PROPOSED CONSTRUCTION

Transcription

1 February 19, 2014 Colorado State University Pueblo 2200 Bonforte Boulevard Pueblo, CO, Attention John Barnosky, Director Subject: Geotechnical Investigation Soccer/Lacrosse Field Modifications Colorado State University Pueblo CTL T Project No. SC This report presents the results of our Geotechnical Investigation for modifications to the soccer/lacrosse field at CSU-Pueblo in Pueblo, Colorado. Our purpose was to evaluate the subsurface conditions in order to provide geotechnical recommendations for the design and construction of the planned modifications. Our scope was described in our proposal dated January 20, 2014 (Proposal No. SC ). This report was prepared from data developed during our field exploration, laboratory testing, engineering analysis and experience with similar conditions. It includes our opinions and recommendations for design and construction details for installation of artificial turf for the soccer/lacrosse field, construction of a new team building and foundations for new bleachers. The report was prepared for use by CSU-Pueblo in design and construction of the proposed improvements. Other types of construction may require revision of this report and the recommended design criteria. SITE CONDITIONS The existing soccer/lacrosse field is located south of Rawlings Boulevard, on the east side of the CSU Pueblo Campus, in Pueblo, Colorado. The ground surface in the overall area is comparatively flat with slopes down to the east adjacent to the field. The area surrounding the soccer/lacrosse field is generally undeveloped. A small asphalt parking lot is located to the northeast of the field. Bleachers are present along the west side of the field. The field is irrigated sod. Figure 1 shows the general location of the site. PROPOSED CONSTRUCTION We understand CSU-Pueblo will be converting the surfacing at the existing soccerlacrosse field to artificial turf. In addition to the turf conversion, a 9000 square foot team building is to be built at the north end of the complex. The existing bleachers on the west side are to be replaced with a more substantial structure and a press box. Figure 1 presents general location for the improvements N. Elizabeth Street Suite C-2 Pueblo, Colorado Telephone Fax

2 SUBSURFACE CONDITIONS Subsurface conditions were explored by drilling three, 30 foot deep borings for the structures and one 15 foot boring in the existing field at the approximate locations shown on Fig. 1. The ground surface at test holes TH-1 through TH-3 was covered with an asphalt pavement section consisting of 3 inches of asphalt pavement over 9 to 15 inches of slag base course. The ground surface at TH-4 was covered with irrigated turf. Clayey sand fill was found below the topsoil at TH-4 and extended to a depth of 7.5 feet. Claystone bedrock was encountered below the fill or pavement in each of the borings. The claystone was weathered t a depth of 4 feet in boring TH-2. The claystone was medium hard to very hard based on field penetration resistance testing. The claystone was underlain by very hard shale bedrock at depths between 8 and 15 feet. Swell testing of the claystone bedrock resulted in low to very high measured swells when wetted under approximate overburden pressures (the weight of the overlying soil). Graphical logs of the conditions found in our borings are presented on Fig. 2. The results of laboratory testing are shown on Figs. 3 through 7 and summarized on Table 1. Groundwater No groundwater was encountered at the time of drilling. When checked 7 days after the completion of drilling, groundwater was measured in three borings at a depth of 15 feet. Test hole TH-4 was dry. Our borings were drilled in late winter when groundwater levels tend to be near their seasonal low. Levels tend to rise in the spring and summer months due to, on and off site, irrigation as well as precipitation. Seismicity The soil and bedrock are not expected to respond unusually to seismic activity. According to the 2009 International Building Code (IBC), we judge the site classifies as Site Class C. This site may classify as a Site Class B; however, geophysical testing would be required to verify that classification. GEOLOGIC HAZARDS Colorado is a challenging location to practice geotechnical engineering. The climate is relatively dry and the near-surface soils are typically dry and comparatively stiff. These soils and related sedimentary bedrock formations tend to react to changes in moisture conditions. Some of the soils swell as they increase in moisture and are referred to as expansive soils. Other soils can settle significantly upon wetting and are identified as collapsing soils. Most of the land available for development east of the Front Range is underlain by expansive clay or claystone bedrock near the surface. The soils that exhibit collapse are more likely west of the continental divide; however, both types of soils occur throughout the state. 2

