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HomeMy WebLinkAboutCROWNE AT OLD TOWN NORTH - Filed SEPD-SURFACE EXPLORATION/PAVEMENT DESIGN REPORT - 2018-09-05Responsive ■ Resourceful ■ Reliable REPORT TOPICS REPORT TOPICS REPORT SUMMARY ....................................................................................................... i INTRODUCTION ............................................................................................................. 1 PROJECT DESCRIPTION .............................................................................................. 1 SITE CONDITIONS ......................................................................................................... 2 GEOTECHNICAL CHARACTERIZATION ...................................................................... 2 CORROSIVITY................................................................................................................ 4 GEOTECHNICAL OVERVIEW ....................................................................................... 4 EARTHWORK................................................................................................................. 4 PAVEMENTS .................................................................................................................. 7 GENERAL COMMENTS ............................................................................................... 10 Note: This report was originally delivered in a web-based format. 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ATTACHMENTS SITE LOCATION AND EXPLORATION PLANS EXPLORATION RESULTS (EXPLORATION AND TESTING PROCEDURES, Boring Logs and Laboratory Data) SUPPORTING INFORMATION (General Notes and Unified Soil Classification System) Geotechnical Engineering Report City-maintained Roadways at Crowne at Old Town North ■ Fort Collins, Colorado September 4, 2018 ■ Terracon Project No. 20185095 Responsive ■ Resourceful ■ Reliable i REPORT SUMMARY Topic 1 Overview Statement 2 Project Overview A geotechnical exploration has been performed for Jerome Street which is a city- maintained roadway planned at the Crowne at Old Town North project to be constructed southwest of the intersection of Conifer Street and Blue Spruce Drive in Fort Collins, Colorado. Three (3) borings were performed to depths of approximately 10½ feet below existing site grades. Subsurface Conditions Subsurface conditions encountered in our exploratory borings generally consisted of about 4 to 7 feet of fill consisting of lean clay with varying amounts of sand over well graded gravel with varying amounts of silt and sand, which extended to the maximum depths of exploration of about 10 feet below existing site grades. Boring logs are presented in the Exploration Results section of this report. Groundwater Conditions Groundwater was encountered in some of our test borings at the time of drilling at depths of about 9 feet below existing site grades. Groundwater levels can fluctuate in response to site development and to varying seasonal and weather conditions, irrigation on or adjacent to the site and fluctuations in nearby water features. We do not anticipate groundwater will significantly impact the proposed construction. Geotechnical Concerns Expansive soils are present on this site and these conditions constitute a geologic hazard. 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 pavements is possible. 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, such as treating the subgrade soils with fly ash. It is imperative the recommendations described in section Grading and Drainage section of the Earthwork section of this report be followed to reduce potential movement. Ground Improvements Results of swell testing indicated swell mitigation may be necessary at this site. We believe swell-mitigation could be completed by properly moisture conditioning the top 12 inches of finished pavement subgrade prior to placement of aggregate base course and asphalt materials. Even with properly prepared and compacted soils, the possibility of damage to the pavements, such as uneven areas and cracking is possible. As an alternative, we believe an initial application of lime and a secondary application of fly ash could be used to treat the upper 12 inches of the on-site soil for swell-mitigation. Grading and Drainage The amount of movement of pavements will be related to the wetting of underlying supporting soils. Therefore, it is imperative the recommendations discussed in the Grading and Drainage section of the Earthwork section this report be followed to reduce potential movement. Pavements Recommended Pavement thicknesses for this project include 5 inches of asphalt over 7 inches of aggregate base course on Jerome Street. Additional pavement section alternatives and discussion are presented in the report. Geotechnical Engineering Report City-maintained Roadways at Crowne at Old Town North ■ Fort Collins, Colorado September 4, 2018 ■ Terracon Project No. 20185095 Responsive ■ Resourceful ■ Reliable ii Topic 1 Overview Statement 2 1. If the reader is reviewing this report as a pdf, the topics (bold orange font) above can be used to access the appropriate section of the report by simply clicking on the topic itself. 