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HomeMy WebLinkAboutTHE UNION ON ELIZABETH (FORMERLY 1208 W. ELIZABETH STREET) - PDP/FDP - FDP170024 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTElizabeth Street Project Fort Collins, Colorado November 18, 2016 Revised April 18, 2017 Terracon Project No. 20165099 Prepared for: EdR Memphis, Tennessee Prepared by: Terracon Consultants, Inc. Fort Collins, Colorado Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable REPORT TOPICS* Project Description Site Conditions Exploration and Testing Procedures Field Exploration Laboratory Testing Geotechnical Model Laboratory Testing Corrosion Protection (Water-Soluble Sulfates) Groundwater Seismic Considerations Geotechnical Overview Existing, Undocumented Fill Shallow Bedrock Shallow Groundwater Expansive Soils and Bedrock Permanent Dewatering Foundation and Floor System Recommendations Site Preparations Demolition Excavation Subgrade preparation Fill Materials Compaction Requirements Utility Trench and Backfill Grading and Drainage Exterior Slab Design and Construction Shallow Foundations Spread Footings Design Recommendations Spread Footings Construction Considerations Deep Foundations Drilled Piers Bottomed in Bedrock Design Recommendations Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable Drilled Piers Bottomed in Bedrock Construction Considerations Floor Systems Floor Systems Design Recommendations Floor Systems Construction Considerations Below-Grade Structures Design Parameters Swimming Pool Recommendations Pavements Pavements Subgrade Preparation Pavements Design Recommendations Pavements Construction Considerations Pavements Maintenance General Comments ATTACHMENTS Site Locations Exploration Plan Exploration Results (Boring Logs and Laboratory Data) Supporting Information (General Notes and USCS, etc.) *This is a paper rendition of a web-based Geotechnical Engineering Report. Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable Our initial understanding of the project was provided in our proposal and was discussed in the project planning stage and our final understanding of the project conditions is as follows: Item Description Project location The project site is located at 1208 and 1220 West Elizabeth Street in Fort Collins, Colorado. Proposed construction The project will include a multi-story building with a unit average of about 1,236 square feet. Portions of the first story are proposed retail space. An in-ground swimming pool is proposed in between and near the center of the proposed buildings. Building construction The proposed buildings will be steel-framed with concrete exterior walls (assumed). Maximum loads Columns: 1,000 kips maximum (assumed) Walls: 10 kips per linear maximum (assumed) Slabs: 150 pounds per square foot maximum (assumed) Grading/slopes Minor grading is anticipated to complete the project. Below-grade construction Other than the swimming pool, no below-grade areas are planned as part of this project. Pavements Paved access drives and parking areas will be constructed on the northern portion of the property We assume that both rigid (concrete) and flexible (asphalt) pavement sections should be considered. Please confirm this assumption. Anticipated traffic is as follows: Autos/Light Trucks: 1,000 vehicles per day Light Delivery and Trash Collection Vehicles: 10 vehicles per week Tractor-trailer trucks: Less than 1 vehicle per week. The pavement design period is 20 years. Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable The following description of site conditions is derived from our site visit in association with the field exploration as well as our review of publically available geologic maps, topographic maps and aerial photographs. Item Description Location The proposed project is located at 1208 and 1220 West Elizabeth Street in Fort Collins, Colorado. The approximate latitude and longitude of the site is 40.57504°N / 105.09762°W Existing improvements On the eastern portion of the site are t Episcopal Church. Mature deciduous trees and landscaping are located along the northern, eastern, and western perimeter of the site. A well maintained grass-covered lawn comprises the southern half of the site and is irrigated with a below-grade sprinkler system. There are a few shrubs, a sprinkler main, and a fire hydrant along the southern boundary of the property near the sidewalk. On the western portion of the site is a single-story multi- company commercial development with associated paved parking area. Current ground cover The southern half of the property, as well as the eastern and western perimeters, are covered with maintained landscaping. The western portion of the site is covered with asphalt paving. Existing topography The site gently slopes from north to the south. Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable Using our understanding of the project as noted in Project Understanding, we developed the following scope of services for field exploration and laboratory testing for this project. Our field exploration work included the drilling and sampling of exploratory soil borings consistent with the following schedule. Proposed borings were completed to the planned depths below existing site grades or to practical auger refusal, if shallower. Number of Borings Boring Depth (ft) Planned Location 3 20 to 25 Building envelopes 3 35 Additional borings 1 25 Swimming pool Locations of soil borings are provided on our Exploration Plan. The locations of exploration points were -held GPS unit to establish boring locations with reference to known points. The accuracy of the exploration points is usually within 10 feet of the noted location. A ground surface elevation at each boring and test pit location was -site benchmark. The borings were drilled with CME-75 and CME-55 truck-mounted rotary drill rigs with hollow- stem augers. Disturbed samples were obtained at selected intervals utilizing a 2-inch outside diameter, split-spoon sampler and a 3-inch outside diameter, ring-barrel sampler. Penetration resistance values were recorded in a manner similar to the standard penetration test (SPT). This test consists of driving the sampler into the ground with a 140-pound hammer free-falling through a distance of 30 inches. The number of blows required to advance the ring-barrel sampler 12 inches (18 inches for standard split-spoon samplers, final 12 inches are recorded) or the interval indicated, is recorded as a standard penetration resistance value (N-value). The blow count values are indicated on the boring logs at the respective sample depths. Ring-barrel sample blow counts are not considered N-values. A CME automatic SPT hammer was used to advance the samplers in the borings performed on this site. A greater efficiency is typically achieved with the automatic hammer compared to the conventional safety hammer operated with a cathead and rope. Published correlations between the SPT values and soil properties are based on the lower efficiency cathead and rope method. This higher efficiency affects the standard penetration resistance blow count value by increasing the penetration per hammer blow over what would be obtained using the cathead and rope method. The effect of the automatic hammer's efficiency has been considered in the interpretation and analysis of the subsurface information for this report. Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable The standard penetration test provides a reasonable indication of the in-place density of sandy type materials, but only provides an indication of the relative stiffness of cohesive materials since the blow count in these soils may be affected by the moisture content of the soil. In addition, considerable care should be exercised in interpreting the N-values in gravelly soils, particularly where the size of the gravel particle exceeds the inside diameter of the sampler. Our exploration team prepared field boring logs as part of the drilling operations. These field logs include visual classifications of the materials encountered during drilling and our interpretation of the subsurface conditions between samples. Groundwater measurements were obtained in the borings at the time of site exploration and approximately 1 day after drilling. Final boring logs were prepared from the field logs. The final boring logs represent the engineer's interpretation of the field logs and include modifications based on observations and tests of the samples in the laboratory. All borings were backfilled after subsequent groundwater measurements were obtained with auger cuttings, borings located on the asphalt pavement were patched with hot-mix asphalt. Excess auger cuttings were disposed of on the site by spreading in the area of each exploration point. Because backfill material often settles below the surface after a period of time, you should observe the exploration points periodically for signs of depressions and backfill them if necessary. The soil and bedrock samples retrieved during the field exploration were returned to the laboratory for observation by the project geotechnical engineer. At that time, the field descriptions were reviewed and an applicable laboratory testing program was formulated to determine engineering properties of the subsurface materials. Laboratory tests were conducted on selected soil and bedrock samples. The results of these tests are presented on the boring logs and in this appendix. The laboratory tests were performed in general accordance with applicable locally accepted standards. Soil samples were classified in general accordance with the Unified Soil Classification System described in the Supporting Information section of this report. Rock samples were visually classified in general accordance with the description of rock properties presented in our Supporting Information section of this report. Procedural standards noted in this report are for reference to methodology in general. In some cases, variations to methods are applied as a result of local practice or professional judgment. Water content Plasticity index Grain-size distribution Consolidation/swell Compressive strength Dry density Water-soluble sulfate content Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable 1 Specific conditions encountered at each boring location are indicated on the individual boring logs. Stratification boundaries on the boring logs represent the approximate location of changes in soil types; in situ, the transition between materials may be gradual. Details for each of the borings can be found in Exploration Results. A discussion of field sampling and laboratory testing procedures and test results are presented in Exploration and Testing Procedures. Based on the results of the borings, subsurface conditions on the project site can be generalized as follows: Material Description Approximate Depth to Bottom of Stratum Consistency/Density/Hardness Fill materials consisting of lean clay, sand, and gravel About 3 to 3½ feet below existing site grades. Only encountered in Boring Nos. 1, 2, 3 and 4. -- Lean clay with varying amounts of sand and gravel About 7 to 8 feet below existing site grades. Only encountered in Boring Nos. 5, 6 and 7. Stiff to very stiff Sand with silt, clay, and gravel About 6 to 9 feet below existing site grades. Medium dense to dense Bedrock consisting of sandstone and claystone To the maximum depth of exploration of about 25½ feet. Hard to very hard Representative soil samples were selected for swell-consolidation testing and 2.2 percent swell to 0.1 percent compression when wetted. A sample of weathered bedrock soil exhibited an unconfined compressive strength of approximately 6,500 pounds per square foot (psf) and a sample of lean clay soils exhibited an unconfined compressive strength of approximately 5,100 pounds per square foot (psf). Samples of site soils and bedrock selected for plasticity testing exhibited moderate plasticity with liquid limits ranging from non-plastic to 42 and plasticity indices ranging from non-plastic to 24. Laboratory test results are presented in the Exploration Results section of this report. Results of water-soluble sulfate testing indicate that ASTM Type II, portland cement should be specified for all project concrete on and below grade. Foundation concrete should be designed for low to moderate sulfate exposure in accordance with the provisions of the ACI Design Manual, Section 318, Chapter 4. Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable 2 The boreholes were observed while drilling and after completion for the presence and level of groundwater. In addition, delayed water levels were also obtained in some borings. The water levels observed in the boreholes are noted on the attached boring logs, and are summarized below: Boring Number Depth to groundwater while drilling, ft. Depth to groundwater 24 hours after drilling, ft. Elevation of groundwater 24 hours after drilling, ft. 1 Not encountered Not encountered NA 2 Not encountered 10.2 5016.7 3 Not encountered 15.8 5011.7 4 Not encountered 20.9 5006.3 Boring Number Depth to groundwater while drilling, ft. Depth to groundwater immediately after drilling, ft. Elevation of groundwater immediately after drilling, ft. 5 11 13.6 5013.9 6 Not encountered Not encountered NA 7 Not encountered Not encountered NA These observations represent groundwater conditions at the time of the field exploration, and may not be indicative of other times or at other locations. Groundwater levels can be expected to fluctuate with varying seasonal and weather conditions, and other factors. Groundwater level fluctuations occur due to seasonal variations, amount of rainfall, runoff and other factors not evident at the time the borings were performed. Therefore, groundwater levels during construction or at other times in the life of the proposed project may be higher or lower than the levels indicated on the boring logs. The possibility of groundwater level fluctuations should be considered when developing the design and construction plans for the project. Fluctuations in groundwater levels can best be determined by implementation of a groundwater monitoring plan. Such a plan would include installation of groundwater piezometers, and periodic measurement of groundwater levels over a sufficient period of time. Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable Code Used Site Classification 2015 International Building Code (IBC) 1 C 2 1. In general accordance with the 2015 International Building Code, Table 1613.5.2. 2. The 2015 International Building Code (IBC) requires a site soil profile determination extending a depth of 100 feet for seismic site classification. The current scope requested does not include the required 100 foot soil profile determination. The borings completed for this project extended to a maximum depth of about 34½ feet and this seismic site class definition considers that similar soil and bedrock conditions exist below the maximum depth of the subsurface exploration. Additional exploration to deeper depths could be performed to confirm the conditions below the current depth of exploration. Alternatively, a geophysical exploration could be utilized in order to attempt to justify a more favorable seismic site class. Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable Based on subsurface conditions encountered in the borings, the site appears suitable for the proposed construction from a geotechnical point of view provided certain precautions and design and construction recommendations described in this report are followed. We have identified several geotechnical conditions that could impact design, construction and performance of the proposed structures, pavements, and other site improvements. These included existing, undocumented fill, shallow bedrock, shallow groundwater, and potentially expansive soils. These conditions will require particular attention in Project Planning, design and during construction and discussed in greater detail in the following sections. The near surface soils are predominantly undocumented fills consisting of clayey sands with gravel or lean clay material with varying amounts of sand. Underlying the fill and lean clays are medium dense to dense silty/clayey sands with gravel soils. Interbedded sandstone and claystone bedrock underlying the site ranges from 6 to 9 feet below the ground surface, based on the limited number of borings completed. Additional site preparation recommendations, including subgrade improvement, fill placement, and excavations are provided in the Site Preparation section. The Shallow Foundation section addresses support of the building bearing on native soils. The Floor Systems section addresses slab-on-grade support of the building. Based on our experience with similar projects, a rigid pavement system is recommended for this site and is addressed in the Pavements section of this report. Existing, undocumented fill was encountered to depths up to about 3½ feet in the borings drilled on the eastern portion of the site. We do not possess any information regarding whether the fill was placed under the observation of a geotechnical engineer. Support of foundations, floor slabs, and pavements on or above existing fill soils is discussed in this report. There is an inherent risk for the owner that compressible fill or unsuitable material within or buried by the fill will not be discovered. This risk of unforeseen conditions cannot be eliminated without completely removing the existing fill, but can be reduced by performing additional testing and evaluation. Bedrock was encountered in all of our test borings at the site, ranging from about 6 to 9 feet below existing site grades. We understand a swimming pool is proposed in between and near the center of the proposed building area planned at this site and is the only below-grade structure planned at the site. Excavation penetrating the bedrock may require the use of specialized heavy-duty Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable equipment, together with ripping or jack-hammering to advance the excavation and facilitate rock break-up and removal. As previously stated, groundwater was measured at depths ranging from about 10.2 to 20.9 feet below existing site grades. We understand a swimming pool is proposed in between and near the center of the proposed building areas planned at this site. Terracon recommends maintaining a separation of at least 3 feet between the bottom of proposed below-grade foundations and measured groundwater levels. It is also possible and likely that groundwater levels below this site due to seasonal variation. Expansive soils and bedrock was identified in the borings completed on this site. This report provides recommendations to help mitigate the effects of soil shrinkage and expansion. However, even if these procedures are followed, some movement and cracking in the structures, pavements, pools, and flatwork should be anticipated. The severity of cracking and other damage such as uneven floor slabs and flat work will probably increase if modification of the site results in excessive wetting or drying of the expansive clays and/or claystone bedrock. Eliminating the risk of movement and cosmetic distress is generally not feasible, but it may be possible to further reduce the risk of movement if significantly more expensive measures are used during construction. It is imperative the recommendations described in section Grading and Drainage of this report be followed to reduce movement. Preliminary site concepts indicate the proposed swimming pool may extend below the observed groundwater levels. Thus, permanent dewatering may be needed to lower groundwater levels below permanent excavations. We recommend that on a long term basis, groundwater levels be maintained at least 3 feet below base of the pool. If a permanent dewatering system is judged necessary by the project team, we suggest the dewatering system consist of a combination of drains and sumps. The configuration of the system will depend on the size of the pool. The locations of the drains and/or sumps must consider maintenance accessibility. A possible configuration would be a subsurface drain around the exterior of the pool perimeter wall. The drain pipe should be properly sized, perforated PVC or other type of hard pipe embedded in properly graded drainage gravel. The invert of the drain pipe should be at least 4 feet below the bottom of the pool. The drain pipe should discharge into a sump(s) accessible within the base of the pool area. Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable The drainage gravel should extend vertically over the drain pipes to at least 2 feet above the highest groundwater levels observed in the soil borings. Thus, the drain gravel will extend into the pool foundation wall backfill. The foundation walls adjacent to the drain gravel should be properly water-proofed. Provision must be made to prevent migration or piping of the native soils into the drainage gravel. Ideally this would be by a properly graded sand filter. Alternatively, a filter fabric could be used. If a filter fabric is used, we strongly recommend that installation be in the dry. That is, the Contractor should dewater the excavation so that it is free of standing water during installation of the drain components. Other issues to be considered include: Disposition of the developed water, which could be to a storm water detention basin. Evaluation of the amount of water likely to be discharged from a permanent dewatering system was not included in our scope of services for this study but should be evaluated, if a permanent dewatering system is selected. Possible permitting requirements. If the dewatering system is considered to be a well, the State of Colorado Department of Public Health and Environment. The permits, should they be needed, will require regular reporting of discharge water quality. Adequate time should be included in the project schedule to obtain the permits. Maintenance. All permanent dewatering systems require regular maintenance to assure the drains and pumps are in proper operating condition. Underground drains associated with the system should have cleanouts so that the system can be flushed/ cleaned periodically as underground dewatering systems can become clogged with anaerobic microbial and other growth. The cleanout locations should be readily accessible and a source of high pressure (water main pressure) water available to flush the drains. Monitoring. By their nature, permanent dewatering system maintenance personnel if the pumps have failed and water levels are rising in the sumps. The proposed buildings can be supported by a shallow, spread footing foundation system. Design recommendations for foundations for the proposed structure and related structural elements are presented in the following paragraphs. We recommend a slab-on-grade floor system for the proposed building development. In addition, we recommend the upper 1 foot, below the proposed slab, be replaced with imported granular meeting Colorado Department of Transportation (CDOT) Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable Class 1 structure backfill specifications. Even when bearing on properly prepared soils, movement of the floor system is possible should the subgrade soils undergo an increase in moisture content. We estimate movement of less than 1 inch is possible. Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable These specifications include critical quality criteria as necessary to render the site in the state anticipated by our geotechnical engineering for foundations, slopes and pavements. Prior to placing any fill, strip and remove existing vegetation and any other deleterious materials from the proposed construction areas. Stripped organic materials should be wasted from the site or used to re-vegetate landscaped areas or exposed slopes after completion of grading operations. Prior to the placement of fills, the site should be graded to create a relatively level surface to receive fill, and to provide for a relatively uniform thickness of fill beneath proposed structures. The following presents recommendations for site demolition, excavation, subgrade preparation and placement of engineered fills on the project. All earthwork on the project should be observed and evaluated by Terracon on a full-time basis. The evaluation of earthwork should include observation of over-excavation operations, testing of engineered fills, subgrade preparation, subgrade stabilization, and other geotechnical conditions exposed during the construction of the project. Demolition of the existing church, shopping center and associated buildings should include complete removal of all foundation systems, below-grade structural elements, pavements, and exterior flat work within the proposed construction area. This should include removal of any utilities to be abandoned along with any loose utility trench backfill or loose backfill found adjacent to existing foundations. All materials derived from the demolition of existing structures and pavements should be removed from the site. The types of foundation systems supporting the existing buildings are not known. If some or all of the existing buildings are supported by drilled piers, the existing piers should be truncated a minimum depth of 3 feet below areas of planned new construction. Consideration could be given to re-using the asphalt and concrete provided the materials are processed and uniformly blended with the on-site soils. Asphalt and/or concrete materials should be processed to a maximum size of 2-inches and blended at a ratio of 30 percent asphalt/concrete to 70 percent of on-site soils. It is anticipated that excavations for the proposed construction can be accomplished with conventional earthmoving equipment. Excavation penetrating the bedrock may require the use of specialized heavy-duty equipment, together with ripping or jack-hammering drilling and blasting to advance the excavation and facilitate rock break-up and removal. Consideration should be given to obtaining a unit price for difficult excavation in the contract documents for the project. Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable The soils to be excavated can vary significantly across the site as their classifications are based solely on the materials encountered in widely-spaced exploratory test borings. The contractor should verify that similar conditions exist throughout the proposed area of excavation. If different subsurface conditions are encountered at the time of construction, the actual conditions should be evaluated to determine any excavation modifications necessary to maintain safe conditions. Although evidence of fills or underground facilities such as septic tanks, vaults, 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. Any over-excavation that extends below the bottom of foundation elevation should extend laterally beyond all edges of the foundations at least 8 inches per foot of over-excavation depth below the foundation base elevation. The over-excavation should be backfilled to the foundation base elevation in accordance with the recommendations presented in this report. Depending upon depth of excavation and seasonal conditions, surface water infiltration and/or groundwater may be encountered in excavations on the site. It is anticipated that pumping from sumps may be utilized to control water within excavations. The subgrade soil conditions should be evaluated during the excavation process and the stability than the OSHA maximum values may have to be used. 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 As a safety measure, it is recommended that all vehicles and soil piles be kept a minimum lateral distance from the crest of the slope equal to the slope height. The exposed slope face should be protected against the elements After the undocumented existing fill and other deleterious materials have been removed from the building and pavement areas, the top 8 inches of the exposed ground surface should be scarified, moisture conditioned, and recompacted to at least 95 percent of the maximum dry unit weight as determined by ASTM D698 before any new fill or foundation or pavement is placed. If pockets of soft, loose, or otherwise unsuitable materials are encountered at the bottom of the foundation excavations and it is inconvenient to lower the foundations, the proposed foundation Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable elevations may be reestablished by over-excavating the unsuitable soils and backfilling with compacted engineered fill or lean concrete. After the bottom of the excavation has been compacted, engineered fill can be placed to bring the building pad and pavement subgrade to the desired grade. Engineered fill should be placed in accordance with the recommendations presented in subsequent sections of this report. The stability of the subgrade may be affected by precipitation, repetitive construction traffic or other factors. If unstable conditions develop, workability may be improved by scarifying and drying. Alternatively, over-excavation of wet zones and replacement with granular materials may until a stable working surface is attained. Lightweight excavation equipment may also be used to reduce subgrade pumping. The on-site soils or approved granular and low plasticity cohesive imported materials may be used as fill material. Granular fill placed below the floor system should meet the specifications of the Colorado Department of Transportation (CDOT) Class 1 structure backfill, presented in the following table: CDOT Class 1 structure backfill should meet the following material property requirements: Gradation Percent finer by weight (ASTM C136) 100 No. 4 Sieve 30-100 No. 50 Sieve 10-60 No 200 Sieve 5-20 Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable Soil Properties Values Liquid Limit 35 (max.) Plastic Limit 6 (max.) The soil removed from this site that is free of organic or objectionable materials, as defined by a field technician who is qualified in soil material identification and compaction procedures, can be re-used as fill for the building pad and pavement subgrade. It should be noted that on-site soils will require reworking to adjust the moisture content to meet the compaction criteria. Imported soils (if required) should meet the following material property requirements: Gradation Percent finer by weight (ASTM C136) 100 70-100 No. 4 Sieve 50-100 No. 200 Sieve 50 (max.) Soil Properties Values Liquid Limit 35 (max.) Plastic Limit 6 (max.) Engineered fill should be placed and compacted in horizontal lifts, using equipment and procedures that will produce recommended moisture contents and densities throughout the lift. Item Description Fill lift thickness 9 inches or less in loose thickness when heavy, self- propelled compaction equipment is used 4 to 6 inches in loose thickness when hand-guided equipment (i.e. jumping jack or plate compactor) is used Minimum compaction requirements 95 percent of the maximum dry unit weight as determined by ASTM D698 Moisture content cohesive soil (clay) -1 to +3 % of the optimum moisture content Moisture content cohesionless soil (sand) -3 to +3 % of the optimum moisture content Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable Item Description 1. We recommend engineered fill be tested for moisture content and compaction during placement. Should the results of the in-place density tests indicate the specified moisture or compaction limits have not been met, the area represented by the test should be reworked and retested as required until the specified moisture and compaction requirements are achieved. 2. Specifically, moisture levels should be maintained low enough to allow for satisfactory compaction to be achieved without the fill material pumping when proofrolled. 3. Moisture conditioned clay materials should not be allowed to dry out. A loss of moisture within these potential. Subsequent wetting of these materials could result in undesirable movement. All trench excavations should be made with sufficient working space to permit construction including backfill placement and compaction. All underground piping within or near the proposed structures should be designed with flexible couplings, so minor deviations in alignment do not result in breakage or distress. Utility knockouts in foundation walls should be oversized to accommodate differential movements. It is imperative that utility trenches be properly backfilled with relatively clean materials. If utility trenches are backfilled with relatively clean granular material, they should be capped with at least 18 inches of cohesive fill in non-pavement areas to reduce the infiltration and conveyance of surface water through the trench backfill. Utility trenches are a common source of water infiltration and migration. All utility trenches that penetrate beneath the buildings should be effectively sealed to restrict water intrusion and flow through the trenches that could migrate below the buildings. We recommend constructing an The plug m water content. The clay fill should be placed to completely surround the utility line and be compacted in accordance with recommendations in this report. It is strongly recommended that a representative of Terracon provide full-time observation and compaction testing of trench backfill within building and pavement areas. All grades must be adjusted to provide effective drainage away from the proposed building(s) and existing buildings during construction and maintained throughout the life of the proposed project. Infiltration of water into foundation excavations must be prevented during construction. Landscape irrigation adjacent to foundations should be minimized or eliminated. Water permitted to pond near or adjacent to the perimeter of the structures (either during or post-construction) can Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable result in significantly higher soil movements than those discussed in this report. As a result, any estimations of potential movement described in this report cannot be relied upon if positive drainage is not obtained and maintained, and water is allowed to infiltrate the fill and/or subgrade. Exposed ground (if any) should be sloped at a minimum of 10 percent grade for at least 10 feet beyond the perimeter of the proposed buildings, where possible. The use of swales, chases and/or area drains may be required to facilitate drainage in unpaved areas around the perimeter of the buildings. Backfill against foundations and exterior walls should be properly compacted and free of all construction debris to reduce the possibility of moisture infiltration. After construction of the proposed buildings and prior to project completion, we recommend verification of final grading be performed to document positive drainage, as described above, has been achieved. Flatwork and pavements will be subject to post-construction movement. Maximum grades practical should be used for paving and flatwork to prevent areas where water can pond. In addition, allowances in final grades should take into consideration post-construction movement of flatwork, particularly if such movement would be critical. Where paving or flatwork abuts the structures, care should be taken that joints are properly sealed and maintained to prevent the infiltration of surface water. Planters located adjacent to structures should preferably be self-contained. Sprinkler mains and spray heads should be located a minimum of 5 feet away from the building line(s). Low-volume, drip style landscaped irrigation should not be used near the building. Roof drains should discharge on to pavements or be extended away from the structures a minimum of 10 feet through the use of splash blocks or downspout extensions. A preferred alternative is to have the roof drains discharge by solid pipe to storm sewers or to a detention pond or other appropriate outfall. Exterior slabs on-grade, exterior architectural features, and utilities founded on, or in backfill or the site soils will likely experience some movement due to the volume change of the material. Potential movement could be reduced by: Minimizing moisture increases in the backfill; Controlling moisture-density during placement of the backfill; Using designs which allow vertical movement between the exterior features and adjoining structural elements; and Placing control joints on relatively close centers. Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable Description Values Bearing material Properly prepared on-site native soil, or new, properly placed engineered fill. Maximum allowable bearing pressure1 2,500 psf Sliding coefficient2 µ = 0.5 Moist soil unit weight = 125 pcf Minimum embedment depth below finished grade 3 30 inches Estimated total movement 4 About 1 inch Estimated differential movement 4 About ½ to ¾ of total movement 1. The recommended maximum allowable bearing pressure assumes any unsuitable fill or soft soils, if encountered, will be over-excavated and replaced with properly compacted engineered fill. The design bearing pressure applies to a dead load plus design live load condition. The design bearing pressure may be increased by one-third when considering total loads that include wind or seismic conditions. 2. The sliding coefficients are ultimate values and do not include a factor of safety. The foundation designer should include the appropriate factors of safety. 3. For frost protection and to reduce the effects of seasonal moisture variations in the subgrade soils. The minimum embedment depth is for perimeter footings beneath unheated areas and is relative to lowest adjacent finished grade, typically exterior grade. 4. The estimated movements presented above are based on the assumption that the maximum footing size is 4 feet for column footings and 3 feet for continuous footings. Footings should be proportioned to reduce differential foundation movement. As discussed, total movement resulting from the assumed structural loads is estimated to be on the order of about 1 inch. Additional foundation movements could occur if water from any source infiltrates the foundation soils; therefore, proper drainage should be provided in the final design and during construction and throughout the life of the structure. Failure to maintain the proper drainage as recommended in the Grading and Drainage section of this report will nullify the movement estimates provided above. Spread footing construction should only be considered if the estimated foundation movement can be tolerated. Subgrade soils beneath footings should be moisture conditioned and compacted as described in the Site Preparation section of this report. The moisture content and compaction of subgrade soils should be maintained until foundation construction. Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable Footings and foundation walls should be reinforced as necessary to reduce the potential for distress caused by differential foundation movement. Unstable surfaces will need to be stabilized prior to backfilling excavations and/or constructing the building foundation, floor slab and/or project pavements. The use of angular rock, recycled means of stabilizing the subgrade. The use of geogrid materials in conjunction with gravel could also be considered and could be more cost effective. Unstable subgrade conditions should be observed by Terracon to assess the subgrade and provide suitable alternatives for stabilization. Stabilized areas should be proof-rolled prior to continuing construction to assess the stability of the subgrade. Foundation excavations should be observed by Terracon. If the soil conditions encountered differ significantly from those presented in this report, supplemental recommendations will be required. . Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable DEEP FOUNDATIONS Description Value Estimated pier length 15 to 20 feet Minimum pier diameter 18 inches Minimum bedrock embedment 1 10 feet Maximum allowable end-bearing pressure 25,000 psf Allowable skin friction (for portion of pier embedded into bedrock) 2,500 psf 1. Drilled piers should be embedded into hard or very hard bedrock materials. Actual structural loads and pier diameters may dictate embedment deeper than the recommended minimum penetration. Site grading details were not fully understood at the time we prepared this report. If significant fills are planned in the proposed building areas, longer drilled pier lengths may be required. Piers should be considered to work in group action if the horizontal spacing is less than three pier diameters. A minimum practical horizontal clear spacing between piers of at least three diameters should be maintained, and adjacent piers should bear at the same elevation. The capacity of individual piers must be reduced when considering the effects of group action. Capacity reduction is a function of pier spacing and the number of piers within a group. If group action analyses are necessary, capacity reduction factors can be provided for the analyses. To satisfy forces in the horizontal direction using LPILE, piers may be designed for the following lateral load criteria: Parameters Clay Sand and Gravel Claystone Bedrock LPILE soil type Soft clay Sand Stiff clay Effective unit weight (pcf) above groundwater 120 125 135 Effective unit weight (pcf) below groundwater 60 65 75 Average undrained shear strength (psf) 500 N/A 9,000 Average angle of internal friction, (degrees) N/A 35 N/A Coefficient of subgrade reaction, k (pci)* 100 - static 30 - cyclic 60 2,000- static 800 cyclic Strain, 50 (%) 0.010 N/A 0.004 For purposes of LPILE analysis, assume a groundwater depth of about 10 feet below existing ground surface (approximately Elev. 5019 feet). Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable Drilling to design depth should be possible with conventional single-flight power augers on the majority of the site; however, specialized drilling equipment may be required for very hard bedrock layers. Groundwater/caving soil conditions indicate that temporary steel casing may be required to properly drill and clean piers prior to concrete placement. Groundwater should be removed from each pier hole prior to concrete placement. Pier concrete should be placed immediately after completion of drilling and cleaning. If pier concrete cannot be placed in dry conditions, a tremie should be used for concrete placement. Free-fall concrete placement in piers will only be acceptable if provisions are taken to avoid striking the concrete on the sides of the hole or reinforcing steel. The use of a bottom-dump hopper, or an elephant's trunk discharging near the bottom of the hole where concrete segregation will be minimized, is recommended. Due to potential sloughing and raveling, foundation concrete quantities may exceed calculated geometric volumes. Casing should be withdrawn in a slow continuous manner maintaining a sufficient head of concrete to prevent infiltration of water or caving soils or the creation of voids in pier concrete. Pier concrete should have a relatively high fluidity when placed in cased pier holes or through a tremie. Pier concrete with slump in the range of 5 to 7 inches is recommended. We recommend the sides of each pier should be mechanically roughened in the claystone bearing strata. This should be accomplished by a roughening tooth placed on the auger. Shaft bearing surfaces must be cleaned prior to concrete placement. A representative of Terracon should observe the bearing surface and shaft configuration. Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable A slab-on-grade may be utilized for the interior floor system for the proposed buildings provided the on-site soils are over-excavated to a depth of at least 2 feet, moisture conditioned, and compacted on-site soils. The bottom of the excavation should be scarified, moisture conditioned and recompacted as described in Site Preparation. Properly compacted and moisture conditioned on-site soils can be used as a portion of the backfill beneath the floor system, provided at least 1 foot of imported granular fill (CDOT Class 1 structure backfill), properly moisture conditioned, compacted, is placed directly beneath the slab. Subgrade soils beneath interior and exterior slabs as well as below the recommended 2 feet of engineered fill below floor slabs should be scarified to a depth of at least 8 inches, moisture conditioned and compacted. The moisture content and compaction of subgrade soils should be maintained until slab construction. Even when bearing on properly prepared soils, movement of the slab-on-grade floor system is possible should the subgrade soils undergo an increase in moisture content. We estimate movement of about 1 inch is possible. If the owner cannot accept the risk of slab movement, a structural floor should be used. If conventional slab-on-grade is utilized, the subgrade soils should be over-excavated and prepared as presented in the Site Preparation section of this report. For structural design of concrete slabs-on-grade subjected to point loadings, a modulus of 200 pci may be used for floors supported on at least 1 foot of CDOT Class 1 structure backfill. 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 saw-cut in slabs in accordance with ACI Design Manual, Section 302.1R-37 8.3.12 (tooled control joints are not recommended) to control the location and extent of cracking. Interior utility trench backfill placed beneath slabs should be compacted in accordance with the recommendations presented in the Site Preparation section of this report. Floor slabs should not be constructed on frozen subgrade. Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable The use of a vapor retarder should be considered beneath concrete slabs that will be covered with wood, tile, carpet or other moisture sensitive or impervious floor coverings, or when the slab will support equipment sensitive to moisture. When conditions warrant the use of a vapor retarder, the slab designer and slab contractor should refer to ACI 302 for procedures and cautions regarding the use and placement of a vapor retarder. Other design and construction considerations, as outlined in the ACI Design Manual, Section 302.1R are recommended. Movements of slabs-on-grade using the recommendations discussed in previous sections of this report will likely be reduced and tend to be more uniform. The estimates discussed above assume that the other recommendations in this report are followed. Additional movement could occur should the subsurface soils become wetted to significant depths, which could result in potential excessive movement causing uneven floor slabs and severe cracking. This could be due to over watering of landscaping, poor drainage, improperly functioning drain systems, and/or broken utility lines. Therefore, it is imperative that the recommendations presented in this report be followed. Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable BELOW-GRADE STRUCTURES Below-grade structures or reinforced concrete walls with unbalanced backfill levels on opposite sides should be designed for earth pressures at least equal to those indicated in the following table. Earth pressures will be influenced by structural design of the walls, conditions of wall restraint, methods of construction and/or compaction and the strength of the materials being restrained. Two wall restraint conditions are shown. Active earth pressure is commonly used for design of free-standing cantilever retaining walls and assumes wall movement. The "at-rest" condition assumes no wall movement. The recommended design lateral earth pressures do not include a factor of safety and do not provide for possible hydrostatic pressure on the walls. Earth Pressure Coefficients Earth Pressure Conditions Coefficient for Backfill Type Equivalent Fluid Density (pcf) Surcharge Pressure, p1 (psf) Earth Pressure, p2 (psf) Active (Ka) Granular - 0.36 Lean Clay - 0.42 40 50 (0.36)S (0.42)S (40)H (50)H At-Rest (Ko) Granular - 0.44 Lean Clay - 0.58 57 70 (0.44)S (0.58)S (57)H (70)H Passive (Kp) Granular 3.5 Lean Clay - 2.4 360 290 --- --- --- --- Applicable conditions to the above include: For active earth pressure, wall must rotate about base, with top lateral movements of about 0.002 H to 0.004 H, where H is wall height For passive earth pressure to develop, wall must move horizontally to mobilize resistance Uniform surcharge, where S is surcharge pressure In-situ soil backfill weight a maximum of 130 pcf for granular materials and 120 for clay soils. Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable Horizontal backfill, compacted between 95 and 98 percent of standard Proctor maximum dry density Loading from heavy compaction equipment not included No hydrostatic pressures acting on wall No dynamic loading No safety factor included Ignore passive pressure in frost zone Backfill placed against structures should consist of granular soils or low plasticity cohesive soils. For the granular values to be valid, the granular backfill must extend out and up from the base of the wall at an angle of at least 45 and 60 degrees from vertical for the active and passive cases, respectively. To calculate the resistance to sliding, a value of 0.32 should be used as the ultimate coefficient of friction between the footing and the underlying soil. A perforated rigid plastic or metal drain line installed behind the base of walls that extend below adjacent grade is recommended to prevent hydrostatic loading on the walls. The invert of a drain line around a below-grade building area or exterior retaining wall should be placed near foundation bearing level. The drain line should be sloped to provide positive gravity drainage or to a sump pit and pump. The drain line should be surrounded by clean, free-draining granular material having less than 5 percent passing the No. 200 sieve. The free-draining aggregate should be encapsulated in a filter fabric. The granular fill should extend to within 2 feet of final grade, where it should be capped with compacted cohesive fill to reduce infiltration of surface water into the drain system. As an alternative to free-draining granular fill, a pre-fabricated drainage structure may be used. A pre-fabricated drainage structure is a plastic drainage core or mesh which is covered with filter fabric to prevent soil intrusion, and is fastened to the wall prior to placing backfill. To control hydrostatic pressure behind the wall we recommend that a drain be installed at the foundation wall with a collection pipe leading to a reliable discharge. If this is not possible, then combined hydrostatic and lateral earth pressures should be calculated for lean clay backfill using an equivalent fluid weighing 90 and 100 pcf for active and at-rest conditions, respectively. For granular backfill, an equivalent fluid weighing 85 and 90 pcf should be used for active and at-rest, respectively. These pressures do not include the influence of surcharge, equipment or floor loading, which should be added. Heavy equipment should not operate within a distance closer than the exposed height of retaining walls to prevent lateral pressures more than those provided. We understand a swimming pool is conceptually planned near the center portion of the project site. The construction and performance of the pool will be highly affected by the presence of shallow bedrock and groundwater below existing site grades. Specialized excavation equipment Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable may be required to excavate bedrock found 6 to 9 feet below site grades. In addition, construction and/or permanent dewatering may be required for swimming pool construction and service. Excavation of the pool area by conventional rubber-tired equipment may encounter soft or very loose soils and/or severe pumping when nearing groundwater level. It may be necessary to excavate the deep portion of the pool with a backhoe or power shovel. If the excavation extends into the groundwater, a one-piece fiberglass or similar pool should be installed. As a precaution, pressure relief valves should be placed in the deep end of any pool constructed to prevent flotation should groundwater rise when the pool is empty. We recommend coordination with a qualified swimming pool specialty contractor to discuss alternatives to address the effects of shallow groundwater on the proposed swimming pool. If groundwater levels rise above the bottom of the pool when the pool is empty, uplift loads could be imposed on the pool bottom slab and hydrostatic pressure could be imposed on the pool walls, which could cause heaving, cracking, or other damage to the pool bottom slab and walls. The pool design is conceptual at this point, and the pool designs should include pressure relief valves that will allow backflow of groundwater into the empty pool in order to help reduce the potential for hydrostatic loading and subsequent heaving, cracking, or other damage. A drainage system should be provided around and beneath the pool. The drain should consist of a minimum 6-inch layer of clean gravel (minimum 3/4-inch size) beneath and along the sides of the pool. The top of the drain layer should be sealed with 18 inches of relatively impermeable soil at the surface. The gravel layer beneath the pool should be sloped so that it will drain into tiles or perforated drainpipe. The layout of the perforated pipe should include at least one pipe running down the center of the pool lengthwise. Cross-connecting pipes, spanning with the pool, should be placed at 6-foot centers. The cross-connecting pipes should be joined to the center pipe with or sloped to a sump located in the equipment room, permitting pump discharge. The bottom of the excavation beneath the gravel layer and the pipe should be lined with an impervious membrane (polyethylene film or equal) to reduce potential moisture fluctuations in the subgrade soils. Pressure relief valves should be provided in the base of the pool to prevent excessive uplift pressures from developing in the event of drain system failure. The soils that will support deck slabs around the pool could expand with increasing moisture content. To reduce possible damage that could be caused by expansive soils, we recommend: Deck slabs be supported on fill with no, or very low, expansion potential; Strict moisture-density control during placement of subgrade fill; Placement of effective control joints on relatively close centers and isolation joints between slabs and other structural elements; Provision for adequate drainage in areas adjoining the slabs; and Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable Use of designs which allow vertical movement between the deck slabs and adjoining structural elements. Fill, backfill, and surface drainage in the pool area should be place in accordance with the recommendations presented in the Site Preparation section of this report. Grading should be provided for diversion of deck surface runoff away from the pool area. In no case should water be allowed to pond around the slab perimeter. Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable On most project sites, the site grading is accomplished relatively early in the construction phase. Fills are typically placed and compacted in a uniform manner. However as construction proceeds, the subgrade may be disturbed due to utility excavations, construction traffic, desiccation, or rainfall/snow melt. As a result, the pavement subgrade may not be suitable for pavement construction and corrective action will be required. The subgrade should be carefully evaluated at the time of pavement construction for signs of disturbance or instability. We recommend the pavement subgrade be thoroughly proofrolled with a loaded tandem-axle dump truck prior to final grading and paving. All pavement areas should be moisture conditioned and properly compacted to the recommendations in this report immediately prior to paving. Design of new privately-maintained pavements for the project has been based on the procedures described by the National Asphalt Pavement Associations (NAPA) and the American Concrete Institute (ACI). We assumed the following design parameters for NAPA flexible pavement thickness design: Automobile Parking Areas Class I - Parking stalls and parking lots for cars and pick-up trucks, with Equivalent Single Axle Load (ESAL) up to 7,000 over 20 years Main Traffic Corridors Class II Parking lots with a maximum of 10 trucks per day with Equivalent Single Axle Load (ESAL) up to 27,000 over 20 years (Including trash trucks) Subgrade Soil Characteristics USCS Classification SC, classified by NAPA as medium We assumed the following design parameters for ACI rigid pavement thickness design based upon the average daily truck traffic (ADTT): Automobile Parking Areas ACI Category A: Automobile parking with an ADTT of 1 over 20 years Main Traffic Corridors ACI Category A: Automobile parking area and service lanes with an ADTT of up to 10 over 20 years Subgrade Soil Characteristics USCS Classification SC Concrete modulus of rupture value of 600 psi Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable We should be contacted to confirm and/or modify the recommendations contained herein if actual traffic volumes differ from the assumed values shown above. Recommended alternatives for flexible and rigid pavements are summarized for each traffic area as follows: Traffic Area Alternative Recommended Pavement Thicknesses (Inches) Asphaltic Concrete Surface Aggregate Base Course Portland Cement Concrete Total Automobile Parking (NAPA Class I and ACI Category A) A 3½ 6 - 9½ B - - 4½ 4½ Service Lanes (NAPA Class II and ACI Category A) A 4½ 6 - 10½ B - - 5 5 Aggregate base course (if used on the site) should consist of a blend of sand and gravel which meets strict specifications for quality and gradation. Use of materials meeting Colorado Department of Transportation (CDOT) Class 5 or 6 specifications is recommended for aggregate base course. Aggregate base course should be placed in lifts not exceeding 6 inches and compacted to a minimum of 95 percent of the maximum dry unit weight as determined by ASTM D698. Asphaltic concrete should be composed of a mixture of aggregate, filler and additives (if required) and approved bituminous material. The asphalt concrete should conform to approved mix designs stating the Superpave properties, optimum asphalt content, job mix formula and recommended mixing and placing temperatures. Aggregate used in asphalt concrete should meet particular gradations. Material meeting CDOT Grading S or SX specifications or equivalent is recommended for asphalt concrete. Mix designs should be submitted prior to construction to verify their adequacy. Asphalt material should be placed in maximum 3-inch lifts and compacted within a range of 92 to 96 percent of the theoretical maximum (Rice) density (ASTM D2041). Where rigid pavements are used, the concrete should be produced from an approved mix design with the following minimum properties: Properties Value Compressive strength 4,000 psi Cement type Type I or II portland cement Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable Properties Value Entrained air content (%) 5 to 8 Concrete aggregate ASTM C33 and CDOT section 703 Concrete should be deposited by truck mixers or agitators and placed a maximum of 90 minutes from the time the water is added to the mix. Longitudinal and transverse joints should be provided as needed in concrete pavements for expansion/contraction and isolation per ACI 325. The location and extent of joints should be based upon the final pavement geometry. Although not required for structural support, a minimum 4-inch thick aggregate base course layer is recommended for the PCC pavements to help reduce the potential for slab curl, shrinkage PCC pavements to prevent excessive slab curling and shrinkage cracking. All joints should be sealed to prevent entry of foreign material and dowelled where necessary for load transfer. For areas subject to concentrated and repetitive loading conditions (if any) such as dumpster pads, truck delivery docks and ingress/egress aprons, we recommend using a portland cement concrete pavement with a thickness of at least 6 inches underlain by at least 4 inches of granular base. Prior to placement of the granular base, the areas should be thoroughly proofrolled. For dumpster pads, the concrete pavement area should be large enough to support the