3 Covering the ground surface with buildings and pavements; coupled with landscape irrigation and changing drainage patterns; leads to an increase in subsurface moisture conditions. As a result, some soil movement is inevitable. It is critical that all recommendations in this report are followed to increase the chance that the improvements will perform satisfactorily. Moisture sensitive soil materials are present at this site. The presence of moisture sensitive soil and bedrock constitutes a geologic hazard. There is risk that ground heave or compression will damage surfical improvements like the track and tennis courts. The foundations and pavements may settle if loose or soft fill and soils are present. The risk of movements can be mitigated, but not eliminated by careful design, construction, and maintenance procedures. We believe the recommendations in this report will help control risk of damage; they will not eliminate that risk. The owner should understand that improvements covered by this report may be affected by movement of the subsoils. Property maintenance will be required to control risk. SITE DEVELOPMENT This site is generally flat. Based on the existing grades and proposed construction at the site, we believe that cuts and fills required to achieve final grades will be minimal. Onsite soils within depths likely to affect foundations consist of fill of claystone with variable swell potential. Sub-excavation as described below is recommended to allow the use of a shallow foundation system, if desired. Sub-Excavation Claystone with low to high swell potential was encountered near the ground surface at this site. Sub-excavation below the building and bleachers and re-placement of the excavated soils as moisture conditioned, compacted fill could be performed to reduce heave potential and enhance performance of foundations, slabs-on-grade and flatwork. Sub-excavation to at least 8 feet below the exterior footing level of the new building will enhance the performance of a footing foundation with reduced potential heave or settlement. Sub-excavation to a depth of 4 feet below the bleacher foundations is expected to allow for the use of spread footings. Excavation and fill placement should be completed per the Excavation and Fill Placement sections of this report. The sub-excavation area should extend at least 5 feet outside the foundation limits. Special attention should be paid to compaction in the corners and along the edges of the excavation, as large equipment cannot easily access these areas. In order for the procedure to perform properly, close control of fill placement to specifications is required. Sub-excavation fill should be moisture conditioned and compacted to the specifications contained in the Fill Placement section. Our representative should observe and test compaction of fill during placement. 3

4 Once fill is placed, it is important that measures be planned to reduce drying of the near-surface materials. If the fill dries excessively prior to building construction, it may be necessary to rework the upper, drier materials just prior to installing foundations. It will be necessary to re-work (scarify, moisture condition and compact) the floor slab subgrade just prior to placing the floor. If foundation excavations remain open more than a few days prior to footing construction, the footing subgrade may also need to be re-worked. Excavation We believe the soils can be excavated with conventional, heavy-duty excavation equipment. Based on our investigation and Occupational Safety and Health Administration (OSHA) standards, we believe the on-site bedrock classify as Type A soil. Type A soil requires a maximum slope inclination of 0.75:1 (horizontal to vertical) for dry conditions. Excavation slopes specified by OSHA are dependent upon the types of soil and groundwater conditions encountered. The contractor s competent person should identify the soils encountered in the excavation and refer to OSHA standards to determine appropriate slopes. Stockpiles of soils and equipment should not be placed within a horizontal distance equal to one-half the excavation depth, from the edge of the excavation. Fill Placement The soils found at this site are suitable to re-use as fill material provided vegetation, asphalt, topsoil, debris and other deleterious materials are substantially removed. Any remnants of previous structures or site improvements should be removed. If imported fill is necessary, it should ideally consist of granular material with 100 percent passing the 2-inch sieve and 30 to 40 percent passing the No. 200 sieve. The import soil should exhibit low plasticity with a Liquid Limit less than 30 and a Plasticity Index less than 10. Import soils similar to the on-site natural soils may also be suitable. A sample of the import material should be submitted to our office for approval before stockpiling at the site. Before fill placement, vegetation, topsoil, asphalt, and other deleterious material should be removed. Areas to receive fill should be scarified to a depth of 8 inches, moisture conditioned to within 2 percent of optimum moisture content and compacted to at least 95 percent of standard Proctor maximum dry density (ASTM D 698). The properties of the fill will affect the performance of foundations and slabs-ongrade. Fill and backfill within the building footprint should be placed in thin, loose lifts of 8 inches or less, moisture conditioned, and compacted to at least 95 percent of standard Proctor maximum dry density (ASTM D 698). Fill should be moisture conditioned to between 1 and 4 percent over the optimum moisture content. We recommend trench backfill be moisture conditioned and compacted as stated above. The placement and compaction of backfill should be observed and tested by a representative of our firm during construction. 4

