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Home My WebLink AboutCROWNE AT OLD TOWN NORTH (FORMERLY CROWNE ON SUNIGA - RESIDENTIAL) - PDP - PDP170007 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTPreliminary Geotechnical Engineering Report Crowne at Conifer Southwest of Conifer Street and Blue Spruce Drive Fort Collins, Colorado August 25, 2016 Terracon Project No. 20165073 Prepared for: Crowne Partners, Inc. Birmingham, Alabama Prepared by: Terracon Consultants, Inc. Fort Collins, Colorado TABLE OF CONTENTS EXECUTIVE SUMMARY ............................................................................................................ i 1.0 INTRODUCTION .............................................................................................................1 2.0 PROJECT INFORMATION .............................................................................................1 2.1 Project Description ...............................................................................................1 2.2 Site Location and Description...............................................................................2 3.0 SUBSURFACE CONDITIONS ........................................................................................2 3.1 Typical Subsurface Profile ...................................................................................2 3.2 Laboratory Testing ...............................................................................................2 3.3 Corrosion Protection (Water-Soluble Sulfates) .....................................................3 3.4 Groundwater ........................................................................................................3 4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION ......................................4 4.1 Preliminary Geotechnical Considerations .............................................................4 4.1.1 Shallow Groundwater ...............................................................................4 4.1.2 Expansive Soils ........................................................................................4 4.2 Earthwork.............................................................................................................5 4.2.1 Site Preparation ........................................................................................5 4.2.2 Excavation ................................................................................................5 4.2.3 Subgrade Preparation ...............................................................................6 4.2.4 Fill Materials and Placement ......................................................................6 4.2.5 Compaction Requirements ........................................................................7 4.2.6 Utility Trench Backfill ................................................................................7 4.2.7 Grading and Drainage ...............................................................................8 4.3 Preliminary Foundation Recommendations ..........................................................9 4.3.1 Preliminary Post-Tensioned Slabs – Design Recommendations ...............9 4.3.2 Preliminary Spread Footings - Design Recommendations ........................9 4.3.3 Preliminary Reinforced Mats - Design Recommendations ......................10 4.4 Seismic Considerations......................................................................................11 4.5 Floor Systems ....................................................................................................11 4.6 Swimming Pool Recommendations ....................................................................11 4.7 Pavements .........................................................................................................12 4.7.1 Pavements – Subgrade Preparation .......................................................12 4.7.2 Pavements – Design Recommendations ................................................12 4.7.3 Pavements – Construction Considerations .............................................14 4.7.4 Pavements – Maintenance .....................................................................15 5.0 GENERAL COMMENTS ...............................................................................................15 TABLE OF CONTENTS (continued) Appendix A – FIELD EXPLORATION Exhibit A-1 Site Location Map Exhibit A-2 Exploration Plan Exhibit A-3 Field Exploration Description Exhibits A-4 to A-6 Boring Logs Appendix B – LABORATORY TESTING Exhibit B-1 Laboratory Testing Description Exhibit B-2 Atterberg Limits Test Results Exhibit B-3 Grain-size Distribution Test Results Exhibit B-4 Swell-consolidation Test Results Exhibit B-5 Water-soluble Sulfate Test Results Appendix C – SUPPORTING DOCUMENTS Exhibit C-1 General Notes Exhibit C-2 Unified Soil Classification System Exhibit C-3 Description of Rock Properties Exhibit C-4 Laboratory Test Significance and Purpose Exhibits C-5 and C-6 Report Terminology Preliminary Geotechnical Engineering Report Crowne at Conifer ■ Fort Collins, Colorado August 25, 2016 ■ Terracon Project No. 20165073 Responsive ■ Resourceful ■ Reliable i EXECUTIVE SUMMARY A preliminary geotechnical investigation has been performed for the proposed Crowne at Conifer to be constructed southwest of the intersection of Conifer Street and Blue Spruce Drive in Fort Collins, Colorado. Three (3) borings, presented as Exhibits A-4 through A-6 and designated as Boring No. 1 through Boring No. 3, were performed to depths of approximately 34 feet below existing site grades. This report specifically addresses the conceptual recommendations for the proposed structure, foundation, floor systems and associated pavements. Borings performed in these areas are for informational purposes and will be utilized by others. Based on the information obtained from our subsurface exploration, the site can be developed for the proposed project. However, the following geotechnical considerations were identified and will need to be considered:  Supplementary geotechnical engineering exploration should be performed at the site upon completion of initial design and studies in order to confirm or modify the recommendations contained in this preliminary report and to allow the development of recommendations more specific to the proposed construction.  