Geotechnical Engineering Report

Transcription

1 The Residence at Yukon Hills Cornwell Drive and Vandament Avenue Yukon, Oklahoma May 20, 2016 Terracon Project No Prepared for: Jones Gillam Renz Architects, Inc. Salina, Kansas Prepared by: Terracon Consultants, Inc. Oklahoma City, Oklahoma

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3 The Residence at Yukon Hills Yukon, Oklahoma May 20, 2016 Terracon Project No TABLE OF CONTENTS Page EXECUTIVE SUMMARY... i 1.0 INTRODUCTION PROJECT INFORMATION Project Description Site Location and Description SUBSURFACE CONDITIONS Typical Profile Groundwater RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION Geotechnical Considerations Earthwork Site Preparation Subgrade Preparation Fill Material Requirements Compaction Requirements Utility Trench Backfill Grading and Drainage Foundations Shallow Foundation Design Recommendations Shallow Foundation Construction Considerations Seismic Considerations Floor Slab Design Recommendations Construction Considerations Pavements Design Recommendations Construction Considerations GENERAL COMMENTS...11 Responsive Resourceful Reliable

4 The Residence at Yukon Hills Yukon, Oklahoma May 20, 2016 Terracon Project No TABLE OF CONTENTS - (Cont d.) APPENDIX A - FIELD EXPLORATION Exhibit A-1 Site Location Plan Exhibit A-2 Boring Location Plan Exhibit A-3 Field Exploration Description Exhibits A-4 to A-9 Borings B-1 to B-6 APPENDIX B - LABORATORY TESTING Exhibit B-1 Laboratory Testing APPENDIX C - SUPPORTING DOCUMENTS Exhibit C-1 Exhibit C-2 Exhibit C-3 General Notes Unified Soil Classification Sedimentary Rock Classification Responsive Resourceful Reliable

5 The Residence at Yukon Hills Yukon, Oklahoma May 20, 2016 Terracon Project No EXECUTIVE SUMMARY Geotechnical engineering services have been performed for The Residence at Yukon Hills to be located at Cornwell Drive and Vandament Avenue in Yukon, Oklahoma. Terracon s geotechnical scope of work included six test borings to approximate depths of 5 to 15 feet below existing site grades. Based on the information obtained from our subsurface exploration, the site can be developed for the proposed project. The following geotechnical considerations were identified: The site surface cover generally consisted of vegetation. The soil profile generally consisted of lean clay and shaley lean clay to depths of about 6.5 to below boring termination depths of 15 feet. The overburden soils were underlain by weathered silty sandstone. Groundwater was not encountered in the test borings at the time of drilling. The proposed building may be supported on shallow footings bearing on the medium stiff to very stiff native soil, or on newly placed engineered fill. Recommendations for designing and constructing the foundations are provided in the following report. The near-surface soils are active and prone to volume change with variations in moisture level. For this reason, we recommend an 24-inch thick low volume change zone be constructed beneath the on-grade floor slab. Chemical treatment of the pavement subgrade is recommended to improve its long term stability and pavement performance. The 2009 International Building Code, Table IBC seismic site classification for this site is C. Close monitoring of the construction operations discussed herein will be critical in achieving the design subgrade support. We therefore recommend that Terracon be retained to monitor this portion of the work. This summary should be used in conjunction with the entire report for design purposes. It should be recognized that details were not included or fully developed in this section, and the report must be read in its entirety for a comprehensive understanding of the items contained herein. The section titled GENERAL COMMENTS should be read for an understanding of the report limitations. Responsive Resourceful Reliable i

6 GEOTECHNICAL ENGINEERING REPORT THE RESIDENCE AT YUKON HILLS CORNWELL DRIVE AND VANDAMENT AVENUE YUKON, OKLAHOMA Terracon Project No May 20, INTRODUCTION This report presents the results of our geotechnical engineering services performed for The Residence at Yukon Hills to be located in Yukon, Oklahoma. Six borings, designated B-1 through B-6, were performed to depths of approximately 5 to 15 feet below the existing ground surface within the proposed building and pavement areas. Logs of the borings along with a site location plan and a boring location plan are included in Appendix A of this report. The purpose of these services is to provide information and geotechnical engineering recommendations relative to: subsurface soil/rock conditions floor slab design and construction groundwater conditions seismic considerations earthwork pavement design and construction foundation design and construction 2.0 PROJECT INFORMATION 2.1 Project Description Site layout Structures Item Description See Appendix A, Exhibit A-2, Boring Location Plan The project will include construction of a two-story, approximately 55,600 square-foot residential building. Associated parking and drive areas will also be constructed. Maximum loads Grading Columns: 60 to 100 kips (assumed) Walls: 2 to 4 klf (assumed) Slabs: 125 psf max (assumed) Grade changes for the proposed site were not provided to us at the time of this report; but, based on the boring elevations and the existing topography, we anticipate about 4 to feet of fill and less than 2 feet of cut will be necessary for this site. Responsive Resourceful Reliable 1

