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Home My WebLink AboutNORTHFIELD COMMONS - FDP210022 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTPRELIMINARY SUBSURFACE EXPLORATION AND GROUNDWATER REPORT SCHLAGEL PROPERTY NORTH OF EAST VINE DRIVE AND WEST OF NORTH LEMAY AVENUE FORT COLLINS, COLORADO EEC PROJECT NO. 1172056 Prepared for: Landmark Homes 1170 West Ash Street Suite 100 Windsor, Colorado 80550 Attn: Mr. Jonathan Mosier (jmosier@mylandmarkhomes.net) 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 August 16, 2017 Landmark Homes 1170 West Ash Street Suite 100 Windsor, Colorado 80550 Attn: Mr. Jonathan Mosier (jmosier@mylandmarkhomes.net) Re: Preliminary Subsurface Exploration and Groundwater Report Schlagel Property North of East Vine Drive and West of North Lemay Avenue Fort Collins, Colorado EEC Project No. 1172056 Mr. Mosier: Earth Engineering Consultants, LLC (EEC) personnel have completed the preliminary subsurface exploration and the installation of the requested two (2) long-term groundwater monitoring wells (MWs) and the seven (7) temporary piezometers (PZs) for the referenced project. The purpose of our study was to provide preliminary geotechnical engineering recommendations as well as a mechanism to measure and evaluate the groundwater fluctuations and characteristics across the property. This subsurface exploration/groundwater study was completed in general accordance with our electronic/e-mail agreement on May 15, 2017. We understand that the approximately 55 acre Schlagel property will be developed for single-family residential lots, including utility and interior roadway infrastructure. Foundation loads for the proposed structures are anticipated to be light with continuous wall loads less than 2½ kips per lineal foot and individual column loads less than 50 kips. Floor loads are expected to be less than 100 psf. Overall site development will also include construction of interior roadways designed in general accordance with Larimer County Urban Area Standards (LCUASS) Pavement Design Standards. For this phase of the project we understand the installation of the requested two (2) MWs (registered with the State of Colorado – Division of Water Resources) and seven (7) PZs, which will assist the design team in evaluating the groundwater conditions on the property. The purpose of this report is to describe the subsurface conditions encountered in the preliminary borings, analyze and evaluate the test data and provide preliminary geotechnical recommendations concerning site development. Earth Engineering Consultants, LLC EEC Project No. 1172056 Preliminary Subsurface Exploration and Groundwater Report – Schlagel Property Fort Collins, Colorado August 16, 2017 Page 2 SITE EXPLORATION AND TESTING PROCEDURES As part of this assessment, EEC personnel completed two (2) MWs and seven (7) PZs / soil borings at the approximate locations as indicated on the site diagrams included with this report. The borings were extended to depths of approximately 14 to 21-1/2 feet below existing site grades. Upon completion of the drilling operations, the boreholes labeled herein as MW-1 and MW-2 were converted to PVC cased monitoring wells while the boreholes labeled herein as PZ-1 through PZ-7 were converted to temporary hand/field slotted piezometers, for use to develop groundwater characteristics. Results of the field and laboratory testing completed for this assessment are included with this report. The two (2) MW and seven (7) PZ locations were established in the field prior to drilling by EEC personnel, with the assistance from Interwest Consulting Group, by use of a hand-held GPS unit and by pacing from identifiable site features at locations accessible to our drilling equipment. The boring locations are presented on the attached boring location diagram and the ground surface elevations, as presented on the boring logs were provided by the project’s surveyor. The soil borings were completed using a truck-mounted, CME 75 drill rig equipped with a hydraulic head employed in drilling and sampling operations. The boreholes were advanced using 4-inch nominal ID hollow stem augers to maintain open boreholes for sampling and PVC piezometer/pipe installation. Samples of the subsurface materials encountered were obtained using the split barrel/Standard Penetration Test (SPT) 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 split barrel sampler 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 sampling sleeves. All samples obtained in the field were sealed and returned to our laboratory for further examination, classification and testing. After completing the drilling and sampling, and prior to removal of the hollow stem augers, PVC casings were installed in the open boreholes through the hollow stem augers. The MWs were constructed with 2-inch nominal diameter schedule 40 manufactured well screen and riser pipe. In general, the MWs consisted of a 10-foot section of flush threaded slotted well screen to depths as Earth Engineering Consultants, LLC EEC Project No. 1172056 Preliminary Subsurface Exploration and Groundwater Report – Schlagel Property Fort Collins, Colorado August 16, 2017 Page 3 indicated on the enclosed boring logs, with flush threaded solid riser pipe, as required, to extend the MWs above ground surface elevations. The screened portion of the MWs were backfilled with 10/20 silica sand, with an approximate 2-foot bentonite plug/seal placed above the sand layer, and then backfilled with a blend of the auger cuttings generated and bentonite to the existing ground surface elevations. For the piezometers (PZs) a hand/field slotted 1-inch diameter PVC casing was installed in each borehole. Cross-sectional schematics of the MW/PZ installations are indicated on the attached boring logs. The State of Colorado Division of Water Resources was notified of intent to construct monitoring holes prior to beginning the field exploration. Copies of those notices with acknowledgement from the State Engineer’s Office are available upon request. The well construction and test reports will be provided to the Division of Water Resources including copies of the boring logs provided with this report. If the monitoring wells (MWs) will remain in place longer than one year, it will be necessary to notify the Division of Water Resources and complete registration of those wells. Installation was completed by a licensed water well driller, (Drilling Engineers of Fort Collins), and was completed in accordance with the water well construction rules from the Division of Water