2. This summary is for convenience only. It should be used in conjunction with the entire report for design purposes. It should be recognized that specific details were not included or fully developed in this section, and the report must be read in its entirety for a comprehensive understanding of the items contained herein. Responsive ■ Resourceful ■ Reliable 1 INTRODUCTION Geotechnical Engineering Report City-maintained Roadways at Crowne at Old Town North Southwest of Conifer Street and Blue Spruce Drive Fort Collins, Colorado Terracon Project No. 20185095 September 4, 2018 INTRODUCTION This report presents the results of our subsurface exploration and geotechnical engineering services performed for Jerome Street within the Crowne at Old Town North subdivision to be located southwest of the intersection of Conifer Street and Blue Spruce Drive in Fort Collins, Colorado. The purpose of these services is to provide information and geotechnical engineering recommendations relative to: ■ Subsurface soil conditions ■ Site preparation and earthwork ■ Groundwater conditions ■ Pavement design and construction The geotechnical engineering scope of services for this project included the advancement of three (3) test borings to depths of approximately 10 feet below existing site grades. Maps showing the site and boring locations are shown in the Site Location and Exploration Plan sections, respectively. The results of the laboratory testing performed on soil samples obtained from the site during the field exploration are included on the boring logs and as separate graphs in the Exploration Results section of this report. PROJECT DESCRIPTION Our initial understanding of the project was provided in our proposal and was discussed in the project planning stage. A period of collaboration has transpired since the project was initiated, and our final understanding of the project conditions is as follows: Item Description Information Provided The following project information is based on conversation with the Connell Resources, Inc. who is currently completing the earthwork for the project. Project Description We understand the new pavements are being constructed as part of the project. Based on site plans, we understand two main city-maintained roads will run through the proposed apartment structures. Jerome Street spans north-south roughly through the center of the development. Geotechnical Engineering Report City-maintained Roadways at Crowne at Old Town North ■ Fort Collins, Colorado September 4, 2018 ■ Terracon Project No. 20185095 Responsive ■ Resourceful ■ Reliable 2 Item Description Grading/Slopes We understand the roadway is currently at finished grade. Pavements Traffic loads were provided to us by the City of Fort Collins. The following traffic conditions were used for the design of Lupine Drive Pavements: ■ Jerome Street: Minor Connector, 18-kip equivalent single-axle load (ESAL) of 182,500 SITE CONDITIONS The following description of site conditions is derived from our site visit in association with the field exploration and our review of publicly available geologic and topographic maps. Item Description Parcel Information The project site is located southwest of the intersection of Conifer Street and Blue Spruce Drive in Fort Collins, Colorado. The project includes Jerome Street which is a city-maintained roadway within the proposed subdivision. The approximate Latitude/Longitude of the center of the site is 40.60156° N/105.07313°W (Please refer to Site Location). Existing Improvements We understand the site was originally a vacant field and is currently under construction for the proposed roadway. Surrounding Developments The site is bordered by retail and commercial buildings to the north and west. To the south and east of the site is undeveloped land followed by single-family residential developments. Current Ground Cover The site is currently covered with graded native soils and properly placed fills in preparation for the construction of the proposed roadways. Existing Topography The site is relatively flat and has been graded for proposed roadways. GEOTECHNICAL CHARACTERIZATION Subsurface Profile 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: Geotechnical Engineering Report City-maintained Roadways at Crowne at Old Town North ■ Fort Collins, Colorado September 4, 2018 ■ Terracon Project No. 20185095 Responsive ■ Resourceful ■ Reliable 3 Material Description Approximate Depth to Bottom of Stratum Fill consisting of lean clay with varying amounts of sand About 4 to 7 feet below existing site grades. Fill consisting of well graded gravel with silt and sand To the maximum depth of exploration of about 10 feet. Groundwater Conditions The boreholes were observed while drilling and after completion for the presence and level of groundwater. 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. 