7 The Residence at Yukon Hills Yukon, Oklahoma May 20, 2016 Terracon Project No Item Cut and fill slopes Traffic loading Description 3H:1V (3 Horizontal to 1 Vertical) max Traffic patterns and anticipated loading conditions were not provided to us at the time of this report. 2.2 Site Location and Description Location Item Current ground cover Surface vegetation and topsoil Existing topography Description This project will be located northeast of the intersection of Cornwell Drive and Vandament Avenue in Yukon, Oklahoma. The site generally slopes downward from the southwest to northeast with about 9 feet of maximum elevation difference between the borings. 3.0 SUBSURFACE CONDITIONS 3.1 Typical Profile Specific conditions encountered at each boring location are indicated on the individual boring logs included in Appendix A. Stratification boundaries on the boring logs represent the approximate location of changes in soil and rock types; in-situ, the transition between materials may be gradual. Based on the results of the borings, subsurface conditions on the project site can be generalized as follows: Stratum 1 Approximate Depth to Bottom of Stratum 6.5 feet to below boring termination depths of 15 feet 2 Not determined Material Description Lean clay and shaley lean clay with varying amounts of sand Weathered silty sandstone Consistency/Density Medium stiff to hard Poorly cemented to cemented Laboratory tests were conducted on selected soil samples and the test results are presented on the boring logs in Appendix A. Responsive Resourceful Reliable 2

8 The Residence at Yukon Hills Yukon, Oklahoma May 20, 2016 Terracon Project No Groundwater The boreholes were observed while drilling and after completion for the presence and level of groundwater. Groundwater was not observed in the borings while drilling, or for the short duration that the borings were allowed to remain open. However, this does not necessarily mean the borings terminated above groundwater. Due to the low permeability of the soils encountered in the borings, a relatively long period of time may be necessary for a groundwater level to develop and stabilize in a borehole in these materials. Long term observations in piezometers or observation wells sealed from the influence of surface water are often required to define groundwater levels in materials of this type. Groundwater level fluctuations occur due to seasonal variations in the amount of rainfall, runoff and other factors not evident at the time the borings were performed. Therefore, groundwater levels during construction or at other times in the life of the structure may be higher or lower than the levels indicated on the boring logs. The possibility of groundwater level fluctuations should be considered when developing the design and construction plans for the project. 4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION 4.1 Geotechnical Considerations The site surface cover generally consisted of vegetation. The soil profile generally consisted of lean clay and shaley lean clay to depths of about 6.5 to below boring termination depths of 15 feet. The overburden soils were underlain by weathered silty sandstone. Groundwater was not encountered in the test borings at the time of drilling. The proposed building may be supported on shallow footings bearing on the medium stiff to very stiff native soil, or on newly placed engineered fill. Recommendations for designing and constructing the foundations are provided in section 4.3 Foundations. The near-surface soils are active and prone to volume change with variations in moisture level. For this reason we recommend a low volume change zone be constructed beneath the ongrade floor slab. Details regarding this low-volume change zone are provided in section 4.5 Floor Slab of this report. Engineered fill placed in the upper 24 inches beneath the building area should meet the plasticity requirements provided in section 4.2 Earthwork of this report. Subgrade treatment of the on-site soils with hydrated lime, Class C fly ash or cement kiln dust (CKD) is recommended to improve long-term support for new pavements. Responsive Resourceful Reliable 3

9 The Residence at Yukon Hills Yukon, Oklahoma May 20, 2016 Terracon Project No This report provides recommendations to help mitigate the effects of soil shrinkage and expansion. However, even if these procedures are followed, some movement and at least minor cracking in the structure could still occur. The severity of cracking and other cosmetic damage such as uneven floor slabs will probably increase if any modification of the site results in excessive wetting or drying of the expansive soils. Eliminating the risk of movement and cosmetic distress may not be feasible, but it may be possible to further reduce the risk of movement if significantly more expensive measures are used during construction. We would be pleased to discuss other construction alternatives with you upon request. Geotechnical engineering recommendations for foundations 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 Appendices A and B), engineering analyses, and our current understanding of the proposed project. 4.2 Earthwork The following subsections present recommendations for site preparation, excavation, subgrade preparation and construction of engineered fills on the project. The recommendations presented for design and construction of earth supported elements including foundations, slabs and pavements are contingent upon following the recommendations outlined in this section. Grading for each structure should extend an appropriate distance beyond the limits of the proposed structure planned building and pavement areas. Earthwork on the project should be observed and evaluated by Terracon. The evaluation of earthwork should include observation and testing of engineered fill, subgrade preparation, and other geotechnical conditions exposed during the construction of the project Site Preparation Site preparation should include removing the vegetation, topsoil, and other unsuitable materials encountered on-site. Actual removal depths should be determined at the time of construction by a representative of the geotechnical engineer Subgrade Preparation After removing the vegetation, topsoil and performing any required cuts, but before placing any fill or constructing the floor slab, we recommend undercutting the building area to allow construction of a minimum 24-inch thickness of low volume change fill below the design finish subgrade elevation. The zone of fill compacted to meet this criteria should extend beyond the building footprint at least 1 foot laterally for each foot of fill required to develop design grade. Responsive Resourceful Reliable 4