Resources. Laboratory testing completed on recovered samples included moisture content and visual classification of the samples. Atterberg limits tests were completed on selected samples to evaluate the soil’s plasticity. Washed sieve analyses were also completed on selected samples to evaluate the grain size distribution of the subsurface materials encountered. The grain size distribution samples were recovered in a standard split-barrel sampler so that any larger size materials in the subsoils would be excluded from the test samples. Results of the outlined tests are indicated on the attached boring logs and summary sheets. As part of the testing program, all samples were examined in the laboratory by an engineer and classified in accordance with the attached General Notes and the Unified Soil Classification System, based on the soil’s texture and plasticity. The estimated group symbol for the Unified Soil Classification System is indicated on the boring logs and a brief description of that classification system is included with this report. Classification of the bedrock was based on visual and tactual observation of disturbed samples and auger cuttings. Coring and/or petrographic analysis may reveal other rock types. Earth Engineering Consultants, LLC EEC Project No. 1172056 Preliminary Subsurface Exploration and Groundwater Report – Schlagel Property Fort Collins, Colorado August 16, 2017 Page 4 SITE AND SUBSURFACE CONDITIONS Schlagel Property is located north of East Vine Drive and West of North Lemay Avenue in Fort Collins, Colorado. The property is generally undeveloped with surficial topsoil and vegetation. An EEC field engineer was on-site during drilling 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. 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. Vegetation growth and topsoil was encountered at the surface of each boring. Underlying the topsoil/vegetation layer was a zone of cohesive subsoils classified lean to fat clay with varying amounts of sand and clayey sand to approximate depths of 2 to 5-1/2 feet. Underlying the cohesive subsoils was a granular layer of poorly to well graded sand with silt and gravel extending to the depths explored at approximately 14 to 21-1/2 feet or to underlying bedrock. Interbedded sandstone/siltstone/claystone bedrock was encountered in several of the borings at depths ranging from 17-1/2 to 20 feet below existing site grades. Bedrock was not encountered in boreholes labeled PZ-2, PZ-3, PZ-5, and PZ-7 which extended to depths of approximately 14 to 19 feet below site grades. The near surface lean to fat clay with varying amounts of sand and sandy clay subsoils were generally relatively moist and soft to very stiff or very loose to medium dense becoming more moist and soft/compressible approaching groundwater. The essentially cohesive materials exhibited low to moderate plasticity and generally low to moderate swell potential at current moisture and density conditions. The underlying granular materials were generally medium dense to very dense with depth and exhibited no swell potential. The sandstone/claystone/siltstone bedrock was moderately hard to hard with increased depth and exhibited high swell potential at current moisture and density conditions. The stratification boundaries indicated on the boring logs represent the approximate locations of changes in soil and bedrock types. In-situ, the transition of materials may be gradual and indistinct. Earth Engineering Consultants, LLC EEC Project No. 1172056 Preliminary Subsurface Exploration and Groundwater Report – Schlagel Property Fort Collins, Colorado August 16, 2017 Page 5 Groundwater Observations Observations were made while drilling and after the completion of drilling to detect the presence and level of free water. Subsequent groundwater measurements were also performed 24 hours after drilling. Groundwater and/or the presence of a piezometric water surface, was generally observed at depths ranging from approximately 3 to 7 feet below ground surface as indicated on the enclosed boring logs. The measured depths to groundwater are recorded near the upper right hand corner of each boring log included with this report. Groundwater measurements provided with this report are indicative of groundwater levels at the locations and at the time the borings/groundwater measurements were completed. Perched and/or trapped water may be encountered in more permeable zones in the subgrade soils at different times throughout the year. Perched water is commonly encountered in soils immediately overlying less permeable clay zones or seams. Fluctuations in ground water levels and in the location and amount of perched/trapped water may occur over time depending on variations in hydrologic conditions, irrigation activities on this and surrounding properties and other conditions not apparent at the time of this report. As part of our geotechnical engineering assessment we prepared a groundwater contour map, based on the water level reading measurements obtained 24 hours after drilling. The contour elevations were based on the approximate ground surface elevations at each boring location and the approximate depth at which water was encountered. As shown on the groundwater contour map, the hydrologic gradient/piezometric surface flow is generally in the southeast direction. The groundwater contour map presented herein is for illustration purposes only; variations may exist between boring locations across the site. ANALYSIS AND RECOMMENDATIONS Swell/Consolidation Test Results As a part of our laboratory testing, we conducted seven (7) swell/consolidation tests on samples of the overburden cohesive subsoils. The swell index values for the samples analyzed generally revealed low to moderate swell characteristics when inundated with water and pre-loaded at 500 psf as well as exhibiting a slight tendency to hydro-compact and consolidate with increased loads. Results of the laboratory swell tests are indicated below in Table I, on the attached boring logs, and on the enclosed summary sheets. Earth Engineering Consultants, LLC EEC Project No. 1172056 Preliminary Subsurface Exploration and Groundwater Report – Schlagel Property Fort Collins, Colorado August 16, 2017 Page 6 TABLE I - Swell Consolidation Test Results Boring No. Depth, ft. Material Type In-Situ Moisture Content, % Dry Density, PCF Inundation Pressure, psf Swell Index, (+/-) % MW-1 2 Clayey Sand (SC) 20.4 106.7 500 (-) 0.2 MW-2 2 Sandy Lean Clay (CL) 21.0 112.3 500 (-) 0.9 PZ-3 2 Clayey Sand (SC) 8.8 113.8 500 (+) 0.8 PZ-4 2 Sandy Lean Clay (CL) 19.5 