1 9 2 9 3 Not encountered 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 pavements may be higher or lower than the levels indicated on the boring logs. However, we do not anticipate groundwater will significantly impact the proposed construction. Laboratory Testing Representative soil samples were selected for swell-consolidation testing and exhibited no movement to 2.8 percent swell when wetted. Samples of site soils selected for plasticity testing exhibited low to moderate plasticity with liquid limits ranging from non-plastic to 41 and plasticity indices ranging from non-plastic to 22. Laboratory test results are presented in the Exploration Results section of this report. Geotechnical Engineering Report City-maintained Roadways at Crowne at Old Town North ■ Fort Collins, Colorado September 4, 2018 ■ Terracon Project No. 20185095 Responsive ■ Resourceful ■ Reliable 4 CORROSIVITY At the time this report was prepared, the laboratory testing for water-soluble sulfates had not been completed. We will submit a supplemental section with the testing results and recommendations once the testing has been completed. However, previous test results indicate comparatively high water-soluble sulfate concentrations should be expected. GEOTECHNICAL OVERVIEW 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 and the owner understands the inherent risks associated with construction on sites underlain by expansive soils. We have identified expansive soils as a possible geotechnical conditions that could impact design, construction and performance of the proposed pavements. This condition will require particular attention in project planning, design and during construction and are discussed in greater detail in the following sections. Expansive Soils Expansive soils are present on this site and these conditions constitute a geologic hazard. 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 pavements is possible. 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, such as treating the subgrade soils with fly ash. It is imperative the recommendations described in section Grading and Drainage section of the Earthwork section of this report be followed to reduce potential movement. The General Comments section provides an understanding of the report limitations. EARTHWORK The following presents recommendations for fly ash treatment and placement of aggregate base course 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 fly ash treatment, testing of aggregate base course, subgrade stabilization, and other geotechnical conditions exposed during the construction of the project. Geotechnical Engineering Report City-maintained Roadways at Crowne at Old Town North ■ Fort Collins, Colorado September 4, 2018 ■ Terracon Project No. 20185095 Responsive ■ Resourceful ■ Reliable 5 Swell-Mitigation and Subgrade Stabilization Results of swell testing indicated swell mitigation is necessary at this site. We believe swell- mitigation could be completed by scarifying, properly moisture conditioning and compacting the top 12 inches of finished pavement subgrade prior to placement of aggregate base course and asphalt materials. Even with properly prepared and compacted soils, the possibility of damage to the pavements, such as uneven areas and cracking is possible. As an alternative, we believe fly ash could be used to treat the upper 12 inches of the on-site soil for swell-mitigation. The sulfate testing for this roadway was not complete at the time of this report; however, based on comparatively high sulfate concentrations encountered on Lupine Drive, we anticipate high sulfate concentration on the soils currently below the proposed roadway. The sulfate concentrations in the soils previously tested are above typical acceptable limits to allow for conventional chemical stabilization of subgrade soils. If fly ash is used to stabilize subgrade below the proposed pavements planned as part of this project, we recommend an initial application of lime, followed by a 5 to 7 days mellowing period. After mellowing, the subgrade soils can be treated with fly ash. Lime and Fly Ash Treatment Recommendations In order to reduce the risk of heave caused by adverse reaction between the sulfates in the subgrade soils and the stabilization agent, we recommend chemical stabilization be performed using double treatment application with lime and fly ash. We recommend the following general procedures for construction of chemically treated pavement subgrade soils for the city-maintained roadways on the project site. The pavement subgrade should be shaped to final grade. We recommend initially treating the upper 12 inches of the pavement subgrade uniformly with 3 percent lime by weight. The lime should meet the requirements of ASTM C207, Type N and be mixed as outlined in ASTM C977. Water should be added (as needed) to the lime-soil mixture during the mixing process until a uniform, homogeneous mixture is achieved at or slightly above optimum moisture content for the mixture. Following initial mixing with the lime, we recommend allowing the lime-soil mixture to mellow for a period of 5 to 7 days. The mellowing time needed for the initial stabilization process will depend on weather conditions, continuous moistening of the lime-soil mixture, protection measures to promote ettringite formation, and soil properties. Terracon will assist the project team with determining the appropriate