10 The Residence at Yukon Hills Yukon, Oklahoma May 20, 2016 Terracon Project No After performing any required undercut, but before placing any fill, we recommend the exposed soils be proofrolled with a loaded, tandem-axle dump truck weighing at least 25 tons (under the observation of Terracon personnel) to locate any soft or unstable zones. The proofrolling should involve overlapping passes in mutually perpendicular directions. Where rutting or pumping is observed during proofrolling, the unstable soils should be overexcavated and replaced with an approved low volume change soil as described in the following sections if it cannot be effectively compacted in-place. After a successful proofroll, we recommend scarifying the exposed subgrade soils to a minimum depth of 8 inches in the building area, and in the pavement area if fill is required. The scarified soil should be adjusted to a workable moisture content that is at or above its optimum value, as determined by test method ASTM D-698 (standard Proctor), prior to being compacted to at least 95 percent of its maximum dry density. Temporary excavations will probably be required during grading operations and installation of utilities. Contractors, by their contract, are usually responsible for designing and constructing stable, temporary excavations and should shore, slope and 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 Occupational Safety and Health Administration (OSHA) Excavation and Trench Safety Standards Fill Material Requirements All fill required to develop the design subgrade elevation should be an approved cohesive material that is free of organic matter and debris as outlined in the following table. Fill Type 1 Imported Low Volume Change Soils (Cohesive Materials with LL<40 and 5<PI<15) 2 Acceptable Location for Placement All locations and elevations On-Site Soils (with 5<PI< 30) Pavement and non-structure areas 3 1. Prior to any filling operations, samples of the proposed borrow and on-site materials should be obtained for laboratory Atterberg limits and moisture-density testing. The tests will provide a basis for material acceptance and evaluation of fill compaction by in-place density testing. A qualified soil technician should perform sufficient in-place density tests during the filling operations to evaluate that proper levels of compaction, including dry unit weight and moisture content, are being attained. Controlled, compacted fill should consist of approved materials free of organic matter and debris and contain a maximum rock size of 3 inches. The proposed fill materials should be approved by the geotechnical engineer prior to placement. 2. We generally did not encounter on-site soils that met the requirements for use as low volume change fill. However, this could be verified during construction by further testing. Responsive Resourceful Reliable 5

11 The Residence at Yukon Hills Yukon, Oklahoma May 20, 2016 Terracon Project No Fill Type 1 Acceptable Location for Placement 3. Provided the top 8 inches of the pavement subgrade is treated with hydrated lime, Class C fly ash or cement kiln dust as discussed in section 4.6 Pavements. Engineered fill should be placed and compacted in horizontal lifts, using equipment and procedures that will produce recommended moisture contents and densities throughout the lift Compaction Requirements Recommended compaction and moisture content criteria for engineered fill materials are as follows: Item Fill Lift Thickness Compaction Requirements Moisture Content Description 9-inches or less in loose thickness At least 95% of the material s maximum dry density as determined by the standard Proctor test method, ASTM D- 698, except the treated depth of pavement subgrade should be compacted to at least 98% Workable moisture content that is at or above its optimum value as determined by the standard Proctor test method, ASTM D-698 at the time of placement and compaction Utility Trench Backfill All trenches created for utility access under the building should be effectively sealed to restrict water intrusion and flow along the trenches. We recommend using a clay soil to construct an effective clay trench plug that extends at least 5 feet out from the face of the building. The clay should have a minimum plasticity index (PI) of 15 and be placed in controlled lifts not exceeding 9 inches in loose thickness so as to surround the utility line and fill the trench. Each lift of clay backfill should be compacted to at least 95 percent of the material s maximum standard Proctor dry density, ASTM 698, at a minimum moisture content that is above its optimum value Grading and Drainage Effective drainage should be developed during construction and maintained throughout the life of the development. Infiltration of water into utility trenches or foundation excavations should be prevented during construction. Planters and other surface features that could retain water in areas adjacent to the building or pavements should be sealed or eliminated. In areas where sidewalks or paving do not immediately adjoin the structure, we recommend that protective slopes be provided with a minimum grade of approximately five percent for at least 10 feet from perimeter walls. Backfill against footings, exterior walls, and in utility and sprinkler line trenches should be well compacted and free of all construction debris to reduce moisture infiltration. Responsive Resourceful Reliable 6

12 The Residence at Yukon Hills Yukon, Oklahoma May 20, 2016 Terracon Project No Downspouts, roof drains or scuppers should discharge in a manner that carries the water several feet away from the building when the ground surface adjacent to the structure is not protected by exterior slabs or paving. Sprinkler systems should not be installed within five feet of foundation walls. Landscape irrigation adjacent to the foundation systems should be minimized or eliminated. 4.3 Foundations The proposed structure can be supported by a shallow, spread footing foundation system bearing on the medium stiff to very stiff native clay or newly placed engineered fill. Foundation design recommendations for the proposed structure and related structural elements are presented in the following paragraphs Shallow Foundation Design Recommendations Foundation Type Bearing Material Description Net Allowable Bearing Pressure 1 Minimum Width Minimum Embedment Depth Below Finished Grade 2 Estimated Total Settlement Estimated Differential Settlement Allowable Passive Pressure 3 Allowable Coefficient of Sliding Friction Value Conventional shallow spread footings Undisturbed native soil or engineered fill 2,000 psf Columns: 30 inches Walls: 16 inches 30 inches <1 inch Approximately 1/2 of total settlement 150 pcf (equivalent fluid pressure) Uplift Resistance Foundation weight and soil weight (120 pcf) 5 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 engineered fill. 2. Minimum depth applies to footings along the building perimeter and in unheated areas. Minimum depth will provide frost protection and reduce the potential for moisture variation below the bearing level. Interior footings should have a minimum depth of 12 inches below the final adjacent subgrade level. 3. With an applied safety factor of 2. This value also assumes that the foundations are poured directly against undisturbed native materials or that backfills placed around formed foundations are compacted to at least 95 percent of the maximum dry density as determined according to ASTM D- 698, the standard Proctor procedure. Unless pavements or on-grade slabs are provided up to and above the footings, the allowable passive pressure should be disregarded to a depth of 2.5 feet below the final grade. Responsive Resourceful Reliable 7