In general, subsurface conditions encountered in the borings performed on the site consisted of about 7 to 9 feet of sandy lean clay over about 12 to 13 feet of well graded sand with silt and gravel. Sandstone bedrock was encountered below the well graded sand and extended to maximum depths explored of about 34 feet below existing site grades.  Groundwater was encountered at depths ranging from about 7.2 to 10 feet below existing site grades. Dewatering may be required in some areas of the site if excavations extend into the groundwater.  We anticipate the proposed buildings may be supported on shallow, post-tensioned slab foundation systems bearing on properly place on-site soils or newly placed engineered fill. Spread footing foundations will also be considered an appropriate foundation system for the proposed buildings.  Results of our preliminary geotechnical study indicate slab-on-grade floor systems should be reasonable for the proposed buildings.  Comparatively soft lean clay soils were encountered within the upper 7 to 9 feet of our borings completed on this site. We believe some ground improvement may be required below proposed foundations, floor systems, and possibly pavements. Ground improvement may consist of 1 to 2 feet of over-excavation and replacement with moisture conditioned, compacted engineered fill. On-site soils can be re-used as over-excavation backfill at this site. Preliminary Geotechnical Engineering Report Crowne at Conifer ■ Fort Collins, Colorado August 25, 2016 ■ Terracon Project No. 20165073 Responsive ■ Resourceful ■ Reliable ii  The 2012 International Building Code, Table 1613.5.2 IBC seismic site classification for this site is D. This summary should be used in conjunction with the entire report for design purposes. It should be recognized that 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. The section titled GENERAL COMMENTS should be read for an understanding of the report limitations. Responsive ■ Resourceful ■ Reliable 1 GEOTECHNICAL ENGINEERING REPORT Crowne at Conifer Southwest of Conifer Street and Blue Spruce Drive Fort Collins, Colorado Terracon Project No. 20165073 August 25, 2016 1.0 INTRODUCTION This report presents the results of our geotechnical engineering services performed for the proposed Crowne at Conifer to be located southwest of the intersection of Conifer Street and Blue Spruce Drive in Fort Collins, Colorado (Exhibit A-1). The purpose of these services is to provide information and geotechnical engineering recommendations relative to:  subsurface soil conditions  foundation design and construction  groundwater conditions  floor slab design and construction  grading and drainage  pavement construction  seismic considerations  earthwork Our geotechnical engineering scope of work for this project included the initial site visit, the advancement of three (3) test borings to a depth of approximately 34 feet below existing site grades, laboratory testing for soil engineering properties and engineering analyses to provide preliminary foundation, floor system and pavement design and construction recommendations. Logs of the borings along with an Exploration Plan (Exhibit A-2) are included in Appendix A. The results of the laboratory testing performed on soil and bedrock samples obtained from the site during the field exploration are included in Appendix B. 2.0 PROJECT INFORMATION 2.1 Project Description Item Description Site layout Refer to the Exploration Plan (Exhibit A-2 in Appendix A) Structures The proposed construction likely includes two to three-story multi- family/apartment structures with no basements. Single-story parking structures and paved parking and drive lanes are also planned, as well as new utility infrastructure. Below-grade areas No below-grade areas are planned for this site. Preliminary Geotechnical Engineering Report Crowne at Conifer ■ Fort Collins, Colorado August 25, 2016 ■ Terracon Project No. 20165073 Responsive ■ Resourceful ■ Reliable 2 Item Description Traffic loading NAPA Traffic Class (assumed): Automobile Parking Areas: Class I Truck traffic and main drives Class II 2.2 Site Location and Description Item Description Location The project site is located southwest of the interesction of Conifer Street and Blue Spruce Drive in Fort Collins, Colorado. Existing site features The site is currently un developed land. Surrounding developments The north and west sides of the site are bordered by retail buildings. The south and east sides of the site are bordered by undeveloped land followed by single-family residential developments. Current ground cover The current ground cover is native grasses and weeds. Existing topography The site is relatively flat. 3.0 SUBSURFACE CONDITIONS 3.1 Typical Subsurface Profile Specific conditions encountered at each boring location are indicated on the individual boring logs included in Appendix A. Stratification boundaries on the boring logs represent the approximate location of changes in soil types; in-situ, the transition between materials may be gradual. 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 Sandy lean clay About 7 to 9 feet below existing site grades. Medium stiff to very stiff Sand with silt and gravel About 20 to 21 feet below existing site grades. Dense to very dense Sandstone bedrock To the maximum depth of exploration of about 34 feet. Very hard 3.2 Laboratory Testing Representative soil samples were selected for swell-consolidation testing and exhibited no movement when wetted. Samples of site soils and bedrock selected for plasticity testing exhibited Preliminary Geotechnical Engineering Report Crowne at Conifer ■ Fort Collins, Colorado August 25, 2016 ■ Terracon Project No. 20165073 Responsive ■ Resourceful ■ Reliable 3 low to moderate plasticity with liquid limits ranging from non-plastic to 35 and plasticity indices ranging from non-plastic to 21. Laboratory test results are presented in Appendix B. 3.3 Corrosion Protection (Water-Soluble Sulfates) Results of water-soluble sulfate testing indicate that ASTM Type V portland cement should be specified for all project concrete on and below grade. As an alternative, ACI allows the use of cement that conforms to ASTM C150 Type II requirements, if it meets the Type V performance requirements (ASTM C452) of ASTM C150 Table 4. ACI 201 also allows a blend of any type of portland cement and fly ash with an expansion of less than 0.05 percent at 6 months when tested in accordance with ASTM C1012. Foundation concrete should be designed for severe sulfate exposure in accordance with the provisions of the ACI Design Manual, Section 318, Chapter 4. 3.4 Groundwater The boreholes were observed while drilling and after completion for the presence and level of groundwater. In addition, temporary piezometers made of slotted PVC pipe were installed in the boreholes and delayed water levels were also obtained. 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 12 days after drilling, ft. Elevation of groundwater 12 days after drilling, ft. 1 7 7.6 89.6 2 10 7.4 89.7 3 8.5 7.2 91.6 These observations represent groundwater conditions at the time of the field exploration and a few days after drilling, 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 structures 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. Preliminary Geotechnical Engineering Report Crowne at Conifer ■ Fort Collins, Colorado August 25, 2016 ■ Terracon Project No. 20165073 Responsive ■ Resourceful ■ Reliable 4 4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION 4.1 Preliminary Geotechnical Considerations 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 geotechnical conditions that could impact design and construction of the proposed structures, pavements, and other site improvements. The preliminary recommendations presented in this report are based on the assumption that the subsurface conditions encountered in the widely spaced preliminary borings provided an accurate representation of the entire site. Supplementary geotechnical engineering exploration should be performed at the site upon completion of initial design studies in order to confirm or modify the recommendations contained in this preliminary report and to allow the development of recommendations more specific to the proposed construction. Comparatively soft lean clay soils were encountered within the upper 7 to 9 feet of our borings completed on this site. We believe some ground improvement may be required below proposed foundations, floor systems, and possibly pavements. Ground improvement may consist of 1 to 2 feet of over-excavation and replacement with moisture conditioned, compacted engineered fill. On-site soils can be re-used as over-excavation backfill at this site. 4.1.1 Shallow Groundwater As previously stated, groundwater was measured at depths ranging from about 7 to 10 feet below existing site grades. 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 may rise due to rainfall and seasonal variations. 4.1.2 Expansive Soils Laboratory testing indicates the native clay soils exhibited low expansive potential at the samples in-situ moisture content. However, it is our opinion these materials will exhibit a higher expansive potential if the clays undergo a significant loss of moisture. 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, and flatwork should be anticipated. The severity of cracking and other damage such as uneven floor slabs will probably increase if any modification of the site results in excessive wetting or drying of the expansive clays. Eliminating the risk of movement and 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 Preliminary Geotechnical Engineering Report Crowne at Conifer ■ Fort Collins, Colorado August 25, 2016 ■ Terracon Project No. 20165073 Responsive ■ Resourceful ■ Reliable 5 recommendations described in section 4.2.7 Grading and Drainage of this report be followed to reduce movement. 4.2 Earthwork The following presents recommendations for site preparation, 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. 4.2.1 Site Preparation 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. 4.2.2 Excavation It is anticipated that excavations for the proposed site development can be accomplished with conventional earthmoving equipment. Excavations into the on-site soils may encounter weak and/or saturated soil conditions with possible caving conditions. 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. 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 of the soils determined at that time by the contractors’ Competent Person. Slope inclinations flatter than the OSHA maximum values may have to be used. The individual contractor(s) should be Preliminary Geotechnical Engineering Report Crowne at Conifer ■ Fort Collins, Colorado August 25, 2016 ■ Terracon Project No. 20165073 Responsive ■ Resourceful ■ Reliable 6 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 4.2.3 Subgrade Preparation 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 pavement is placed. 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 be used, or crushed gravel and/or rock can be tracked or “crowded” into the unstable surface soil until a stable working surface is attained. Use of geotextile could also be considered as a stabilization technique. Lightweight excavation equipment may also be used to reduce subgrade pumping. 4.2.4 Fill Materials and Placement The on-site soils or approved granular and low plasticity cohesive imported materials may be used as fill material. 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. It should be noted that lean clay may 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) 4” 100 3” 70-100 No. 4 Sieve 50-100 No. 200 Sieve 15-60 Soil Properties Values Liquid Limit 35 (max.) Plastic Limit 6 (max.) Preliminary Geotechnical Engineering Report Crowne at Conifer ■ Fort Collins, Colorado August 25, 2016 ■ Terracon Project No. 20165073 Responsive ■ Resourceful ■ Reliable 7 Soil Properties Values Maximum Expansive Potential (%) Non-expansive1 1. Measured on a sample compacted to approximately 95 percent of the maximum dry unit weight as determined by ASTM D698 at optimum moisture content. The sample is confined under a 100 psf surcharge and submerged. 4.2.5 Compaction Requirements 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 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. 