mellowing time as the process approaches 5 days. Following the mellowing period, we recommend thoroughly remixing the lime-soil mixture to mechanically break down any ettringite formation that has occurred. An additional 8 percent fly ash should then be remixed uniformly into the lime-soil mixture. Fly ash should meet the requirements specified in ASTM C618 for Class C fly ash. The fly ash-lime-soil mixture should be moisture conditioned to within 2 percent of optimum moisture content and compacted to at Geotechnical Engineering Report City-maintained Roadways at Crowne at Old Town North ■ Fort Collins, Colorado September 4, 2018 ■ Terracon Project No. 20185095 Responsive ■ Resourceful ■ Reliable 6 least 95 percent of the mixture’s maximum dry unit weight as determined by ASTM D698. Compaction of the mixture should be completed within 2 hours of the addition of water to the fly ash-lime-soil mixture. The subgrade should be compacted and sealed with a pneumatic-tire roller that is sufficiently light in weight so as to not cause hairline cracking of the treated subgrade. After completion of the double application and compaction, the treated subgrade should be allowed to cure for a minimum of 48 hours prior to placing aggregate base course. A longer cure time may be necessary depending on adverse weather conditions and protection measures implemented by the contractor. During this cure time, the surface of the treated subgrade should be kept moist by periodically sprinkling with water. Strength gains of the treated subgrade will be slower during cooler weather periods, particularly if the temperature drops below 40 degrees Fahrenheit. Construction traffic on the treated subgrade prior to placement of the aggregate base course and pavement construction should be limited and the subgrade should be protected from freezing or drying at all times until paving. Covering the subgrade or other protective measures may be required. Once trimming and the final subgrade elevation has been reached, the treated subgrade should be proof-rolled with a rubber tire vehicle with at least 18 kips per axle. Areas of the treated subgrade that are soft, excessively wet, or unstable should be repaired by drying and/or removal and replacement. Chemically treated soils can be re-used as backfill for repaired areas. Compaction Requirements Fly ash treated subgrade (if used) and aggregate base course 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 AASHTO T99. 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 Geotechnical Engineering Report City-maintained Roadways at Crowne at Old Town North ■ Fort Collins, Colorado September 4, 2018 ■ Terracon Project No. 20185095 Responsive ■ Resourceful ■ Reliable 7 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 materials could result in an increase in the material’s expansive potential. Subsequent wetting of these materials could result in undesirable movement. Grading and Drainage All grades must be adjusted to provide effective drainage away from the proposed pavements during construction and maintained throughout the life of the proposed project. Infiltration of water into excavations must be prevented during construction. Water permitted to pond near or adjacent to the perimeter of the pavements (either during or post-construction) can 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. Backfill against curbs and gutters should be properly compacted and free of all construction debris to reduce the possibility of moisture infiltration. After construction of the proposed pavements and prior to project completion, we recommend verification of final grading be performed to document positive drainage, as described above, has been achieved The General Comments section provides an understanding of the report limitations. PAVEMENTS Pavements - Subgrade Preparation 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. Areas of soft spots should be stabilized with removal, moisture conditioning and recompaction. All pavement areas should be moisture conditioned and properly compacted to the recommendations in this report immediately prior to paving. Samples of the fill material selected for swell-consolidation testing swelled approximately no movement to 2.8 percent when wetted under an applied pressure of 150 psf which is more than the Geotechnical Engineering Report City-maintained Roadways at Crowne at Old Town North ■ Fort Collins, Colorado September 4, 2018 ■ Terracon Project No. 20185095 Responsive ■ Resourceful ■ Reliable 8 maximum 2 percent criteria established for determining if swell-mitigation procedures in the pavement sections are required per LCUASS standards. Therefore, swell-mitigation of the subgrade materials prior to pavement operations is required. We believe scarifying, moisture conditioning and properly compacting the upper 12 inches of on-site soils immediately prior to placement of pavement materials will help mitigate possible swell potential of on-site soils. As a lower risk alternative, fly ash treatment can be used, provided the subgrade soils are first treated with lime in order to reduce the risk of heave caused by adverse reaction between the sulfates