container and tipping axle of the refuse truck. Pavement performance is affected by its surroundings. In addition to providing preventive maintenance, the civil engineer should consider the following recommendations in the design and layout of pavements: Site grades should slope a minimum of 2 percent away from the pavements; The subgrade and the pavement surface have a minimum 2 percent slope to promote proper surface drainage; Consider appropriate edge drainage and pavement under drain systems; Install pavement drainage surrounding areas anticipated for frequent wetting; Install joint sealant and seal cracks immediately; Seal all landscaped areas in, or adjacent to pavements to reduce moisture migration to subgrade soils; and Placing compacted, low permeability backfill against the exterior side of curb and gutter. Openings in pavement, such as landscape islands, are sources for water infiltration into surrounding pavements. Water collects in the islands and migrates into the surrounding subgrade soils thereby degrading support of the pavement. This is especially applicable for islands with Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable raised concrete curbs, irrigated foliage, and low permeability near-surface soils. The civil design for the pavements with these conditions should include features to restrict or to collect and discharge excess water from the islands. Examples of features are edge drains connected to the storm water collection system or other suitable outlet and impermeable barriers preventing lateral migration of water such as a cutoff wall installed to a depth below the pavement structure. Preventative maintenance should be planned and provided for an ongoing pavement management program in order to enhance future pavement performance. Preventive maintenance consists of both localized maintenance (e.g. crack and joint sealing and patching) and global maintenance (e.g. surface sealing). Preventative maintenance is usually the first priority when implementing a planned pavement maintenance program and provides the highest return on investment for pavements. Elizabeth Street Project Fort Collins, Colorado April 18, 2017 Terracon Project No. 20165099 (revised) Responsive Resourceful Reliable Our work is conducted with the understanding of the project as described in the proposal, and will incorporate collaboration with the design team prior to completing our services. Terracon has requested verification of all stated assumptions. Revision of our understanding to reflect actual conditions important to our work will be based on these verifications and will be reflected in the final report. The design team should collaborate with Terracon to confirm these assumptions. The design team should also collaborate with Terracon to prepare the final design plans and specifications. This facilitates the incorporation of our opinions related to implementation of our geotechnical recommendations. Our analysis and opinions are based upon our understanding of the geotechnical conditions in the area, the data obtained from the site exploration performed and from our understanding of the project. Variations will occur between exploration point locations, across the site, or due to the modifying effects of construction or weather. The nature and extent of such variations may not become evident until during or after construction. So, Terracon should be retained to provide observation and testing services during grading, excavation, foundation construction and other earth-related construction phases of the project. If variations appear, we can provide further evaluation and supplemental recommendations. If variations are noted in the absence of our observation and testing services on-site, we should be immediately notified so that we can provide evaluation and supplemental recommendations. Our scope of services does not include either specifically or by implication any environmental or biological (e.g., mold, fungi, bacteria) assessment of the site or identification or prevention of pollutants, hazardous materials or conditions. If the owner is concerned about the potential for such contamination or pollution, other studies should be undertaken. Our services and any correspondence are intended for the exclusive use of our client for specific application to the project discussed and are accomplished in accordance with generally accepted geotechnical engineering practices. No warranties, either express or implied, are intended or made. Site characteristics as provided are for design purposes and not to estimate excavation cost. Any use of our report in that regard is done at the sole risk of the excavating cost estimator as there may be variations on the site that are not apparent in the data that could significantly impact excavation cost. Any parties charged with estimating excavation costs should seek their own site characterization for that specific purposes to obtain the specific level of detail necessary for costing. Site safety, and cost estimating including, excavation support, and dewatering requirements/design are the responsibility of others. In the event that changes in the nature, design, or location of the project are planned, our conclusions and recommendations shall not be considered valid unless we review the changes and either verify or modify our conclusions in writing. SITE LOCATION Elizabeth Street Project 1208 and 1220 West Elizabeth Fort Collins, CO TOPOGRAPHIC MAP IMAGE COURTESY OF THE U.S. GEOLOGICAL SURVEY QUADRANGLES INCLUDE: FORT COLLINS, CO (1984). 20165099 MGH EDB EDB 4/10/2017 EDB SITE EXPLORATION PLAN Elizabeth Street Project 1208 and 1220 West Elizabeth Fort Collins, CO DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES 20165099 AERIAL PHOTOGRAPHY PROVIDED BY MICROSOFT BING MAPS MGH EDB EDB AS SHOWN 4/10/2017 EDB 9-50 7-6-10 N=16 20 50/5" 26-50 31 50/4" 3.5 9.0 19.8 FILL: CLAYEY SAND with GRAVEL, fine to coarse grained, brown, on cobble at 2 feet SILTY SAND WITH GRAVEL, fine to coarse grained, reddish-brown to yellowish-brown, medium dense, up to 1/2 inch gravel BEDROCK: INTERBEDDED SANDSTONE and CLAYSTONE, fine grained, yellowish-brown to greenish-brown, hard to very hard Boring Terminated at 19.8 Feet 14 12 15 13 12 119 5024.5 5019 5008 GRAPHIC LOG StratificationAutomatic lines are approximate. In-situ, the transition may be gradual. Hammer Type: THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20165099.GPJ TERRACON_DATATEMPLATE.GDT 4/18/17 STRENGTH TEST FIELD TEST RESULTS DEPTH LOCATION Latitude: 40.57509° Longitude: -105.09798° See Exploration Plan Page 1 of 1 Advancement Method: 3.25 (ID) Hollow-stem auger Abandonment Method: Borings backfilled with soil cuttings upon completion. 1901 Sharp Point Dr Ste C Fort Collins, CO Notes: Project No.: 20165099 Drill Rig: CME-75 Boring Started: 11/3/2016 BORING LOG NO. 1 CLIENT: EdR Memphis, Tennessee Driller: R. Geary Boring Completed: 11/3/2016 PROJECT: Elizabeth Street Project Referenced City of Fort Collins BM 19-97 (El. 5025.74 NAVD88) 1208 and 1220 West Elizabeth Street Fort Collins, Colorado 6-8-12 N=20 12-17-10 N=27 31 50/5" 21-25-45 N=70 23-37-48 N=85 50/5" 3.0 9.0 24.4 FILL: CLAYEY SAND with GRAVEL (SC), fine to coarse grained, brown CLAYEY SAND WITH GRAVEL, fine to coarse grained, reddish-brown to yellowish-brown, medium dense BEDROCK: INTERBEDDED SANDSTONE and CLAYSTONE, fine grained, yellowish-brown to greenish-brown, hard to very hard Boring Terminated at 24.4 Feet 10 31 6 14 16 10 5024 37-17-20 5018 5002.5 GRAPHIC LOG StratificationAutomatic lines are approximate. In-situ, the transition may be gradual. Hammer Type: THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20165099.GPJ TERRACON_DATATEMPLATE.GDT 4/18/17 STRENGTH TEST FIELD TEST RESULTS DEPTH LOCATION Latitude: 40.5748° Longitude: -105.09799° See Exploration Plan Page 1 of 1 Advancement Method: 3.25 (ID) Hollow-stem auger Abandonment Method: Borings backfilled with soil cuttings upon completion. 1901 Sharp Point Dr Ste C Fort Collins, CO Notes: Project No.: 20165099 Drill Rig: CME-75 Boring Started: 11/3/2016 BORING LOG NO. 2 CLIENT: EdR Memphis, Tennessee Driller: R. Geary Boring Completed: 11/3/2016 PROJECT: Elizabeth Street Project Referenced City of Fort Collins BM 19-97 (El. 5025.74 NAVD88) 10-11 13-15-22 N=37 35 50/5" 13-37 50/4" 33-50 15 50/3" 3.5 9.0 24.8 FILL: CLAYEY SAND with GRAVEL, fine to coarse grained, brown SILTY SAND WITH GRAVEL (SM), fine to coarse grained, reddish-brown to yellowish-brown, dense BEDROCK: INTERBEDDED SANDSTONE and CLAYSTONE (CL), fine grained, yellowish-brown to greenish-brown, hard to very hard, trace of iron oxidation Boring Terminated at 24.8 Feet 16 65 18 5 13 12 8 11 109 121 NP 40-18-22 5024 5018.5 5002.5 GRAPHIC LOG StratificationAutomatic lines are approximate. In-situ, the transition may be gradual. Hammer Type: THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20165099.GPJ TERRACON_DATATEMPLATE.GDT 4/18/17 STRENGTH TEST FIELD TEST RESULTS DEPTH LOCATION Latitude: 40.57495° Longitude: -105.09783° See Exploration Plan Page 1 of 1 Advancement Method: 3.25 (ID) Hollow-stem auger Abandonment Method: Borings backfilled with soil cuttings upon completion. 1901 Sharp Point Dr Ste C Fort Collins, CO Notes: Project No.: 20165099 Drill Rig: CME-75 Boring Started: 11/3/2016 BORING LOG NO. 3 CLIENT: EdR 5-6-8 N=14 13-26 12-24 20-50 30-41-44 N=85 18-29-47 N=76 3.5 6.0 25.5 FILL: CLAYEY SAND with GRAVEL, fine to coarse grained, brown CLAYEY SAND WITH GRAVEL, fine to coarse grained, reddish-brown to yellowish-brown, medium dense BEDROCK: INTERBEDDED SANDSTONE and CLAYSTONE, fine grained, yellowish-brown to greenish-brown, hard to very hard Boring Terminated at 25.5 Feet UC 6492 4.6 12 17 17 12 13 14 111 110 5023.5 5021 5001.5 GRAPHIC LOG StratificationAutomatic lines are approximate. In-situ, the transition may be gradual. Hammer Type: THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20165099.GPJ TERRACON_DATATEMPLATE.GDT 4/18/17 STRENGTH TEST FIELD TEST RESULTS DEPTH LOCATION Latitude: 40.57493° Longitude: -105.0976° See Exploration Plan Page 1 of 1 Advancement Method: 3.25 (ID) Hollow-stem auger Abandonment Method: Borings backfilled with soil cuttings upon completion. 1901 Sharp Point Dr Ste C Fort Collins, CO Notes: Project No.: 20165099 Drill Rig: CME-75 Boring Started: 11/3/2016 BORING LOG NO. 4 CLIENT: EdR Memphis, Tennessee Driller: R. Geary Boring Completed: 11/3/2016 PROJECT: Elizabeth Street Project 5-10 6-10 10-12-15 N=27 45-50/2" 50/6" 50/5" 50/5" 50/5" 0.3 0.6 8.0 12.0 34.4 ASPHALT, approximately 4 inches BASE COURSE, approximately 3 inches SANDY LEAN CLAY, brown, stiff SILTY SAND WITH GRAVEL (SM), brown to to red brown, medium dense BEDROCK: INTERBEDDED SANDSTONE and CLAYSTONE, light brown to yellow/orange brown, very hard Boring Terminated at 34.4 Feet UC 5113 7.9 21 21 17 11 14 17 15 15 13 105 107 NP 5027 5027 5019.5 5015.5 4993 GRAPHIC LOG StratificationAutomatic lines are approximate. In-situ, the transition may be gradual. Hammer Type: THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20165099.GPJ TERRACON_DATATEMPLATE.GDT 4/18/17 STRENGTH TEST FIELD TEST RESULTS DEPTH LOCATION Latitude: 40.57549° Longitude: -105.09822° See Exploration Plan Page 1 of 1 Advancement Method: 4-inch solid-stem augers Abandonment Method: Borings backfilled immediately after drilling with soil cuttings and patched with hot mix asphalt 1901 Sharp Point Dr Ste C Fort Collins, CO Notes: 5-12 6-8-9 N=17 10-35 39-50/4" 50/4" 50/5" 50/5" 50/6" 0.3 0.7 4.5 8.0 34.5 ASPHALT, approximately 4 inches BASE COURSE, approximately 4 inches SANDY LEAN CLAY (CL), dark brown, stiff to very stiff LEAN CLAY WITH SAND, with gravel, light brown, stiff to very stiff BEDROCK: INTERBEDDED SANDSTONE and CLAYSTONE, light brown to yellow/orange brown, firm to very hard, approximately 2 feet of weathered bedrock Boring Terminated at 34.5 Feet 53 23 19 14 11 10 11 11 10 100 118 42-18-24 5028.5 5028 5024 5020.5 4994 GRAPHIC LOG StratificationAutomatic lines are approximate. In-situ, the transition may be gradual. Hammer Type: THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20165099.GPJ TERRACON_DATATEMPLATE.GDT 4/18/17 STRENGTH TEST FIELD TEST RESULTS DEPTH LOCATION Latitude: 40.57525° Longitude: -105.09813° See Exploration Plan Page 1 of 1 Advancement Method: 4-inch solid-stem augers Abandonment Method: Borings backfilled immediately after drilling with soil cuttings and patched with hot mix asphalt 1901 Sharp Point Dr Ste C Fort Collins, CO 6-5-7 N=12 6-15 10-12-20 N=32 26-50/5" 30-50/5" 50/6" 39-50/3" 50/5" 0.3 0.6 7.0 34.4 ASPHALT, approximately 3 inches BASE COURSE, approximately 4 inches SANDY LEAN CLAY (CL), with gravel, red brown, stiff to very stiff BEDROCK: INTERBEDDED SANDSTONE and CLAYSTONE, brown to light brown and orange brown, medium hard to very hard, approximately 3 feet of weathered bedrock Boring Terminated at 34.4 Feet 18 53 13 13 13 11 11 10 10 114 32-18-14 5029 5029 5022.5 4995 GRAPHIC LOG StratificationAutomatic lines are approximate. In-situ, the transition may be gradual. Hammer Type: THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20165099.GPJ TERRACON_DATATEMPLATE.GDT 4/18/17 STRENGTH TEST FIELD TEST RESULTS DEPTH LOCATION Latitude: 40.57494° Longitude: -105.09815° See Exploration Plan Page 1 of 1 Advancement Method: 4-inch solid-stem auger Abandonment Method: Borings backfilled immediately after drilling with soil cuttings and patched with hot mix asphalt 1901 Sharp Point Dr Ste C Fort Collins, CO Notes: Project No.: 20165099 Drill Rig: CME-55 Boring Started: 3/16/2017 BORING LOG NO. 7 0 10 20 30 40 50 60 0 20 40 60 80 100 CL or OL CH or OH ML or OL MH or OH Boring ID Depth PL PI Description CLAYEY SAND with GRAVEL SILTY SAND with GRAVEL SANDY LEAN CLAY SILTY SAND with GRAVEL SANDY LEAN CLAY SANDY LEAN CLAY SC SM CL SM CL CL Fines P L A S T I C I T Y I N D E X LIQUID LIMIT "U" Line "A" Line 37 NP 40 NP 42 32 17 NP 18 NP 18 18 31 16 65 21 53 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 100 10 1 0.1 0.01 0.001 2 3 3 5 6 37 NP 40 NP 42 0.45 0.197 0.525 2.392 1.515 0.139 12.5 19 4.75 19 12.5 6 16 20 30 40 50 1.5 6 200 810 15.3 25.5 0.0 22.7 1.7 14 LL PL PI 1 4 3/4 1/2 60 fine 2 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 100 10 1 0.1 0.01 0.001 7 32 19 0.144 6 16 20 30 40 50 1.5 6 200 810 9.9 14 LL PL PI 1 4 3/4 1/2 60 fine 7 GRAIN SIZE IN MILLIMETERS PERCENT FINER BY WEIGHT coarse fine U.HYDROMETERS. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS 18 14 D100 Cc Cu SILT OR CLAY 4 D30 D10 %Gravel %Sand 2 - 3.5 3/8 3 100 3 2 140 COBBLES GRAVEL SAND 37.2 D60 coarse medium Boring ID Depth Boring ID Depth GRAIN SIZE DISTRIBUTION 2 - 3.5 ASTM D422 / ASTM C136 WC (%) -10 -8 -6 -4 -2 0 2 4 100 1,000 10,000 AXIAL STRAIN, % PRESSURE, psf SWELL CONSOLIDATION TEST ASTM D4546 NOTES: Sample exhibited 0.1 percent compression at an applied pressure of 500 psf. PROJECT: Elizabeth Street Project PROJECT NUMBER: 20165099 SITE: 1208 and 1220 West Elizabeth Street Fort Collins, Colorado CLIENT: EdR Memphis, Tennessee 1901 Sharp Point Dr Ste C Fort Collins, CO Specimen Identification Classification , pcf 4 111 17 WC, % 6 - 7 ft BEDROCK: INTERBEDDED SANDSTONE and CLAYSTONE LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS 20165099.GPJ TERRACON_DATATEMPLATE.GDT 4/18/17 -10 -8 -6 -4 -2 0 2 4 100 1,000 10,000 AXIAL STRAIN, % PRESSURE, psf SWELL CONSOLIDATION TEST ASTM D4546 NOTES: Sample exhibited 1.6 percent swell upon wetting under an applied pressure of 150 psf. PROJECT: Elizabeth Street Project PROJECT NUMBER: 20165099 SITE: 1208 and 1220 West Elizabeth Street Fort Collins, Colorado CLIENT: EdR Memphis, Tennessee 1901 Sharp Point Dr Ste C Fort Collins, CO Specimen Identification Classification , pcf 5 105 21 WC, % 2 - 3 ft SANDY LEAN CLAY LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS 20165099.GPJ TERRACON_DATATEMPLATE.GDT 4/18/17 -10 -8 -6 -4 -2 0 2 4 100 1,000 10,000 AXIAL STRAIN, % PRESSURE, psf SWELL CONSOLIDATION TEST ASTM D4546 NOTES: Sample exhibited 2.2 percent swell upon wetting under an applied pressure of 500 psf. PROJECT: Elizabeth Street Project PROJECT NUMBER: 20165099 SITE: 1208 and 1220 West Elizabeth Street Fort Collins, Colorado CLIENT: EdR Memphis, Tennessee 1901 Sharp Point Dr Ste C Fort Collins, CO Specimen Identification Classification , pcf 6 118 14 WC, % 9 - 10 ft BEDROCK: INTERBEDDED SANDSTONE and CLAYSTONE LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS 20165099.GPJ TERRACON_DATATEMPLATE.GDT 4/18/17 -10 -8 -6 -4 -2 0 2 4 100 1,000 10,000 AXIAL STRAIN, % PRESSURE, psf SWELL CONSOLIDATION TEST ASTM D4546 NOTES: Sample exhibited 0.1 percent compression upon wetting under an applied pressure of 500 psf. PROJECT: Elizabeth Street Project PROJECT NUMBER: 20165099 SITE: 1208 and 1220 West Elizabeth Street Fort Collins, Colorado CLIENT: EdR Memphis, Tennessee 1901 Sharp Point Dr Ste C Fort Collins, CO Specimen Identification Classification , pcf 7 114 13 WC, % 4 - 5 ft SANDY LEAN CLAY LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS 20165099.GPJ TERRACON_DATATEMPLATE.GDT 4/18/17 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000 5,500 6,000 6,500 0 2 4 6 8 10 2.40 4.82 6492 Assumed Specific Gravity: Unconfined Compressive Strength (psf) Undrained Shear Strength: (psf) Calculated Void Ratio: Height / Diameter Ratio: SPECIMEN FAILURE MODE SPECIMEN TEST DATA 2.01 4.57 Moisture Content: % Dry Density: pcf COMPRESSIVE STRESS - psf DESCRIPTION: BEDROCK: INTERBEDDED SANDSTONE and CLAYSTONE 17 3246 LL PL PI Percent < #200 Sieve AXIAL STRAIN - % Remarks: ASTM D2166 UNCONFINED COMPRESSION TEST Failure Mode: Shear (dashed) Diameter: in. Height: in. Calculated Saturation: % Failure Strain: % Strain Rate: in/min 115 SAMPLE TYPE: D&M RING SAMPLE LOCATION: 4 @ 6 - 7 feet PROJECT NUMBER: 20165099 PROJECT: Elizabeth Street Project SITE: 1208 and 1220 West Elizabeth Street Fort Collins, Colorado CLIENT: EdR Memphis, Tennessee 1901 Sharp Point Dr Ste C Fort Collins, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. UNCONFINED 20165099.GPJ TERRACON_DATATEMPLATE.GDT 4/18/17 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000 5,500 6,000 6,500 0 2 4 6 8 10 2.39 6.05 5113 Assumed Specific Gravity: Unconfined Compressive Strength (psf) Undrained Shear Strength: (psf) Calculated Void Ratio: Height / Diameter Ratio: SPECIMEN FAILURE MODE SPECIMEN TEST DATA 2.53 7.93 Moisture Content: % Dry Density: pcf COMPRESSIVE STRESS - psf DESCRIPTION: 17 2557 LL PL PI Percent < #200 Sieve AXIAL STRAIN - % Remarks: ASTM D2166 UNCONFINED COMPRESSION TEST Failure Mode: Shear (dashed) Diameter: in. Height: in. Calculated Saturation: % Failure Strain: % Strain Rate: in/min 107 SAMPLE TYPE: D&M RING SAMPLE LOCATION: 5 @ 4 - 5 feet PROJECT NUMBER: 20165099 PROJECT: Elizabeth Street Project SITE: 1208 and 1220 West Elizabeth Street Fort Collins, Colorado CLIENT: EdR Memphis, Tennessee 1901 Sharp Point Dr Ste C Fort Collins, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. UNCONFINED 20165099.GPJ TERRACON_DATATEMPLATE.GDT 4/18/17 TASK NO: 161107023 Analytical Results Terracon, Inc. - Fort Collins Kurt F. Stauder Company: Report To: Company: Bill To: 1901 Sharp Point Drive Suite C Fort Collins CO 80525 Accounts Payable Terracon, Inc. - A/P 18001 W. 106th St Suite 300 Olathe KS 66061 Date Reported: 11/9/16 Task No.: 161107023 Matrix: Soil - Geotech Date Received: 11/7/16 Client Project: Client PO: Customer Sample ID 2016 B3 @ 9ft Test Method Lab Number: 161107023-01 Result Sulfate - Water Soluble 0.006 % AASHTO T290-91/ ASTM D4327 Customer Sample ID 2016 B1 @ 2ft Test Method Lab Number: 161107023-02 Result Sulfate - Water Soluble 0.018 % AASHTO T290-91/ ASTM D4327 240 South Main Street / Brighton, CO 80601-0507 / 303-659-2313 Mailing Address: P.O. Box 507 / Brighton, CO 80601-0507 / Fax: 303-659-2315 DATA APPROVED FOR RELEASE BY Abbreviations/ References: 161107023 AASHTO - American Association of State Highway and Transportation Officials. ASTM - American Society for Testing and Materials. ASA - American Society of Agronomy. DIPRA - Ductile Iron Pipe Research Association Handbook of Ductile Iron Pipe. TASK NO: 170327012 Analytical Results Terracon, Inc. - Fort Collins Eric D. Bernhardt Company: Report To: Company: Bill To: 1901 Sharp Point Drive Suite C Fort Collins CO 80525 Accounts Payable Terracon, Inc. - A/P 18001 W. 106th St Suite 300 Olathe KS 66061 20165099 Date Reported: 4/3/17 Task No.: 170327012 Matrix: Soil - Geotech Date Received: 3/27/17 Client Project: Client PO: Customer Sample ID 6 @ 4-5.5 Test Method Lab Number: 170327012-01 Result Sulfate - Water Soluble 0.027 % AASHTO T290-91/ ASTM D4327 240 South Main Street / Brighton, CO 80601-0507 / 303-659-2313 Mailing Address: P.O. Box 507 / Brighton, CO 80601-0507 / Fax: 303-659-2315 DATA APPROVED FOR RELEASE BY Abbreviations/ References: 170327012 AASHTO - American Association of State Highway and Transportation Officials. ASTM - American Society for Testing and Materials. ASA - American Society of Agronomy. DIPRA - Ductile Iron Pipe Research Association Handbook of Ductile Iron Pipe. 11/11/2016 20165099 Elizabeth Street Project Fort Collins, Colorado 2,000 to 4,000 Unconfined Compressive Strength Qu, (psf) less than 500 500 to 1,000 1,000 to 2,000 4,000 to 8,000 > 8,000 Modified Dames & Moore Ring Sampler Standard Penetration Test Trace PLASTICITY DESCRIPTION Water levels indicated on the soil boring logs are the levels measured in the borehole at the times indicated. Groundwater level variations will occur over time. In low permeability soils, accurate determination of groundwater levels is not possible with short term water level observations. DESCRIPTION OF SYMBOLS AND ABBREVIATIONS GENERAL NOTES > 30 11 - 30 Low 1 - 10 Non-plastic Plasticity Index #4 to #200 sieve (4.75mm to 0.075mm Boulders Cobbles 12 in. to 3 in. (300mm to 75mm) Gravel 3 in. to #4 sieve (75mm to 4.75 mm) Sand Silt or Clay Passing #200 sieve (0.075mm) Particle Size Water Level After a Specified Period of Time Water Level After a Specified Period of Time Water Initially Encountered Soil classification is based on the Unified Soil Classification System. Coarse Grained Soils have more than 50% of their dry weight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand. Fine Grained Soils have less than 50% of their dry weight retained on a #200 sieve; they are principally 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 in-place relative density and fine-grained soils on the basis of their consistency. Unless otherwise noted, Latitude and Longitude are approximately determined using a hand-held GPS device. The accuracy of such devices is variable. Surface elevation data annotated with +/- indicates that no ctual topographical survey was conducted to confirm the surface elevation. Instead, the surface elevation was approximately determined from topographic maps of the area. GRAIN SIZE TERMINOLOGY RELATIVE PROPORTIONS OF SAND AND GRAVEL RELATIVE PROPORTIONS OF FINES DESCRIPTIVE SOIL CLASSIFICATION UNIFIED SOIL CLASSIFICATION SYSTEM Exhibit C-2 Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests A Soil Classification Group Symbol Group Name B Coarse Grained Soils: More than 50% retained on No. 200 sieve Gravels: More than 50% of coarse fraction retained on No. 4 sieve Clean Gravels: Less than 5% fines C Cu 4 and 1 Cc 3 E GW Well-graded gravel F Cu 4 and/or 1 Cc 3 E GP Poorly graded gravel F Gravels with Fines: More than 12% fines C Fines classify as ML or MH GM Silty gravel F,G,H Fines classify as CL or CH GC Clayey gravel F,G,H Sands: 50% or more of coarse fraction passes No. 4 sieve Clean Sands: Less than 5% fines D Cu 6 and 1 Cc 3 E SW Well-graded sand I Cu 6 and/or 1 Cc 3 E SP Poorly graded sand I Sands with Fines: More than 12% fines D Fines classify as ML or MH SM Silty sand G,H,I Fines classify as CL or CH SC Clayey sand G,H,I Fine-Grained Soils: 50% or more passes the No. 200 sieve Silts and Clays: Liquid limit less than 50 Inorganic: PI 7 and plots on or above “A” line J CL Lean clay K,L,M PI 4 or plots below “A” line J ML Silt K,L,M Organic: Liquid limit - oven dried 0.75 OL Organic clay K,L,M,N Liquid limit - not dried Organic silt K,L,M,O Silts and Clays: Liquid limit 50 or more 