5 FOUNDATIONS We understand the university anticipates the use of drilled pier foundations for the proposed building and bleachers. While this method is considered to be a reliable foundation alternative, we believe the use of a shallow foundation system constructed on new sub-excavation fill can be considered and could be a more economical foundation system. The use of footings on sub-excavation fill may result in an increased risk of movement and the risks should be evaluated when determining the appropriate foundation type. Our borings at this site and understanding of the proposed project suggest claystone with low to very high swell potential will be near the shallow foundation levels. We believe a significant risk of detrimental differential movement will exist for conventional spread footing foundations supported by the natural in-place materials. Our calculations indicate that about 4 inches of ground heave may occur at the building and bleacher sites should the expansive bedrock become wetted. Ground heave of about 1 inch should be expected at the building site and 2 inches at the bleacher site for the bedrock after sub-excavation has been completed to depths of 8 and 4 feet respectively. Recommended foundation design and construction criteria are presented below. These criteria were developed from analysis of field and laboratory data and our experience. Spread Footings with Minimum Deadload We recommend spread footings with minimum deadload be designed and constructed in accordance with the criteria presented below. 1. We recommend the spread footings be constructed on at least 8 feet of new sub-excavation fill at the building site and 4 feet of new subexcavation fill at the bleachers. Excavations should extend 5 feet beyond foundations at the bottom of the excavation. Materials loosened during the excavation process should be removed or moisture conditioned and compacted as specified below, prior to the placement of concrete. 2. Sub-excavation backfill placed below footings should be moisture conditioned and compacted per the Fill Placement section of the report. 3. Footings underlain by newly compacted fill may be designed for a maximum allowable soil pressure of 3,000 psf and should impose a minimum deadload of 1,000 psf. The minimum deadload requirement may be omitted for the bleachers. 4. We recommend footings beneath continuous foundation walls be at least 16 inches wide. Footings beneath isolated column pads should be at least 24 inches square. Larger footing sizes may be required to accommodate the anticipated structural loads. 5

6 5. Foundations should be designed to span an unsupported distance of 10 feet. 6. We recommend designs consider total movement of 1-inch and differential movement of 1/2-inch. 7. Exterior footings must be protected from frost action with a soil cover of at least 26 inches. 8. A representative of our firm should observe the completed foundation excavation to confirm the exposed conditions are similar to those encountered in our exploratory borings. The placement and compaction of below-footing fill and footing subgrade preparation should be observed and tested by a representative of our firm during construction. Drilled Piers 1. Piers should be designed for a maximum allowable end pressure of 40,000 psf and an allowable skin friction of 4,000 psf for the portion of pier in the shale bedrock bedrock. An allowable skin friction of 2,500 psf may be used for the claystone bedrock. Skin friction should be neglected where bedrock occurs within the upper 8 feet of the pier. 2. Piers should be designed for a minimum deadload pressure of 10,000 psf based on pier cross-sectional area. If this deadload cannot be achieved through the weight of the structure, the pier length and bedrock penetration should be increased beyond the minimum values specified in the next paragraph. The shale bedrock should be assigned a skin friction value of 4,000 psf for uplift resistance. 3. Piers should penetrate at least 7 feet into the comparatively unweathered shale bedrock and have total lengths of at least 20 feet. We anticipate a large, heavy-duty drill rig will be required to penetrate the shale. 4. Drilled piers should be designed to resist an ultimate uplift force of at least 85 kips times the pier diameter in feet, minus the deadload. Reinforcement should extend into grade beams and foundation walls. 5. There should be an 6-inch (or thicker) continuous void beneath all grade beams and foundation walls, between piers, to concentrate the deadload of the structure onto the piers. 6. Foundation walls and grade beams should be well reinforced. The reinforcement should be designed by the structural engineer considering lateral earth pressures. 6