likely in the subgrade soils and the stabilization agent. Recommendations for lime and fly ash treatment are provided in the Earthwork section of this report. Pavements – Design Recommendations Design of pavements for the project have been based on the procedures outlined in the 1993 Guideline for Design of Pavement Structures prepared by the American Association of State Highway and Transportation Officials (AASHTO) and the Larimer County Urban Area Street Standards (LCUASS). Traffic patterns and anticipated loading conditions were provided to us by the City of Fort Collins. For our pavement thicknesses design recommendations, we used an 18-kip equivalent single- axle load (ESAL) of 182,500 for Jerome Street. This traffic design values should be verified by the civil engineer or owner prior to final design and construction. If the actual traffic values vary from the assumed values, the pavement thickness recommendations may not be applicable. When the actual traffic design information is available Terracon should be contacted so that the design recommendations can be reviewed and revised if necessary. For flexible pavement design, a terminal serviceability index of 2.3 was utilized along with an inherent reliability of 85 percent and a design life of 20 years. Using the calculated design R-value of 16, appropriate ESAL, environmental criteria and other factors, the structural numbers (SN) of the pavement sections were determined on the basis of the 1993 AASHTO design equation. In addition to the flexible pavement design analyses, a rigid pavement design analysis was completed based upon AASHTO design procedures. Rigid pavement design is based on an evaluation of the Modulus of Subgrade Reaction of the soils (k-value), the Modulus of Rupture of the concrete, and other factors previously outlined. The design k-value of 80 for the subgrade soil was determined by correlation to the laboratory test results. A modulus of rupture of 600 psi (working stress 450 psi) was used for pavement concrete. The rigid pavement thickness for each traffic category was determined on the basis of the AASHTO design equation. Recommended minimum pavement sections are provided in the table below. Geotechnical Engineering Report City-maintained Roadways at Crowne at Old Town North ■ Fort Collins, Colorado September 4, 2018 ■ Terracon Project No. 20185095 Responsive ■ Resourceful ■ Reliable 9 Alternative Recommended Pavement Thicknesses (Inches) Asphaltic Concrete Surface Aggregate Base Course Fly Ash Treated Subgrade Portland Cement Concrete Total A 5 7 - - 12 B 4 6 12 - 22 C - - 5½ 5½ 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 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. Joints should be sealed to prevent entry of foreign material and doweled where necessary for load transfer. Geotechnical Engineering Report City-maintained Roadways at Crowne at Old Town North ■ Fort Collins, Colorado September 4, 2018 ■ Terracon Project No. 20185095 Responsive ■ Resourceful ■ Reliable 10 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. Pavements – Construction Considerations 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 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. Pavements – Maintenance 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. GENERAL COMMENTS As the project progresses, we address assumptions by incorporating information provided by the design team, if any. Revised project information that reflects actual conditions important to our services is reflected in the final report. The design team should collaborate with Terracon to confirm these assumptions and to prepare the final design plans and specifications. This facilitates the incorporation of our opinions related to implementation of our geotechnical recommendations. Geotechnical Engineering Report City-maintained Roadways at Crowne at Old Town North ■ Fort Collins, Colorado September 4, 2018 ■ Terracon Project No. 20185095 Responsive ■ Resourceful ■ Reliable 11 Any information conveyed prior to the final report is for informational purposes only and should not be considered or used for decision-making purposes. Our analysis and opinions are based upon our understanding of the project, the geotechnical conditions in the area, and the data obtained from our site exploration. Natural variations will occur between exploration point locations 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. Terracon should be retained as the Geotechnical Engineer, where noted in the final report, to provide observation and testing services during pertinent construction phases. 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 or collaboration through this system are intended for the sole benefit and exclusive use of our client for specific application to the project discussed and are accomplished in accordance with generally accepted geotechnical engineering practices with no third party beneficiaries intended. Any third party access to services or correspondence is solely for information purposes to support the services provided by Terracon to our client. Reliance upon the services and any work product is limited to our client, and is not intended for third parties. Any use or reliance of the provided information by third parties is done solely at their own risk. 