Geotechnical Engineering Report

Transcription

1 Geotechnical Engineering Report Skiatook City Substation Skiatook, Oklahoma October 05, 2017 Terracon Project No Prepared for: GRDA Tulsa, Oklahoma Prepared by: Terracon Consultants, Inc. Tulsa, Oklahoma

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3 TABLE OF CONTENTS Page 1.0 INTRODUCTION PROJECT INFORMATION Project Description Site Location and Description SUBSURFACE CONDITIONS Typical Subsurface Profile Groundwater RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION Geotechnical Considerations Earthwork Site Preparation Fill Material Types Compaction Requirements Drilled Pier Foundations Slab Foundations Seismic Site Class GENERAL COMMENTS... 8 APPENDIX A - FIELD EXPLORATION Exhibit A-1 Exhibit A-2 Exhibit A-3 Exhibits A-4 Site Location Map Boring Location Plan Field Exploration Description Boring Log APPENDIX B - LABORATORY TESTING Exhibit B-1 Laboratory Test Description APPENDIX C FOUNDATION DESIGN TABLES Exhibit C-1 Axial and Lateral Capacity Analyses Table A.1 Exhibit C-2 LPILE 2012 Lateral Capacity Analyses Table B.1 Exhibit C-3 MFAD 5.0/HFAD 5.0 Analyses Table C.1 APPENDIX D - SUPPORTING DOCUMENTS Exhibit D-1 Exhibit D-2 Exhibit D-3 General Notes Unified Soil Classification System Sedimentary Rock Classification Responsive Resourceful Reliable

4 GEOTECHNICAL ENGINEERING REPORT SKIATOOK CITY SUBSTATION SKIATOOK, OKLAHOMA Terracon Project No October 05, INTRODUCTION This report presents the results of our geotechnical services performed for the proposed addition to the Skiatook City Substation located at 1001 South Lombard Lane in Skiatook, Oklahoma. One boring, designated B-1, was performed for the project to a depth of approximately 30 feet below the existing ground surface. The boring log along with a site location map and 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 and rock conditions groundwater conditions seismic consideration foundation design and construction earthwork 2.0 PROJECT INFORMATION 2.1 Project Description Item Description Site Layout See Exhibit A-1 Site Location Pap in Appendix A. Structures Maximum loads Grading We understand that the project will include the installation of different structures such as transmission line structures, transformers, etc. Foundation types will be drilled concrete piers (both laterally and vertically loaded) and concrete slab foundations. Not provided at the time of this report. Grade changes for the proposed site were not provided to us at the time of this report; however, based on the existing topography, we anticipate approximately 2 feet of cut and/or fill will be necessary for this site. Responsive Resourceful Reliable 1

5 Geotechnical Engineering Report Skiatook City Substation Skiatook, Oklahoma October 05, 2017 Terracon Project No Site Location Description Item Location Current Ground Cover Existing topography Description South of the existing Skiatook City substation located at 1001 South Lombard Lane in Skiatook, Oklahoma. Grass and vegetation. Relatively flat. 3.0 SUBSURFACE CONDITIONS 3.1 Typical Subsurface Profile Based on the results of the boring, subsurface conditions at the project location can be generalized as follows: Stratum Approximate Depth to Bottom of Stratum Material Encountered Consistency Surface 4 inches Topsoil and vegetation N/A 1 4 feet Lean clay and lean to fat clay Stiff to very stiff feet Highly weathered sandy shale and weathered sandy shale feet Shaley lean to fat clay Very stiff 4 Boring termination depth of about 30 feet Shale (with well-cemented sandstone layers) Soft Moderately hard to hard Laboratory tests were performed on selected soil samples. Based on visual observation and laboratory test results, the on-site soils generally classified as moderately to highly plastic clays. The results of the laboratory tests performed are reported on the boring log. Conditions encountered at the boring location are indicated on the boring log in Appendix A. Stratification boundaries on the boring log represent the approximate location of changes in material types; in-situ, the transition between materials may be gradual. 3.2 Groundwater The borehole was observed while drilling and immediately after boring completion for the presence and level of groundwater. Groundwater was observed at a depth of 14 feet in the boring while drilling and after boring completion. Responsive Resourceful Reliable 2