7 7. Piers should be carefully cleaned prior to placement of concrete. Groundwater was measured at a depth of 15 feet during this investigation, several days after drilling. We believe a drill-and-pour procedure for pier installation will be applicable. Concrete should be on site and placed in the pier holes immediately after the holes are drilled, cleaned and observed by our representative to avoid collecting water and possible contamination of open pier holes. Concrete should not be placed by free fall if there is more than about 3 inches of water at the bottom of the hole. 8. Concrete should have sufficient slump to fill the pier holes and not hang on the reinforcement. We recommend a slump in the range of 5 to 7 inches. 9. Formation of mushrooms or enlargements at the tops of piers should be avoided during pier drilling and subsequent construction operations. 10. Installation of drilled piers should be observed by a representative of our firm to identify the proper bearing strata and to observe the contractor s installation procedures. Laterally Loaded Piers Lateral load analysis of piers can be performed with the software analysis package LPILE by Ensoft, Inc. We believe this method of analysis is appropriate for piers with a pier length to diameter ratio of seven or greater. Suggested criteria for LPILE analysis are presented in the following table. SOIL INPUT DATA FOR LPILE Recommended p-y Curve Model Weak Rock Density (pci) p-y Modulus, k rm (pci) RQD 70 Young s Modulus, E r (psi) 0.05 x 10 6 Compressive Strength (psi) 120 Other procedures require input of a horizontal modulus of subgrade reaction (K h ). We believe the following formulas are appropriate for calculating horizontal modulus of subgrade reaction (K h ) values. 7

8 HORIZONTAL MODULUS OF SUBGRADE REACTION Bedrock Horizontal Modulus of Subgrade Reaction, K h (tcf) Where z = depth (ft); d = pier diameter (ft). K h = 200 d Closely-Spaced Pier Reduction Factors For axial loading, no reduction is needed for a minimum spacing of three diameters (centerto-center). At one diameter (piers touching), the skin friction reduction factor for both piers would be 0.5. End pressure values would not be reduced provided the bases of the piers are at similar elevations. Interpolation can be used between one and three diameters. For lateral loading, no reduction is needed for piers in-line with the direction of lateral loads with a minimum spacing of six diameters (center-to-center) based upon the larger pier. If a closer spacing is required, the modulus of subgrade reaction for initial and trailing piers should be reduced. At a spacing of three diameters, the effective modulus of subgrade reaction of the first pier can be estimated by multiplying the given modulus by 0.6; for trailing piers in a line at three-diameter spacing, the factor is 0.4. Linear interpolation can be used for spacing between three and six diameters. Reductions to the modulus of subgrade reaction can be accomplished in LPILE by inputting the appropriate modification factors for p-y curves. Reducing the modulus of subgrade reaction in trailing piers will result in greater computed deflections on these piers. In practice, a grade beam can force deflections of all piers to be equal. Load-deflection graphs can be generated for each pier by using the appropriate p-multiplier values. The sum of the piers lateral load resistance at selected deflections can be used to develop a total lateral load versus deflection graph for the system of piers. For lateral loads perpendicular to the line of piers, a minimum spacing of three diameters can be used with no capacity reduction. At one diameter (piers touching) the piers should be analyzed as one unit. Interpolation can be used for intermediate conditions. FLOOR SYSTEMS AND SLABS-ON-GRADE We anticipate the building finished floor elevation will be near the existing grades. Our borings indicate the materials below the floors include claystone with low to vey high swell potential. Expansive soils are stable at existing moisture contents, but upon wetting can cause heave of slab-on-grade floors resulting in slab damage. Heave cannot be resisted by concentrating slab loads. Calculations suggest about 4 inches of potential heave may occur at the building site, with the bedrock in its current condition. We believe the more reliable option would be to install structurally supported floors (crawl space construction). To allow the use of a slab-on-grade floor, we recommend the 8

