Geotechnical Engineering Report
Geotechnical Engineering Report Spanish Fork Fairgrounds Grandstand 475 South Main Street Spanish Fork, Utah
September 8, 2011 Terracon Project No. 61115033
Prepared for: Spanish Fork City 40 South Main Spanish Fork, Utah 84660
Prepared by: Terracon Consultants, Inc. 14850 Pony Express Road, Suite 150N Bluffdale, Utah 84065
TABLE OF CONTENTS Page 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 Profile ................................................................................................................. 2 3.2 Groundwater ................................................................................................................... 3 4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION....................................... 3 4.1 Geotechnical Considerations .......................................................................................... 3 4.2 Earthwork ....................................................................................................................... 4 4.3 Foundations – Drilled Piers ............................................................................................ 6 4.4 Foundations – Spread Footings ..................................................................................... 8 4.5 Seismic Considerations .................................................................................................. 9 4.6 Chemical Tests ............................................................................................................. 10 5.0 GENERAL COMMENTS ................................................................................................. 10
APPENDICIES APPENDIX A – FIELD EXPLORATION
Exhibits
Project Vicinity Map ....................................................................................................... A-1 Boring Location Diagram .............................................................................................. A-2 Field Exploration Description ........................................................................................ A-3 Boring Logs .................................................................................................................. A-4 General Notes ............................................................................................................... A-5 Unified Soil Classification .............................................................................................. A-6 APPENDIX B – LABORATORY TESTING
Exhibits
Laboratory Testing ........................................................................................................ B-1 Grain Size Distribution ........................................................................................ B-2 to B-3 UU Triaxial ................................................................................................................... B-4 Consolidation ..................................................................................................... B-5 to B-6 Sulfate Test Results ...................................................................................................... B-7
GEOTECHNICAL ENGINEERING REPORT Spanish Fork Fairgrounds Grandstand 475 South Main Street Spanish Fork, Utah Terracon Project No. 61115033 September 8, 2011 EXECUTIVE SUMMARY A geotechnical investigation has been performed for the proposed fairground grandstand reconstruction to be completed at the Spanish Fork Fairgrounds in the Spanish Fork, Utah. Four soil borings were drilled to depths ranging between approximately 21½ to 42 feet below the existing ground surface. This report presents geotechnical recommendations for design and construction of foundations for the proposed grandstands reconstruction. Based on the information obtained from our subsurface exploration, the site can be developed for the proposed project. The following geotechnical considerations were identified: Site Soils: The site surface generally consisted of asphaltic concrete, gravel and exposed clay soil. The underlying near surface and subsurface soils generally consisted of interbedded clay, sandy silt to silt, silty sand and gravel. Groundwater was encountered at depths of 3½ to 5 feet in the test borings at the time of field exploration. Foundations: The grandstand structure may be supported by shallow strip or spread footings bearing on a minimum of 2 feet of structural fill with a net allowable bearing capacity of 2,500 psf for strip and 3,300 psf for spread footings. As an alternative, the structure may be supported on straight shaft drilled piers with a minimum shaft length of 20 feet and a maximum shaft length of 25 feet. Seismic: The site is best represented by an IBC 2009 Site Class F. Liquefiable soils were encountered in all the borings between 5 and 20 feet and to a depth of 32 feet in B-04. Liquefaction induced settlement is estimated to range from 3 to 9 inches. 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.
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GEOTECHNICAL ENGINEERING REPORT Spanish Fork Fairgrounds Grandstand 475 South Main Street Spanish Fork, Utah Terracon Project No. 61115033 September 8, 2011 1.0
INTRODUCTION
A geotechnical exploration report has been completed for the proposed grandstand reconstruction project at the Spanish Fork Grandstands in Spanish Fork, Utah. . The purpose of this exploration is to provide information and geotechnical engineering recommendations relative to:
subsurface soil conditions groundwater conditions earthwork
foundation design and construction seismic considerations
Four soil borings were drilled to depths ranging from approximately 21½ to 42 feet below the existing ground surface. Logs of the borings along with a Project Vicinity Map and Boring Location Diagram (Exhibits 1 and 2) are included in Appendix A of this report. The results of the laboratory testing performed on soil samples obtained from the site during the field exploration are included in Appendix B of this report. Descriptions of the field exploration and laboratory testing are included in their respective appendices.
2.0
PROJECT INFORMATION
2.1
Project Description Item
Existing site layout
Structure
Arena Construction
Description Refer to the Project Vicinity Map and Boring Location Diagram (Appendix A, Exhibits A-1 and A-2). The existing main arena grandstand (Lance Money Arena: 7,000 seating capacity with 42,000 square feet arena floor area) will be replaced with new arena grandstand that is approximately 10 feet larger on all sides. Canopies will be constructed on both sides of the arena with an announcer booth. Steel frame.
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Geotechnical Engineering Report Spanish Fork Fairgrounds Grandstand ■ Spanish Fork, Utah September 8, 2011 ■ Terracon Project No. 61115033 Item Maximum loads Maximum allowable settlement Grading
Description Dead Load: 5 to 10 kips (assumed) Live Load: 25 to 50 kips (assumed) Uplift: 10 to 15 kips (assumed) Pier and Shallow Footings: 1-inch (Assumed) Unknown; minimal grade changes on the order of 1 foot or less are assumed
Should any of the above information or assumptions be inconsistent with the planned construction, Terracon should be notified to review, and revise if necessary, recommendations provided in this report.
2.2
Site Location and Description Item
Description
Location
475 South Main Street, Spanish Fork, Utah
Existing improvements
The site currently consists of a rodeo facility including an arena and surrounding grandstands. The stands are partially covered on both sides of the arena. The complex is about 240 feet wide and 350 feet long.
Surrounding Developments
North: Asphalt parking lots. South: Fence demarcating fairground property boundary and large barn structure. East: Corrals, small building, and parking lots. West: Asphalt parking lots with Main Street beyond.
Current ground cover
Bare soil in the rodeo arena with asphaltic concrete surrounding the stands.
Existing topography
Relatively flat. Approximately 1/2 feet vertical difference across the site based on surveying relative elevations of the ground surface at each boring location.
3.0
SUBSURFACE CONDITIONS
3.1
Typical Profile
Specific conditions encountered at each boring location are indicated on the individual boring logs. Stratification boundaries on the boring logs represent the approximate location of changes in soil types; in-situ, the transition between materials may be gradual. Details for each of the borings can be found on the boring logs included in Appendix A of this report. Based on the results of the borings, subsurface conditions on the project site can be generalized as follows:
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Geotechnical Engineering Report Spanish Fork Fairgrounds Grandstand ■ Spanish Fork, Utah September 8, 2011 ■ Terracon Project No. 61115033
Description
Approximate Depth to Bottom of Stratum (feet)
Stratum 1
¼
Stratum 2 Stratum 3
5 ½ to 10 14 ½ to 19 18 to 32 (not encountered in B-2) 21 ½ to 33 (termination depth of B-1 and B-3)
Stratum 4 Stratum 5 Stratum 6
3.2
42
Material Encountered
Consistency/Density
Asphaltic concrete and gravel Clay Sandy Silt to Silt
NA
Silty Sand Gravel Clay
Very Soft to Soft Soft Very Loose to Medium Dense Medium Dense to Very Dense Soft to Medium Stiff
Groundwater
Groundwater was observed at depths of approximately 3½ to 5 feet after drilling completion. It should be recognized that fluctuations of the groundwater table may occur due to seasonal and longer term variations in the amount of precipitation and runoff, future construction and other factors not evident at the time the borings were drilled. Evaluation of these factors is beyond the scope of this exploration.
4.0
RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION
4.1
Geotechnical Considerations
Based on the results of this exploration, it is our opinion that the site is suitable for the proposed construction. The proposed grandstand may be supported on shallow spread foundations bearing on a minimum of 2 feet of properly placed and compacted structural fill, or on drilled pier foundations with minimum tip depth of 20 feet and a maximum depth of 25 feet. Groundwater was encountered at depths of approximately 3½ to 5 feet below existing site grade. Dewatering will be required for excavations extending down to or below groundwater. Existing foundations and any existing fill that may be encountered during demolition of the existing grandstand should be completely removed from within the construction area and replaced with properly placed and compacted structural fill. Soft pumping soils may be encountered during earthwork. Stabilization using a combination of geotextiles and crushed rock may be required to form a firm surface for construction. Low pressure construction equipment may be required to minimize disturbance to subgrade soil. If drilled pier foundations are used, temporary casing and drilling fluid should be used to maintain an open hole and prevent sloughing during excavation and construction of the piers.
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Geotechnical Engineering Report Spanish Fork Fairgrounds Grandstand ■ Spanish Fork, Utah September 8, 2011 ■ Terracon Project No. 61115033
Geotechnical engineering recommendations for design and construction of foundation systems and other earth connected phases of the project are outlined below. The recommendations contained in this report are based upon the results of field and laboratory testing (which are presented in Appendix A and B), engineering analyses, and our current understanding of the proposed project.
4.2
Earthwork
All existing foundations, utilities, existing fill, disturbed, loose, soft, or frozen soil, and other unsuitable materials should be removed from beneath proposed shallow foundations. Care should be taken during excavation to reduce the potential for disturbance of the native soils. After removal of any unsuitable materials and prior to placing fill, excessively soft or disturbed areas encountered during subgrade preparation should be removed and replaced with properly placed and compacted structural fill as described below. Due to near surface soft soils, stabilization rock in combination with geogrid and filter fabric may be required to form a stable working platform on which to place and compact structural fill. After removal of existing foundations and fill materials and excavating down to final subgrade elevation, and prior to the start of fill operations, we recommend that the geotechnical engineer be retained to observe the bearing material for structural fill placement below footing foundations areas. Dewatering will be required for shallow spread footing excavations extending to and below groundwater. The design recommendations presented in this report are based on the observed soil conditions at specific exploration locations and on the assumption that earthwork for site grading, foundations and fill areas will be monitored by a qualified geotechnical engineer from Terracon.
4.2.1 Fill Materials and Placement Structural and stabilization fill should meet the following material property requirements: Fill Type 1
Material
3
Acceptable Location for Placement 2
Structural
Well graded granular 3
Stabilization
All locations and elevations 4
Clean, Crushed Angular Rock
Stabilization areas
1.
Controlled, compacted fill should consist of approved materials that are free of organic matter and debris. Frozen material should not be used, and fill should not be placed on a frozen subgrade. A sample of each material type should be submitted to the geotechnical engineer for evaluation.
2.