99.1 500 (+) 2.1 PZ-5 2 Fat Clay with Sand (CH)14.9 112.6 500 (+) 3.5 PZ-6 2 Clayey Sand (SC) 20.7 106.7 500 (-) 0.4 PZ-7 2 Lean Clay with Sand (CL) 20.6 110.7 500 (+) 0.3 The Colorado Association of Geotechnical Engineers (CAGE) uses the following information to provide uniformity in terminology between geotechnical engineers to provide a relative correlation risk performance 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 of overburden subsoils were generally in the low to moderate risk range. General Considerations General guidelines are provided below for the site subgrade preparation. However, it should be noted that compaction and moisture requirements vary between home builders and, consequently, between geotechnical engineering companies. If the development lots will be marketed to a target group of tract builders, fill placement criteria should be obtained from those builders and/or their Earth Engineering Consultants, LLC EEC Project No. 1172056 Preliminary Subsurface Exploration and Groundwater Report – Schlagel Property Fort Collins, Colorado August 16, 2017 Page 7 engineers prior to beginning earthwork activities on the site. Representatives from those entities should verify that the fill is being placed consistent with the home builders’ guide lines. The near surface soils at the site were relatively moist and soft to very stiff at the time of drilling and exhibited low to moderate potential to swell. If these soils were to become wetted subsequent to construction of overlying improvements, heaving caused by those soils could result in significant total and differential movement of site improvements. Therefore, to reduce the potential movement of foundations, floor slabs and pavements, included herein are preliminary considerations/recommendations for an over excavation and replacement concept, however to be determined by the individual/lot-specific home builder. Generally, an over excavation process involves removing a zone of expansive soils beneath site improvements and replacing them with low to non-expansive engineered fill material or structural fill. An over excavation and replacement process will not eliminate the possibility of foundation and/or slab heave; but movements should be reduced and tend to be more uniform. Constructing improvements on a site which exhibits potential for swelling is inherently at risk for post construction heaving, causing distress of site improvements. The following recommendations provided within the “Site Preparation Section” are to reduce the risk of post construction heaving; however, that risk cannot be eliminated. If the owner does not accept that risk, we would be pleased to provide more stringent recommendations. 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 4 feet above the maximum anticipated rise in groundwater levels, or a combination exterior and interior perimeter drainage system(s) be installed. Also, 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 required 4-foot separation to the maximum anticipated rise in groundwater. Site Preparation All existing vegetation and topsoil should be removed from beneath site fills, roadways or building subgrade areas. Stripping depths should be expected to vary, depending, in part, on past agricultural Earth Engineering Consultants, LLC EEC Project No. 1172056 Preliminary Subsurface Exploration and Groundwater Report – Schlagel Property Fort Collins, Colorado August 16, 2017 Page 8 and/or site usage activities. Any soft native soils observed following over excavation should be removed from improvement, backfill and fill areas. In addition, any soft/loose native soils or any existing fill materials without documentation of controlled fill placement would generally require removal from improvement and/or new fill areas. In areas where existing improvements are in- place, those improvements and any associated fill soils should be completely removed prior to placing overlying improvements or fill. Over excavation of expansive subgrade materials would also likely be required in individual building areas; the specific extent of over excavation may vary with different home builders. The extent and depth of material removal and replacement may also be significantly impacted by site grading. After stripping and completing all cuts, including the over excavation depths required by the lot- specific home builders, and prior to placement of any fill, building improvements or pavements, the exposed soils would likely be scarified to 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 with ASTM Specification D698, the standard Proctor procedure. The moisture content of the scarified materials would be adjusted, potentially, 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 building areas or site pavement subgrades should consist of approved, low-volume change materials which are free from organic matter and debris. We believe the on-site lean clay with sand soils could be used as fill in these areas. Approved low volume change fill soils would generally 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 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. Higher moisture contents may be required by individual home builders. Care should be taken to develop relatively uniform fills and avoid placing “pockets” of clean granular soils within predominately cohesive fill embankments. 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. A greater or lesser degree of compaction could be specified for specific individual structures along with alternative moisture requirements. The preliminary recommendations Earth Engineering Consultants, LLC EEC Project No. 1172056 Preliminary Subsurface Exploration and Groundwater Report – Schlagel Property Fort Collins, Colorado August 16, 2017 Page 9 provided in this report are, by necessity, general in nature and would be superseded by site specific explorations/recommendations. 