9 existing subsoils be uniformly sub-excavated to at least 8 feet below the bottom of the proposed slabs-on-grade prior to placing compacted fill to grade. The fill should be constructed as discussed under the Sub-Excavation section of this report. Calculations suggest about 1-inch of potential heave may occur after sub-excavation is performed. The placement and compaction of below-slab fill should be observed and tested by a representative of our firm during construction. If the drilled pier option is selected and the sub-excavation is not performed, structurally supported floors are recommended. The void below the slab should be at least 12 inches thick. If the owner elects to use slab-on-grade construction and accepts the risk of movement and the associated damage, we recommend the following precautions for slabon-grade construction. These precautions can help reduce, but will not eliminate damage or distress due to slab movement. 1. Slabs should be separated from exterior walls and interior bearing members with a slip joint that allows free vertical movement of the slabs. This approach can reduce cracking if some movement of the slab occurs. 2. From a geotechnical viewpoint, we believe the floor slabs can be placed directly on the subgrade soils. The 2009 International Building Code (IBC) requires a vapor retarder be placed between base course or subgrade soils and the concrete slab-on-grade floor, unless the designer of the floor (structural engineer) waives this requirement. The merits of installation of a vapor retarder below a floor slab depend on the sensitivity of floor coverings and building use to moisture. A properly installed vapor retarder (10 mil minimum) is more beneficial below concrete slab-on-grade floors where floor coverings, painted floor surfaces or products stored on the floor will be sensitive to moisture. The vapor retarder is most effective when concrete is placed directly on top of it, rather than placing a sand or gravel leveling course between the vapor retarder and the floor slab. The placement of concrete on the vapor retarder may increase the risk of shrinkage cracking and curling. Use of concrete with reduced shrinkage characteristics including minimized water content, maximized coarse aggregate content, and reasonably low slump will reduce the risk of shrinkage cracking and curling. Considerations and recommendations for the installation of vapor retarders below concrete slabs are outlined in Section of the 2006 report of the American Concrete Institute (ACI) Committee 302, Guide for Concrete Floor and Slab Construction (ACI 302.R-96). 3. Masonry partition walls should be supported on foundations, independent of floor slabs. These walls should not be constructed on a thickened slab. 4. If slab-bearing partitions are installed, they should be designed and constructed to allow for slab movement. At least a 2-inch void should be 9

10 maintained below or above the partitions. If the float is provided at the top of partitions, the connection between interior, slab-supported partitions and exterior, foundation-supported walls should be detailed to allow differential movement. 5. Under-slab plumbing should be eliminated where feasible. Where such plumbing is unavoidable it should be thoroughly pressure tested for leaks prior to slab construction and be provided with flexible couplings. Pressurized water supply lines should be brought above the floor slabs as quickly as possible. 6. Plumbing and utilities that pass through the slabs should be isolated from the slabs and constructed with flexible couplings. Where water and gas lines are connected to slab-supported mechanical units, the lines should be constructed with sufficient flexibility to allow for movement. Utilities should be sleeved or separated from foundations and slabs to accommodate potential movements. 7. Mechanical or HVAC equipment on a slab floor should be provided with a collapsible connection between the equipment and the ductwork, with allowance for at least 2 inches of vertical movement. 8. Exterior flatwork and sidewalks should be separated from the structure. These slabs should be reinforced to function as independent units. Movements of these slabs should not be transmitted directly to the foundation of the structure. 9. Frequent control joints should be provided in floor slabs to reduce problems associated with shrinkage cracking and curling, in accordance with American Concrete Institute (ACI) recommendations. Exterior Flatwork We recommend exterior flatwork and sidewalks be isolated to reduce the risk of transferring slab movement to the structure. One alternative would be to construct the inner edges of the flatwork on haunches or steel angles bolted to the foundation walls and detail the connections such that movement will cause less distress to the building, rather than tying the slabs directly into the building foundations. Construction on haunches or steel angles and reinforcing the sidewalks and other exterior flatwork will reduce the potential for differential settlement and better allow them to span across wall backfill. Frequent control joints should be provided to reduce problems associated with shrinkage cracking and curling. Panels that are approximately square perform better than rectangular areas. Subexcavation or partial removal can be considered to improve exterior flatwork performance. 10