Granular soil with a maximum particle size of 3 inches, 25 to 60 percent passing the No. 4 sieve and having less than 15 percent fines. Fines should have a Plasticity Index (PI) less than 12.
3.
Appropriate geotechnical testing should be performed on all fill prior to its usage on-site in order to verify conformance to the standards for structural fill outlined in this report.
4.
Two to 4 inch minus, clean, crushed rock with angular edges, and having less than 5 percent fines.
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Geotechnical Engineering Report Spanish Fork Fairgrounds Grandstand ■ Spanish Fork, Utah September 8, 2011 ■ Terracon Project No. 61115033
4.2.2 Compaction Requirements Item
Description
Fill Lift Thickness
8-inches or less in loose thickness
Compaction 1
95% of the material’s maximum dry density (modified Proctor - ASTM D 1557) in foundation areas
Moisture Content
Within two percent of the optimum moisture content as determined by the modified Proctor test at the time of placement and compaction
1.
Fill should be tested frequently 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 compaction is achieved. This may require adjustment of the moisture content.
If stabilization rock is used, rock should be placed in lifts of 12 to 18 inches in loose thickness and seated in-place by tamping using the bucket of an excavator or backhoe, or by making several passes using a static compactor. Vibratory or excessive compaction effort should not be applied, and care should be taken to minimize disturbance to underlying native soils.
4.2.3 Grading and Drainage Positive drainage away from the proposed structures should be provided during construction and maintained throughout the life of the proposed project.
4.2.4 Construction Considerations Unstable subgrade conditions could develop during general construction operations, particularly if the soils are wetted and/or subjected to repetitive construction traffic. The use of light construction equipment, minimize repetitive trafficking and construction during dryer seasons would aid in reducing subgrade disturbance. If the subgrade should become frozen or disturbed, the affected material should be replaced with structural fill or stabilization rock as appropriate. Groundwater was encountered approximately 3 feet below existing site grade. Excavations extending to and below the subgrade will require dewatering. We recommend that if excavations extending below groundwater are planned, a qualified dewatering professional be retained to evaluate appropriate dewatering methods for the site. The contractor should be responsible for the design and implementation of the dewatering system. As a minimum, all temporary excavations should be sloped or braced as required by Occupational Health and Safety Administration (OSHA) regulations to provide stability and safe working conditions. Temporary excavations will probably be required during grading operations. The grading contractor is responsible for designing and constructing stable, temporary excavations and should shore, slope or bench the sides of the excavations as required, to maintain stability of both the excavation sides and bottom. All excavations should comply with applicable local, state and federal safety regulations, including the current OSHA Excavation and Trench Safety Standards.
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Geotechnical Engineering Report Spanish Fork Fairgrounds Grandstand ■ Spanish Fork, Utah September 8, 2011 ■ Terracon Project No. 61115033
Earthwork on the project should be observed and evaluated by Terracon. The evaluation of earthwork should include observation and testing of structural fill, site grading, subgrade preparation and proof rolling, foundation bearing soils, and other geotechnical conditions exposed during the construction of the project.
4.3
Foundations – Drilled Piers
Soil parameters to be used in the design of the drilled pier foundation are included in the following table. The values included in the table were estimated based on the observed soil conditions during our field exploration, visual classifications, and presumptive values for similar materials. Note that the soil parameters are not intrinsic values of the soil, and depend on the state of the soil (density, depositional history, water content, etc.) and the loading conditions, among other factors. The soil parameters presented in the table are intended to be used in the design of drilled pier foundations at the site assuming soil conditions are similar to those encountered during our field exploration. The applicability of these soil parameters for other uses should be discussed with the geotechnical engineer. The allowable end bearing pressure, skin friction, and horizontal constant of subgrade reaction for the three depth intervals are summarized in the table below. The allowable end bearing pressure and skin friction values presented in the table are based on a factor of safety of 3. Also, the allowable skin friction to resist both vertical downward loads and uplift forces assume bored piers having concrete cast in direct contact with adjacent soil (uncased). We recommend that, the pier extend to a minimum depth of 20 feet for a shaft with a minimum diameter of 2 feet. The pier should not extend past 25 feet to reduce the rick of punching failure due to the underlining clay material. The contribution of the upper 2.5 feet should be neglected due to the potential freeze-thaw, wet-dry cycles and other disturbance in this zone that could further loosen the soil around the pier foundation. We estimate that settlement of the drilled pier foundation bearing in undisturbed native soil will be less than one inch. Based on the results of the borings, we have developed the following drilled pier design parameters.
Depth Interval
Depth (ft)
Layer Thickness, T (ft)
1(a) 2 3
0-8 8-19 19-32
8 11 13
Notes:
Approx. Moist Unit Weight Of Soil, γ (pcf) 128 115 115
Friction Cohesion, Angle, C φ (psf) (degrees) -23 30
745 200 --
Net Allowable Allowable Allowable Skin Skin Soil End Friction; Friction; Modulus, Bearing Compression, Uplift, k Pressure, sd su (pci) Q (psf) (psf) (psf) 600 220 220 80 600 150 120 100 5,300 170 100 150
(a) Neglect soil resistance in upper 2.5 feet on pier due to frost action and other disturbance.
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Geotechnical Engineering Report Spanish Fork Fairgrounds Grandstand ■ Spanish Fork, Utah September 8, 2011 ■ Terracon Project No. 61115033
Allowable pier capacity in compression (Qallow) can be calculated by the following equation: n
2
Qallow = (Q)(d )/4 +
∑ (sd)(d)(ti)
[pounds]
i=1
Where:
Q = allowable bearing pressure (psf) d = pier diameter (ft) sd = allowable skin friction in compression (psf) ti = ith soil layer thickness in contact with pier (ft) i = individual layer n = total number of layers su = allowable skin friction in uplift (psf)
The first and second terms in the above equation represent allowable end bearing and skin friction components of pier capacity, respectively. The allowable uplift capacity can be calculated by substituting su for sd in the second term of the equation, neglecting the end bearing component and adding the weight of the pier. Following drilling, soft, loose or disturbed soil should be removed from the bottom of the shaft prior to placement of concrete. Temporary casing and the use of drilling fluid may be required to maintain an open hole and prevent heaving and sloughing during excavation of the pier and placement of reinforcing steel and concrete. The contractor should be aware of this and provide the necessary provisions to maintain stability of the excavation during construction. Use of temporary casing will require special care during construction to ensure a high quality pier. Construction of piers should only be performed by contractors experienced in installation of this type of foundation, and in the use of temporary casing. Reinforcing steel and concrete should be placed inside the casing. The casing should be pulled as the concrete is placed to provide final contact between the soil and the concrete. A minimum head of 5 feet of concrete should be maintained above the lower edge of the casing as it is pulled to prevent intrusion of soil during extraction. Concrete should be placed into the excavation through a tremie pipe extending to the bottom of the excavation. Concrete must not be allowed to free fall into the excavation or be placed through water or slurry without the use of a tremie. An uninterrupted supply and placement of concrete should be performed to produce a monolithic pier. Use clean, watertight tremie pipes large enough in diameter to allow the free flow of concrete. The tremie pipes should be placed within one foot above the bottom of the excavation prior to the commencement of concrete placement. Release a full hopper of concrete as an initial surge to cause displacement of the slurry mixture or water at the bottom. Maintain a minimum 5 feet embedment of the tremie pipe in the concrete during concrete placement to prevent re-entry of drilling fluid into the tremie pipe.
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Geotechnical Engineering Report Spanish Fork Fairgrounds Grandstand ■ Spanish Fork, Utah September 8, 2011 ■ Terracon Project No. 61115033
4.4
Foundations – Spread Footings
In our opinion, the proposed structure may be supported on lightly-loaded, shallow strip and spread footings bearing on a minimum of 2 feet of properly placed and compacted structural fill. Design recommendations for shallow foundations are presented in the following paragraphs.
4.4.1 Design Recommendations Description
Column
Strip
Net allowable bearing pressure on 2 feet of structural fill
3,300 psf
2,500 psf
Minimum dimensions
30 inches
16 inches
30 inches
30 inches
< 1 inch
< 1 inch
< ¾ inch between columns
< ¾ inch over 40 feet
1
Minimum embedment below finished grade for frost protection 2 Approximate total settlement from foundation loads
3
Estimated differential settlement from foundation loads 3 Ultimate coefficient of sliding friction 4
0.40 for granular fill
1. The recommended net allowable bearing pressure is the pressure in excess of the minimum surrounding overburden pressure at the footing base elevation. Assumes any unsuitable fill or soft soils, if encountered, will be undercut and replaced with compacted structural fill. Based upon a Factor of Safety of 3. 2. Embedment depth is for perimeter footings and footings beneath unheated areas. 3. The foundation settlement will depend upon the variations within the subsurface soil profile, the structural loading conditions, the embedment depth of the footings, the thickness of compacted fill, and the quality of the earthwork operations. 4. The sides of the excavation for the spread footing foundation must be nearly vertical and the concrete should be placed neat against these vertical faces for the passive earth pressure values to be valid. If the loaded side is sloped or benched, and then backfilled, the allowable passive pressure will be significantly reduced. Passive resistance in the upper 2.5 feet of the soil profile should be neglected. If passive resistance is used to resist lateral loads, the base friction should be neglected.
4.4.2 Construction Considerations The base of all foundation excavations should be free of water and loose or soft soil prior to placing concrete. Concrete should be placed soon after excavating to reduce bearing soil disturbance. If the soils at bearing level become excessively dry, disturbed or saturated, or frozen, the affected soil should be removed prior to placing concrete. It is recommended that the geotechnical engineer be retained to observe and test the soil foundation bearing materials. If unsuitable bearing soils are encountered in footing excavations, the excavations should be extended deeper to suitable soils and the footings bear directly on properly compacted structural fill extending down to the suitable soils. If unsuitable bearing soil is extensive stabilization
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Geotechnical Engineering Report Spanish Fork Fairgrounds Grandstand ■ Spanish Fork, Utah September 8, 2011 ■ Terracon Project No. 61115033
using a geogrid and crushed stone should be used to stabilize the subgrade soil. Overexcavation for compacted backfill placement below footings should extend laterally beyond all edges of the footings at least 8 inches per foot of overexcavation depth below footing base elevation. The overexcavation should then be backfilled up to the footing base elevation with well-graded granular material placed in lifts of 8 inches or less in loose thickness and compacted to at least 95 percent of the material's maximum modified effort maximum dry density (ASTM D 1557). The overexcavation and backfill procedure is shown in the adjacent figure.