4.2.6 Utility Trench Backfill 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. Preliminary Geotechnical Engineering Report Crowne at Conifer ■ Fort Collins, Colorado August 25, 2016 ■ Terracon Project No. 20165073 Responsive ■ Resourceful ■ Reliable 8 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 effective clay “trench plug” that extends at least 5 feet out from the face of the building exteriors. The plug material should consist of clay compacted at a water content at or above the soil’s optimum 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. 4.2.7 Grading and Drainage All grades must be adjusted to provide effective drainage away from the proposed 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 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. Preliminary Geotechnical Engineering Report Crowne at Conifer ■ Fort Collins, Colorado August 25, 2016 ■ Terracon Project No. 20165073 Responsive ■ Resourceful ■ Reliable 9 4.3 Preliminary Foundation Recommendations In our opinion, the proposed buildings can be supported by shallow foundation systems consisting of spread footings, reinforced concrete mats or post-tensioned slabs. Preliminary design recommendations for the proposed foundation types are presented in the following paragraphs. 4.3.1 Preliminary Post-Tensioned Slabs – Design Recommendations Based on the soil conditions encountered, use of post-tensioned slabs is feasible for support of the structures provided some foundation movement can be tolerated and:  The post-tensioned slab foundations are properly designed and constructed.  Approved materials supporting the foundation are properly placed and compacted.  Proper surface drainage is maintained throughout the life of the structures.  Prudent landscaping measures are used. In our opinion, total foundation movements on the order of about 1 inch should be expected with some ground improvement likely necessary. Provided foundations are properly designed, foundation movements could result in periodic, and possibly seasonal, cosmetic distress to drywall, window frames, door frames and other features. We would anticipate that the frequency of distress and amount of movement would generally diminish with time provided proper drainage is established and/or maintained.  Maximum Allowable Net Bearing Pressure ................................................. 1,500 to 2,500 psf  Slab-Subgrade Friction Coefficient,   on polyethylene sheeting ................................................................................ 0.75  on cohesionless soils ...................................................................................... 1.00  on cohesive soils............................................................................................. 2.00 The maximum allowable net bearing pressure will depend on recommendations from future design-level study and may be increased by 1/3 for transient wind or seismic loading. 4.3.2 Preliminary Spread Footings - Design Recommendations Description Values Bearing material Properly prepared on-site soil or possibly 1 to 2 feet of over-excavation with properly placed engineered fill. Maximum allowable bearing pressure 1 1,500 to 2,000 psf Minimum embedment depth below finished grade 3 30 inches Estimated total movement About 1 inch Preliminary Geotechnical Engineering Report Crowne at Conifer ■ Fort Collins, Colorado August 25, 2016 ■ Terracon Project No. 20165073 Responsive ■ Resourceful ■ Reliable 10 Description Values 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. 2. 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. 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 4.2.8 Grading and Drainage section of this report will nullify the movement estimates provided above. 4.3.3 Preliminary Reinforced Mats - Design Recommendations Description Values Bearing material Properly prepared on-site soil or possibly 1 to 2 feet of over-excavation with properly placed engineered fill. Maximum allowable bearing pressure 1 1,500 to 2000 psf Moist soil unit weight Native Clay Soils: 125 pcf Minimum embedment depth below finished grade 30 inches Total estimated settlement Up to 1 inch Estimated differential settlement ½ to ¾ of total settlement 1. The design bearing pressure applies to dead loads plus design live load conditions. The design bearing pressure may be increased by one-third when considering total loads that include wind or seismic conditions. Foundations should be proportioned to reduce differential foundation movement. Proportioning on the basis of equal total settlement is recommended; however, proportioning to relative constant dead-load pressure will also reduce differential movement between adjacent foundations. Foundations should be reinforced as necessary to reduce the potential for distress caused by differential foundation movement. 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. Preliminary Geotechnical Engineering Report Crowne at Conifer ■ Fort Collins, Colorado August 25, 2016 ■ Terracon Project No. 20165073 Responsive ■ Resourceful ■ Reliable 11 4.4 Seismic Considerations Code Used Site Classification 2012 International Building Code (IBC) 1 D 2 1. In general accordance with the 2012 International Building Code, Table 1613.5.2. 2. The 2012 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 34 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. However, we believe a higher seismic site class for this site is unlikely. 4.5 Floor Systems If a post-tensioned slab foundation system is selected for the foundation, it will also function as a floor system for the proposed buildings. If spread footings or reinforced mats are selected for the foundation, then we anticipate a slab-on-grade floor system will be appropriate. Comparatively soft lean clay soils were encountered within the upper 7 to 9 feet of our borings completed on this site. We believe some ground improvement may be required below proposed floor systems. Ground improvement may consist of 1 to 2 feet of over-excavation and replacement with moisture conditioned, compacted engineered fill. On-site soils can be re-used as over-excavation backfill at this site. 4.6 Swimming Pool Recommendations We understand a swimming pool is conceptually planned near the courtyard in the southeastern portion of the project site. The construction and performance of the pool will be highly affected by the presence of groundwater encountered at depths ranging from approximately 7 to 10 feet below existing site grades. Construction and/or permanent dewatering will 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, conceptual plans should include placement of pressure relief valves 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. Preliminary Geotechnical Engineering Report Crowne at Conifer ■ Fort Collins, Colorado August 25, 2016 ■ Terracon Project No. 20165073 Responsive ■ Resourceful ■ Reliable 12 4.7 Pavements 4.7.1 Pavements – Subgrade Preparation 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. 