6 Geotechnical Engineering Report Skiatook City Substation Skiatook, Oklahoma October 05, 2017 Terracon Project No The groundwater level observations made during our exploration provide an indication of the groundwater conditions at the time the boring was drilled. Longer monitoring in piezometers or cased holes, sealed from the influence of surface water, would be required to evaluate longerterm groundwater conditions. During some periods of the year, perched water could be present at various depths. Fluctuations in groundwater levels should be expected throughout the year depending upon variations in the amount of rainfall, runoff, evaporation, and other hydrological factors not apparent at the time the boring was performed. 4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION 4.1 Geotechnical Considerations Based on the subsurface conditions encountered, structures subjected to heavy vertical or lateral loads can be effectively supported on drilled pier foundations; lighter loaded structures and transformers can be supported by shallow footing foundations. 4.2 Earthwork Site Preparation Areas within the limits of construction should be stripped and cleared of surface vegetation, and debris. After stripping the site, but before placing any new fill, we recommend the substation area 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 soil as described in following sections, if it cannot be effectively compacted and stabilized in-place. After completing the proofrolling, and before placing fill, the exposed subgrade should be scarified to a minimum depth of 9 inches, moisture conditioned, and compacted as recommended in Section Compaction Requirements Fill Material Types Engineered fill should meet the following material property requirements: Fill Type 1 USCS Classification Acceptable Location for Placement Imported Low Volume Change (LVC) Material 2 CL or SC (8 < PI 18) All locations and elevations. Required to depth of 24 inches below slab foundations within proposed substation area (see section 4.4 Slab Foundations). Responsive Resourceful Reliable 3

7 Geotechnical Engineering Report Skiatook City Substation Skiatook, Oklahoma October 05, 2017 Terracon Project No Fill Type 1 USCS Classification Acceptable Location for Placement On-Site Clay Soils CL, CL-CH Depths greater than 24 inches below slab foundations within substation area. All locations and elevations in non-structure areas within substation. 1. Controlled, compacted fill should consist of approved materials that are free of organic matter and debris and contain maximum rock size of 3 inches. 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 prior to its use. 2. Low plasticity cohesive soil having a plasticity index (PI) of 8 to 18 and containing at least 15% fines (material passing the No. 200 sieve, based on dry weight). An approved ODOT Type A aggregate base material per section of the ODOT Standard Specifications for Highway Construction can be used as Imported LVC material Compaction Requirements Recommended compaction and moisture content criteria for engineered fill materials are as follows: ITEM Fill Lift Thickness Compaction Requirements 1 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 On-Site Soils or Imported Cohesive LVC Fill: -1% to +3% of optimum moisture content Aggregate Base: Workable moisture content 2 1. We recommend that engineered fill (including scarified compacted subgrade) be tested for moisture content and compaction during placement. Should the results of the in-place density tests indicate the specified moisture or compaction limits have not been met, the area represented by the test should be reworked and retested as required until the specified moisture and compaction requirements are achieved. 2. Moisture content sufficient to achieve satisfactory compaction without causing pumping when proofrolled. The recommended moisture content should be maintained in the scarified and compacted subgrade and fills, until fills are completed and the foundations are constructed Earthwork Construction Considerations Upon completion of filling and grading, care should be taken to maintain the subgrade moisture content prior to construction of foundations. Construction traffic over the completed subgrade should be avoided to the extent practical. The site should also be graded to prevent ponding of Responsive Resourceful Reliable 4