4.5
Seismic Considerations
Based on the results of our exploration, the subsurface soil profile is best represented by Site Class F according to the 2009 International Building Code (IBC). The National Seismic Hazard Map database was searched to identify the peak ground acceleration (PGA) and spectral accelerations for 0.2 second (Ss) and 1.0 second (S1) periods for a 2% probability of exceedance (PE) in 50 years at the project site for site class B. These values should be adjusted for site effects using appropriate site class factors from the 2006 IBC. Description Site Class
1
Site Latitude Site Longitude
Value E2,3 N 40.102 W 111.654
So PGA
0.56g
Ss Spectral Acceleration for a Short Period
1.29g
S1 Spectral Acceleration for a 1-Second Period
0.53g
Fa Site Coefficient for a Short Period
0.93
Fv Site Coefficient for a 1-Second Period
2.43
1
Note: In general accordance with the 2009 International Building Code, Table 1613.5.2. IBC Site Class is based on the average characteristics of the upper 100 feet of the subsurface profile. 2
Note: The 2009 International Building Code (IBC) requires a site soil profile determination extending to a depth of 100 feet for seismic site classification. The current scope does not include the required 100 foot soil profile determination. The boring extended to a maximum depth of 42 feet, and this seismic site class definition considers that similar soil conditions continue below the maximum depth of the subsurface exploration. Additional exploration to deeper depths would be required to confirm the conditions below the current depth of exploration. 3
Note: As discussed in this report, the site soils are liquefiable; consequently, the Site Class is F per 2009 IBC, Table 1613.5.2, for any profile containing soils vulnerable to potential failure or collapse under seismic loading such as liquefiable soils. However, Section 20.3.1 of ASCE 7-05 allows site coefficients Fa and Fv to be determined assuming that liquefaction does not occur for structures with fundamental periods of vibration less than 0.5 second. Based on the results of the field exploration, Site Class E may be used to determine the values of Fa and Fv in accordance with Section 1316.5.2 of the 2009 IBC.
Potentially liquefiable soils were encountered within the depths explored between 5 and 20 feet in all borings and to a depth of 32 feet in B-4. Liquefaction induced settlement ranges from 3 to 9 inches. However, borings extended to a maximum depth of 42 feet, and additional potentially liquefiable soils may be encountered at greater depths. The proposed site is located in an area Responsive ■ Resourceful ■ Reliable
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Geotechnical Engineering Report Spanish Fork Fairgrounds Grandstand ■ Spanish Fork, Utah September 8, 2011 ■ Terracon Project No. 61115033
mapped1 as having a high potential for liquefaction. Liquefaction induced lateral spread on the order of 1 foot may also occur at the site during an earthquake event. If liquefaction induced settlement or lateral spread is deemed to be excessively high, Terracon should be contacted to discuss liquefaction mitigation options. Mitigation options may include rammed aggregate piers, stone columns or other approved method.
4.6
Chemical Tests
The results of sulfate tests performed on samples from the site are presented in the following table. Analytical Test Results Sample
Sulfate (ppm)
B-1 @ 2.5
8.3
Based ACI 318 Table 4.3.1, the potential for sulfate attack on concrete is estimated to be negligible. ACI 318 recommends the use of Type I cement for negligible sulfate exposure and.
5.0
GENERAL COMMENTS
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 testing and observation during excavation, grading, foundation and 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 location and from other information discussed in this report. This report does not reflect variations that may occur away from the borings, across the site, or due to the modifying effects of 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, 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. 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 1
Christensen, Gary E., Shaw, Lucas M., 2008, Liquefaction Special Study Areas Wasatch Front and Nearby Areas, Utah, Supplement Map to Utah Geological Survey Circular 106.
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Geotechnical Engineering Report Spanish Fork Fairgrounds Grandstand ■ Spanish Fork, Utah September 8, 2011 ■ Terracon Project No. 61115033
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 outlined 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.
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APPENDIX A FIELD EXPLORATION
SUBJECT SITE
REFERENCE: MICROSOFT VIRTUAL EARTH DIAGRAM IS FOR GENERAL LOCATION ONLY,, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES.
Project Mngr: Drawn By: Checked By: Approved By:
ABD CRC ABD RLC
Project No. Task No. Scale: Date:
PROJECT VICINITY MAP
61115033 0
Spanish Fork Grandstand Spanish Fork, Utah
Not to Scale 9/2/2011
14850 Pony Express Road, Suite 150N Bluffdale, Utah 84065
Spanish Fork City
FIGURE
A-1
B-4
B-3
B1 B-1 B-2
LEGEND: Approximate Boring Location
REFERENCE: MICROSOFT VIRTUAL EARTH DIAGRAM IS FOR GENERAL LOCATION ONLY,, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES.
Project Mngr: Drawn By: Checked By: Approved By:
ABD CRC ABD RLC
Project No. Task No. Scale: Date:
BORING LOCATION DIAGRAM
61115033 00
Spanish Fork Grandstand Spanish Fork, Utah
Not to Scale 9/2/2011
14850 Pony Express Road, Suite 150 N Bluffdale, Utah 84065
Spanish Fork City
FIGURE
A-2
Field Exploration Description The boring locations were chosen based upon our understanding of the proposed work. The location of the borings should be considered accurate only to the degree implied by the means and methods used to define it. The borings were drilled with a Mobile B-80 truck-mounted drill rig using continuous flight hollowstem augers to advance the boreholes. Samples of the soil encountered in the boring were obtained using the split barrel sampling procedure. In the split-barrel sampling procedure, the number of blows required to advance a standard 2-inch O.D. split-barrel sampler the last 12 inches of the typical total 18-inch penetration by means of a 140-pound hammer with a free fall of 30 inches, is the standard penetration resistance value (SPT-N). This value is used to estimate the in-situ relative density of cohesionless soils and consistency of cohesive soils. An automatic SPT hammer was used to advance the split-barrel sampler in the borings performed on this site. A significantly greater efficiency is achieved with the automatic hammer compared to the conventional safety hammer operated with a cathead and rope. This higher efficiency has an appreciable effect on the SPT-N value. The effect of the automatic hammer's efficiency has been considered in the interpretation and analysis of the subsurface information for this report. The samples were tagged for identification, sealed to reduce moisture loss, and taken to our laboratory for further examination, testing, and classification. Information provided on the boring log attached to this report includes soil descriptions, consistency evaluations, boring depths, sampling intervals, and groundwater conditions. The boring was backfilled with auger cuttings prior to the drill crew leaving the site. A field log of the boring was prepared by the field engineer. The log included visual classifications of the materials encountered during drilling as well as the driller’s interpretation of the subsurface conditions between samples. The final boring log included with this report represent the engineer's interpretation of the field logs and include modifications based on laboratory observation and tests of the samples.
Exhibit A-3
LOG OF BORING NO. B-1
Page 1 of 1
OWNER
Spanish Fork City 475 South Main Street Spanish Fork, Utah
PROJECT
0.25
ASPHALT: Approximately 3 inches thick CLAY: soft, brown
5.5
99.8
94.6
SANDY SILT: soft, brown, with silty clay layers
14.5
18
85.6
SILTY SAND: loose, brown, trace gravel, with silty clay layers GRAVEL: with sand, dense, light brown and gray
21.5
82.1
78.6
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
LIQUID LIMIT
% PASSING NO. 200 SIEVE
TESTS
PLASTICITY INDEX
SAMPLES
PENETRATION RESISTANCE BLOWS / ft. WATER CONTENT, % DRY UNIT WEIGHT, PCF
NUMBER
DESCRIPTION
USCS Soil Symbol
Approx. 10 ft south of corral and 15 ft west of edge of existing grandstand Relative Surface Elevation: 100.1 ft DEPTH, ft.
GRAPHIC LOG
Boring Location:
RECOVERY, in.
Spanish Fork Fairgrounds Grandstand
TYPE
SITE
1 SS 5
2
23
ML 2 ST 24
--
26
98 NP NP 60
3 SS 18
2
ML 4 SS 18
3
27
NP NP 67
5 SS 18
4
6 SS 18
6
7 SS 14
30
OTHER
Consol., sieve
Sieve
BOREHOLE_99 61115033.GPJ TERRACON.GDT 9/8/11
BOTTOM OF BORING AT APPROXIMATELY 21.5 FEET
The stratification lines represent the approximate boundary lines between soil and rock types: in-situ, the transition may be gradual.
WATER LEVEL OBSERVATIONS, ft WL 3.5 AB
BORING STARTED
8-16-11
BORING COMPLETED
8-16-11
WL
RIG
B-80 FOREMAN
WL
APPROVED
RLC JOB #
ABD
61115033
LOG OF BORING NO. B-2
Page 1 of 1
OWNER
Spanish Fork City 475 South Main Street Spanish Fork, Utah
PROJECT
0.25
GRAVEL: Approximately 3 inches thick SANDY CLAY: soft, dark brown to brown, with silty clay layers
8.5
99.4
91.2
SILT: soft, brown, with clay and silty sand layers
19
80.7
GRAVEL: with silt and sand, medium dense to very dense, brown, gray, and brownish-gray
33
66.7
BOREHOLE_99 61115033.GPJ TERRACON.GDT 9/8/11
CLAY: soft to medium stiff, light gray
41.5
58.2
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41
LIQUID LIMIT
CL 1 SS 12
3
2 SS 14
4
CL 3 ST 24 ML
--
4 SS 18
2
5 SS 18
3
6 SS 12
17
7 SS 12
30
8 SS 12
65
9 SS 14
5
10 SS 16
3
22
30
88
% PASSING NO. 200 SIEVE
TESTS
PLASTICITY INDEX
SAMPLES
PENETRATION RESISTANCE BLOWS / ft. WATER CONTENT, % DRY UNIT WEIGHT, PCF
NUMBER
DESCRIPTION
USCS Soil Symbol
Approx. 25 ft southeast of western covered structure and 15 ft southwest of grandstand Relative Surface Elevation: 99.7 ft DEPTH, ft.
GRAPHIC LOG
Boring Location:
RECOVERY, in.
Spanish Fork Fairgrounds Grandstand
TYPE
SITE
25
8
70
24
5
79
OTHER
Sieve
Consol., Sieve
25
27
BOTTOM OF BORING AT APPROXIMATELY 41.5 FEET
The stratification lines represent the approximate boundary lines between soil and rock types: in-situ, the transition may be gradual.