4.7.2 Pavements – Design Recommendations 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 – CL, classified by NAPA as poor 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 – CL  Concrete modulus of rupture value of 600 psi We should be contacted to confirm and/or modify the recommendations contained herein if actual traffic volumes differ from the assumed values shown above. Preliminary Geotechnical Engineering Report Crowne at Conifer ■ Fort Collins, Colorado August 25, 2016 ■ Terracon Project No. 20165073 Responsive ■ Resourceful ■ Reliable 13 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 Course1 Portland Cement Concrete Total Automobile Parking Areas (NAPA Class I and ACI Category A) A 4 4 -- 8 B - - 5 5 Main Traffic Corridors (NAPA Class II and ACI Category A) A 4½ 6 - 10½ B - - 6 6 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 type1 Type V portland cement Entrained air content (%) 5 to 8 Concrete aggregate ASTM C33 and CDOT section 703 1. If aggregate base course is used under rigid pavements then type I or II portland cement may be used since it is not in contact with the on-site soils. Preliminary Geotechnical Engineering Report Crowne at Conifer ■ Fort Collins, Colorado August 25, 2016 ■ Terracon Project No. 20165073 Responsive ■ Resourceful ■ Reliable 14 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 cracking, and subgrade “pumping” through joints. Proper joint spacing will also be required for 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. 4.7.3 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. Preliminary Geotechnical Engineering Report Crowne at Conifer ■ Fort Collins, Colorado August 25, 2016 ■ Terracon Project No. 20165073 Responsive ■ Resourceful ■ Reliable 15 4.7.4 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. 5.0 GENERAL COMMENTS When more detailed plans for the proposed construction become available supplemental exploration and analyses should be undertaken in order to confirm or develop final design parameters and to confirm and/or modify the preliminary recommendations and conclusions contained in this report. Terracon’s Scope of Services has been provided under the belief that this site will be used as apartments. As such, Terracon would like to inform the Client that if this apartment project is converted at any time to another purpose such as condominiums, the Client understands the services Terracon is providing is not applicable for a condominium project and that a separate consultant will need to be retained for such services. Terracon will have no liability for any such unintended use of our services and Client agrees to defend, indemnify, and hold harmless Terracon for any such unintended usage. Terracon should be retained to review the final design plans and specifications so comments can be made regarding interpretation and implementation of our geotechnical recommendations in the design and specifications. Terracon also should be retained to provide observation and testing services during grading, excavation, foundation construction and other earth-related construction phases of the project. The analysis and recommendations presented in this report are based upon the data obtained from the borings performed at the indicated locations and from other information discussed in this report. This report does not reflect variations that may occur between borings, 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. If variations appear, we should be immediately notified so that further evaluation and supplemental recommendations can be provided. The scope of services for this project does not include either specifically or by implication any environmental or biological (e.g., mold, fungi, and 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. Preliminary Geotechnical Engineering Report Crowne at Conifer ■ Fort Collins, Colorado August 25, 2016 ■ Terracon Project No. 20165073 Responsive ■ Resourceful ■ Reliable 16 This report has been prepared for the exclusive use of our client for specific application to the project discussed and has been prepared in accordance with generally accepted geotechnical engineering practices. No warranties, either express or implied, are intended or made. Site safety, excavation support, and dewatering requirements are the responsibility of others. In the event that changes in the nature, design, or location of the project as described in this report are planned, the conclusions and recommendations contained in this report shall not be considered valid unless Terracon reviews the changes and either verifies or modifies the conclusions of this report in writing. APPENDIX A FIELD EXPLORATION SITE LOCATION MAP Crowne at Conifer Southwest of Conifer Street and Blue Spruce Drive Fort Collins, CO TOPOGRAPHIC MAP IMAGE COURTESY OF THE U.S. GEOLOGICAL SURVEY QUADRANGLES INCLUDE: WELLINGTON, CO (1978) and FORT COLLINS, CO (1984). 1901 Sharp Point Dr Ste C Fort Collins, CO 80525-4429 20165073 Project Manager: Drawn by: Checked by: Approved by: MGH EDB EDB 1”=2,000’ 8/22/2016 Project No. Scale: File Name: Date: A-1 EDB Exhibit SITE LEGEND APPROXIMATE BORING LOCATION APPROXIMATE TEMPORARY BENCHMARK – green box for electric utility EXPLORATION PLAN Crowne at Conifer Southwest of Conifer Street and Blue Spruce Drive Fort Collins, CO 1901 Sharp Point Dr Ste C Fort Collins, CO 80525-4429 DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES 20165073 AERIAL PHOTOGRAPHY PROVIDED BY MICROSOFT BING MAPS MGH EDB EDB AS SHOWN 8/22/2016 Scale: A-2 Project Manager: Exhibit Drawn by: Checked by: Approved by: Project No. File Name: Date: EDB Preliminary Geotechnical Engineering Report Crowne at Conifer ■ Fort Collins, Colorado August 25, 2016 ■ Terracon Project No. 20165073 Responsive ■ Resourceful ■ Reliable Exhibit A-3 Field Exploration Description The locations of borings were based upon the proposed development shown on the provided preliminary site plan. The borings were located in the field by measuring from existing site features. The ground surface elevation was surveyed at each boring location referencing the temporary benchmark shown on Exhibit A-2 using an engineer’s level. The borings were drilled with a CME-75 truck-mounted rotary drill rig with solid-stem augers. During the drilling operations, lithologic logs of the borings were recorded by the field engineer. 