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. Foundation Systems – General Considerations The cohesive subsoils will require particular attention in the design and construction to reduce the amount of movement due to the in-situ soft/compressible characteristics. Groundwater was also encountered at relatively shallow depths across the site 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. Spread footing foundation systems were evaluated for use on the site; however final subsurface explorations should be performed after building footprints and elevations have been better defined and actual design loads determined. Preliminary Spread Footing Foundation Recommendations We anticipate use of conventional footing foundations could be considered for lightly loaded structures at this site. We expect footing foundations would be supported either on the native soils or on newly placed and compacted fills. Soft zones were observed in the lean clay soils so that care will be necessary to see that potential deeper foundations (i.e. basements) are not supported directly on soft materials. Mitigation for soft subgrade soils should be expected over much of the site if basements are considered. Additionally, a separation between the groundwater and the building footings should be maintained. In areas where the cohesive subsoils exhibited elevated moisture contents near and/or encroaching the groundwater levels and/or where relatively low SPT N-Blows/ft. were recorded indicating “soft soils” we would expect these soft zones would require particular attention/ground modification procedures to develop increased support capacity characteristics. We expect enhancing/stiffening of Earth Engineering Consultants, LLC EEC Project No. 1172056 Preliminary Subsurface Exploration and Groundwater Report – Schlagel Property Fort Collins, Colorado August 16, 2017 Page 10 the subgrade/bearing soils could be accomplished by incorporating into the soft/compressible subsoils a layer of granular rock (i.e., 1-½ inches minus crushed concrete aggregate) into the top 12- inches (+/-) of the subgrades as an initial means and method. Depending on the proximity to groundwater and/or severity of the soft soils, consideration could be given to a minimum 2-foot over excavation/backfill procedure beneath site structures in areas where soft soils are expected. 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 imported granular structural fill material placed and compacted as outlined in the section “Site Preparation”. For design of footing foundations bearing on approved native subsoils, (i.e., the native subsoils in which soft/compressible conditions are not encountered), 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 4 feet 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 or grade beam 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. Preliminary Floor Slab/Exterior Flatwork Subgrades We recommend all existing vegetation/topsoil be removed from beneath the floor slab and exterior flatwork areas as previously outlined. After stripping and completing all cuts and prior to Earth Engineering Consultants, LLC EEC Project No. 1172056 Preliminary Subsurface Exploration and Groundwater Report – Schlagel Property Fort Collins, Colorado August 16, 2017 Page 11 placement of any flatwork concrete or fill, the exposed subgrades should be scarified, adjusted in moisture content and compacted as outlined in the section “Site Preparation”. If the subgrades become dry and desiccated prior to floor slab construction, it may be necessary to rework the subgrades prior to floor slab placement. Fill soils required to develop the floor slab subgrades should consist of approved, low-volume change materials which are free from organic matter and debris. Those fill materials should be placed as outlined in the section “Site Preparation”. Preliminary Basement Design and Construction Groundwater was encountered across the site within the preliminary soil borings at approximate depths of 10 to 13 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 4-feet above maximum anticipated rise in groundwater levels, or a combination exterior and interior perimeter drainage system(s) be installed. 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 required four (4) foot separation to the maximum anticipated rise in groundwater. EEC is available to assist in the underdrain design if requested. The following information should also be considered, which as previously mentioned, would be to install an interior and exterior perimeter drainage system for each individual residence. To reduce the potential for groundwater to enter the lower level/basement area of the structure(s), installation of a dewatering system is recommended. The dewatering system should, at a minimum, include an underslab gravel drainage layer sloped to an interior perimeter drainage system. The following provide preliminary design recommendations for interior and exterior perimeter drainage systems. The underslab 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 Earth Engineering Consultants, LLC EEC Project No. 1172056 Preliminary Subsurface Exploration and Groundwater Report – Schlagel Property Fort Collins, Colorado August 16, 2017 Page 12 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 lot. To reduce the potential for surface water infiltration from impacting foundation bearing soils and/or entering any planned below grade portion of any residential structure, installation of an exterior perimeter drainage system is recommended. This 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, 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 Elements of the residential structures constructed below grade may be subject to lateral earth pressures. Passive lateral earth pressures may help resist the driving forces for retaining walls or Earth Engineering Consultants, LLC EEC Project No. 1172056 Preliminary Subsurface Exploration and Groundwater Report – Schlagel Property Fort Collins, Colorado August 16, 2017 Page 13 other similar site structures. Active lateral earth pressures could be used for design of structures where some movement of the structure is anticipated, such as retaining walls. The total deflection of structures for design with active earth pressure is estimated to be on the order of one half of one percent of the height of the down slope side of the structure. We recommend at-rest pressures be used for design of structures where rotation of the walls is restrained, such as basement walls. Passive pressures and friction between the footing and bearing soils could be used for design of resistance to movement of retaining walls. Typical 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 Coefficients Soil Type On-Site Low Plasticity Cohesive Subsoils Imported Granular Structural Fill Poorly Graded Sand (SM/SP) Wet Unit Weight 115 135 Saturated Unit Weight 135 140 Friction Angle (ϕ) – (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 Earth Engineering Consultants, LLC EEC Project No. 1172056 Preliminary Subsurface Exploration and Groundwater Report – Schlagel Property Fort Collins, Colorado August 16, 2017 Page 14 for hydrostatic loads developing on the walls. Those systems would likely include