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 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. If 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. ATTACH MENTS ATTACHMENTS SITE LOCA TION AND EXPLORATION PLANS SITE LOCATION AND EXPLORATION PLANS SITE LOCATION City-Maintained Roadways at Crowne at Old Town North ■ Fort Collins, CO September 4, 2018 ■ Terracon Project No. 20185095 TOPOGRAPHIC MAP IMAGE COURTESY OF THE U.S. GEOLOGICAL SURVEY QUADRANGLES INCLUDE: WELLINGTON, CO (1978) and FORT COLLINS, CO (1984). DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES SITE EXPLORATION PLAN City-Maintained Roadways at Crowne at Old Town North ■ Fort Collins, CO September 4, 2018 ■ Terracon Project No. 20185095 DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES AERIAL PHOTOGRAPHY PROVIDED BY MICROSOFT BING MAPS EXPLORATION RESULTS EXPLORATION RESULTS Geotechnical Engineering Report City-maintained Roadways at Crowne at Old Town North ■ Fort Collins, Colorado September 4, 2018 ■ Terracon Project No. 20185095 Responsive ■ Resourceful ■ Reliable EXPLORATION AND TESTING PROCEDURES Field Exploration The field exploration program consisted of the following: Number of Borings Planned Boring Depth (feet) 1 Planned Location 3 10 or auger refusal Approximately every 500 feet along Jerome Street 1. Proposed borings will be completed to the planned depths below existing site grades or practical auger refusal, if shallower. Boring Layout and Elevations: We used handheld GPS equipment to locate borings with an estimated horizontal accuracy of +/-20 feet. We understand the ground surface elevation at the time we completed our borings was at the finished grade of the planned Lupine Drive. Subsurface Exploration Procedures: We advanced soil borings with a truck-mounted drill rig using 4-inch solid-stem continuous-flight augers. Three samples were obtained in the upper 10 feet of each boring. Soil sampling was performed using modified California barrel, and standard split-barrel sampling procedures. For the standard split-barrel sampling procedure, a standard 2- inch outer diameter split-barrel sampling spoon is driven into the ground by a 140-pound automatic hammer falling a distance of 30 inches. The number of blows required to advance the sampling spoon the last 12 inches of a normal 18-inch penetration is recorded as the Standard Penetration Test (SPT) resistance value. The SPT resistance values, also referred to as N-values, are indicated on the boring logs at the test depths. For the modified California barrel sampling procedure, a 2½-inch outer diameter split-barrel sampling spoon is used for sampling. Modified California barrel sampling procedures are similar to standard split-barrel sampling procedures; however, blow counts are typically recorded for 6-inch intervals for a total of 12 inches of penetration. In addition, a bulk sample of soils obtained in the upper 5 feet of both borings completed for the proposed roadways was collected. The samples were placed in appropriate containers, taken to our soil laboratory for testing, and classified by a geotechnical engineer. In addition, we observed and recorded groundwater levels during drilling observations. Our exploration team prepared field boring logs as part of standard drilling operations including sampling depths, penetration distances, and other relevant sampling information. Field logs include visual classifications of materials encountered during drilling, and our interpretation of subsurface conditions between samples. Final boring logs, prepared from field logs, represent the geotechnical engineer's interpretation, and include modifications based on observations and laboratory test results. Geotechnical Engineering Report City-maintained Roadways at Crowne at Old Town North ■ Fort Collins, Colorado September 4, 2018 ■ Terracon Project No. 20185095 Responsive ■ Resourceful ■ Reliable Property Disturbance: We backfilled borings with auger cuttings after completion. Our services did not include repair of the site beyond backfilling our boreholes. Excess auger cuttings were dispersed in the general vicinity of the boreholes. Because backfill material often settles below the surface after a period, we recommend checking boreholes periodically and backfilling, if necessary. We can provide this service, or grout the boreholes for additional fees, at your request. Laboratory Testing The project engineer reviewed field data and assigned various laboratory tests to better understand the engineering properties of various soil strata. Laboratory testing was conducted in general accordance with applicable or other locally recognized standards. Testing was performed under the direction of a geotechnical engineer and included the following: ■ Visual classification ■ Moisture content ■ Dry density ■ Atterberg limits ■ Grain-size analysis ■ One-dimensional swell ■ Water-soluble sulfates ■ R-value Our laboratory testing program included examination of soil samples by an engineer. Based on the material’s texture and plasticity, we