11 BELOW GRADE CONSTRUCTION We are not aware of any proposed habitable below grade construction. If plans should change to include habitable below grade construction, we should be contacted to provide recommendations for lateral earth pressures and perimeter foundation drains. ARTIFICIAL TURF CONSTRUCTION Our boring information suggests the surfical materials below the existing sod soccer/lacrosse field consist of clayey sand fill and claystone bedrock. These materials typically have low permeability. We understand a subsurface drainage system consisting of a gravel horizontal drain blanket connected to trench drains is a typical detail for the construction of an artificial turf. We concur with the inclusion of a subsurface drain system below the turf. If fill is needed to adjust site grades, we believe the on-site materials that are free of debris or deleterious materials and less than 3-inches in size can be used. Existing topsoil and organic materials should be removed prior to fill placement. Fill should be placed in thin loose lifts; moisture conditioned to within 2 percent of optimum and compacted to at least 90 percent of standard Proctor maximum dry density (ASTM D 698). CONCRETE Concrete in contact with soil can be subject to sulfate attack. We measured watersoluble sulfate concentrations 1.05 and 1.75 percent in samples from this site. Watersoluble sulfate concentrations between 0.2 and 2 percent indicate Class 2 exposure to sulfate attack, according to the American Concrete Institute (ACI) Guide To Durable Concrete (ACI 201.2R). For sites with Class 2 sulfate exposure, ACI 201 recommends using a cement meeting the requirements for Type V (sulfate resistant) cement or the equivalent, with a maximum water-to-cementitious material ratio of The concrete should have a total air content of 6 percent percent. As an alternative, ACI allows the use of cement that conforms to ASTM C 150 Type II requirements, if it meets the Type V performance requirements (ASTM C 452) of ASTM C 150 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 C ACI 318 indicates concrete in severe exposure should have a specified compressive strength of 4,500 psi. The use of sulfate resistant concrete is most appropriate for foundation elements. Surface flatwork (such as sidewalks) is usually constructed with a mix that exhibits moderate resistance to sulfate attack. We have rarely seen instances of sulfate attack on surface flatwork. The risk of poor finish quality often associated with retardation of set and plastic shrinkage cracking caused by the use of Type V cement, fly ash, and/or low water-tocementitious material ratios is probably greater than the risk of sulfate attack in concrete flatwork. Concrete containing Type II cement and at least 564 pounds of cementitious materials per cubic yard provides better resistance to sulfate attack than the concrete that 11