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 0.75 OH Organic clay K,L,M,P Liquid limit - not dried Organic silt K,L,M,Q Highly organic soils: Primarily organic matter, dark in color, and organic odor PT Peat A Based on the material passing the 3-inch (75-mm) sieve B If field sample contained cobbles or boulders, or both, add “with cobbles or boulders, or both” to group name. DESCRIPTION OF ROCK PROPERTIES Exhibit C-3 WEATHERING Fresh Rock fresh, crystals bright, few joints may show slight staining. Rock rings under hammer if crystalline. Very slight Rock generally fresh, joints stained, some joints may show thin clay coatings, crystals in broken face show bright. Rock rings under hammer if crystalline. Slight Rock generally fresh, joints stained, and discoloration extends into rock up to 1 in. Joints may contain clay. In granitoid rocks some occasional feldspar crystals are dull and discolored. Crystalline rocks ring under hammer. Moderate Significant portions of rock show discoloration and weathering effects. In granitoid rocks, most feldspars are dull and discolored; some show clayey. Rock has dull sound under hammer and shows significant loss of strength as compared with fresh rock. Moderately severe All rock except quartz discolored or stained. In granitoid rocks, all feldspars dull and discolored and majority show kaolinization. Rock shows severe loss of strength and can be excavated with geologist’s pick. Severe All rock except quartz discolored or stained. Rock “fabric” clear and evident, but reduced in strength to strong soil. In granitoid rocks, all feldspars kaolinized to some extent. Some fragments of strong rock usually left. Very severe All rock except quartz discolored or stained. Rock “fabric” discernible, but mass effectively reduced to “soil” with only fragments of strong rock remaining. Complete Rock reduced to ”soil”. Rock “fabric” not discernible or discernible only in small, scattered locations. Quartz may be present as dikes or stringers. HARDNESS (for engineering description of rock – not to be confused with Moh’s scale for minerals) Very hard Cannot be scratched with knife or sharp pick. Breaking of hand specimens requires several hard blows of geologist’s pick. Hard Can be scratched with knife or pick only with difficulty. Hard blow of hammer required to detach hand specimen. Moderately hard Can be scratched with knife or pick. Gouges or grooves to ¼ in. deep can be excavated by hard blow of point of a geologist’s pick. Hand specimens can be detached by moderate blow. Medium Can be grooved or gouged 1/16 in. deep by firm pressure on knife or pick point. Can be excavated in small chips to pieces about 1-in. maximum size by hard blows of the point of a geologist’s pick. Soft Can be gouged or grooved readily with knife or pick point. Can be excavated in chips to pieces several inches in size by moderate blows of a pick point. Small thin pieces can be broken by finger pressure. Very soft Can be carved with knife. Can be excavated readily with point of pick. Pieces 1-in. or more in thickness can be broken with finger pressure. Can be scratched readily by fingernail. Joint, Bedding, and Foliation Spacing in Rock a Spacing Joints Bedding/Foliation Less than 2 in. Very close Very thin 2 in. – 1 ft. Close Thin 1 ft. – 3 ft. Moderately close Medium 3 ft. – 10 ft. Wide Thick More than 10 ft. Very wide Very thick a. Spacing refers to the distance normal to the planes, of the described feature, which are parallel to each other or nearly so. Rock Quality Designator (RQD) a Joint Openness Descriptors RQD, as a percentage Diagnostic description Openness Descriptor Exceeding 90 Excellent No Visible Separation Tight 90 – 75 Good Less than 1/32 in. Slightly Open 75 – 50 Fair 1/32 to 1/8 in. Moderately Open 50 – 25 Poor 1/8 to 3/8 in. Open Less than 25 Very poor 3/8 in. to 0.1 ft. Moderately Wide a. RQD (given as a percentage) = length of core in pieces Greater than 0.1 ft. Wide 4 in. and longer/length of run. References: American Society of Civil Engineers. Manuals and Reports on Engineering Practice - No. 56. Subsurface Investigation for Design and Construction of Foundations of Buildings. New York: American Society of Civil Engineers, 1976. U.S. Department of the Interior, Bureau of Reclamation, Engineering Geology Field Manual. C Gravels with 5 to 12% fines require dual symbols: GW-GM well-graded gravel with silt, GW-GC well-graded gravel with clay, GP-GM poorly graded gravel with silt, GP-GC poorly graded gravel with clay. D Sands with 5 to 12% fines require dual symbols: 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 E Cu = D60/D10 Cc = 10 60 2 30 D x D (D ) F If soil contains 15% sand, add “with sand” to group name. G If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM. H If fines are organic, add “with organic fines” to group name. I If soil contains 15% gravel, add “with gravel” to group name. J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay. K If soil contains 15 to 29% plus No. 200, add “with sand” or “with gravel,” whichever is predominant. L If soil contains 30% plus No. 200 predominantly sand, add “sandy” to group name. M If soil contains 30% plus No. 200, predominantly gravel, add “gravelly” to group name. N PI 4 and plots on or above “A” line. O PI 4 or plots below “A” line. P PI plots on or above “A” line. Q PI plots below “A” line. LOCATION AND ELEVATION NOTES SAMPLING WATER LEVEL FIELD TESTS N (HP) (T) (DCP) UC (PID) (OVA) Standard Penetration Test Resistance (Blows/Ft.) Hand Penetrometer Torvane Dynamic Cone Penetrometer Unconfined Compressive Strength Photo-Ionization Detector Organic Vapor Analyzer Medium Over 12 in. (300 mm) 0 >12 5-12 <5 Percent of Dry Weight Major Component of Sample Term Modifier With Trace Descriptive Term(s) of other constituents Modifier >30 <15 Percent of Dry Weight Descriptive Term(s) of other constituents With 15-29 High 2 - 4 BEDROCK Standard Penetration or N-Value Blows/Ft. Very Loose 0 - 3 STRENGTH TERMS Very Soft (More than 50% retained on No. 200 sieve.) Density determined by Standard Penetration Resistance (50% or more passing the No. 200 sieve.) Consistency determined by laboratory shear strength testing, field visual-manual procedures or standard penetration resistance RELATIVE DENSITY OF COARSE-GRAINED SOILS 30 - 49 50 - 79 >79 Descriptive Term (Consistency) Firm < 20 Weathered Hard Very Hard Ring Sampler Blows/Ft. Ring Sampler Blows/Ft. Soft Medium Stiff Stiff Very Stiff Hard 30 - 50 > 50 5 - 9 10 - 18 Descriptive Term (Consistency) 8 - 15 > 30 Ring Sampler Blows/Ft. 10 - 29 > 99 Medium Hard < 3 3 - 4 19 - 42 CONSISTENCY OF FINE-GRAINED SOILS Standard Penetration or N-Value Blows/Ft. > 42 Loose Medium Dense Dense Very Dense 7 - 18 19 - 58 Descriptive Term (Density) 0 - 6 4 - 9 59 - 98 _ 20 - 29 < 30 30 - 49 50 - 89 90 - 119 15 - 30 > 119 Standard Penetration or N-Value Blows/Ft. 18 USCS Classification SANDY LEAN CLAY (CL) %Silt %Fines 52.9 %Clay PROJECT NUMBER: 20165099 PROJECT: Elizabeth Street Project SITE: 1208 and 1220 West Elizabeth Street Fort Collins, Colorado CLIENT: EdR Memphis, Tennessee 1901 Sharp Point Dr Ste C Fort Collins, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS-2 20165099.GPJ TERRACON2015.GDT 4/18/17 3 3 5 6 GRAIN SIZE IN MILLIMETERS PERCENT FINER BY WEIGHT coarse fine U.HYDROMETERS. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS 17 NP 18 NP 18 20 NP 22 NP 24 D100 Cc Cu SILT OR CLAY 4 D30 D10 %Gravel %Sand 2 - 3.5 4 - 5.5 14 - 15.4 9 - 10.5 4 - 5.5 3/8 3 100 3 2 140 COBBLES GRAVEL SAND 53.4 58.0 35.3 56.5 45.7 D60 coarse medium Boring ID Depth Boring ID Depth GRAIN SIZE DISTRIBUTION 2 - 3.5 4 - 5.5 14 - 15.4 9 - 10.5 4 - 5.5 ASTM D422 / ASTM C136 WC (%) 10 5 12 11 19 USCS Classification CLAYEY SAND with GRAVEL (SC) SILTY SAND with GRAVEL (SM) SANDY LEAN CLAY (CL) SILTY SAND with GRAVEL (SM) SANDY LEAN CLAY (CL) %Silt %Fines 31.4 16.5 64.7 20.8 52.7 %Clay PROJECT NUMBER: 20165099 PROJECT: Elizabeth Street Project SITE: 1208 and 1220 West Elizabeth Street Fort Collins, Colorado CLIENT: EdR Memphis, Tennessee 1901 Sharp Point Dr Ste C Fort Collins, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS-2 20165099.GPJ TERRACON2015.GDT 4/18/17 53 LL USCS 2 3 3 5 6 7 ATTERBERG LIMITS RESULTS ASTM D4318 2 - 3.5 4 - 5.5 14 - 15.4 9 - 10.5 4 - 5.5 2 - 3.5 20 NP 22 NP 24 14 PROJECT NUMBER: 20165099 PROJECT: Elizabeth Street Project SITE: 1208 and 1220 West Elizabeth Street Fort Collins, Colorado CLIENT: EdR Memphis, Tennessee 1901 Sharp Point Dr Ste C Fort Collins, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. ATTERBERG LIMITS 20165099.GPJ TERRACON_DATATEMPLATE.GDT 4/18/17 CL-ML CLIENT: EdR Memphis, Tennessee Driller: Drilling Engineers Inc. Boring Completed: 3/16/2017 PROJECT: Elizabeth Street Project 1208 and 1220 West Elizabeth Street Fort Collins, Colorado SITE: No free water observed during drilling or immediately after drilling WATER LEVEL OBSERVATIONS TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) PERCENT FINES WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI ELEVATION (Ft.) Surface Elev.: 5029.5 (Ft.) WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 15 20 25 30 SAMPLE TYPE Notes: Project No.: 20165099 Drill Rig: CME-55 Boring Started: 3/16/2017 BORING LOG NO. 6 CLIENT: EdR Memphis, Tennessee Driller: Drilling Engineers, Inc. Boring Completed: 3/16/2017 PROJECT: Elizabeth Street Project 1208 and 1220 West Elizabeth Street Fort Collins, Colorado SITE: No free water observed during drilling or immediately after drilling WATER LEVEL OBSERVATIONS TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) PERCENT FINES WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI ELEVATION (Ft.) Surface Elev.: 5028.6 (Ft.) WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 15 20 25 30 SAMPLE TYPE Project No.: 20165099 Drill Rig: CME-55 Boring Started: 3/16/2017 BORING LOG NO. 5 CLIENT: EdR Memphis, Tennessee Driller: Drilling Engineers, Inc. Boring Completed: 3/16/2017 PROJECT: Elizabeth Street Project 1208 and 1220 West Elizabeth Street Fort Collins, Colorado SITE: 11' while drilling 13.6' immediately after drilling WATER LEVEL OBSERVATIONS TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) PERCENT FINES WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI ELEVATION (Ft.) Surface Elev.: 5027.5 (Ft.) WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 15 20 25 30 SAMPLE TYPE Referenced City of Fort Collins BM 19-97 (El. 5025.74 NAVD88) 1208 and 1220 West Elizabeth Street Fort Collins, Colorado SITE: No free water observed during drilling 20.9 feet after 24 hours WATER LEVEL OBSERVATIONS TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) PERCENT FINES WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI ELEVATION (Ft.) Surface Elev.: 5027.2 (Ft.) WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 15 20 25 SAMPLE TYPE Memphis, Tennessee Driller: R. Geary Boring Completed: 11/3/2016 PROJECT: Elizabeth Street Project Referenced City of Fort Collins BM 19-97 (El. 5025.74 NAVD88) 1208 and 1220 West Elizabeth Street Fort Collins, Colorado SITE: No free water observed during drilling 15.8 feet after 24 hours WATER LEVEL OBSERVATIONS TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) PERCENT FINES WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI ELEVATION (Ft.) Surface Elev.: 5027.5 (Ft.) WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 15 20 SAMPLE TYPE 1208 and 1220 West Elizabeth Street Fort Collins, Colorado SITE: No free water observed during drilling 10.2 feet after 24 hours WATER LEVEL OBSERVATIONS TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) PERCENT FINES WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI ELEVATION (Ft.) Surface Elev.: 5026.9 (Ft.) WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 15 20 SAMPLE TYPE SITE: No free water observed during drilling No free water observed after 24 hours WATER LEVEL OBSERVATIONS TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) PERCENT FINES WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI ELEVATION (Ft.) Surface Elev.: 5028.0 (Ft.) WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 15 SAMPLE TYPE