8 Geotechnical Engineering Report Skiatook City Substation Skiatook, Oklahoma October 05, 2017 Terracon Project No surface water on the prepared subgrades or in excavations. If the subgrade should become frozen, desiccated, saturated, or disturbed, the affected material should be reworked. 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, by his contract, is usually 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. The geotechnical engineer should be retained during the construction phase of the project to provide observation and testing during earthwork activities. The exposed subgrade and each lift of compacted fill should be tested, evaluated, and reworked, as necessary, until approved by the geotechnical engineer s representative prior to placement of additional lifts. 4.3 Drilled Pier Foundations Based on the subsurface conditions encountered, more heavily loaded structures can be supported on drilled pier foundations. The tables attached in the Appendix C, present allowable design criteria for the drilled pier foundations. The tables include effective soil unit weight, allowable end bearing pressure, allowable passive pressure, allowable side friction, estimated undrained cohesion, estimated angle of internal friction values; and strength parameters for the LPILE and MFAD/HFAD computer program. In the table, the net allowable bearing pressure has a safety factor of at least 3. Also, the allowable side friction and allowable passive pressure values have safety factors of at least 2. Design soil parameters shown in the table are applicable to the natural, undisturbed soils and should not be applied to disturbed materials or newly placed fill materials. Because soil strength varies due to frost action and moisture variations, we recommend neglecting passive pressure and side friction resistance forces for the soils within 3 feet of the final ground surface. The straight shaft piers should have a minimum diameter of 24 inches and be provided with enough steel reinforcement to provide adequate structural integrity. A heavy-duty pier rig equipped with a rock auger and a rock coring bit will be required to complete pier excavations into the bedrock materials. If the pier drilling equipment is not able to adequately clean the bearing surface, a larger shaft diameter may be required to permit sufficient cleaning. Care should be taken so that the sides and bottom of the excavations are not disturbed during construction. Responsive Resourceful Reliable 5

9 Geotechnical Engineering Report Skiatook City Substation Skiatook, Oklahoma October 05, 2017 Terracon Project No The bottom of the shaft excavation should be free of loose material when concrete is placed. Also, preferably the bottom of the pier excavation should be free of water accumulation at the time of concrete placement. However, a relatively small amount of water accumulation may be acceptable at the pier excavation bottom, based upon evaluation and approval of the geotechnical engineer during construction. Concrete should be placed as soon as possible after the foundation excavation is completed to reduce the potential disturbance of the bearing surface. Based on the results of the boring, we anticipate temporary casing will be required to help control groundwater inflow and complete pier excavations. However, the need for casing should be determined based on actual conditions encountered during construction. With the use of temporary casing, a concrete slump of at least 6 inches is recommended to facilitate casing removal. While withdrawing casing, care should be exercised to maintain concrete inside the casing at a sufficient level to resist earth and hydrostatic pressures acting on the casing exterior. Arching of the concrete, loss of seal and other problems can occur during casing removal and result in contamination of the drilled pier. These conditions should be considered during the design and construction phases. Placement of loose soil backfill should not be permitted around the casing prior to removal. If water is present in the pier excavations, water should be removed by pumping or drilled out, or the concrete should be tremied completely to the bottom of the excavation with a closed-end tremie. If soil and rock at the bottom and along the sides of the foundation excavation soften as a result of water accumulation, those materials should be removed before placing concrete. Drilled pier foundations designed and constructed according to the recommendations presented herein above and bearing within approved shale bedrock materials should experience a total long-term settlement of less than 1 inch. 4.4 Slab Foundations Lightly loaded substation structures can be supported on slab foundations. To reduce potential movements due to shrink-swell of the native clays and provide more uniform support, we recommend that a minimum 24-inch thick layer of tested and approved, engineered fill be constructed beneath the slab foundations. The engineered fill should consist of Imported Low Volume Change material as defined in section Fill Material Types. The engineered fill should extend laterally at least 8 inches beyond the sides of the slab foundation for each 12- inch depth of engineered fill placed below the bearing level. The on-site soils should be undercut sufficiently to allow for construction of the engineered fill layer below slab foundations. Design parameters and construction considerations for slab foundations are presented in the following sections. Responsive Resourceful Reliable 6