12 has typically been used in the past, yet results in minimal finishing problems. This approach may be considered for sites where high sulfate levels are found. A minimum compressive strength of 4,000 psi, a maximum water-to-cementitious material ratio of 0.45, and a total air content of 6.5 percent percent will provide some sulfate resistance, as well as some protection against surface damage due to freeze-thaw cycles. We recommend all belowgrade walls in contact with the subsoils be damp-proofed. SURFACE DRAINAGE AND LANDSCAPING The moisture conditions of the subsoils impacts the performance of the materials. It is important that surface drainage during and after construction provide for the rapid removal of runoff away from pavements like the track, over the artificial turf as well as building foundations. Overall landscaping should consider plants that require little irrigation after the establishment period. Water quality features should be located well down slope of the improvements or lined to eliminate infiltration of retained water into the subsoils. GEOTECHNICAL RISK The concept of risk is an important aspect with any geotechnical evaluation primarily because the methods used to develop geotechnical recommendations do not comprise an exact science. We never have complete knowledge of subsurface conditions. Our analysis must be tempered with engineering judgment and experience. Therefore, the recommendations presented in any geotechnical evaluation should not be considered riskfree. Our recommendations represent our judgment of those measures that are necessary to increase the chances that the buildings will perform satisfactorily. It is critical that all recommendations in this report are followed. DESIGN CONSULTATION AND CONSTRUCTION OBSERVATIONS This report has been prepared for the use of NorthStar Engineering and Surveying for the purpose of providing geotechnical design and construction criteria for the proposed project. The information, conclusions, and recommendations presented herein are based upon consideration of many factors including, but not limited to, the type of construction proposed, the geologic setting, and the subsurface conditions encountered. The conclusions and recommendations contained in the report are not valid for use by others. Standards of practice evolve in the area of geotechnical engineering. The recommendations provided are appropriate for about three years. If the proposed facilities are not constructed within about three years, we should be contacted to determine if we should update this report. CTL Thompson, Inc. should be retained to provide general review of the design and construction plans prior to construction. Our firm should also provide geotechnical and materials testing during construction. The purpose is to observe the construction with respect to the geotechnical design concepts, specifications or recommendations, and to facilitate design changes in areas where the subsurface conditions differ from those anticipated prior to start of construction. When construction schedules and quantities are defined, we can work with the owner and/or contractor to develop an appropriate scope of 12

13

14

15 TH - 1 TH - 2 TH - 3 TH /7 WC=13.8 DD= =100 SS= /5 WC=10.9 DD=111 22/12 WC=18.1 DD=111 SW=1.1 LL=43 PI=20-200=81 50/8 50/8 50/9 WC=13.4 DD=113 SW=0.5 17/12 WC=18.3 DD=111 SW=1.1 15/ LEGEND: TOPSOIL. ASPHALT PAVEMENT, 3 INCHES THICK. SLAG BASE COURSE. 9 TO 15 INCHES THICK /3 50/9 WC=13.2 DD=122 SW=4.7 SS= /3 WC=12.6 DD=124 SW= =98 45/12 WC=15.5 DD=118 LL=47 PI=27 10 FILL, SAND, CLAYEY, MEDIUM DENSE, DRY, BROWN. BEDROCK. WEATHERED CLAYSTONE, SANDY, MEDIUM HARD, MOIST, BROWN /3 50/4 50/3 50/10 WC=17.3 DD=115 UC=17, BEDROCK. CLAYSTONE, SANDY, HARD TO VERY HARD, MOIST, BROWN, GRAY BROWN /2 50/3 50/2 20 BEDROCK. SHALE, FISSEL, VERY HARD, DRY, GRAY. DEPTH - FEET 25 50/2 25 DEPTH - FEET DRIVE SAMPLE. THE SYMBOL 50/7 INDICATES 50 BLOWS OF A 140-POUND HAMMER FALLING 30 INCHES WERE REQUIRED TO DRIVE A 2.5-INCH O.D. SAMPLER 7 INCHES. GROUND WATER LEVEL MEASURED 7 DAYS AFTER DRILLING /2 50/1 50/ NOTES: 1. THE BORINGS WERE DRILLED JANUARY 27, 2014 USING A 4-INCH DIAMETER, CONTINUOUS-FLIGHT AUGER AND A DIEDRICH D-50, TRUCK-MOUNTED DRILL RIG. 2. NO GROUNDWATER WAS FOUND AT THE TIME OF DRILLING. 3. THESE LOGS ARE SUBJECT TO THE EXPLANATIONS, LIMITATIONS, AND CONCLUSIONS AS CONTAINED IN THIS REPORT. 4. WC - INDICATES MOISTURE CONTENT. (%) DD - INDICATES DRY DENSITY. (PCF) SW - INDICATES SWELL WHEN WETTED UNDER 1 KSF LOAD. (%) LL - INDICATES LIQUID LIMIT. (%) (NV : NO VALUE) PI - INDICATES PLASTICITY INDEX. (%) (NP : NON-PLASTIC) INDICATES PASSING NO. 200 SIEVE. (%) SS - INDICATES WATER-SOLUBLE SULFATE CONTENT. (%) UC - INDICATES UNCONFINED COMPRESSIVE STRENGTH. (PSF) COLORADO STATE UNIVERSITY - PUEBLO SOCCER LACROSSE FIELD MODIFICATIONS CTL T S:\SC \SC \125\2. REPORTS\SC _GINT.GPJ Summary Logs of Exploratory Borings FIG. 2