WATER LEVEL OBSERVATIONS, ft WL 4.5 AB
BORING STARTED
8-16-11
BORING COMPLETED
8-16-11
WL
RIG
B-80 FOREMAN
WL
APPROVED
RLC JOB #
ABD
61115033
LOG OF BORING NO. B-3
Page 1 of 1
OWNER
Spanish Fork City 475 South Main Street Spanish Fork, Utah
PROJECT
0.25
ASPHALT: Approximately 3 inches thick CLAY: very soft to soft, brown
10
99.7
89.9
SANDY SILT: soft, brown 15
84.9
SILTY SAND: medium dense, medium dense, brown
BOREHOLE_99 61115033.GPJ TERRACON.GDT 9/8/11
20.5 21.5
GRAVEL: with sand, medium dense, fine-grained, brown and gray BOTTOM OF BORING AT APPROXIMATELY 21.5 FEET
79.4 78.4
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
LIQUID LIMIT
1 SS 12
3
2 SS 8
2
3 SS 12
1
ML 4 ST 24
--
26
5 SS 18
2
24
6 ST 24
--
7 SS 14
23
% PASSING NO. 200 SIEVE
TESTS
PLASTICITY INDEX
SAMPLES
PENETRATION RESISTANCE BLOWS / ft. WATER CONTENT, % DRY UNIT WEIGHT, PCF
NUMBER
DESCRIPTION
USCS Soil Symbol
Approx. 20 ft north of small building north of western covered stands and 15 ft west of regular stands Relative Surface Elevation: 99.9 ft DEPTH, ft.
GRAPHIC LOG
Boring Location:
RECOVERY, in.
Spanish Fork Fairgrounds Grandstand
TYPE
SITE
OTHER
22
NP NP 59
Sieve
The stratification lines represent the approximate boundary lines between soil and rock types: in-situ, the transition may be gradual.
WATER LEVEL OBSERVATIONS, ft WL 5.2 AB
BORING STARTED
8-16-11
BORING COMPLETED
8-16-11
WL
RIG
B-80 FOREMAN
WL
APPROVED
RLC JOB #
ABD
61115033
LOG OF BORING NO. B-4
Page 1 of 1
OWNER
Spanish Fork City 475 South Main Street Spanish Fork, Utah
PROJECT
CLAY: soft, brown
7
92.6
SANDY SILT: soft, brown with clay layers
19
80.6
SILTY SAND: very loose to loose, fine-grained, brown to brownish-gray
32
67.6
BOREHOLE_99 61115033.GPJ TERRACON.GDT 9/8/11
CLAY: medium stiff, gray
42
57.6
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42
LIQUID LIMIT
1 ST 18
--
2 SS 6
2
3 ST 30
--
% PASSING NO. 200 SIEVE
TESTS
PLASTICITY INDEX
SAMPLES
PENETRATION RESISTANCE BLOWS / ft. WATER CONTENT, % DRY UNIT WEIGHT, PCF
NUMBER
DESCRIPTION
USCS Soil Symbol
Approx. 10 ft north o f the northern corral entrance on the eastern side of arena Relative Surface Elevation: 99.6 ft DEPTH, ft.
GRAPHIC LOG
Boring Location:
RECOVERY, in.
Spanish Fork Fairgrounds Grandstand
TYPE
SITE
21 106
26
OTHER
UU Triax.
NP NP 63 Sieve
4 SS 14
2
5 ST 24
--
6 SS 18
3
7 SS 18
8
8 SS 0
4
9 SS 16
4
10 ST 24
--
25
NP NP 22
Sieve
32
BOTTOM OF BORING AT APPROXIMATELY 42 FEET The stratification lines represent the approximate boundary lines between soil and rock types: in-situ, the transition may be gradual.
WATER LEVEL OBSERVATIONS, ft WL 5 AB
BORING STARTED
8-16-11
BORING COMPLETED
8-16-11
WL
RIG
B-80 FOREMAN
WL
APPROVED
RLC JOB #
ABD
61115033
APPENDIX B LABORATORY TESTING
Laboratory Testing Terracon personnel prepared a log of the boring during the field exploration in general accordance with the Unified Soil Classification System (USCS). The USCS is described in Appendix A. Collected soil samples from the boring were packaged and transported to our laboratory in Draper for further observation and testing. Laboratory tests were conducted on selected soil samples and the test results are presented in the soil boring log. The laboratory test results were used for the geotechnical engineering analyses and the development of foundation design and construction recommendations. Laboratory tests were performed in general accordance with the applicable ASTM, local or other accepted standards. Selected soil samples obtained from the site were tested for the following engineering properties:
Sieve Analysis Atterberg Limits Shear Strength
In-situ Water Content Consolidation Sulfate Content
Exhibit B-1
U.S. SIEVE OPENING IN INCHES 6
4
3
2
1
1.5
3/4
U.S. SIEVE NUMBERS 1/2
3/8
3
4
6
8
10
14
16
20
30
40
50
HYDROMETER 60
100
140
200
100 95 90 85 80 75
PERCENT FINER BY WEIGHT
70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 100
10
1
0.1
0.01
0.001
GRAIN SIZE IN MILLIMETERS
TC_GRAIN_SIZE 61115033.GPJ TERRACON.GDT 9/1/11
COBBLES
GRAVEL coarse
Specimen Identification B-1 5.0ft B-1 10.0ft B-2 2.5ft B-2 7.5ft B-3 10.0ft Specimen Identification B-1 5.0ft B-1 10.0ft B-2 2.5ft B-2 7.5ft B-3 10.0ft
SAND
fine
D100 0.15 4.75 0.15 4.75 0.15
coarse
medium
fine
Classification SANDY SILT(ML) SANDY SILT(ML) SANDY LEAN CLAY(CL) SILTY CLAY with SAND(CL-ML) SANDY SILT(ML) D60 D30 D10 0.075
0.077
SILT OR CLAY LL PL NP NP NP NP 25 17 24 19 NP NP %Gravel %Sand 0.0 40.3 0.0 32.8 0.0 30.5 0.0 20.8 0.0 41.3
GRAIN SIZE DISTRIBUTION Project: Spanish Fork Fairgrounds Grandstand Site: 475 South Main Street Spanish Fork, Utah Job #: 61115033 Date: 9-1-11
PI Cc Cu NP NP 8 5 NP %Silt %Clay 59.7 67.2 69.5 79.2 58.7
U.S. SIEVE OPENING IN INCHES 6
4
3
2
1
1.5
3/4
U.S. SIEVE NUMBERS 1/2
3/8
3
4
6
8
10
14
16
20
30
40
50
HYDROMETER 60
100
140
200
100 95 90 85 80 75
PERCENT FINER BY WEIGHT
70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 100
10
1
0.1
0.01
0.001
GRAIN SIZE IN MILLIMETERS
COBBLES
GRAVEL coarse
fine
TC_GRAIN_SIZE 61115033.GPJ TERRACON.GDT 9/1/11
Specimen Identification B-4 7.5ft B-4 20.0ft
Specimen Identification B-4 7.5ft B-4 20.0ft
SAND coarse
medium
Classification SANDY SILT(ML) SILTY SAND(SM)
D100 4.75 0.15
D60
D30
0.105
0.08
SILT OR CLAY
fine
LL NP NP
D10
%Gravel 0.0 0.0
PL NP NP
%Sand 37.0 77.9
GRAIN SIZE DISTRIBUTION Project: Spanish Fork Fairgrounds Grandstand Site: 475 South Main Street Spanish Fork, Utah Job #: 61115033 Date: 9-1-11
PI NP NP
%Silt
Cc
Cu
%Clay 63.0 22.1
Unconsolidated-Undrained Triaxial Compression Test (ASTM D2850) Axial Strain (%) 0.00 0.15 0.31 0.49 0.99 1.31 1.65 1.99 4.01 6.04 8.06 10.08 12.09 14.10 16.13 18.16 20.00
1600
1490.5
1400
1200
Deviator Stress, psf
1000
800
Deviator Stress (psf) 0.0 125.9 202.9 268.9 425.2 506.5 599.9 695.1 1082.6 1275.0 1361.0 1415.4 1455.5 1476.2 1464.7 1490.5 1478.8
Shear Stress (psf) 0.0 63.0 101.5 134.5 212.6 253.3 299.9 347.5 541.3 637.5 680.5 707.7 727.8 738.1 732.4 745.3 739.4
600
400
200
0 0
5
10
15
20
25
Strain, %
Sample Diameter (in): Sample Height (in): Sample Volume (cf):
2.84 6.44 0.0236
Moist Unit Weight (pcf): Moisture Content (%): Dry Unit Weight (pcf):
128 21 106
Confining Stress (psf): Strain Rate (%/min): Strain Rate (in/min):
292.88 2.00 0.1297
Strain at Falure (%): Shear Stress at Falure (psf):
18 745
Project Name: Project No.: Location: Sample: Sample Description:
Spanish Fork Grandstands 61115033 Spanish Fork B-4 @ 2.5 Clay
Consolidation Test Data (ASTM D 2435-04 ) 0.0
2.0
VERTICAL STRAIN, %
4.0
6.0
8.0
10.0
12.0 0.1
1
10
100
VERTICAL STRESS, ksf Before Consolidation Sample Diameter (in): Sample Height (in): Sample Volume (cf):
2.50 1 0.0028
Moist Unit Weight (pcf): Moisture Content (%): Dry Unit Weight (pcf):
123 26 98
2.50 0.8998 0.0026
Moist Unit Weight (pcf): Moisture Content (%): Dry Unit Weight (pcf):
137 20 114
After Consolidation Sample Diameter (in): Sample Height (in): Sample Volume (cf): Liquid Limit: NP Plasticity Index: NP
Percent Fines: 59.7 Classification: Sandy Silt (ML) Project Name: Project No.: Location: Sample:
Spanish Fork Grandstand 61115033 Spanish Fork B-1 @ 5'
Consolidation Test Data (ASTM D 2435-04 ) 0.0 2.0 4.0
VERTICAL STRAIN, %
6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 0.1
1
10
100
VERTICAL STRESS, ksf Before Consolidation Sample Diameter (in): Sample Height (in): Sample Volume (cf):
2.50 1 0.0028
Moist Unit Weight (pcf): Moisture Content (%): Dry Unit Weight (pcf):
115 30 88
Sample Diameter (in): Sample Height (in): Sample Volume (cf):
2.50 0.8557 0.0024
Moist Unit Weight (pcf): Moisture Content (%): Dry Unit Weight (pcf):
134 26 106
Liquid Limit: Plasticity Index:
24 5
After Consolidation
Percent Fines: Classification: Silty Clay (CL-ML) Project Name: Project No.: Location: Sample:
Spanish Fork Grandstand 61115033 Spanish Fork B-2 @ 7.5'
September 8, 2011 Terracon Project No. 61115033
Prepared for: Spanish Fork City 40 South Main Spanish Fork, Utah 84660
Prepared by: Terracon Consultants, Inc. 14850 Pony Express Road, Suite 150N Bluffdale, Utah 84065
TABLE OF CONTENTS Page 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 Profile ................................................................................................................. 2 3.2 Groundwater ................................................................................................................... 3 4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION....................................... 3 4.1 Geotechnical Considerations .......................................................................................... 3 4.2 Earthwork ....................................................................................................................... 4 4.3 Foundations – Drilled Piers ............................................................................................ 6 4.4 Foundations – Spread Footings ..................................................................................... 8 4.5 Seismic Considerations .................................................................................................. 9 4.6 Chemical Tests ............................................................................................................. 10 5.0 GENERAL COMMENTS ................................................................................................. 10
APPENDICIES APPENDIX A – FIELD EXPLORATION
Exhibits
Project Vicinity Map ....................................................................................................... A-1 Boring Location Diagram .............................................................................................. A-2 Field Exploration Description ........................................................................................ A-3 Boring Logs .................................................................................................................. A-4 General Notes ............................................................................................................... A-5 Unified Soil Classification .............................................................................................. A-6 APPENDIX B – LABORATORY TESTING
Exhibits
Laboratory Testing ........................................................................................................ B-1 Grain Size Distribution ........................................................................................ B-2 to B-3 UU Triaxial ................................................................................................................... B-4 Consolidation ..................................................................................................... B-5 to B-6 Sulfate Test Results ...................................................................................................... B-7