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. Disturbed bulk samples were obtained from auger cuttings. 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. 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. Groundwater measurements were obtained in the borings at the time of site exploration. After completion of drilling, the borings were backfilled with auger cuttings. Some settlement of the backfill and/or patch may occur and should be repaired as soon as possible. 15 17 13 13 16 17 21 99 35-14-21 NP 96.5 90 77 63 0.0/500 6-6-6 N=12 5-5 14-18-19 N=37 22-29-50/4" N=79/10" 44-50/2" N=94/8" N=50/1" N=50/1" N=50/0" 0.5 7.0 20.0 34.0 6-INCH VEGETATIVE LAYER SANDY LEAN CLAY (CL), light brown to brown, stiff WELL GRADED SAND WITH SILT AND GRAVEL (SW-SM), with cobbles, coarse to medium grained, gray and reddish-brown, dense SEDIMENTARY BEDROCK - SANDSTONE, light brown and gray, very hard Boring Terminated at 34 Feet Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic GRAPHIC LOG THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20165073.GPJ TERRACON2015.GDT 8/25/16 Southwest of Conifer Street and Blue Spruce Drive Fort Collins, Colorado SITE: Page 1 of 1 Advancement Method: 6-inch hollow-stem auger Abandonment Method: temporary piezometer installed 1901 Sharp Point Dr Ste C Fort Collins, CO Notes: Project No.: 20165073 Drill Rig: CME-75 Boring Started: 8/10/2016 BORING LOG NO. 1 CLIENT: Crowne Partners, Inc. Birmingham, Alabama Driller: Drilling Engineers, Inc. Boring Completed: 8/10/2016 16 18 7 6 7 16 21 132 29-17-12 96.5 88 76 63 6-10-13 N=23 5-5-5 N=10 14-28 14-20-30 N=50 24-50/6" N=74/12" N=50/3" N=50/2" N=50/0" 0.5 9.0 21.0 34.0 6-INCH VEGETATIVE LAYER SANDY LEAN CLAY (CL), with gravel, light brown to brown, stiff to very stiff WELL GRADED SAND WITH SILT AND GRAVEL, with cobbles, coarse to medium grained, reddish-brown to brown, very dense SEDIMENTARY BEDROCK - SANDSTONE, gray, very hard Boring Terminated at 34 Feet Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic GRAPHIC LOG THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20165073.GPJ TERRACON2015.GDT 8/25/16 Southwest of Conifer Street and Blue Spruce Drive Fort Collins, Colorado SITE: Page 1 of 1 Advancement Method: 4-inch solid-stem auger Abandonment Method: temporary piezometer installed 1901 Sharp Point Dr Ste C Fort Collins, CO Notes: Project No.: 20165073 Drill Rig: CME-75 Boring Started: 8/10/2016 BORING LOG NO. 2 CLIENT: Crowne Partners, Inc. Birmingham, Alabama Driller: Drilling Engineers, Inc. Boring Completed: 8/10/2016 Exhibit: A-5 See Exhibit A-3 for description of field procedures. 12 22 8 6 9 23 114 102 NP 98.5 91 78.5 65 11-7 2-3 19-18-11 N=29 27-31-42 N=73 27-34-50/2" N=84/8" N=50/1" N=50/0" N=50/0" 0.5 8.0 20.5 34.0 6-INCH VEGETATIVE LAYER SANDY LEAN CLAY, fine to coarse grained, light brown to brown, medium stiff to stiff WELL GRADED SAND WITH SILT (SW-SM), with gravel and cobbles, coarse to medium grained, reddish-brown, dense to very dense SEDIMENTARY BEDROCK - SANDSTONE, light brown and gray, very hard Boring Terminated at 34 Feet Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic GRAPHIC LOG THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20165073.GPJ TERRACON2015.GDT 8/25/16 Southwest of Conifer Street and Blue Spruce Drive Fort Collins, Colorado SITE: Page 1 of 1 Advancement Method: 6-inch hollow-stem auger Abandonment Method: temporary piezometer installed 1901 Sharp Point Dr Ste C Fort Collins, CO Notes: Project No.: 20165073 Drill Rig: CME-75 Boring Started: 8/10/2016 BORING LOG NO. 3 CLIENT: Crowne Partners, Inc. Birmingham, Alabama Driller: Drilling Engineers, Inc. Boring Completed: 8/10/2016 Exhibit: A-6 APPENDIX B LABORATORY TESTING Preliminary Geotechnical Engineering Report Crowne at Conifer ■ Fort Collins, Colorado August 25, 2016 ■ Terracon Project No. 20165073 Responsive ■ Resourceful ■ Reliable Exhibit B-1 Laboratory Testing Description 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 test results were used for the geotechnical engineering analyses, and the development of preliminary foundation and earthwork recommendations. 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 Appendix C. Rock samples were visually classified in general accordance with the description of rock properties presented in Appendix C. 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  Dry density  Water-soluble sulfate content 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 SANDY LEAN CLAY WELL-GRADED SAND with SILT and GRAVEL SANDY LEAN CLAY WELL-GRADED SAND with SILT CL SW-SM CL SW-SM Fines P L A S T I C I T Y I N D E X LIQUID LIMIT "U" Line "A" Line 35 NP 29 NP 14 NP 17 NP 21 NP 12 NP 64 10 59 11 LL USCS 1 1 2 3 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 1 1 2 3 35 NP 29 NP 0.381 0.196 1.708 0.08 0.469 4.75 19 19 19 6 16 20 30 40 50 1.5 6 200 810 0.0 14.9 0.1 9.0 0.076 14 63.9 9.9 58.7 11.3 %Fines LL PL PI 1 4 3/4 1/2 60 fine -4 -2 0 2 4 6 8 10 100 1,000 10,000 AXIAL STRAIN, % PRESSURE, psf SWELL CONSOLIDATION TEST ASTM D4546 NOTES: The sample exhibited no movement upon wetting under an applied pressure of 500 psf. Specimen Identification Classification , pcf 1 105 17 WC, % 4 - 5 ft PROJECT NUMBER: 20165073 PROJECT: Crowne at Conifer SITE: Southwest of Conifer Street and Blue Spruce Drive Fort Collins, Colorado CLIENT: Crowne Partners, Inc. Birmingham, Alabama EXHIBIT: B-4 1901 Sharp Point Dr Ste C Fort Collins, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS 20165073.GPJ TERRACON2012.GDT 8/25/16 TASK NO: 160818013 