perimeter drain systems extending to sump areas or free outfall where reverse flow cannot occur into the system. Where necessary, appropriate hydrostatic load values should be used for design. Preliminary Pavement Subgrades All existing vegetation and/or topsoil and any soft or loose materials should be removed from pavement areas. After stripping and completing all cuts and prior to placement of any fill or pavements, we recommend the exposed soils be scarified to 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 with ASTM Specification D698, the standard Proctor procedure. The moisture content of the scarified soils should be adjusted to be within the range of 2% of standard Proctor optimum moisture. Fill materials required to develop the pavement subgrades should consist of approved, low-volume change materials, free from organic matter and debris. The near surface clayey sand and lean clay with varying amounts of sand could be used for fill in these areas. We recommend those 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 standard Proctor maximum dry density. After completion of the pavement subgrades, care should be taken to prevent disturbance of those materials prior to placement of the overlying pavements. Soils which are disturbed by construction activities should be reworked in-place or, if necessary, removed and replaced prior to placement of overlying fill or pavements. Depending on final site grading and/or weather conditions at the time of pavement construction, stabilization of a portion of the site pavement subgrades may be required to develop a paving platform. The site clayey soils could be subject to instability at higher moisture contents. Stabilization could also be considered as part of the pavement design, although prior to finalizing those sections, a stabilization mix design would be required. Preliminary Site Pavements Pavement sections are based on traffic volumes and subgrade strength characteristics. The lean clay site soils have low remolded strength. An R-value of 10 would be appropriate for design of the Earth Engineering Consultants, LLC EEC Project No. 1172056 Preliminary Subsurface Exploration and Groundwater Report – Schlagel Property Fort Collins, Colorado August 16, 2017 Page 15 pavements supported on the subgrade soils. Suggested preliminary pavement sections for the local residential and minor collector roadways are provided below in Table IV. Thicker pavement sections may be required for roadways classified as minor or major collectors. A final pavement design thickness evaluation will be determined when a pavement design exploration is completed (after subgrades are developed to ± 6 inches of design and wet utilities installed in the roadways). The projected traffic may vary from the traffic assumed from the roadway classification based on a site-specific traffic study. TABLE IV – PRELIMINARY PAVEMENT SECTIONS Local Residential Roadways Minor Collectors Roadways EDLA – assume local residential roadways Reliability Resilient Modulus PSI Loss – (Initial 4.5, Terminal 2.0 and 2.3 respectively) 10 75% 3562 2.5 25 85% 3562 2.2 Design Structure Number 2.60 3.20 Composite Section without Fly Ash – Alternative A Hot Mix Asphalt (HMA) Grading S (75) PG 58-28 Aggregate Base Course ABC – CDOT Class 5 or 6 Design Structure Number 4ʺ 8ʺ (2.64) 5ʺ 9-1/2ʺ (3.25) Composite Section with Fly Ash – Alternative B Hot Mix Asphalt (HMA) Grading S (75) PG 58-28 Aggregate Base Course ABC – CDOT Class 5 or 6 Fly Ash Treated Subgrade Design Structure Number 4ʺ 6 ʺ 12″ (3.02) 4ʺ 8ʺ 12ʺ (3.24) PCC (Non-reinforced) – placed on an approved subgrade 6″ 7″ Asphalt surfacing should consist of grading S-75 or SX-75 hot bituminous pavement with PG 64-22 or PG 58-28 binder in accordance with LCUASS requirements. HMA should be compacted to achieve 92 to 96% of the mix’s theoretical maximum specific gravity (Rice Value). Aggregate base should be consistent with CDOT requirements for Class 5 or Class 6 aggregate base. A suggested specification for stabilization of the subgrades with class C fly ash is included with this report. As previously mentioned a final subgrade investigation and pavement design should be performed in general accordance with LCUASS prior to placement of any pavement sections, to determine the required pavement section after design configurations, roadway utilities have been installed and roadways have been prepared to “rough” subgrade elevations. Earth Engineering Consultants, LLC EEC Project No. 1172056 Preliminary Subsurface Exploration and Groundwater Report – Schlagel Property Fort Collins, Colorado August 16, 2017 Page 16 Underground Utility Systems All piping should be adequately bedded for proper load distribution. It is suggested that clean, graded gravel compacted to 70 percent of Relative Density ASTM D4253 be used as bedding. Where utilities are excavated below groundwater, temporary dewatering will be required during excavation, pipe placement and backfilling operations for proper construction. Utility trenches should be excavated on safe and stable slopes in accordance with OSHA regulations as further discussed herein. Backfill should consist of the on-site soils or approved imported materials. The pipe backfill should be compacted to a minimum of 95 percent of Standard Proctor Density ASTM D698. Water Soluble Sulfates – (SO4) The water-soluble sulfate (SO4) testing of the on-site overburden and bedrock materials taken during our subsurface exploration at varying depths are provided in Table V below. Based on the reported sulfate content 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 and bedrock. TABLE V - Water Soluble Sulfate Test Results Sample Location Description Soluble Sulfate Content (mg/kg) Soluble Sulfate Content (%) PZ-1, S-1 at 2’ Well Graded Sand with Silt and Gravel (SW / SM) 2,660 0.27 PZ-3, S-2, at 4’ Sand / Gravel (SP / GP) 210 0.02 MW-2, S-5, at 19’ Sandstone / Siltstone / Claystone 770 0.08 Based on the results as presented in Table V above, ACI 318, Section 4.2 indicates the site overburden soils generally have a low risk of sulfate attack on Portland cement concrete except for the bedrock sample from PZ-1 at 2 feet below grade which indicated a high risk of sulfate attack. Therefore Class 0 and/or Type I/II cement could be used, depending on location, for concrete on and below site grade within the overburden soils and/or bedrock. In locations with high risk of sulfate attack, Class 2 cement should be used. 