GEOTECHNICAL ENGINEERING REPORT Spanish Fork Fairgrounds Grandstand 475 South Main Street Spanish Fork, Utah Terracon Project No. 61115033 September 8, 2011 EXECUTIVE SUMMARY A geotechnical investigation has been performed for the proposed fairground grandstand reconstruction to be completed at the Spanish Fork Fairgrounds in the Spanish Fork, Utah. Four soil borings were drilled to depths ranging between approximately 21½ to 42 feet below the existing ground surface. This report presents geotechnical recommendations for design and construction of foundations for the proposed grandstands reconstruction. Based on the information obtained from our subsurface exploration, the site can be developed for the proposed project. The following geotechnical considerations were identified: Site Soils: The site surface generally consisted of asphaltic concrete, gravel and exposed clay soil. The underlying near surface and subsurface soils generally consisted of interbedded clay, sandy silt to silt, silty sand and gravel. Groundwater was encountered at depths of 3½ to 5 feet in the test borings at the time of field exploration. Foundations: The grandstand structure may be supported by shallow strip or spread footings bearing on a minimum of 2 feet of structural fill with a net allowable bearing capacity of 2,500 psf for strip and 3,300 psf for spread footings. As an alternative, the structure may be supported on straight shaft drilled piers with a minimum shaft length of 20 feet and a maximum shaft length of 25 feet. Seismic: The site is best represented by an IBC 2009 Site Class F. Liquefiable soils were encountered in all the borings between 5 and 20 feet and to a depth of 32 feet in B-04. Liquefaction induced settlement is estimated to range from 3 to 9 inches. 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.
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GEOTECHNICAL ENGINEERING REPORT Spanish Fork Fairgrounds Grandstand 475 South Main Street Spanish Fork, Utah Terracon Project No. 61115033 September 8, 2011 1.0
INTRODUCTION
A geotechnical exploration report has been completed for the proposed grandstand reconstruction project at the Spanish Fork Grandstands in Spanish Fork, Utah. . The purpose of this exploration is to provide information and geotechnical engineering recommendations relative to:
subsurface soil conditions groundwater conditions earthwork
foundation design and construction seismic considerations
Four soil borings were drilled to depths ranging from approximately 21½ to 42 feet below the existing ground surface. Logs of the borings along with a Project Vicinity Map and Boring Location Diagram (Exhibits 1 and 2) are included in Appendix A of this report. The results of the laboratory testing performed on soil samples obtained from the site during the field exploration are included in Appendix B of this report. Descriptions of the field exploration and laboratory testing are included in their respective appendices.
2.0
PROJECT INFORMATION
2.1
Project Description Item
Existing site layout
Structure
Arena Construction
Description Refer to the Project Vicinity Map and Boring Location Diagram (Appendix A, Exhibits A-1 and A-2). The existing main arena grandstand (Lance Money Arena: 7,000 seating capacity with 42,000 square feet arena floor area) will be replaced with new arena grandstand that is approximately 10 feet larger on all sides. Canopies will be constructed on both sides of the arena with an announcer booth. Steel frame.
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Geotechnical Engineering Report Spanish Fork Fairgrounds Grandstand ■ Spanish Fork, Utah September 8, 2011 ■ Terracon Project No. 61115033 Item Maximum loads Maximum allowable settlement Grading
Description Dead Load: 5 to 10 kips (assumed) Live Load: 25 to 50 kips (assumed) Uplift: 10 to 15 kips (assumed) Pier and Shallow Footings: 1-inch (Assumed) Unknown; minimal grade changes on the order of 1 foot or less are assumed
Should any of the above information or assumptions be inconsistent with the planned construction, Terracon should be notified to review, and revise if necessary, recommendations provided in this report.
2.2
Site Location and Description Item
Description
Location
475 South Main Street, Spanish Fork, Utah
Existing improvements
The site currently consists of a rodeo facility including an arena and surrounding grandstands. The stands are partially covered on both sides of the arena. The complex is about 240 feet wide and 350 feet long.
Surrounding Developments
North: Asphalt parking lots. South: Fence demarcating fairground property boundary and large barn structure. East: Corrals, small building, and parking lots. West: Asphalt parking lots with Main Street beyond.
Current ground cover
Bare soil in the rodeo arena with asphaltic concrete surrounding the stands.
Existing topography
Relatively flat. Approximately 1/2 feet vertical difference across the site based on surveying relative elevations of the ground surface at each boring location.
3.0
SUBSURFACE CONDITIONS
3.1
Typical Profile
Specific conditions encountered at each boring location are indicated on the individual boring logs. Stratification boundaries on the boring logs represent the approximate location of changes in soil types; in-situ, the transition between materials may be gradual. Details for each of the borings can be found on the boring logs included in Appendix A of this report. Based on the results of the borings, subsurface conditions on the project site can be generalized as follows:
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Geotechnical Engineering Report Spanish Fork Fairgrounds Grandstand ■ Spanish Fork, Utah September 8, 2011 ■ Terracon Project No. 61115033
Description
Approximate Depth to Bottom of Stratum (feet)
Stratum 1
¼
Stratum 2 Stratum 3
5 ½ to 10 14 ½ to 19 18 to 32 (not encountered in B-2) 21 ½ to 33 (termination depth of B-1 and B-3)
Stratum 4 Stratum 5 Stratum 6
3.2
42
Material Encountered
Consistency/Density
Asphaltic concrete and gravel Clay Sandy Silt to Silt
NA
Silty Sand Gravel Clay
Very Soft to Soft Soft Very Loose to Medium Dense Medium Dense to Very Dense Soft to Medium Stiff
Groundwater
Groundwater was observed at depths of approximately 3½ to 5 feet after drilling completion. It should be recognized that fluctuations of the groundwater table may occur due to seasonal and longer term variations in the amount of precipitation and runoff, future construction and other factors not evident at the time the borings were drilled. Evaluation of these factors is beyond the scope of this exploration.
4.0
RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION
4.1
Geotechnical Considerations
Based on the results of this exploration, it is our opinion that the site is suitable for the proposed construction. The proposed grandstand may be supported on shallow spread foundations bearing on a minimum of 2 feet of properly placed and compacted structural fill, or on drilled pier foundations with minimum tip depth of 20 feet and a maximum depth of 25 feet. Groundwater was encountered at depths of approximately 3½ to 5 feet below existing site grade. Dewatering will be required for excavations extending down to or below groundwater. Existing foundations and any existing fill that may be encountered during demolition of the existing grandstand should be completely removed from within the construction area and replaced with properly placed and compacted structural fill. Soft pumping soils may be encountered during earthwork. Stabilization using a combination of geotextiles and crushed rock may be required to form a firm surface for construction. Low pressure construction equipment may be required to minimize disturbance to subgrade soil. If drilled pier foundations are used, temporary casing and drilling fluid should be used to maintain an open hole and prevent sloughing during excavation and construction of the piers.
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Geotechnical Engineering Report Spanish Fork Fairgrounds Grandstand ■ Spanish Fork, Utah September 8, 2011 ■ Terracon Project No. 61115033
Geotechnical engineering recommendations for design and construction of foundation systems and other earth connected phases of the project are outlined below. The recommendations contained in this report are based upon the results of field and laboratory testing (which are presented in Appendix A and B), engineering analyses, and our current understanding of the proposed project.
4.2
Earthwork
All existing foundations, utilities, existing fill, disturbed, loose, soft, or frozen soil, and other unsuitable materials should be removed from beneath proposed shallow foundations. Care should be taken during excavation to reduce the potential for disturbance of the native soils. After removal of any unsuitable materials and prior to placing fill, excessively soft or disturbed areas encountered during subgrade preparation should be removed and replaced with properly placed and compacted structural fill as described below. Due to near surface soft soils, stabilization rock in combination with geogrid and filter fabric may be required to form a stable working platform on which to place and compact structural fill. After removal of existing foundations and fill materials and excavating down to final subgrade elevation, and prior to the start of fill operations, we recommend that the geotechnical engineer be retained to observe the bearing material for structural fill placement below footing foundations areas. Dewatering will be required for shallow spread footing excavations extending to and below groundwater. The design recommendations presented in this report are based on the observed soil conditions at specific exploration locations and on the assumption that earthwork for site grading, foundations and fill areas will be monitored by a qualified geotechnical engineer from Terracon.
4.2.1 Fill Materials and Placement Structural and stabilization fill should meet the following material property requirements: Fill Type 1
Material
3
Acceptable Location for Placement 2
Structural
Well graded granular 3
Stabilization
All locations and elevations 4
Clean, Crushed Angular Rock
Stabilization areas
1.
Controlled, compacted fill should consist of approved materials that are free of organic matter and debris. Frozen material should not be used, and fill should not be placed on a frozen subgrade. A sample of each material type should be submitted to the geotechnical engineer for evaluation.
2.
Granular soil with a maximum particle size of 3 inches, 25 to 60 percent passing the No. 4 sieve and having less than 15 percent fines. Fines should have a Plasticity Index (PI) less than 12.