16 7 6 5 EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING COMPRESSION % EXPANSION APPLIED PRESSURE - KSF Sample of CLAYSTONE, SANDY DRY UNIT WEIGHT= 111 PCF From TH-2 AT 2 FEET MOISTURE CONTENT= 18.1 % COLORADO STATE UNIVERSITY - PUEBLO SOCCER LACROSSE FIELD MODIFICATIONS CTL T S:\SC \SC \125\2. Reports\SC _SWELL.xls Swell Consolidation Test Results FIG. 3

17 7 6 5 EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING COMPRESSION % EXPANSION APPLIED PRESSURE - KSF Sample of CLAYSTONE DRY UNIT WEIGHT= 122 PCF From TH-2 AT 9 FEET MOISTURE CONTENT= 13.2 % COLORADO STATE UNIVERSITY - PUEBLO SOCCER LACROSSE FIELD MODIFICATIONS CTL T S:\SC \SC \125\2. Reports\SC _SWELL.xls Swell Consolidation Test Results FIG. 4

18 7 6 5 EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING COMPRESSION % EXPANSION APPLIED PRESSURE - KSF Sample of CLAYSTONE DRY UNIT WEIGHT= 113 PCF From TH-3 AT 4 FEET MOISTURE CONTENT= 13.4 % COLORADO STATE UNIVERSITY - PUEBLO SOCCER LACROSSE FIELD MODIFICATIONS CTL T S:\SC \SC \125\2. Reports\SC _SWELL.xls Swell Consolidation Test Results FIG. 5

19 EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING COMPRESSION % EXPANSION APPLIED PRESSURE - KSF Sample of CLAYSTONE DRY UNIT WEIGHT= 124 PCF From TH-3 AT 9 FEET MOISTURE CONTENT= 12.6 % COLORADO STATE UNIVERSITY - PUEBLO SOCCER LACROSSE FIELD MODIFICATIONS CTL T S:\SC \SC \125\2. Reports\SC _SWELL.xls Swell Consolidation Test Results FIG. 6

20 7 6 5 EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING COMPRESSION % EXPANSION APPLIED PRESSURE - KSF Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT= 111 PCF From TH-4 AT 2 FEET MOISTURE CONTENT= 18.3 % COLORADO STATE UNIVERSITY - PUEBLO SOCCER LACROSSE FIELD MODIFICATIONS CTL T S:\SC \SC \125\2. Reports\SC _SWELL.xls Swell Consolidation Test Results FIG. 7

21 TABLE 1 SUMMARY OF LABORATORY TESTING CTL T ATTERBERG LIMITS SWELL TEST RESULTS* PASSING WATER MOISTURE DRY LIQUID PLASTICITY APPLIED SWELL UNCONFINED NO. 200 SOLUBLE DEPTH CONTENT DENSITY LIMIT INDEX SWELL PRESSURE PRESSURE COMPRESSION SIEVE SULFATES BORING (FEET) (%) (PCF) (%) (%) (%) (PSF) (PSF) (PSF) (%) (%) DESCRIPTION TH CLAYSTONE TH CLAYSTONE TH CLAYSTONE, SANDY TH ,100 9, CLAYSTONE TH CLAYSTONE TH ,100 31, CLAYSTONE TH CLAY, SANDY (CL) TH CLAYSTONE TH ,300 CLAYSTONE * SWELL MEASURED WITH ESTIMATED IN-SITU OVERBURDEN PRESSURE. NEGATIVE VALUE INDICATES COMPRESSION. Page 1 of 1