13 The Residence at Yukon Hills Yukon, Oklahoma May 20, 2016 Terracon Project No Description Value 4. With an applied safety factor of Assumed the soils compacted to at least 95 percent of their maximum standard dry density (ASTM D- 698). Finished grade is defined as the lowest adjacent grade within five feet of the foundation for perimeter (or exterior) footings and finished floor level for interior footings. Footings and masonry walls should be effectively reinforced to reduce the potential for distress caused by differential foundation movement. The use of joints at openings or other discontinuities in masonry walls is recommended Shallow Foundation Construction Considerations Care should be taken to prevent wetting or drying of the exposed bearing materials during construction. Any extremely wet or dry material, or any loose or disturbed material in the bottom of the footing excavations, should be removed prior to placing concrete. The potential for wetting or drying of the bearing materials can be reduced by placing concrete as soon as possible after completing the footing excavation and evaluating the bearing strata. Foundation excavations should be observed by the geotechnical engineer. If the soil conditions encountered differ significantly from those presented in this report, supplemental recommendations will be required. 4.4 Seismic Considerations Description 2009 International Building Code Site Classification (IBC) 1 C 2 1. In general accordance with the 2009 International Building Code, Table Value 2. 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 100 foot soil profile determination. Borings extended to a maximum depth of 15 feet. This seismic site class definition considers that soft rock continues below the maximum depth of the subsurface exploration. Additional exploration to deeper depths could be performed to confirm the conditions below the current depth of exploration. Alternatively, a geophysical exploration could be utilized in order to attempt to justify a higher seismic site class. 4.5 Floor Slab Design Recommendations Description Interior floor system Slab-on-grade concrete. Value Responsive Resourceful Reliable 8

14 The Residence at Yukon Hills Yukon, Oklahoma May 20, 2016 Terracon Project No Description Floor slab support Value 24 inches of low volume change soils placed and compacted in accordance with section 4.2 Earthwork Floor slabs should be structurally independent of building foundations and walls to reduce the possibility of floor slab cracking caused by differential movements between the slab and foundations. By constructing a low volume change fill layer beneath the slab, closely controlling the moisture and density of the scarified soils and controlling the potential for moisture migration beneath the slab, the potential for floor slab movements should be reduced. However, because of the remaining thickness of moderate plasticity clay soils, the potential for some future movement still exists. Based on constructing a minimum 24-inch thick low volume change fill layer beneath the floor slab, we anticipate potential slab movement could approach 1 inch. This magnitude of slab movement could occur differentially. To further reduce the potential for slab movements, a greater thickness of low volume change fill could be placed beneath the slab. In areas of exposed concrete, control joints should be saw cut into the slab after concrete placement in accordance with ACI Design Manual, Section 302.1R (tooled control joints are not recommended). Additionally, dowels should be placed at the location of proposed construction joints. To control the width of cracking (should it occur) continuous slab reinforcement should be considered in exposed concrete slabs. Positive separations and/or isolation joints should be provided between slabs and all foundations, columns or utility lines penetrating the slab to allow independent movement. Interior trench backfill placed beneath slabs should be compacted in accordance with recommendations outlined in section 4.2 Earthwork. Other design and construction considerations, as outlined in the ACI Design Manual, Section 302.1R are recommended. The use of a vapor retarder or barrier should be considered beneath concrete slabs on grade that will be covered with wood, tile, carpet or other moisture sensitive or impervious coverings, or when the slab will support equipment sensitive to moisture. When conditions warrant the use of a vapor retarder, the slab designer and slab contractor should refer to ACI 302 and ACI 360 for procedures and cautions regarding the use and placement of a vapor retarder/barrier Construction Considerations Even low volume change soils can experience sufficient volume change to cause differential slab movements if they experience wide fluctuations in moisture content. Therefore, it is critical that recommended moisture levels are developed within the engineered fill as it is placed and compacted, and care must be taken to maintain the recommended moisture level in the fill until the floor slabs are constructed. Poor drainage around the perimeter of the buildings can contribute moisture to aggravate the wetting and drying cycles that naturally occur. Also, water migration through utility trenches that penetrate beneath the building can contribute to subgrade Responsive Resourceful Reliable 9