3.
Appropriate geotechnical testing should be performed on all fill prior to its usage on-site in order to verify conformance to the standards for structural fill outlined in this report.
4.
Two to 4 inch minus, clean, crushed rock with angular edges, and having less than 5 percent fines.
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Geotechnical Engineering Report Spanish Fork Fairgrounds Grandstand ■ Spanish Fork, Utah September 8, 2011 ■ Terracon Project No. 61115033
4.2.2 Compaction Requirements Item
Description
Fill Lift Thickness
8-inches or less in loose thickness
Compaction 1
95% of the material’s maximum dry density (modified Proctor - ASTM D 1557) in foundation areas
Moisture Content
Within two percent of the optimum moisture content as determined by the modified Proctor test at the time of placement and compaction
1.
Fill should be tested frequently 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 compaction is achieved. This may require adjustment of the moisture content.
If stabilization rock is used, rock should be placed in lifts of 12 to 18 inches in loose thickness and seated in-place by tamping using the bucket of an excavator or backhoe, or by making several passes using a static compactor. Vibratory or excessive compaction effort should not be applied, and care should be taken to minimize disturbance to underlying native soils.
4.2.3 Grading and Drainage Positive drainage away from the proposed structures should be provided during construction and maintained throughout the life of the proposed project.
4.2.4 Construction Considerations Unstable subgrade conditions could develop during general construction operations, particularly if the soils are wetted and/or subjected to repetitive construction traffic. The use of light construction equipment, minimize repetitive trafficking and construction during dryer seasons would aid in reducing subgrade disturbance. If the subgrade should become frozen or disturbed, the affected material should be replaced with structural fill or stabilization rock as appropriate. Groundwater was encountered approximately 3 feet below existing site grade. Excavations extending to and below the subgrade will require dewatering. We recommend that if excavations extending below groundwater are planned, a qualified dewatering professional be retained to evaluate appropriate dewatering methods for the site. The contractor should be responsible for the design and implementation of the dewatering system. As a minimum, all temporary excavations should be sloped or braced as required by Occupational Health and Safety Administration (OSHA) regulations to provide stability and safe working conditions. Temporary excavations will probably be required during grading operations. The grading contractor is responsible for designing and constructing stable, temporary excavations and should shore, slope or bench the sides of the excavations as required, to maintain stability of both the excavation sides and bottom. All excavations should comply with applicable local, state and federal safety regulations, including the current OSHA Excavation and Trench Safety Standards.
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Geotechnical Engineering Report Spanish Fork Fairgrounds Grandstand ■ Spanish Fork, Utah September 8, 2011 ■ Terracon Project No. 61115033
Earthwork on the project should be observed and evaluated by Terracon. The evaluation of earthwork should include observation and testing of structural fill, site grading, subgrade preparation and proof rolling, foundation bearing soils, and other geotechnical conditions exposed during the construction of the project.
4.3
Foundations – Drilled Piers
Soil parameters to be used in the design of the drilled pier foundation are included in the following table. The values included in the table were estimated based on the observed soil conditions during our field exploration, visual classifications, and presumptive values for similar materials. Note that the soil parameters are not intrinsic values of the soil, and depend on the state of the soil (density, depositional history, water content, etc.) and the loading conditions, among other factors. The soil parameters presented in the table are intended to be used in the design of drilled pier foundations at the site assuming soil conditions are similar to those encountered during our field exploration. The applicability of these soil parameters for other uses should be discussed with the geotechnical engineer. The allowable end bearing pressure, skin friction, and horizontal constant of subgrade reaction for the three depth intervals are summarized in the table below. The allowable end bearing pressure and skin friction values presented in the table are based on a factor of safety of 3. Also, the allowable skin friction to resist both vertical downward loads and uplift forces assume bored piers having concrete cast in direct contact with adjacent soil (uncased). We recommend that, the pier extend to a minimum depth of 20 feet for a shaft with a minimum diameter of 2 feet. The pier should not extend past 25 feet to reduce the rick of punching failure due to the underlining clay material. The contribution of the upper 2.5 feet should be neglected due to the potential freeze-thaw, wet-dry cycles and other disturbance in this zone that could further loosen the soil around the pier foundation. We estimate that settlement of the drilled pier foundation bearing in undisturbed native soil will be less than one inch. Based on the results of the borings, we have developed the following drilled pier design parameters.
Depth Interval
Depth (ft)
Layer Thickness, T (ft)
1(a) 2 3
0-8 8-19 19-32
8 11 13
Notes:
Approx. Moist Unit Weight Of Soil, γ (pcf) 128 115 115
Friction Cohesion, Angle, C φ (psf) (degrees) -23 30
745 200 --
Net Allowable Allowable Allowable Skin Skin Soil End Friction; Friction; Modulus, Bearing Compression, Uplift, k Pressure, sd su (pci) Q (psf) (psf) (psf) 600 220 220 80 600 150 120 100 5,300 170 100 150
(a) Neglect soil resistance in upper 2.5 feet on pier due to frost action and other disturbance.
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Geotechnical Engineering Report Spanish Fork Fairgrounds Grandstand ■ Spanish Fork, Utah September 8, 2011 ■ Terracon Project No. 61115033
Allowable pier capacity in compression (Qallow) can be calculated by the following equation: n
2
Qallow = (Q)(d )/4 +
∑ (sd)(d)(ti)
[pounds]
i=1
Where:
Q = allowable bearing pressure (psf) d = pier diameter (ft) sd = allowable skin friction in compression (psf) ti = ith soil layer thickness in contact with pier (ft) i = individual layer n = total number of layers su = allowable skin friction in uplift (psf)
The first and second terms in the above equation represent allowable end bearing and skin friction components of pier capacity, respectively. The allowable uplift capacity can be calculated by substituting su for sd in the second term of the equation, neglecting the end bearing component and adding the weight of the pier. Following drilling, soft, loose or disturbed soil should be removed from the bottom of the shaft prior to placement of concrete. Temporary casing and the use of drilling fluid may be required to maintain an open hole and prevent heaving and sloughing during excavation of the pier and placement of reinforcing steel and concrete. The contractor should be aware of this and provide the necessary provisions to maintain stability of the excavation during construction. Use of temporary casing will require special care during construction to ensure a high quality pier. Construction of piers should only be performed by contractors experienced in installation of this type of foundation, and in the use of temporary casing. Reinforcing steel and concrete should be placed inside the casing. The casing should be pulled as the concrete is placed to provide final contact between the soil and the concrete. A minimum head of 5 feet of concrete should be maintained above the lower edge of the casing as it is pulled to prevent intrusion of soil during extraction. Concrete should be placed into the excavation through a tremie pipe extending to the bottom of the excavation. Concrete must not be allowed to free fall into the excavation or be placed through water or slurry without the use of a tremie. An uninterrupted supply and placement of concrete should be performed to produce a monolithic pier. Use clean, watertight tremie pipes large enough in diameter to allow the free flow of concrete. The tremie pipes should be placed within one foot above the bottom of the excavation prior to the commencement of concrete placement. Release a full hopper of concrete as an initial surge to cause displacement of the slurry mixture or water at the bottom. Maintain a minimum 5 feet embedment of the tremie pipe in the concrete during concrete placement to prevent re-entry of drilling fluid into the tremie pipe.
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Geotechnical Engineering Report Spanish Fork Fairgrounds Grandstand ■ Spanish Fork, Utah September 8, 2011 ■ Terracon Project No. 61115033
4.4
Foundations – Spread Footings
In our opinion, the proposed structure may be supported on lightly-loaded, shallow strip and spread footings bearing on a minimum of 2 feet of properly placed and compacted structural fill. Design recommendations for shallow foundations are presented in the following paragraphs.
4.4.1 Design Recommendations Description
Column
Strip
Net allowable bearing pressure on 2 feet of structural fill
3,300 psf
2,500 psf
Minimum dimensions
30 inches
16 inches
30 inches
30 inches
< 1 inch
< 1 inch
< ¾ inch between columns
< ¾ inch over 40 feet
1
Minimum embedment below finished grade for frost protection 2 Approximate total settlement from foundation loads
3
Estimated differential settlement from foundation loads 3 Ultimate coefficient of sliding friction 4
0.40 for granular fill
1. The recommended net allowable bearing pressure is the pressure in excess of the minimum surrounding overburden pressure at the footing base elevation. Assumes any unsuitable fill or soft soils, if encountered, will be undercut and replaced with compacted structural fill. Based upon a Factor of Safety of 3. 2. Embedment depth is for perimeter footings and footings beneath unheated areas. 3. The foundation settlement will depend upon the variations within the subsurface soil profile, the structural loading conditions, the embedment depth of the footings, the thickness of compacted fill, and the quality of the earthwork operations. 4. The sides of the excavation for the spread footing foundation must be nearly vertical and the concrete should be placed neat against these vertical faces for the passive earth pressure values to be valid. If the loaded side is sloped or benched, and then backfilled, the allowable passive pressure will be significantly reduced. Passive resistance in the upper 2.5 feet of the soil profile should be neglected. If passive resistance is used to resist lateral loads, the base friction should be neglected.
4.4.2 Construction Considerations The base of all foundation excavations should be free of water and loose or soft soil prior to placing concrete. Concrete should be placed soon after excavating to reduce bearing soil disturbance. If the soils at bearing level become excessively dry, disturbed or saturated, or frozen, the affected soil should be removed prior to placing concrete. It is recommended that the geotechnical engineer be retained to observe and test the soil foundation bearing materials. If unsuitable bearing soils are encountered in footing excavations, the excavations should be extended deeper to suitable soils and the footings bear directly on properly compacted structural fill extending down to the suitable soils. If unsuitable bearing soil is extensive stabilization
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Geotechnical Engineering Report Spanish Fork Fairgrounds Grandstand ■ Spanish Fork, Utah September 8, 2011 ■ Terracon Project No. 61115033
using a geogrid and crushed stone should be used to stabilize the subgrade soil. Overexcavation for compacted backfill placement below footings should extend laterally beyond all edges of the footings at least 8 inches per foot of overexcavation depth below footing base elevation. The overexcavation should then be backfilled up to the footing base elevation with well-graded granular material placed in lifts of 8 inches or less in loose thickness and compacted to at least 95 percent of the material's maximum modified effort maximum dry density (ASTM D 1557). The overexcavation and backfill procedure is shown in the adjacent figure.