described and classified soil samples in accordance with the Unified Soil Classification System (USCS). Soil and bedrock samples obtained during our field work will be disposed of after laboratory testing is complete unless a specific request is made to temporarily store the samples for a longer period of time. 16 73 16 14 110 114 30-17-13 4-4-5 N=9 4-6 4-6-10 N=16 0/150 6.0 10.5 FILL - LEAN CLAY WITH SAND (CL), with gravel, brown to light brown POORLY GRADED GRAVEL WITH SILT AND SAND, brown, medium dense Boring Terminated at 10.5 Feet GRAPHIC LOG Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20185095 CITY-MAINTAINED R.GPJ TERRACON_DATATEMPLATE.GDT 8/24/18 PERCENT FINES WATER CONTENT (%) DRY UNIT WEIGHT (pcf) LL-PL-PI ATTERBERG LIMITS WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 SAMPLE TYPE FIELD TEST RESULTS SWELL / LOAD (%/psf) DEPTH LOCATION See Exploration Plan Latitude: 40.6025° Longitude: -105.0738° Page 1 of 1 Advancement Method: 4-inch solid-stem auger Abandonment Method: Boring backfilled with soil cuttings upon completion. 1901 Sharp Point Dr, Ste C Fort Collins, CO Notes: Project No.: 20185095 Drill Rig: CME-55 BORING LOG NO. 3 CLIENT: Crowne Partners, Inc. Birmingham, AL Driller: Drilling Engineers, Inc. Boring Completed: 08-17-2018 PROJECT: City-Maintained Roadways at Crowne at Old Town North 11 20 6 8 NP 5-6-10 N=16 7-12 5-7-12 N=19 4.0 10.5 FILL - LEAN CLAY WITH SAND , with gravel, brown to light brown POORLY GRADED GRAVEL WITH SILT AND SAND (GP-GM), brown, medium dense Boring Terminated at 10.5 Feet GRAPHIC LOG Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20185095 CITY-MAINTAINED R.GPJ TERRACON_DATATEMPLATE.GDT 8/24/18 PERCENT FINES WATER CONTENT (%) DRY UNIT WEIGHT (pcf) LL-PL-PI ATTERBERG LIMITS WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 SAMPLE TYPE FIELD TEST RESULTS SWELL / LOAD (%/psf) DEPTH LOCATION See Exploration Plan Latitude: 40.6015° Longitude: -105.0739° Page 1 of 1 Advancement Method: 4-inch solid-stem auger Abandonment Method: Boring backfilled with soil cuttings upon completion. 1901 Sharp Point Dr, Ste C Fort Collins, CO Notes: Project No.: 20185095 Drill Rig: CME-55 BORING LOG NO. 4 CLIENT: Crowne Partners, Inc. Birmingham, AL Driller: Drilling Engineers, Inc. Boring Completed: 08-17-2018 PROJECT: City-Maintained Roadways at Crowne at Old Town North See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of 92 17 21 18 103 41-19-22 6-8-10 N=18 6-10 13-17-20 N=37 +2.8/150 7.0 10.5 FILL - LEAN CLAY (CL), with gravel, brown to light brown POORLY GRADED GRAVEL WITH SILT AND SAND, brown, medium dense Boring Terminated at 10.5 Feet GRAPHIC LOG Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20185095 CITY-MAINTAINED R.GPJ TERRACON_DATATEMPLATE.GDT 8/24/18 PERCENT FINES WATER CONTENT (%) DRY UNIT WEIGHT (pcf) LL-PL-PI ATTERBERG LIMITS WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 SAMPLE TYPE FIELD TEST RESULTS SWELL / LOAD (%/psf) DEPTH LOCATION See Exploration Plan Latitude: 40.6005° Longitude: -105.0742° Page 1 of 1 Advancement Method: 4-inch solid-stem auger Abandonment Method: Boring backfilled with soil cuttings upon completion. 1901 Sharp Point Dr, Ste C Fort Collins, CO Notes: Project No.: 20185095 Drill Rig: CME-55 BORING LOG NO. 5 CLIENT: Crowne Partners, Inc. Birmingham, AL Driller: Drilling Engineers, Inc. Boring Completed: 08-17-2018 PROJECT: City-Maintained Roadways at Crowne at Old Town North See Exploration and Testing Procedures for a description of field and laboratory procedures used 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 "U" Line "A" Line ATTERBERG LIMITS RESULTS ASTM D4318 P L A S T I C I T Y I N D E X LIQUID LIMIT 1901 Sharp Point Dr, Ste C Fort Collins, CO PROJECT NUMBER: 20185095 SITE: Southwest of Conifer Street and Blue Spruce Drive Fort Collins, Colorado PROJECT: City-Maintained Roadways at Crowne at Old Town North CLIENT: Crowne Partners, Inc. Birmingham, AL LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. ATTERBERG LIMITS 20185095 CITY-MAINTAINED R.GPJ TERRACON_DATATEMPLATE.GDT 8/24/18 30 NP 41 17 NP 19 13 NP 22 CL GP-GM CL LEAN CLAY with SAND POORLY GRADED GRAVEL with SILT and SAND LEAN CLAY Boring ID Depth LL PL PI Fines USCS Description 3 4 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 30 40 50 1.5 6 200 8 10 4 14 1 3/4 1/2 60 GRAIN SIZE IN MILLIMETERS PERCENT FINER BY WEIGHT U.HYDROMETERS. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS 4 3/8 3 100 3 140 2 GRAIN SIZE DISTRIBUTION ASTM D422 / ASTM C136 6 16 20 1901 Sharp Point Dr, Ste C Fort Collins, CO PROJECT NUMBER: 20185095 SITE: Southwest of Conifer Street and Blue Spruce Drive Fort Collins, Colorado PROJECT: City-Maintained Roadways at Crowne at Old Town North CLIENT: Crowne Partners, Inc. Birmingham, AL LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS-2 20185095 CITY-MAINTAINED R.GPJ TERRACON_DATATEMPLATE.GDT 8/24/18 LEAN CLAY with SAND (CL) POORLY GRADED GRAVEL with SILT and SAND (GP-GM) -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 no movement upon wetting under an applied pressure of 150 psf. 1901 Sharp Point Dr, Ste C Fort Collins, CO PROJECT NUMBER: 20185095 SITE: Southwest of Conifer Street