15 The Residence at Yukon Hills Yukon, Oklahoma May 20, 2016 Terracon Project No swelling and floor slab heave. Effective drainage and plugging of utility trenches as discussed in section Grading and Drainage are considered critical to the long-term performance of this project. 4.6 Pavements The subgrade and any fill required in the pavement areas should be prepared and placed in accordance with the section 4.2 Earthwork. We expect the subgrade soils in the pavement areas will generally consist of moderate plasticity cohesive soils. These soils will tend to cause trafficability problems during construction when the subgrade gets wet and, in their existing condition, do not appear suitable for the long-term support of pavements. To reduce potential trafficability problems and strength loss, and to improve the long-term subgrade support, we recommend that the top 8 inches of the subgrade be treated with hydrated lime, Class C fly ash or cement kiln dust. Based on past experience with soils similar to those present at the site, we estimate 5 to 7 percent hydrated lime or 10 to 14 percent Class C fly ash or cement kiln dust will be needed to adequately treat the on-site soils. The actual percentage of additive should be determined at the time of construction by the geotechnical engineer. If lime is used, it should be blended into the subgrade and allowed to cure for 48 to 72 hours before being remixed and compacted. Before compaction, the treated soil zone should be adjusted to within 2 percent of the material s optimum moisture as determined by test method ASTM D-698. After conditioning the soil to the required moisture content, the treated subgrade should be compacted to at least 98 percent of the material s maximum dry density as determined by test method ASTM D-698. If Class C fly ash or cement kiln dust is used, compaction should be completed within about two hours after initially mixing the soil and stabilizing agent to optimize the stabilization benefit. Traffic patterns and anticipated loading conditions were not available at the time that this report was prepared. However, we have assumed that traffic loads will consist primarily of automobile traffic and occasional single-unit delivery trucks and trash removal trucks. Pavement sections for two traffic categories have been provided. The light-duty parking category is for areas expected to receive only car traffic. The heavy-duty parking and drive category assumes two single-unit trucks per day and two trash-removal trucks per week in addition to car traffic. If the traffic loading expected is different than our assumptions, we should be provided the traffic information and allowed to review these pavement sections. The owner/user should consider placing signs at entryways to deter heavy trucks from light-duty pavement areas. Responsive Resourceful Reliable 10

16 The Residence at Yukon Hills Yukon, Oklahoma May 20, 2016 Terracon Project No Design Recommendations Section I Portland Cement Concrete (3,500 psi, Air Entrained) Section II Full Depth Asphaltic Concrete Minimum Pavement Recommendations 1 Light-Duty Parking 5.0 Concrete 8.0 Treated Subgrade 2.0 Type B Asphaltic Concrete 3.0 Type A Asphaltic Concrete 8.0 Treated Subgrade Heavy-Duty Parking and Drive 6.0 Concrete 8.0 Treated Subgrade 2.0 Type B Asphaltic Concrete 5.0 Type A Asphaltic Concrete 8.0 Treated Subgrade 1. All materials should meet the ODOT Standard Specifications for Highway Construction. Note: We recommend that reinforced concrete pads be provided in front of and beneath trash receptacles. The dumpster trucks should be parked on the rigid concrete pavement when the trash receptacles are lifted. The concrete pads should be a minimum of 7 inches thick and properly reinforced. These pavement sections are considered minimal sections based upon our assumed traffic loading and the existing subgrade conditions. However, they are expected to function with periodic maintenance and overlays if effective drainage is provided and maintained Construction Considerations Pavement materials should not be placed when the surface is wet. Surface drainage should be provided away from the edge of paved areas to minimize lateral moisture transmission into the subgrade. Preventative maintenance should consist of both localized maintenance (e.g. crack sealing and patching) and global maintenance (e.g. surface sealing). It should be planned and provided for through an on-going pavement management program to enhance future pavement performance and preserve the pavement investment. 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 observation and testing services during grading, excavation, foundation construction and other earth-related construction phases of the project. The analysis and recommendations presented in this report are based upon the data obtained from the borings performed at the indicated locations and from other information discussed in this report. This report does not reflect variations that may occur between borings, across the site, or due to the modifying effects of construction or weather. The nature and extent of such Responsive Resourceful Reliable 11

17 The Residence at Yukon Hills Yukon, Oklahoma May 20, 2016 Terracon Project No 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 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. Responsive Resourceful Reliable 12