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 20165073 Date Reported: 8/25/16 Task No.: 160818013 Matrix: Soil - Geotech Date Received: 8/18/16 Client Project: Client PO: CustomerFt Sample ID 20165073 - BH#2 @ 4 Test Method Lab Number: 160818013-01 Result Sulfate - Water Soluble 0.316 % AASHTO T290-91/ ASTM D4327 CustomerFt Sample ID 20165073 - BH#3 @ 19 Test Method Lab Number: 160818013-02 Result Sulfate - Water Soluble 0.011 % 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: 160818013 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. APPENDIX C SUPPORTING DOCUMENTS Exhibit: C-1 Unconfined Compressive Strength Qu, (psf) 500 to 1,000 2,000 to 4,000 4,000 to 8,000 1,000 to 2,000 less than 500 > 8,000 Non-plastic Low Medium High DESCRIPTION OF SYMBOLS AND ABBREVIATIONS SAMPLING WATER LEVEL FIELD TESTS GENERAL NOTES Over 12 in. (300 mm) 12 in. to 3 in. (300mm to 75mm) 3 in. to #4 sieve (75mm to 4.75 mm) #4 to #200 sieve (4.75mm to 0.075mm Passing #200 sieve (0.075mm) Particle Size < 5 5 - 12 > 12 Percent of Dry Weight Descriptive Term(s) of other constituents RELATIVE PROPORTIONS OF FINES 0 1 - 10 11 - 30 > 30 Plasticity Index 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. LOCATION AND ELEVATION NOTES Percent of Dry Weight Major Component of Sample Trace With Modifier RELATIVE PROPORTIONS OF SAND AND GRAVEL GRAIN SIZE TERMINOLOGY Trace With Modifier DESCRIPTIVE SOIL CLASSIFICATION Boulders Cobbles Gravel Sand 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. Exhibit C-4 LABORATORY TEST SIGNIFICANCE AND PURPOSE Test Significance Purpose California Bearing Ratio Used to evaluate the potential strength of subgrade soil, subbase, and base course material, including recycled materials for use in road and airfield pavements. Pavement Thickness Design Consolidation Used to develop an estimate of both the rate and amount of both differential and total settlement of a structure. Foundation Design Direct Shear Used to determine the consolidated drained shear strength of soil or rock. Bearing Capacity, Foundation Design, and Slope Stability Dry Density Used to determine the in-place density of natural, inorganic, fine-grained soils. Index Property Soil Behavior Expansion Used to measure the expansive potential of fine-grained soil and to provide a basis for swell potential classification. Foundation and Slab Design Gradation Used for the quantitative determination of the distribution of particle sizes in soil. Soil Classification Liquid & Plastic Limit, Plasticity Index Used as an integral part of engineering classification systems to characterize the fine-grained fraction of soils, and to specify the fine-grained fraction of construction materials. Soil Classification Permeability Used to determine the capacity of soil or rock to conduct a liquid or gas. Groundwater Flow Analysis pH Used to determine the degree of acidity or alkalinity of a soil. Corrosion Potential Resistivity Used to indicate the relative ability of a soil medium to carry electrical currents. Corrosion Potential R-Value Used to evaluate the potential strength of subgrade soil, subbase, and base course material, including recycled materials for use in road and airfield pavements. Pavement Thickness Design Soluble Sulfate Used to determine the quantitative amount of soluble sulfates within a soil mass. Corrosion Potential Unconfined Compression To obtain the approximate compressive strength of soils that Exhibit C-5 REPORT TERMINOLOGY (Based on ASTM D653) Allowable Soil Bearing Capacity The recommended maximum contact stress developed at the interface of the foundation element and the supporting material. Alluvium Soil, the constituents of which have been transported in suspension by flowing water and subsequently deposited by sedimentation. Aggregate Base Course A layer of specified material placed on a subgrade or subbase usually beneath slabs or pavements. Backfill A specified material placed and compacted in a confined area. Bedrock A natural aggregate of mineral grains connected by strong and permanent cohesive forces. Usually requires drilling, wedging, blasting or other methods of extraordinary force for excavation. Bench A horizontal surface in a sloped deposit. Caisson (Drilled Pier or Shaft) A concrete foundation element cast in a circular excavation which may have an enlarged base. Sometimes referred to as a cast-in-place pier or drilled shaft. Coefficient of Friction A constant proportionality factor relating normal stress and the corresponding shear stress at which sliding starts between the two surfaces. Colluvium Soil, the constituents of which have been deposited chiefly by gravity such as at the foot of a slope or cliff. Compaction The densification of a soil by means of mechanical manipulation Concrete Slab-on- Grade A concrete surface layer cast directly upon a base, subbase or subgrade, and typically used as a floor system. Differential Movement Unequal settlement or heave between, or within foundation elements of structure. Earth Pressure The pressure exerted by soil on any boundary such as a foundation wall. ESAL Equivalent Single Axle Load, a criteria used to convert traffic to a uniform standard, (18,000 pound axle loads). Engineered Fill Specified material placed and compacted to specified density and/or moisture conditions under observations of a representative of a geotechnical engineer. Equivalent Fluid A hypothetical fluid having a unit weight such that it will produce a pressure against a lateral support presumed to be equivalent to that produced by the actual soil. This simplified approach is valid only when deformation conditions are such that the pressure increases linearly with depth and the wall friction is neglected. Existing Fill (or Man-Made Fill) Materials deposited throughout the action of man prior to exploration of the site. Existing Grade The ground surface at the time of field exploration. Exhibit C-6 REPORT TERMINOLOGY (Based on ASTM D653) Expansive Potential The potential of a soil to expand (increase in volume) due to absorption of moisture. Finished Grade The final grade created as a part of the project. Footing A portion of the foundation of a structure that transmits loads directly to the soil. Foundation The lower part of a structure that transmits the loads to the