and Blue Spruce Drive Fort Collins, Colorado PROJECT: City-Maintained Roadways at Crowne at Old Town North CLIENT: Crowne Partners, Inc. Birmingham, AL LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS 20185095 CITY-MAINTAINED R.GPJ TERRACON_DATATEMPLATE.GDT 8/24/18 3 2 - 3.5 ft LEAN CLAY with SAND(CL) 110 16 Specimen Identification Classification , pcf 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 2.8 percent swell upon wetting under an applied pressure of 150 psf. 1901 Sharp Point Dr, Ste C Fort Collins, CO PROJECT NUMBER: 20185095 SITE: Southwest of Conifer Street and Blue Spruce Drive Fort Collins, Colorado PROJECT: City-Maintained Roadways at Crowne at Old Town North CLIENT: Crowne Partners, Inc. Birmingham, AL LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS 20185095 CITY-MAINTAINED R.GPJ TERRACON_DATATEMPLATE.GDT 8/24/18 5 4 - 5 ft LEAN CLAY(CL) 103 21 Specimen Identification Classification , pcf WC, % 1901 Sharp Point Dr, Suite C Fort Collins, Colorado 80525 (970) 484-0359 FAX (970) 484-0454 CLIENT: Crowne Partners, Inc. DATE OF TEST: 23-Aug-18 PROJECT: City-Maintained Roadways at Crowne LOCATION: Bulk from Jerome Street TERRACON NO. 20185095 CLASSIFICATION: Lean clay with sand TEST SPECIMEN NO. 1 2 3 COMPACTION PRESSURE (PSI) 80 120 160 DENSITY (PCF) 104.6 107.7 108.3 MOISTURE CONTENT (%) 22.0 21.0 19.9 EXPANSION PRESSURE (PSI) 0.00 0.00 0.00 HORIZONTAL PRESSURE @ 160 PSI 136 123 110 SAMPLE HEIGHT (INCHES) 2.23 2.16 2.20 EXUDATION PRESSURE (PSI) 159.6 303.3 446.5 CORRECTED R-VALUE 9.9 16.5 25.3 UNCORRECTED R-VALUE 11.1 19.1 28.7 R-VALUE @ 300 PSI EXUDATION PRESSURE = 16 AASHTO T190 PRESSURE OF COMPACTED SOIL RESISTANCE R-VALUE & EXPANSION SAMPLE DATA TEST RESULTS 0 10 20 30 40 50 60 70 80 90 100 0 100 200 300 400 500 600 700 800 R-VALUE EXUDATION PRESSURE - PSI SUPPORTING INFORMA TION SUPPORTING INFORMATION City-Maintained Roadways at Crowne at Old Town North Fort Collins, Colorado September 4, 2018 Terracon Project No. 20185095 less than 0.25 0.50 to 1.00 > 4.00 Unconfined Compressive Strength Qu, (tsf) 0.25 to 0.50 1.00 to 2.00 2.00 to 4.00 Modified California 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. GRAIN SIZE TERMINOLOGY RELATIVEFINES PROPORTIONS OF SAND AND GRAVEL RELATIVE PROPORTIONS OF DESCRIPTIVE SOIL CLASSIFICATION LOCATION AND ELEVATION NOTES SAMPLING WATER LEVEL FIELD TESTS N (HP) (T) UNIFIED SOIL CLASSIFICATION SYSTEM City-maintained Roadways at Crowne at Old Town North ■ Fort Collins, Colorado September 4, 2018 ■ Terracon Project No. 20185095 UNIFIED SOIL C LASSIFICATION SYSTEM 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. 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. (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 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 actual topographical survey was conducted to confirm the surface elevation. Instead, the surface elevation was approximately determined from topographic maps of the area. Descriptive Term (Consistency) 0 - 6 CONSISTENCY OF FINE-GRAINED SOILS Hard Very Loose Loose Medium Dense Dense Very Dense Descriptive Term (Density) Standard Penetration or N-Value Blows/Ft. 0 - 3 4 - 9 7 - 18 10 - 29 19 - 58 30 - 50 59 - 98 > 50 > 99 Very Stiff Standard Penetration or N-Value Blows/Ft. Ring Sampler Blows/Ft. Ring Sampler Blows/Ft. 5 - 9 Stiff Medium Stiff Soft Very Soft (50% or more passing the No. 200 sieve.) Consistency determined by laboratory shear strength testing, field visual-manual procedures or standard penetration resistance STRENGTH TERMS RELATIVE DENSITY OF COARSE-GRAINED SOILS (More than 50% retained on No. 200 sieve.) Density determined by Standard Penetration Resistance 2 - 4 4 - 8 8 - 15 15 - 30 > 30 0 - 1 3 - 4 < 3 10 - 18 19 - 42 > 42 LEAN CLAY (CL) 10.752 12.5 25 9.5 30 NP 41 72.6 10.8 91.5 1.4 53.0 0.1 1.425 16 8 21 WC (%) LL D30 D10 %Gravel %Fines %Clay 3 4 5 4.60 13 NP 22 17 NP 19 261.98 Boring ID Depth USCS Classification PL PI Cc Cu D100 D60 2 - 3.5 9 - 10.5 4 - 5 Boring ID Depth %Sand %Silt medium 3 4 5 coarse fine coarse fine COBBLES GRAVEL SAND SILT OR CLAY 2 - 3.5 9 - 10.5 4 - 5 26.0 36.3 8.3 5 2 - 3.5 9 - 10.5 4 - 5 73 11 92 CL-ML and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. Southwest of Conifer Street and Blue Spruce Drive Fort Collins, Colorado SITE: Boring Started: 08-17-2018 No free water observed WATER LEVEL OBSERVATIONS symbols and abbreviations. Southwest of Conifer Street and Blue Spruce Drive Fort Collins, Colorado SITE: Boring Started: 08-17-2018 9' while drilling WATER LEVEL OBSERVATIONS See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. Southwest of Conifer Street and Blue Spruce Drive Fort Collins, Colorado SITE: Boring Started: 08-17-2018 9' while drilling WATER LEVEL OBSERVATIONS Construction Observation and Testing Close monitoring of the construction operations and implementing drainage recommendations discussed herein will be critical in achieving the intended foundation, slab and pavement performance. We therefore recommend that Terracon be retained to monitor this portion of the work. General Comments This section contains important information about the limitations of this geotechnical engineering report.