18 APPENDIX A FIELD EXPLORATION

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21 The Residence at Yukon Hills Yukon, Oklahoma May 20, 2016 Terracon Project No Field Exploration Description Six test borings were drilled at the site on March 24, The borings were drilled to depths ranging from approximately 5 to 15 feet below the ground surface at the approximate locations shown on the attached Boring Location Plan, Exhibit A-2. Terracon personnel used a measuring wheel and a hand-held GPS unit to establish our boring locations in the field. We estimated the right angles for the boring location measurements. Our drill crew obtained the approximate ground surface elevation indicated on the boring logs using a surveyor s level and rod. We referenced this elevation to the top nut of the fire hydrant located approximately as shown on the boring location plan. We assigned this reference point an arbitrary elevation of feet. Based on this benchmark, the ground surface elevations at the boring locations ranged from 102 to 111 feet. We rounded the elevations on the boring log to the nearest one-half foot. Consider the location and elevation of the boring accurate only to the degree implied by the methods used to make these measurements. A truck-mounted, rotary drill rig equipped with continuous flight augers was used to advance the boreholes. Representative samples were obtained by the split-barrel and thin-walled tube sampling procedures. The split-barrel sampling procedure uses a standard 2-inch O.D. split-barrel sampling spoon that is driven into the bottom of the boring with a 140-pound drive hammer falling 30 inches. The number of blows required to advance the sampling spoon the last 12 inches, or less, of a typical 18-inch sampling interval or portion thereof, is recorded as the standard penetration resistance value, N. The N value is used to estimate the in-situ relative density of cohesionless soils and, to a lesser degree of accuracy, the consistency of cohesive soils and the hardness of sedimentary bedrock. In the thin-walled tube sampling procedure, a seamless steel tube with a sharpened cutting end is hydraulically pushed into the bottom of the boring to obtain a relatively undisturbed cohesive soil sample. The sampling depths, penetration distances, and the N values are reported on the boring logs. The samples were tagged for identification, sealed to reduce moisture loss and returned to the laboratory for further examination, testing and classification. An automatic Standard Penetration Test (SPT) drive hammer was used to advance the splitbarrel sampler. The automatic drive hammer achieves a greater mechanical efficiency when compared to a conventional safety drive hammer operated with a cathead and rope. We considered this higher efficiency in our interpretation and analysis of the subsurface information provided with this report. Responsive Resourceful Reliable Exhibit A-3

22 The Residence at Yukon Hills Yukon, Oklahoma May 20, 2016 Terracon Project No Field logs were prepared as part of the drilling operations. These boring logs included visual classifications of the materials encountered during drilling and the field personnel s interpretation of the subsurface conditions between samples. The final boring logs included with this report may include modifications based on observations and tests of the samples in the laboratory. Responsive Resourceful Reliable Exhibit A-3

23 PROJECT: The Residence at Yukon Hills BORING LOG NO. B-1 Jones Gillam Renz Architects, Inc. CLIENT: Salina, Kansas Page 1 of 1 SITE: GRAPHIC LOG Cornwell Drive & Vandament Avenue Yukon, Oklahoma LOCATION See Exhibit A-2 Latitude: Longitude: DEPTH LEAN CLAY (CL), reddish-brown, stiff DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE RECOVERY (In.) FIELD TEST RESULTS LABORATORY TORVANE/HP (psf) UNCONFINED COMPRESSIVE STRENGTH (psf) WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI PERCENT FINES N= hard below 3.5' red with light gray below 6' N=30 16 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL THE RESIDENCE AT YUKON HILLS.GPJ WEATHERED SILTY SANDSTONE, red, trace light gray, cemented Boring Terminated at 14 Feet Stratification lines are approximate. In-situ, the transition may be gradual. +Classification estimated from disturbed samples. Core samples and petrographic analysis may reveal other rock types. Advancement Method: See Exhibit A-3 for description of field procedures. Power Auger Abandonment Method: Boring backfilled with soil cuttings upon completion. WATER LEVEL OBSERVATIONS No free water observed 10 See Appendix B for description of laboratory procedures and additional data (if any) N Stiles Ave Oklahoma City, OK 16 See Appendix C for explanation of symbols and abbreviations /4" 50/4" Hammer Type: Automatic Notes: Vegetation At Surface Boring Started: 3/24/2016 Drill Rig: 747 Project No.: Boring Completed: 3/24/2016 Driller: R. Peters Exhibit: A-4

24 PROJECT: The Residence at Yukon Hills BORING LOG NO. B-2 Jones Gillam Renz Architects, Inc. CLIENT: Salina, Kansas Page 1 of 1 SITE: GRAPHIC LOG Cornwell Drive & Vandament Avenue Yukon, Oklahoma LOCATION See Exhibit A-2 Latitude: Longitude: DEPTH LEAN CLAY (CL), reddish-brown, very stiff DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE RECOVERY (In.) FIELD TEST RESULTS LABORATORY TORVANE/HP (psf) UNCONFINED COMPRESSIVE STRENGTH (psf) WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI PERCENT FINES N= hard below 3.5' N=40 14 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL THE RESIDENCE AT YUKON HILLS.GPJ WEATHERED SILTY SANDSTONE, reddish-brown, poorly cemented -reddish-brown with light gray below 13.5' Boring Terminated at 14 Feet Stratification lines are approximate. In-situ, the transition may be gradual. +Classification estimated from disturbed samples. Core samples and petrographic analysis may reveal other rock types. Advancement Method: See Exhibit A-3 for description of field procedures. Power Auger Abandonment Method: Boring backfilled with soil cuttings upon completion. WATER LEVEL OBSERVATIONS No free water observed 10 See Appendix B for description of laboratory procedures and additional data (if any) N Stiles Ave Oklahoma City, OK 11 See Appendix C for explanation of symbols and abbreviations /5" 50/6" 50/6" Hammer Type: Automatic Notes: Vegetation At Surface Boring Started: 3/24/2016 Drill Rig: 747 Project No.: Boring Completed: 3/24/2016 Driller: R. Peters Exhibit: A-5