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 VI. Specific explorations should be completed for each building/individual residential lot to develop recommendations specific to the proposed area, structure and owner/builder. Earth Engineering Consultants, LLC EEC Project No. 1172056 Preliminary Subsurface Exploration and Groundwater Report – Schlagel Property Fort Collins, Colorado August 16, 2017 Page 17 Table VI - 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 Other Considerations and Recommendations Groundwater was observed at an approximate depth of 3 to 7 feet below present site grades. Excavations extending to the wetter soils could create difficulties for backfilling of the utility/pipe 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. Excavations into the on-site soils will encounter a variety of conditions. Excavations into the clays 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 site structure(s) with a minimum slope of 1 inch per foot for the first 10 feet away from the building in landscaped areas. Flatter slopes could be used in hardscape areas provided positive drainage is maintained. Potential settlement adjacent to the structure should be considered when developing positive drainage. GENERAL COMMENTS The analysis and information presented in this report is based upon the data obtained from the soil borings performed at the indicated locations as discussed in this report. This report does not reflect any variations which may occur between boring or across the site. The nature and extent of such 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 12PZ-2MW-1PZ-1PZ-5PZ-6MW-2PZ-4PZ-3PZ-7Figure 1: Boring Location DiagramSchlagel PropertyFort Collins, ColoradoEEC Project #: 1172056 Date: August 2017EARTH ENGINEERING CONSULTANTS, LLCMW-1 & MW-2:Approximate MonitorWell Locations1LegendSite Photos(Photos taken in approximatelocation, in direction of arrow)PZ-1 thru PZ-7:ApproximatePiezometer Locations PZ-2MW-1PZ-1PZ-5PZ-6MW-2PZ-4PZ-3PZ-7(4956.1)[4948.9](4957.3)[4951.3](4956.1)[4951.0](4953.5)[4948.5](4954.2)[4947.4](4951.8)[4946.5](4953.2)[4948.6](4954.6)[4958.5](4956.5)[4950.8]49514950494949484947Figure 2: Groundwater Contour MapSchlagel PropertyFort Collins, ColoradoEEC Project #: 1172056 Date: August 2017EARTH ENGINEERING CONSULTANTS, LLCMW-1 & MW-2:Approximate MonitorWell LocationsLegendPZ-1 thru PZ-7:ApproximatePiezometer LocationsApproximate GroundSurface ElevationApproximateGroundwater Elevation(4950.8)[4950.8]ApproximateGroundwater ContoursApproximateGroundwaterDirectional Flow SCHLAGEL PROPERTY FORT COLLINS, COLORADO EEC PROJECT NO. 1172056 JULY 2017 Earth Engineering Consultants, LLC RIG TYPE: CME-55 WATER DEPTH AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC N/A DN QU MCDD -200 SWELL (feet) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF VEGETATION & TOPSOIL _ _ SANDY LEAN CLAY (CL)1 brown _ _ very soft to medium stiff 2 _ _ CS 3 6 2000 21.0 106.6 33 18 65.3 <500 psf none _ _ 4 _ _ 5 0 1500 17.9 _ _ 6 SAND / GRAVEL (SP / GP) _ _ brown 7 very dense _ _ with cobbles 8 _ _ 9 SS _ _50/2"-- 13.3 10 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ SS 15 50/3.5"-- 21.5 _ _ 16 _ _ 17 _ _ 18 SANDSTONE / SILTSTONE / CLAYSTONE _ _ gray 19 weathered, moderately hard to hard _ _ SS 20 50/7" 9000+ 21.7 BOTTOM OF BORING DEPTH 20' _ _ 21 _ _ 22 PIEZOMETER LEGEND _ _ 23 2-Inch Diameter Flush Threaded- Schedule 40 PVC riser pipe _ _ Bentonite Seal 24 2-Inch Dia. Flush Threaded- Schedule 40 PVC Slotted pipe - 5'_ _ Silica Sand and/or Sand & Gravel Cave-In 25 _ _ Earth Engineering Consultants, LLC 24 HOUR 5.3' SOIL DESCRIPTION A-LIMITS SS WHILE DRILLING 5.0' GROUND SURFACE ELEV N/A AFTER DRILLING N/A PZ DETAILS START DATE 7/26/2017 FOREMAN: DG FINISH DATE 7/26/2017 TOP OF CASING ELEV. SCHLAGEL PROPERTY FORT COLLINS, COLORADO PROJECT NO: 1172056 LOG OF GROUND MONITORING WELL MW-2 DATE: AUGUST 2017 SHEET 1 OF 1 DATE: RIG TYPE: CME55 FOREMAN: DG AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC SOIL DESCRIPTION DN QU MCDD -200 TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF VEGETATION & TOPSOIL _ _ CLAYEY SAND (SC) 1 brown _ _ medium dense to dense 2 _ _ CS 3 35 -- 2.3 123.2 _ _ 4 brown _ _ dense to very dense SS 550 -- 4.8 with cobbles _ _ 6 _ _ 7 _ _ 8 _ _ 9 _ _ SS 10 50/10.5" -- 7.5 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ 15 _ _ 16 _ _ 17 _ _ 18 SANDSTONE / SILTSTONE / CLAYSTONE _ _ brown / gray, moderately hard to hard 19 -- 1000 21.8 BOTTOM OF BORING DEPTH 19' _ _ 20 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ 25 _ _ Earth Engineering Consultants, LLC SHEET 1 OF 1 WATER DEPTH START DATE SCHLAGEL PROPERTY FORT COLLINS, COLORADO PROJECT NO: 1172056 LOG OF PIEZOMETER PZ-1 AUGUST 2017 7/26/2017 WHILE DRILLING 5.0' FINISH DATE 7/26/2017 AFTER DRILLING N/A SURFACE ELEV N/A 24 HOUR 4.7' *Note: Hand/field slotted 1-1/2-inch diameter PVC casing was installed after completion of drilling operations. A-LIMITS SWELL WELL GRADED SAND with SILT and GRAVEL (SW / SM) DATE: RIG TYPE: CME55 FOREMAN: DG AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC SOIL DESCRIPTION DN QU MCDD -200 TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF VEGETATION & TOPSOIL _ _ 1 CLAYEY SAND (SC) _ _ brown, medium dense to dense 2 _ _ SAND / GRAVEL (SP / GP)CS 3 50/9" -- 4.5 112.1 brown _ _ dense to very dense 4 with cobbles _ _ SS 5 50/7" -- 5.0 _ _ 6 _ _ 7 _ _ 8 _ _ 9 _ _ SS 10 50/4" -- 7.6 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ 15 _ _ 16 _ _ 17 _ _ 18 _ _ 19 -- 1000 11.8 BOTTOM OF BORING DEPTH 19' _ _ 20 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ 25 _ _ Earth Engineering Consultants, LLC SCHLAGEL PROPERTY FORT COLLINS, COLORADO PROJECT NO: 1172056 LOG OF PIEZOMETER PZ-2 AUGUST 2017 SHEET 1 OF 1 WATER DEPTH START DATE 7/26/2017 WHILE DRILLING 5.5' SURFACE ELEV N/A 24 HOUR 4.6' FINISH DATE 7/26/2017 AFTER DRILLING N/A *Note: Hand/field slotted 1-1/2-inch diameter PVC casing was installed after completion of drilling operations. A-LIMITS SWELL DATE: RIG TYPE: CME55 FOREMAN: DG AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC SOIL DESCRIPTION DN QU MCDD -200 TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF VEGETATION & TOPSOIL _ _ 1 CLAYEY SAND (SC) _ _ brown 2 medium dense _ _ with trace gravel and calcareous deposits CS 3 14 8000 9.2 92.6 33 18 38.8 1400 psf 0.8% _ _ SAND / GRAVEL (SP / GP)4 brown _ _ medium dense SS 519 -- 4.2 with cobbles _ _ 6 _ _ 7 _ _ 8 _ _ 9 -- -- 4.9 _ _ 10 _ _ 11 _ _ 12 _ _ 13 _ _ 14 BOTTOM OF BORING DEPTH 14' _ _ 15 _ _ 16 _ _ 17 _ _ 18 _ _ 19 _ _ 20 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ 25 _ _ Earth Engineering Consultants, LLC SCHLAGEL PROPERTY FORT