4.5
Seismic Considerations
Based on the results of our exploration, the subsurface soil profile is best represented by Site Class F according to the 2009 International Building Code (IBC). The National Seismic Hazard Map database was searched to identify the peak ground acceleration (PGA) and spectral accelerations for 0.2 second (Ss) and 1.0 second (S1) periods for a 2% probability of exceedance (PE) in 50 years at the project site for site class B. These values should be adjusted for site effects using appropriate site class factors from the 2006 IBC. Description Site Class
1
Site Latitude Site Longitude
Value E2,3 N 40.102 W 111.654
So PGA
0.56g
Ss Spectral Acceleration for a Short Period
1.29g
S1 Spectral Acceleration for a 1-Second Period
0.53g
Fa Site Coefficient for a Short Period
0.93
Fv Site Coefficient for a 1-Second Period
2.43
1
Note: In general accordance with the 2009 International Building Code, Table 1613.5.2. IBC Site Class is based on the average characteristics of the upper 100 feet of the subsurface profile. 2
Note: The 2009 International Building Code (IBC) requires a site soil profile determination extending to a depth of 100 feet for seismic site classification. The current scope does not include the required 100 foot soil profile determination. The boring extended to a maximum depth of 42 feet, and this seismic site class definition considers that similar soil conditions continue below the maximum depth of the subsurface exploration. Additional exploration to deeper depths would be required to confirm the conditions below the current depth of exploration. 3
Note: As discussed in this report, the site soils are liquefiable; consequently, the Site Class is F per 2009 IBC, Table 1613.5.2, for any profile containing soils vulnerable to potential failure or collapse under seismic loading such as liquefiable soils. However, Section 20.3.1 of ASCE 7-05 allows site coefficients Fa and Fv to be determined assuming that liquefaction does not occur for structures with fundamental periods of vibration less than 0.5 second. Based on the results of the field exploration, Site Class E may be used to determine the values of Fa and Fv in accordance with Section 1316.5.2 of the 2009 IBC.
Potentially liquefiable soils were encountered within the depths explored between 5 and 20 feet in all borings and to a depth of 32 feet in B-4. Liquefaction induced settlement ranges from 3 to 9 inches. However, borings extended to a maximum depth of 42 feet, and additional potentially liquefiable soils may be encountered at greater depths. The proposed site is located in an area Responsive ■ Resourceful ■ Reliable
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Geotechnical Engineering Report Spanish Fork Fairgrounds Grandstand ■ Spanish Fork, Utah September 8, 2011 ■ Terracon Project No. 61115033
mapped1 as having a high potential for liquefaction. Liquefaction induced lateral spread on the order of 1 foot may also occur at the site during an earthquake event. If liquefaction induced settlement or lateral spread is deemed to be excessively high, Terracon should be contacted to discuss liquefaction mitigation options. Mitigation options may include rammed aggregate piers, stone columns or other approved method.
4.6
Chemical Tests
The results of sulfate tests performed on samples from the site are presented in the following table. Analytical Test Results Sample
Sulfate (ppm)
B-1 @ 2.5
8.3
Based ACI 318 Table 4.3.1, the potential for sulfate attack on concrete is estimated to be negligible. ACI 318 recommends the use of Type I cement for negligible sulfate exposure and.
5.0
GENERAL COMMENTS
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 testing and observation during excavation, grading, foundation and 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 location and from other information discussed in this report. This report does not reflect variations that may occur away from the borings, across the site, or due to the modifying effects of 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, 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. 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 1
Christensen, Gary E., Shaw, Lucas M., 2008, Liquefaction Special Study Areas Wasatch Front and Nearby Areas, Utah, Supplement Map to Utah Geological Survey Circular 106.
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Geotechnical Engineering Report Spanish Fork Fairgrounds Grandstand ■ Spanish Fork, Utah September 8, 2011 ■ Terracon Project No. 61115033
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 outlined 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.
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APPENDIX A FIELD EXPLORATION
SUBJECT SITE
REFERENCE: MICROSOFT VIRTUAL EARTH DIAGRAM IS FOR GENERAL LOCATION ONLY,, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES.
Project Mngr: Drawn By: Checked By: Approved By:
ABD CRC ABD RLC
Project No. Task No. Scale: Date:
PROJECT VICINITY MAP
61115033 0
Spanish Fork Grandstand Spanish Fork, Utah
Not to Scale 9/2/2011
14850 Pony Express Road, Suite 150N Bluffdale, Utah 84065
Spanish Fork City
FIGURE
A-1
B-4
B-3
B1 B-1 B-2
LEGEND: Approximate Boring Location
REFERENCE: MICROSOFT VIRTUAL EARTH DIAGRAM IS FOR GENERAL LOCATION ONLY,, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES.
Project Mngr: Drawn By: Checked By: Approved By:
ABD CRC ABD RLC
Project No. Task No. Scale: Date:
BORING LOCATION DIAGRAM
61115033 00
Spanish Fork Grandstand Spanish Fork, Utah
Not to Scale 9/2/2011
14850 Pony Express Road, Suite 150 N Bluffdale, Utah 84065
Spanish Fork City
FIGURE
A-2
Field Exploration Description The boring locations were chosen based upon our understanding of the proposed work. The location of the borings should be considered accurate only to the degree implied by the means and methods used to define it. The borings were drilled with a Mobile B-80 truck-mounted drill rig using continuous flight hollowstem augers to advance the boreholes. Samples of the soil encountered in the boring were obtained using the split barrel sampling procedure. In the split-barrel sampling procedure, the number of blows required to advance a standard 2-inch O.D. split-barrel sampler the last 12 inches of the typical total 18-inch penetration by means of a 140-pound hammer with a free fall of 30 inches, is the standard penetration resistance value (SPT-N). This value is used to estimate the in-situ relative density of cohesionless soils and consistency of cohesive soils. An automatic SPT hammer was used to advance the split-barrel sampler in the borings performed on this site. A significantly greater efficiency is achieved with the automatic hammer compared to the conventional safety hammer operated with a cathead and rope. This higher efficiency has an appreciable effect on the SPT-N value. The effect of the automatic hammer's efficiency has been considered in the interpretation and analysis of the subsurface information for this report. The samples were tagged for identification, sealed to reduce moisture loss, and taken to our laboratory for further examination, testing, and classification. Information provided on the boring log attached to this report includes soil descriptions, consistency evaluations, boring depths, sampling intervals, and groundwater conditions. The boring was backfilled with auger cuttings prior to the drill crew leaving the site. A field log of the boring was prepared by the field engineer. The log included visual classifications of the materials encountered during drilling as well as the driller’s interpretation of the subsurface conditions between samples. The final boring log included with this report represent the engineer's interpretation of the field logs and include modifications based on laboratory observation and tests of the samples.
Exhibit A-3
LOG OF BORING NO. B-1
Page 1 of 1
OWNER
Spanish Fork City 475 South Main Street Spanish Fork, Utah
PROJECT
0.25
ASPHALT: Approximately 3 inches thick CLAY: soft, brown
5.5
99.8
94.6
SANDY SILT: soft, brown, with silty clay layers
14.5
18
85.6
SILTY SAND: loose, brown, trace gravel, with silty clay layers GRAVEL: with sand, dense, light brown and gray
21.5
82.1
78.6
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
LIQUID LIMIT
% PASSING NO. 200 SIEVE
TESTS
PLASTICITY INDEX
SAMPLES
PENETRATION RESISTANCE BLOWS / ft. WATER CONTENT, % DRY UNIT WEIGHT, PCF
NUMBER
DESCRIPTION
USCS Soil Symbol
Approx. 10 ft south of corral and 15 ft west of edge of existing grandstand Relative Surface Elevation: 100.1 ft DEPTH, ft.
GRAPHIC LOG
Boring Location:
RECOVERY, in.
Spanish Fork Fairgrounds Grandstand
TYPE
SITE
1 SS 5
2
23
ML 2 ST 24
--
26
98 NP NP 60
3 SS 18
2
ML 4 SS 18
3
27
NP NP 67
5 SS 18
4
6 SS 18
6
7 SS 14
30
OTHER
Consol., sieve
Sieve
BOREHOLE_99 61115033.GPJ TERRACON.GDT 9/8/11
BOTTOM OF BORING AT APPROXIMATELY 21.5 FEET
The stratification lines represent the approximate boundary lines between soil and rock types: in-situ, the transition may be gradual.
WATER LEVEL OBSERVATIONS, ft WL 3.5 AB
BORING STARTED
8-16-11
BORING COMPLETED
8-16-11
WL
RIG
B-80 FOREMAN
WL
APPROVED
RLC JOB #
ABD
61115033
LOG OF BORING NO. B-2
Page 1 of 1
OWNER
Spanish Fork City 475 South Main Street Spanish Fork, Utah
PROJECT
0.25
GRAVEL: Approximately 3 inches thick SANDY CLAY: soft, dark brown to brown, with silty clay layers
8.5
99.4
91.2
SILT: soft, brown, with clay and silty sand layers
19
80.7
GRAVEL: with silt and sand, medium dense to very dense, brown, gray, and brownish-gray
33
66.7
BOREHOLE_99 61115033.GPJ TERRACON.GDT 9/8/11
CLAY: soft to medium stiff, light gray
41.5
58.2
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41
LIQUID LIMIT
CL 1 SS 12
3
2 SS 14
4
CL 3 ST 24 ML
--
4 SS 18
2
5 SS 18
3
6 SS 12
17
7 SS 12
30
8 SS 12
65
9 SS 14
5
10 SS 16
3
22
30
88
% PASSING NO. 200 SIEVE
TESTS
PLASTICITY INDEX
SAMPLES
PENETRATION RESISTANCE BLOWS / ft. WATER CONTENT, % DRY UNIT WEIGHT, PCF
NUMBER
DESCRIPTION
USCS Soil Symbol
Approx. 25 ft southeast of western covered structure and 15 ft southwest of grandstand Relative Surface Elevation: 99.7 ft DEPTH, ft.
GRAPHIC LOG
Boring Location:
RECOVERY, in.
Spanish Fork Fairgrounds Grandstand
TYPE
SITE
25
8
70
24
5
79
OTHER
Sieve
Consol., Sieve
25
27
BOTTOM OF BORING AT APPROXIMATELY 41.5 FEET
The stratification lines represent the approximate boundary lines between soil and rock types: in-situ, the transition may be gradual.