soil or bedrock. Frost Depth The depth at which the ground becomes frozen during the winter season. Grade Beam A foundation element or wall, typically constructed of reinforced concrete, used to span between other foundation elements such as drilled piers. Groundwater Subsurface water found in the zone of saturation of soils or within fractures in bedrock. Heave Upward movement. Lithologic The characteristics which describe the composition and texture of soil and rock by observation. Native Grade The naturally occurring ground surface. Native Soil Naturally occurring on-site soil, sometimes referred to as natural soil. Optimum Moisture Content The water content at which a soil can be compacted to a maximum dry unit weight by a given compactive effort. Perched Water Groundwater, usually of limited area maintained above a normal water elevation by the presence of an intervening relatively impervious continuous stratum. Scarify To mechanically loosen soil or break down existing soil structure. Settlement Downward movement. Skin Friction (Side Shear) The frictional resistance developed between soil and an element of the structure such as a drilled pier. Soil (Earth) Sediments or other unconsolidated accumulations of solid particles produced by the physical and chemical disintegration of rocks, and which may or may not contain organic matter. Strain The change in length per unit of length in a given direction. Stress The force per unit area acting within a soil mass. Strip To remove from present location. Subbase A layer of specified material in a pavement system between the subgrade and base course. Subgrade The soil prepared and compacted to support a structure, slab or pavement system. possess sufficient cohesion to permit testing in the unconfined state. Bearing Capacity Analysis for Foundations Water Content Used to determine the quantitative amount of water in a soil mass. Index Property Soil Behavior 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. Silt or Clay Descriptive Term(s) of other constituents N (HP) (T) (DCP) (PID) (OVA) < 15 15 - 29 > 30 Term 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. Water Level After a Specified Period of Time Water Level After a Specified Period of Time Water Initially Encountered Auger Cuttings Modified Dames & Moore Ring Sampler Standard Penetration Test 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. Standard Penetration Test Resistance (Blows/Ft.) Hand Penetrometer Torvane Dynamic Cone Penetrometer Photo-Ionization Detector Organic Vapor Analyzer STRENGTH TERMS Standard Penetration or N-Value Blows/Ft. Descriptive Term (Consistency) Descriptive Term (Density) CONSISTENCY OF FINE-GRAINED SOILS (50% or more passing the No. 200 sieve.) Consistency determined by laboratory shear strength testing, field visual-manual procedures or standard penetration resistance Standard Penetration or N-Value Blows/Ft. (More than 50% retained on No. 200 sieve.) Density determined by Standard Penetration Resistance RELATIVE DENSITY OF COARSE-GRAINED SOILS Hard > 30 > 50 Very Stiff 15 - 30 Stiff Medium Stiff Very Soft 0 - 1 Medium Dense Loose Soft Very Dense Dense 30 - 50 8 - 15 10 - 29 4 - 8 4 - 9 2 - 4 Very Loose 0 - 3 1 1 2 3 22.41 7.05 GRAIN SIZE IN MILLIMETERS PERCENT FINER BY WEIGHT coarse fine U.HYDROMETERS. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS 14 NP 17 NP 21 NP 12 NP 1.12 1.23 D100 Cc Cu SILT OR CLAY 4 D30 D10 %Gravel %Sand 2 - 3.5 14 - 15.3 4 - 5.5 9 - 10.5 3/8 3 100 3 2 140 COBBLES GRAVEL SAND USCS Classification 35.3 61.8 31.2 77.2 D60 coarse medium Boring ID Depth Boring ID Depth GRAIN SIZE DISTRIBUTION 2 - 3.5 14 - 15.3 4 - 5.5 9 - 10.5 SANDY LEAN CLAY (CL) WELL-GRADED SAND with SILT and GRAVEL (SW-SM) SANDY LEAN CLAY (CL) WELL-GRADED SAND with SILT (SW-SM) ASTM D422 / ASTM C136 PROJECT NUMBER: 20165073 PROJECT: Crowne at Conifer SITE: Southwest of Conifer Street and Blue Spruce Drive Fort Collins, Colorado CLIENT: Crowne Partners, Inc. Birmingham, Alabama EXHIBIT: B-3 1901 Sharp Point Dr Ste C Fort Collins, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS-2 20165073.GPJ 35159097 - ATTERBERG ISSUE.GPJ 8/18/16 ATTERBERG LIMITS RESULTS ASTM D4318 2 - 3.5 14 - 15.3 4 - 5.5 9 - 10.5 PROJECT NUMBER: 20165073 PROJECT: Crowne at Conifer SITE: Southwest of Conifer Street and Blue Spruce Drive Fort Collins, Colorado CLIENT: Crowne Partners, Inc. Birmingham, Alabama EXHIBIT: B-2 1901 Sharp Point Dr Ste C Fort Collins, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. ATTERBERG LIMITS 20165073.GPJ TERRACON2015.GDT 8/18/16 CL-ML See Exhibit A-3 for description of field procedures. See Appendix B for description of laboratory procedures and additional data (if any). See Appendix C for explanation of symbols and abbreviations. PROJECT: Crowne at Conifer WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI Surface Elev.: 98.79 (Ft.) ELEVATION (Ft.) SAMPLE TYPE 7.2' on 8/22/2016 WATER LEVEL OBSERVATIONS WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 15 20 25 30 SWELL - CONSOL / LOAD (%/psf) FIELD TEST RESULTS DEPTH LOCATION Latitude: 40.60217° Longitude: -105.07329° See Exhibit A-2 8.5' while drilling See Appendix B for description of laboratory procedures and additional data (if any). See Appendix C for explanation of symbols and abbreviations. PROJECT: Crowne at Conifer WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI Surface Elev.: 97.07 (Ft.) ELEVATION (Ft.) SAMPLE TYPE WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 15 20 25 30 SWELL - CONSOL / LOAD (%/psf) FIELD TEST RESULTS DEPTH LOCATION Latitude: 40.60089° Longitude: -105.07318° See Exhibit A-2 10' while drilling 7.4' on 8/22/2016 WATER LEVEL OBSERVATIONS Exhibit: A-4 See Exhibit A-3 for description of field procedures. See Appendix B for description of laboratory procedures and additional data (if any). See Appendix C for explanation of symbols and abbreviations. PROJECT: Crowne at Conifer WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI Surface Elev.: 97.18 (Ft.) ELEVATION (Ft.) SAMPLE TYPE WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 15 20 25 30 SWELL - CONSOL / LOAD (%/psf) FIELD TEST RESULTS DEPTH LOCATION Latitude: 40.60076° Longitude: -105.07403° See Exhibit A-2 7' while drilling 7.6' on 8/22/16 WATER LEVEL OBSERVATIONS