25 PROJECT: The Residence at Yukon Hills BORING LOG NO. B-3 Jones Gillam Renz Architects, Inc. CLIENT: Salina, Kansas Page 1 of 1 SITE: GRAPHIC LOG Cornwell Drive & Vandament Avenue Yukon, Oklahoma LOCATION See Exhibit A-2 Latitude: Longitude: DEPTH LEAN CLAY (CL), reddish-brown, medium stiff DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE RECOVERY (In.) FIELD TEST RESULTS LABORATORY TORVANE/HP (psf) UNCONFINED COMPRESSIVE STRENGTH (psf) WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI PERCENT FINES N=8 21 -very stiff below 3.5' N=22 18 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL THE RESIDENCE AT YUKON HILLS.GPJ SHALEY LEAN CLAY (CL), reddish-brown, hard Boring Terminated at 15 Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: Power Auger Abandonment Method: Boring backfilled with soil cuttings upon completion. WATER LEVEL OBSERVATIONS No free water observed N Stiles Ave Oklahoma City, OK See Exhibit A-3 for description of field procedures. See Appendix B for description of laboratory procedures and additional data (if any). See Appendix C for explanation of symbols and abbreviations N= N=55 Hammer Type: Automatic Notes: Vegetation At Surface Boring Started: 3/24/2016 Drill Rig: 747 Project No.: Boring Completed: 3/24/2016 Driller: R. Peters Exhibit: A-6

26 PROJECT: The Residence at Yukon Hills BORING LOG NO. B-4 Jones Gillam Renz Architects, Inc. CLIENT: Salina, Kansas Page 1 of 1 SITE: GRAPHIC LOG Cornwell Drive & Vandament Avenue Yukon, Oklahoma LOCATION See Exhibit A-2 Latitude: Longitude: DEPTH LEAN CLAY (CL), dark brown, stiff DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE RECOVERY (In.) FIELD TEST RESULTS LABORATORY TORVANE/HP (psf) UNCONFINED COMPRESSIVE STRENGTH (psf) WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI PERCENT FINES N= LEAN CLAY WITH SAND (CL), reddish-brown, medium stiff N= SHALEY LEAN CLAY (CL), reddish-brown, hard N=34 16 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL THE RESIDENCE AT YUKON HILLS.GPJ WEATHERED SILTY SANDSTONE, reddish-brown, cemented Boring Terminated at 14.5 Feet Stratification lines are approximate. In-situ, the transition may be gradual. +Classification estimated from disturbed samples. Core samples and petrographic analysis may reveal other rock types. Advancement Method: See Exhibit A-3 for description of field procedures. Power Auger Abandonment Method: Boring backfilled with soil cuttings upon completion. WATER LEVEL OBSERVATIONS No free water observed 10 See Appendix B for description of laboratory procedures and additional data (if any) N Stiles Ave Oklahoma City, OK 16 See Appendix C for explanation of symbols and abbreviations N= /3" Hammer Type: Automatic Notes: Vegetation At Surface Boring Started: 3/24/2016 Drill Rig: 747 Project No.: Boring Completed: 3/24/2016 Driller: R. Peters Exhibit: A-7

27 PROJECT: The Residence at Yukon Hills BORING LOG NO. B-5 Jones Gillam Renz Architects, Inc. CLIENT: Salina, Kansas Page 1 of 1 SITE: GRAPHIC LOG Cornwell Drive & Vandament Avenue Yukon, Oklahoma LOCATION See Exhibit A-2 Latitude: Longitude: DEPTH LEAN CLAY (CL), reddish-brown, stiff DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE RECOVERY (In.) FIELD TEST RESULTS LABORATORY TORVANE/HP (psf) UNCONFINED COMPRESSIVE STRENGTH (psf) WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI PERCENT FINES N= SHALEY LEAN CLAY (CL), red, trace gray, hard Boring Terminated at 5 Feet N=54 12 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL THE RESIDENCE AT YUKON HILLS.GPJ Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: Power Auger Abandonment Method: Boring backfilled with soil cuttings upon completion. WATER LEVEL OBSERVATIONS No free water observed See Exhibit A-3 for description of field procedures. See Appendix B for description of laboratory procedures and additional data (if any). See Appendix C for explanation of symbols and abbreviations N Stiles Ave Oklahoma City, OK Hammer Type: Automatic Notes: Vegetation At Surface Boring Started: 3/24/2016 Drill Rig: 747 Project No.: Boring Completed: 3/24/2016 Driller: R. Peters Exhibit: A-8

28 PROJECT: The Residence at Yukon Hills BORING LOG NO. B-6 Jones Gillam Renz Architects, Inc. CLIENT: Salina, Kansas Page 1 of 1 SITE: GRAPHIC LOG Cornwell Drive & Vandament Avenue Yukon, Oklahoma LOCATION See Exhibit A-2 Latitude: Longitude: DEPTH LEAN CLAY (CL), reddish-brown, stiff DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE RECOVERY (In.) FIELD TEST RESULTS LABORATORY TORVANE/HP (psf) UNCONFINED COMPRESSIVE STRENGTH (psf) WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI PERCENT FINES N= SHALEY LEAN CLAY (CL), reddish-brown, hard Boring Terminated at 5 Feet N=42 13 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL THE RESIDENCE AT YUKON HILLS.GPJ Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: Power Auger Abandonment Method: Boring backfilled with soil cuttings upon completion. WATER LEVEL OBSERVATIONS No free water observed See Exhibit A-3 for description of field procedures. See Appendix B for description of laboratory procedures and additional data (if any). See Appendix C for explanation of symbols and abbreviations N Stiles Ave Oklahoma City, OK Hammer Type: Automatic Notes: Vegetation At Surface Boring Started: 3/24/2016 Drill Rig: 747 Project No.: Boring Completed: 3/24/2016 Driller: R. Peters Exhibit: A-9