WATER LEVEL OBSERVATIONS, ft WL 4.5 AB
BORING STARTED
8-16-11
BORING COMPLETED
8-16-11
WL
RIG
B-80 FOREMAN
WL
APPROVED
RLC JOB #
ABD
61115033
LOG OF BORING NO. B-3
Page 1 of 1
OWNER
Spanish Fork City 475 South Main Street Spanish Fork, Utah
PROJECT
0.25
ASPHALT: Approximately 3 inches thick CLAY: very soft to soft, brown
10
99.7
89.9
SANDY SILT: soft, brown 15
84.9
SILTY SAND: medium dense, medium dense, brown
BOREHOLE_99 61115033.GPJ TERRACON.GDT 9/8/11
20.5 21.5
GRAVEL: with sand, medium dense, fine-grained, brown and gray BOTTOM OF BORING AT APPROXIMATELY 21.5 FEET
79.4 78.4
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
LIQUID LIMIT
1 SS 12
3
2 SS 8
2
3 SS 12
1
ML 4 ST 24
--
26
5 SS 18
2
24
6 ST 24
--
7 SS 14
23
% PASSING NO. 200 SIEVE
TESTS
PLASTICITY INDEX
SAMPLES
PENETRATION RESISTANCE BLOWS / ft. WATER CONTENT, % DRY UNIT WEIGHT, PCF
NUMBER
DESCRIPTION
USCS Soil Symbol
Approx. 20 ft north of small building north of western covered stands and 15 ft west of regular stands Relative Surface Elevation: 99.9 ft DEPTH, ft.
GRAPHIC LOG
Boring Location:
RECOVERY, in.
Spanish Fork Fairgrounds Grandstand
TYPE
SITE
OTHER
22
NP NP 59
Sieve
The stratification lines represent the approximate boundary lines between soil and rock types: in-situ, the transition may be gradual.
WATER LEVEL OBSERVATIONS, ft WL 5.2 AB
BORING STARTED
8-16-11
BORING COMPLETED
8-16-11
WL
RIG
B-80 FOREMAN
WL
APPROVED
RLC JOB #
ABD
61115033
LOG OF BORING NO. B-4
Page 1 of 1
OWNER
Spanish Fork City 475 South Main Street Spanish Fork, Utah
PROJECT
CLAY: soft, brown
7
92.6
SANDY SILT: soft, brown with clay layers
19
80.6
SILTY SAND: very loose to loose, fine-grained, brown to brownish-gray
32
67.6
BOREHOLE_99 61115033.GPJ TERRACON.GDT 9/8/11
CLAY: medium stiff, gray
42
57.6
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42
LIQUID LIMIT
1 ST 18
--
2 SS 6
2
3 ST 30
--
% PASSING NO. 200 SIEVE
TESTS
PLASTICITY INDEX
SAMPLES
PENETRATION RESISTANCE BLOWS / ft. WATER CONTENT, % DRY UNIT WEIGHT, PCF
NUMBER
DESCRIPTION
USCS Soil Symbol
Approx. 10 ft north o f the northern corral entrance on the eastern side of arena Relative Surface Elevation: 99.6 ft DEPTH, ft.
GRAPHIC LOG
Boring Location:
RECOVERY, in.
Spanish Fork Fairgrounds Grandstand
TYPE
SITE
21 106
26
OTHER
UU Triax.
NP NP 63 Sieve
4 SS 14
2
5 ST 24
--
6 SS 18
3
7 SS 18
8
8 SS 0
4
9 SS 16
4
10 ST 24
--
25
NP NP 22
Sieve
32
BOTTOM OF BORING AT APPROXIMATELY 42 FEET The stratification lines represent the approximate boundary lines between soil and rock types: in-situ, the transition may be gradual.
WATER LEVEL OBSERVATIONS, ft WL 5 AB
BORING STARTED
8-16-11
BORING COMPLETED
8-16-11
WL
RIG
B-80 FOREMAN
WL
APPROVED
RLC JOB #
ABD
61115033
APPENDIX B LABORATORY TESTING
Laboratory Testing Terracon personnel prepared a log of the boring during the field exploration in general accordance with the Unified Soil Classification System (USCS). The USCS is described in Appendix A. Collected soil samples from the boring were packaged and transported to our laboratory in Draper for further observation and testing. Laboratory tests were conducted on selected soil samples and the test results are presented in the soil boring log. The laboratory test results were used for the geotechnical engineering analyses and the development of foundation design and construction recommendations. Laboratory tests were performed in general accordance with the applicable ASTM, local or other accepted standards. Selected soil samples obtained from the site were tested for the following engineering properties:
Sieve Analysis Atterberg Limits Shear Strength
In-situ Water Content Consolidation Sulfate Content
Exhibit B-1
U.S. SIEVE OPENING IN INCHES 6
4
3
2
1
1.5
3/4
U.S. SIEVE NUMBERS 1/2
3/8
3
4
6
8
10
14
16
20
30
40
50
HYDROMETER 60
100
140
200
100 95 90 85 80 75
PERCENT FINER BY WEIGHT
70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 100
10
1
0.1
0.01
0.001
GRAIN SIZE IN MILLIMETERS
TC_GRAIN_SIZE 61115033.GPJ TERRACON.GDT 9/1/11
COBBLES
GRAVEL coarse
Specimen Identification B-1 5.0ft B-1 10.0ft B-2 2.5ft B-2 7.5ft B-3 10.0ft Specimen Identification B-1 5.0ft B-1 10.0ft B-2 2.5ft B-2 7.5ft B-3 10.0ft
SAND
fine
D100 0.15 4.75 0.15 4.75 0.15
coarse
medium
fine
Classification SANDY SILT(ML) SANDY SILT(ML) SANDY LEAN CLAY(CL) SILTY CLAY with SAND(CL-ML) SANDY SILT(ML) D60 D30 D10 0.075
0.077
SILT OR CLAY LL PL NP NP NP NP 25 17 24 19 NP NP %Gravel %Sand 0.0 40.3 0.0 32.8 0.0 30.5 0.0 20.8 0.0 41.3
GRAIN SIZE DISTRIBUTION Project: Spanish Fork Fairgrounds Grandstand Site: 475 South Main Street Spanish Fork, Utah Job #: 61115033 Date: 9-1-11
PI Cc Cu NP NP 8 5 NP %Silt %Clay 59.7 67.2 69.5 79.2 58.7
U.S. SIEVE OPENING IN INCHES 6
4
3
2
1
1.5
3/4
U.S. SIEVE NUMBERS 1/2
3/8
3
4
6
8
10
14
16
20
30
40
50
HYDROMETER 60
100
140
200
100 95 90 85 80 75
PERCENT FINER BY WEIGHT
70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 100
10
1
0.1
0.01
0.001
GRAIN SIZE IN MILLIMETERS
COBBLES
GRAVEL coarse
fine
TC_GRAIN_SIZE 61115033.GPJ TERRACON.GDT 9/1/11
Specimen Identification B-4 7.5ft B-4 20.0ft
Specimen Identification B-4 7.5ft B-4 20.0ft
SAND coarse
medium
Classification SANDY SILT(ML) SILTY SAND(SM)
D100 4.75 0.15
D60
D30
0.105
0.08
SILT OR CLAY
fine
LL NP NP
D10
%Gravel 0.0 0.0
PL NP NP
%Sand 37.0 77.9
GRAIN SIZE DISTRIBUTION Project: Spanish Fork Fairgrounds Grandstand Site: 475 South Main Street Spanish Fork, Utah Job #: 61115033 Date: 9-1-11
PI NP NP
%Silt
Cc
Cu
%Clay 63.0 22.1
Unconsolidated-Undrained Triaxial Compression Test (ASTM D2850) Axial Strain (%) 0.00 0.15 0.31 0.49 0.99 1.31 1.65 1.99 4.01 6.04 8.06 10.08 12.09 14.10 16.13 18.16 20.00
1600
1490.5
1400
1200
Deviator Stress, psf
1000
800
Deviator Stress (psf) 0.0 125.9 202.9 268.9 425.2 506.5 599.9 695.1 1082.6 1275.0 1361.0 1415.4 1455.5 1476.2 1464.7 1490.5 1478.8
Shear Stress (psf) 0.0 63.0 101.5 134.5 212.6 253.3 299.9 347.5 541.3 637.5 680.5 707.7 727.8 738.1 732.4 745.3 739.4
600
400
200
0 0
5
10
15
20
25
Strain, %
Sample Diameter (in): Sample Height (in): Sample Volume (cf):
2.84 6.44 0.0236
Moist Unit Weight (pcf): Moisture Content (%): Dry Unit Weight (pcf):
128 21 106
Confining Stress (psf): Strain Rate (%/min): Strain Rate (in/min):
292.88 2.00 0.1297
Strain at Falure (%): Shear Stress at Falure (psf):
18 745
Project Name: Project No.: Location: Sample: Sample Description:
Spanish Fork Grandstands 61115033 Spanish Fork B-4 @ 2.5 Clay
Consolidation Test Data (ASTM D 2435-04 ) 0.0
2.0
VERTICAL STRAIN, %
4.0
6.0
8.0
10.0
12.0 0.1
1
10
100
VERTICAL STRESS, ksf Before Consolidation Sample Diameter (in): Sample Height (in): Sample Volume (cf):
2.50 1 0.0028
Moist Unit Weight (pcf): Moisture Content (%): Dry Unit Weight (pcf):
123 26 98
2.50 0.8998 0.0026
Moist Unit Weight (pcf): Moisture Content (%): Dry Unit Weight (pcf):
137 20 114
After Consolidation Sample Diameter (in): Sample Height (in): Sample Volume (cf): Liquid Limit: NP Plasticity Index: NP
Percent Fines: 59.7 Classification: Sandy Silt (ML) Project Name: Project No.: Location: Sample:
Spanish Fork Grandstand 61115033 Spanish Fork B-1 @ 5'
Consolidation Test Data (ASTM D 2435-04 ) 0.0 2.0 4.0
VERTICAL STRAIN, %
6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 0.1
1
10
100
VERTICAL STRESS, ksf Before Consolidation Sample Diameter (in): Sample Height (in): Sample Volume (cf):
2.50 1 0.0028
Moist Unit Weight (pcf): Moisture Content (%): Dry Unit Weight (pcf):
115 30 88
Sample Diameter (in): Sample Height (in): Sample Volume (cf):
2.50 0.8557 0.0024
Moist Unit Weight (pcf): Moisture Content (%): Dry Unit Weight (pcf):
134 26 106
Liquid Limit: Plasticity Index:
24 5
After Consolidation
Percent Fines: Classification: Silty Clay (CL-ML) Project Name: Project No.: Location: Sample:
Spanish Fork Grandstand 61115033 Spanish Fork B-2 @ 7.5'