COLLINS, COLORADO PROJECT NO: 1172056 LOG OF PIEZOMETER PZ-3 AUGUST 2017 SHEET 1 OF 1 WATER DEPTH START DATE 7/26/2017 WHILE DRILLING 5.0' SURFACE ELEV N/A 24 HOUR 5.1' FINISH DATE 7/26/2017 AFTER DRILLING N/A *Note: Hand/field slotted 1-1/2-inch diameter PVC casing was installed after completion of drilling operations. A-LIMITS SWELL DATE: RIG TYPE: CME55 FOREMAN: DG AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC SOIL DESCRIPTION DN QU MCDD -200 TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF VEGETATION & TOPSOIL _ _ 1 SANDY LEAN CLAY (CL) _ _ brown 2 loose _ _ with organics CS 3 7 5500 19.5 102.7 3500 psf 2.1% _ _ 4 _ _ SS 517 -- 9.4 _ _ 6 brown _ _ medium dense to dense 7 with cobbles _ _ 8 _ _ 9 _ _ SS 10 50 -- 14.4 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ SS 15 50 1000 9.2 _ _ 16 _ _ 17 _ _ 18 SANDSTONE / SILTSTONE / CLAYSTONE _ _ gray, moderately hard to hard 19 -- 1000 12.3 BOTTOM OF BORING DEPTH 19' _ _ 20 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ 25 _ _ Earth Engineering Consultants, LLC SHEET 1 OF 1 WATER DEPTH START DATE SCHLAGEL PROPERTY FORT COLLINS, COLORADO PROJECT NO: 1172056 LOG OF PIEZOMETER PZ-4 AUGUST 2017 7/26/2017 WHILE DRILLING 5.0' FINISH DATE 7/26/2017 AFTER DRILLING N/A SURFACE ELEV N/A 24 HOUR 5.0' *Note: Hand/field slotted 1-1/2-inch diameter PVC casing was installed after completion of drilling operations. A-LIMITS SWELL WELL GRADED SAND with SILT and GRAVEL (SW / SM) DATE: RIG TYPE: CME55 FOREMAN: DG AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC SOIL DESCRIPTION DN QU MCDD -200 TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF VEGETATION & TOPSOIL _ _ 1 FAT CLAY with SAND (CH) _ _ brown 2 very stiff _ _ with calcareous deposits CS 3 27 9000+ 14.9 106.1 52 31 82.8 2500 psf 3.5% with organics _ _ 4 _ _ SILTY SAND (SM) SS 5 3 2000 20.2 brown _ _ very loose to medium dense 6 _ _ 7 _ _ 8 _ _ 9 _ _ SS 10 21 -- 26.4 SAND / GRAVEL (SP / GP) _ _ brown 11 medium dense _ _ with cobbles 12 _ _ 13 _ _ 14 _ _ 15 _ _ 16 _ _ 17 _ _ 18 _ _ 19 BOTTOM OF BORING DEPTH 19' _ _ 20 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ 25 _ _ Earth Engineering Consultants, LLC SCHLAGEL PROPERTY FORT COLLINS, COLORADO PROJECT NO: 1172056 LOG OF PIEZOMETER PZ-5 AUGUST 2017 SHEET 1 OF 1 WATER DEPTH START DATE 7/26/2017 WHILE DRILLING 5.0' SURFACE ELEV N/A 24 HOUR 6.0' FINISH DATE 7/26/2017 AFTER DRILLING N/A *Note: Hand/field slotted 1-1/2-inch diameter PVC casing was installed after completion of drilling operations. A-LIMITS SWELL DATE: RIG TYPE: CME55 FOREMAN: DG AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC SOIL DESCRIPTION DN QU MCDD -200 TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF VEGETATION & TOPSOIL _ _ 1 CLAYEY SAND (SC) _ _ brown 2 loose to medium dense _ _ CS 3 5 2500 20.7 101.3 <500 psf none _ _ 4 _ _ SS 5 18 -- 19.9 _ _ 6 _ _ brown, medium dense to dense 7 _ _ 8 _ _ 9 _ _ SS 10 50/8" -- 11.1 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ SS 15 50/7" -- 11.9 _ _ 16 _ _ 17 SANDSTONE / SILTSTONE / CLAYSTONE _ _ gray 18 weathered, moderately hard to hard _ _ 19 -- 1000 21.5 BOTTOM OF BORING DEPTH 19' _ _ 20 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ 25 _ _ Earth Engineering Consultants, LLC SHEET 1 OF 1 WATER DEPTH START DATE SCHLAGEL PROPERTY FORT COLLINS, COLORADO PROJECT NO: 1172056 LOG OF PIEZOMETER PZ-6 AUGUST 2017 7/26/2017 WHILE DRILLING 6.5' FINISH DATE 7/26/2017 AFTER DRILLING N/A SURFACE ELEV N/A 24 HOUR 6.8' *Note: Hand/field slotted 1-1/2-inch diameter PVC casing was installed after completion of drilling operations. A-LIMITS SWELL WELL GRADED SAND with SILT and GRAVEL (SW / SM) DATE: RIG TYPE: CME55 FOREMAN: DG AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC SOIL DESCRIPTION DN QU MCDD -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 _ _ with organics CS 3 9 5000 20.6 104.6 42 26 75.8 1000 psf 0.3% _ _ 4 _ _ SS 5 9 7000 12.2 _ _ 6 _ _ 7 brown _ _ very dense 8 with cobbles _ _ 9 _ _ SS 10 50/7" -- 4.9 _ _ 11 _ _ 12 _ _ 13 _ _ 14 -- -- 8.3 _ _ 15 _ _ 16 _ _ 17 _ _ 18 _ _ 19 BOTTOM OF BORING DEPTH 19' _ _ 20 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ 25 _ _ Earth Engineering Consultants, LLC SHEET 1 OF 1 WATER DEPTH START DATE SCHLAGEL PROPERTY FORT COLLINS, COLORADO PROJECT NO: 1172056 LOG OF PIEZOMETER PZ-7 AUGUST 2017 7/26/2017 WHILE DRILLING 7.0' FINISH DATE 7/26/2017 AFTER DRILLING N/A SURFACE ELEV N/A 24 HOUR 7.2' *Note: Hand/field slotted 1-1/2-inch diameter PVC casing was installed after completion of drilling operations. A-LIMITS SWELL WELL GRADED SAND with SILT and GRAVEL (SW / SM) Project: Location: Project #: Date: Schlagel Property Fort Collins, Colorado 1172056 Aug-17 Beginning Moisture: 20.4% Dry Density: 106.7 pcf Ending Moisture: 19.4% Swell Pressure: <500 psf % Swell @ 500: None Sample Location: Monitoring Well 1, Sample 1, Depth 2' Liquid Limit: 29 Plasticity Index: 14 % Passing #200: 48.9% SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown Clayey Sand (SC) -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Schlagel Property Fort Collins, Colorado 1172056 Aug-17 Beginning Moisture: 21.0% Dry Density: 112.3 pcf Ending Moisture: 19.5% Swell Pressure: <500 psf % Swell @ 500: None Sample Location: Monitoring Well 2, Sample 1, Depth 2' Liquid Limit: 33 Plasticity Index: 18 % Passing #200: 65.3% SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown Sandy Lean Clay (CL) -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Schlagel Property Fort Collins, Colorado 1172056 Aug-17 Beginning Moisture: 8.8% Dry Density: 113.8 pcf Ending Moisture: 16.8% Swell Pressure: 1400 psf % Swell @ 500: 0.8% Sample Location: Piezometer 3, Sample 1, Depth 2' Liquid Limit: 33 Plasticity Index: 18 % Passing #200: 38.8% SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown Clayey Sand (SC) -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Schlagel Property Fort Collins, Colorado 1172056 Aug-17 Beginning Moisture: 19.5% Dry Density: 99.1 pcf Ending Moisture: 21.3% Swell Pressure: 3500 psf % Swell @ 500: 2.1% Sample Location: Piezometer 4, Sample 1, Depth 2' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown Sandy Lean Clay (CL) -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Schlagel Property Fort Collins, Colorado 1172056 Aug-17 Beginning Moisture: 14.9% Dry Density: 112.6 pcf Ending Moisture: 21.9% Swell Pressure: 2500 psf % Swell @ 500: 3.5% Sample Location: Piezometer 5, Sample 1, Depth 2' Liquid Limit: 52 Plasticity Index: 31 % Passing #200: 82.8% SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown Fat Clay with Sand (CH) -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: Schlagel Property Fort Collins, Colorado 1172056 Aug-17 Beginning Moisture: 20.7% Dry Density: 106.7 pcf Ending Moisture: 20.1% Swell Pressure: <500 psf % Swell @ 500: None Sample Location: Piezometer 6, Sample 1, Depth 2' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown Clayey Sand (SC) -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Schlagel Property Fort Collins, Colorado 1172056 Aug-17 Beginning Moisture: 20.6% Dry Density: 110.7 pcf Ending Moisture: 19.1% Swell Pressure: 1000 psf % Swell @ 500: 0.3% Sample Location: Piezometer 7, Sample 1, Depth 2' Liquid Limit: 42 Plasticity Index: 26 % Passing #200: 75.8% SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown 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 1 1/2" (37.5 mm) 1" (25 mm) 3/4" (19 mm) 1/2" (12.5 mm) 3/8" (9.5 mm) No. 4 (4.75 mm) No. 8 (2.36 mm) No. 10 (2 mm) No. 16 (1.18 mm) No. 30 (0.6 mm) No. 40 (0.425 mm) No. 50 (0.3 mm) No. 100 (0.15 mm) No. 200 (0.075 mm) Project: Schlagel Properties Location: Fort Collins, Colorado Project No: 1172056 Sample ID: MW-1, S-2, 4' Sample Desc.: Poorly Graded Sand with Silt and Gravel (SP - SM) Date: August 2017 48 40 29 24 19 75 61 50 12 7.7 100 100 93 81 EARTH ENGINEERING CONSULTANTS, LLC SUMMARY OF LABORATORY TEST RESULTS Sieve Analysis (AASHTO T 11 & T 27 / ASTM C 117 & C 136) Sieve Size Percent Passing EARTH ENGINEERING CONSULTANTS, LLCSummary of Washed Sieve Analysis Tests (ASTM C117 & C136)Date:Project:Location:Project No:Sample ID:Sample Desc.:CobbleSilt or ClayGravelCoarse FineSandCoarse MediumAugust 201725.00 4.51 2.34Schlagel PropertiesFort Collins, Colorado1172056MW-1, S-2, 4'Poorly Graded Sand with Silt and Gravel (SP - SM)D100D60D500.65 0.11Fine39.96 0.84D30D10CuCC6"5"4"3"2.5"2"1.5"1"3/4"1/2"3/8"No. 4No. 8No. 10No. 16No. 30No. 40No. 50No. 100No. 20001020304050607080901000.010.11101001000Finer by Weight (%)Grain Size (mm)Standard Sieve Size 1 1/2" (37.5 mm) 1" (25 mm) 3/4" (19 mm) 1/2" (12.5 mm) 3/8" (9.5 mm) No. 4 (4.75 mm) No. 8 (2.36 mm) No. 10 (2 mm) No. 16 (1.18 mm) No. 30 (0.6 mm) No. 40 (0.425 mm) No. 50 (0.3 mm) No. 100 (0.15 mm) No. 200 (0.075 mm) Project: Schlagel Properties Location: Fort Collins, Colorado Project No: 1172056 Sample ID: PZ-1, S-3, 9' Sample Desc.: Well Graded Sand with Silt and Gravel (SW - SM) Date: August 2017 EARTH ENGINEERING CONSULTANTS, LLC SUMMARY OF LABORATORY TEST RESULTS Sieve Analysis (AASHTO T 11 & T 27 / ASTM C 117 & C 136) Sieve Size Percent Passing 100 89 83 69 62 49 37 9 5.8 35 29 20 17 13 1.35 0.19Fine45.92 1.11D30D10CuCCAugust 201737.50 8.64 5.11Schlagel PropertiesFort Collins, Colorado1172056PZ-1, S-3, 9'Well Graded Sand with Silt and Gravel (SW - SM)D100D60D50EARTH ENGINEERING CONSULTANTS, LLCSummary of Washed Sieve Analysis Tests (ASTM C117 & C136)Date:Project:Location:Project No:Sample ID:Sample Desc.:CobbleSilt or ClayGravelCoarse FineSandCoarse Medium6"5"4"3"2.5"2"1.5"1"3/4"1/2"3/8"No. 4No. 8No. 10No. 16No. 30No. 40No. 50No. 100No. 20001020304050607080901000.010.11101001000Finer by Weight (%)Grain Size (mm)Standard Sieve Size 1 1/2" (37.5 mm) 1" (25 mm) 3/4" (19 mm) 1/2" (12.5 mm) 3/8" (9.5 mm) No. 4 (4.75 mm) No. 8 (2.36 mm) No. 10 (2 mm) No. 16 (1.18 mm) No. 30 (0.6 mm) No. 40 (0.425 mm) No. 50 (0.3 mm) No. 100 (0.15 mm) No. 200 (0.075 mm) Project: Schlagel Properties Location: Fort Collins, Colorado Project No: 1172056 Sample ID: PZ-4, S-4, 14' Sample Desc.: Well Graded Sand with Silt and Gravel (SW - SM) Date: August 2017 42 35 28 24 21 67 55 44 15 11.1 100 88 85 73 EARTH ENGINEERING CONSULTANTS, LLC SUMMARY OF LABORATORY TEST RESULTS Sieve Analysis (AASHTO T 11 & T 27 / ASTM C 117 & C 136) Sieve Size Percent Passing EARTH ENGINEERING CONSULTANTS, LLCSummary of Washed Sieve Analysis Tests (ASTM C117 & C136)Date:Project:Location:Project No:Sample ID:Sample Desc.:CobbleSilt or ClayGravelCoarse FineSandCoarse MediumAugust 201737.50 6.69 3.64Schlagel PropertiesFort Collins, Colorado1172056PZ-4, S-4, 14'Well Graded Sand with Silt and Gravel (SW - SM)D100D60D500.78 0.08Fine89.15 1.22D30D10CuCC6"5"4"3"2.5"2"1.5"1"3/4"1/2"3/8"No. 4No. 8No. 10No. 16No. 30No. 40No. 50No. 100No. 20001020304050607080901000.010.11101001000Finer by Weight (%)Grain Size (mm)Standard Sieve Size 1 1/2" (37.5 mm) 1" (25 mm) 3/4" (19 mm) 1/2" (12.5 mm) 3/8" (9.5 mm) No. 4 (4.75 mm) No. 8 (2.36 mm) No. 10 (2 mm) No. 16 (1.18 mm) No. 30 (0.6 mm) No. 40 (0.425 mm) No. 50 (0.3 mm) No. 100 (0.15 mm) No. 200 (0.075 mm) Project: Schlagel Properties Location: Fort Collins, Colorado Project No: 1172056 Sample ID: PZ-6, S-3, 9' Sample Desc.: Well Graded Sand with Silt and Gravel (SW - SM) Date: August 2017 EARTH ENGINEERING CONSULTANTS, LLC SUMMARY OF LABORATORY TEST RESULTS Sieve Analysis (AASHTO T 11 & T 27 / ASTM C 117 & C 136) Sieve Size Percent Passing 100 100 95 85 79 70 59 14 9.0 56 46 33 27 21 0.52 0.09Fine29.80 1.12D30D10CuCCAugust 201725.00 2.68 1.51Schlagel PropertiesFort Collins, Colorado1172056PZ-6, S-3, 9'Well Graded Sand with Silt and Gravel (SW - SM)D100D60D50EARTH ENGINEERING CONSULTANTS, LLCSummary of Washed Sieve Analysis Tests (ASTM C117 & C136)Date:Project:Location:Project No:Sample ID:Sample Desc.:CobbleSilt or ClayGravelCoarse FineSandCoarse Medium6"5"4"3"2.5"2"1.5"1"3/4"1/2"3/8"No. 4No. 8No. 10No. 16No. 30No. 40No. 50No. 100No. 20001020304050607080901000.010.11101001000Finer by Weight (%)Grain Size (mm)Standard Sieve Size 1 1/2" (37.5 mm) 1" (25 mm) 3/4" (19 mm) 1/2" (12.5 mm) 3/8" (9.5 mm) No. 4 (4.75 mm) No. 8 (2.36 mm) No. 10 (2 mm) No. 16 (1.18 mm) No. 30 (0.6 mm) No. 40 (0.425 mm) No. 50 (0.3 mm) No. 100 (0.15 mm) No. 200 (0.075 mm) Project: Schlagel Properties Location: Fort Collins, Colorado Project No: 1172056 Sample ID: PZ-7, S-3, 9' Sample Desc.: Well Graded Sand with Silt and Gravel (SW - SM) Date: August 2017 EARTH ENGINEERING CONSULTANTS, LLC SUMMARY OF LABORATORY TEST RESULTS Sieve Analysis (AASHTO T 11 & T 27 / ASTM C 117 & C 136) Sieve Size Percent Passing 100 90 78 71 65 55 44 11 7.4 42 33 23 19 16 1.00 0.13Fine53.94 1.09D30D10CuCCAugust 201737.50 7.04 3.61Schlagel PropertiesFort Collins, Colorado1172056PZ-7, S-3, 9'Well Graded Sand with Silt and Gravel (SW - SM)D100D60D50EARTH ENGINEERING CONSULTANTS, LLCSummary of Washed Sieve Analysis Tests (ASTM C117 & C136)Date:Project:Location:Project No:Sample ID:Sample Desc.:CobbleSilt or ClayGravelCoarse FineSandCoarse Medium6"5"4"3"2.5"2"1.5"1"3/4"1/2"3/8"No. 4No. 8No. 10No. 16No. 30No. 40No. 50No. 100No. 20001020304050607080901000.010.11101001000Finer by Weight (%)Grain Size (mm)Standard Sieve Size