: 9.1% Dry Density: 111.9 pcf Ending Moisture: 17.8% Swell Pressure: 1600 psf % Swell @ 500: 1.6% Montava Development - Phase E Fort Collins, Colorado 1172058 December 2022 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: Sandy Lean Clay (CL) Sample Location: Boring 14, Sample 1, Depth 4' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - Beginning Moisture: 14.9% Dry Density: 108.9 pcf Ending Moisture: 17.6% Swell Pressure: <500 psf % Swell @ 500: None Montava Development - Phase E Fort Collins, Colorado 1172058 December 2022 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: Sandy Lean Clay (CL) Sample Location: Boring 15, Sample 1, Depth 4' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - Beginning Moisture: 14.0% Dry Density: 112.1 pcf Ending Moisture: 15.5% Swell Pressure: <500 psf % Swell @ 500: None Montava Development - Phase E Fort Collins, Colorado 1172058 December 2022 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Montava Development - Phase E Fort Collins, Colorado 1172058 December 2022 Beginning Moisture: 8.0% Dry Density: 74.1 pcf Ending Moisture: 21.8% Swell Pressure: 2000 psf % Swell @ 500: 2.4% Sample Location: Boring 16, Sample 1, Depth 4' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - SWELL / CONSOLIDATION TEST RESULTS Material Description: Lean Clay (CL) -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Montava Development - Phase E Fort Collins, Colorado 1172058 December 2022 Beginning Moisture: 8.6% Dry Density: 125.9 pcf Ending Moisture: 15.0% Swell Pressure: 28000 psf % Swell @ 1000: 4.8% Sample Location: Boring 16, Sample 3, Depth 14' Liquid Limit: 42 Plasticity Index: 28 % Passing #200: 88.6% SWELL / CONSOLIDATION TEST RESULTS Material Description: Lean Clay (CL) -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: Sandy Lean Clay (CL) Sample Location: Boring 17, Sample 1, Depth 2' Liquid Limit: 35 Plasticity Index: 21 % Passing #200: 69.2% Beginning Moisture: 8.6% Dry Density: 114.4 pcf Ending Moisture: 16.6% Swell Pressure: 7000 psf % Swell @ 150: 7.3% Montava Development - Phase E Fort Collins, Colorado 1172058 December 2022 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: Sandy Lean Clay (CL) Sample Location: Boring 17, Sample 3, Depth 9' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - Beginning Moisture: 8.3% Dry Density: 126.8 pcf Ending Moisture: 13.9% Swell Pressure: 5000 psf % Swell @ 500: 6.3% Montava Development - Phase E Fort Collins, Colorado 1172058 December 2022 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added