29 APPENDIX B LABORATORY TESTING

30 The Residence at Yukon Hills Yukon, Oklahoma May 20, 2016 Terracon Project No Laboratory Testing Samples retrieved during the field exploration were taken to the laboratory for further observation by the project geotechnical engineer and were classified in accordance with the Unified Soil Classification System (USCS) described in Appendix C. Samples of bedrock were classified in accordance with the general notes for Sedimentary Rock Classification. At that time, the field descriptions were confirmed or modified as necessary and an applicable laboratory testing program was formulated to determine engineering properties of the subsurface materials. Laboratory tests were conducted on selected soil and bedrock samples and the test results are presented on the boring logs in Appendix A. The laboratory test results were used for the geotechnical engineering analyses, and the development of foundation and earthwork recommendations. Laboratory tests were performed in general accordance with the applicable ASTM, local or other accepted standards. Selected soil and bedrock samples obtained from the site were tested for the following engineering properties: Visual Classification (ASTM D2488) In-situ Water Content (ASTM D2216) Atterberg Limits (ASTM D4318) In-situ Dry Density (ASTM D7263) Unconfined Compressive Strength (ASTM D2166) Procedural standards noted above are for reference to methodology in general. In some cases variations to methods are applied as a result of local practice or professional judgment. Responsive Resourceful Reliable Exhibit B-1

31 APPENDIX C SUPPORTING DOCUMENTS

32 DESCRIPTION OF SYMBOLS AND ABBREVIATIONS GENERAL NOTES Water Initially Encountered (HP) Hand Penetrometer Auger Split Spoon Water Level After a Specified Period of Time (T) Torvane SAMPLING Shelby Tube Texas Cone Grab Sample Pressure Meter Rock Core No Recovery WATER LEVEL Water Level After a Specified Period of Time Water levels indicated on the soil boring logs are the levels measured in the borehole at the times indicated. Groundwater level variations will occur over time. In low permeability soils, accurate determination of groundwater levels is not possible with short term water level observations. FIELD TESTS (b/f) (PID) (OVA) (TCP) Standard Penetration Test (blows per foot) Photo-Ionization Detector Organic Vapor Analyzer Texas Cone Penetrometer DESCRIPTIVE SOIL CLASSIFICATION Soil classification is based on the Unified Soil Classification System. Coarse Grained Soils have more than 50% of their dry weight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand. Fine Grained Soils have less than 50% of their dry weight retained on a #200 sieve; they are principally described as clays if they are plastic, and silts if they are slightly plastic or non-plastic. Major constituents may be added as modifiers and minor constituents may be added according to the relative proportions based on grain size. In addition to gradation, coarse-grained soils are defined on the basis of their in-place relative density and fine-grained soils on the basis of their consistency. LOCATION AND ELEVATION NOTES Unless otherwise noted, Latitude and Longitude are approximately determined using a hand-held GPS device. The accuracy of such devices is variable. Surface elevation data annotated with +/- indicates that no actual topographical survey was conducted to confirm the surface elevation. Instead, the surface elevation was approximately determined from topographic maps of the area. RELATIVE DENSITY OF COARSE-GRAINED SOILS (More than 50% retained on No. 200 sieve.) Density determined by Standard Penetration Resistance Includes gravels, sands and silts. CONSISTENCY OF FINE-GRAINED SOILS (50% or more passing the No. 200 sieve.) Consistency determined by laboratory shear strength testing, field visual-manual procedures or standard penetration resistance STRENGTH TERMS Descriptive Term (Density) Loose Medium Dense Dense Standard Penetration or N-Value Blows/Ft. Ring Sampler Blows/Ft. Descriptive Term (Consistency) Very Loose Very Soft Standard Penetration or N-Value Blows/Ft. Ring Sampler Blows/Ft. 0-1 < Soft 500 to 1, Stiff Unconfined Compressive Strength, Qu, psf less than 500 Medium-Stiff 1,000 to 2, ,000 to 4, Very Dense > 50 > _ 99 Very Stiff 4,000 to 8, Hard > 8,000 > 30 > 42 RELATIVE PROPORTIONS OF SAND AND GRAVEL Descriptive Term(s) of other constituents Percent of Dry Weight Major Component of Sample GRAIN SIZE TERMINOLOGY Particle Size Trace With Modifier < > 30 Boulders Cobbles Gravel Sand Silt or Clay Over 12 in. (300 mm) 12 in. to 3 in. (300mm to 75mm) 3 in. to #4 sieve (75mm to 4.75 mm) #4 to #200 sieve (4.75mm to 0.075mm Passing #200 sieve (0.075mm) RELATIVE PROPORTIONS OF FINES Descriptive Term(s) of other constituents Trace With Modifier Percent of Dry Weight < > 12 Term Non-plastic Low Medium High PLASTICITY DESCRIPTION Plasticity Index > 30 Exhibit C-1