10 Geotechnical Engineering Report Skiatook City Substation Skiatook, Oklahoma October 05, 2017 Terracon Project No Slab Foundations Design Recommendations Foundation type Bearing material Description Net allowable bearing pressure 1 Minimum foundation depth (below lowest finished exterior grade) 2 Estimated total and differential movement Design Slab foundation Minimum 24 inches of tested and approved, engineered fill 2,000 psf 24 inches 1 inch or less 1. The net allowable bearing pressure is the pressure in excess of the minimum surrounding overburden pressure at the foundation base elevation. 2. Minimum depth will provide frost protection. Where the slab foundation will not bear at depths of 24 inches below the final adjacent grade, the foundations should be provided with perimeter turned-down edges extending at least 24 inches below the final adjacent grade Construction Considerations for Slab Foundations Foundation bearing surfaces should be free of loose or disturbed material and water when concrete is placed. Concrete should be placed as soon as possible after fill placement is completed to reduce the potential for wetting, drying, or disturbance of the bearing materials. The foundation bearing surfaces should be evaluated for suitability prior to placing reinforcing steel and concrete. Overexcavations required to construct the recommended engineered fill layer below slab foundations should be cleaned of all loose material, debris, and water before placing any backfill. To verify that suitable bearing materials are encountered, we recommend the base of all foundation overexcavations be observed and evaluated by the geotechnical engineer prior to placing the engineered fill. If unsuitable bearing soils are encountered in foundation overexcavations, the unsuitable soils should be removed and replaced with engineered fill. Overexcavation for compacted backfill placement below foundations should extend laterally beyond all sides of the foundations at least 8 inches per foot of overexcavation depth below foundation base elevation. 4.5 Seismic Site Class Code Used Site Classification 2015 International Building Code (IBC) 1 C 1. In general accordance with the 2015 International Building Code; Table , Chapter 20, ASCE 7. The 2015 International Building Code (IBC) uses a site soil profile determination extending a depth of 100 feet for seismic site classification. The current scope requested does not include a 100 foot soil profile determination. The boring was extended to a maximum depth Responsive Resourceful Reliable 7

11 Geotechnical Engineering Report Skiatook City Substation Skiatook, Oklahoma October 05, 2017 Terracon Project No Continued from Page 7 of approximately 30 feet and this seismic site class definition considers shale 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. 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 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 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 8

12 APPENDIX A FIELD EXPLORATION

13 APPROXIMATE SITE LOCATION 2017 GOOGLE APPROXIMATE SCALE IN FEET N Project Mngr: Drawn By: Checked By: Approved By: SG MM SG BMW Project No. Scale: File No. Date: SEE BAR SCALE OCTOBER 2017 Consulting Engineers and Scientists 9522 EAST 47TH PLACE, UNIT D TULSA, OKLAHOMA PH. (918) FAX. (918) SKIATOOK SITE LOCATION MAP GEOTECHNICAL EXPLORATION SKIATOOK CITY SUBSTATION 1001 SOUTH LOMBARD LANE OKLAHOMA EXHIBIT NO. A-1

14 B GOOGLE APPROXIMATE SCALE IN FEET N LEGEND BORING LOCATION DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES Project Mngr: Drawn By: Checked By: Approved By: SG MM SG BMW Project No. Scale: File No. Date: SEE BAR SCALE OCTOBER 2017 Consulting Engineers and Scientists 9522 EAST 47TH PLACE, UNIT D TULSA, OKLAHOMA PH. (918) FAX. (918) SKIATOOK BORING LOCATION PLAN GEOTECHNICAL EXPLORATION SKIATOOK CITY SUBSTATION 1001 SOUTH LOMBARD LANE OKLAHOMA EXHIBIT NO. A-2

15 Geotechnical Engineering Report Skiatook City Substation Skiatook, Oklahoma October 05, 2017 Terracon Project No Field Exploration Description The boring location was staked in the field by GRDA personnel. We drilled the boring with an ATV-mounted rotary drill rig using continuous flight augers to advance the borehole. Representative samples were obtained by the split-barrel 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 an 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 weathered bedrock. 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. The sampling depths, penetration distances, and 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. A field log of the boring was prepared by the drill crew. This 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 represents the engineer's interpretation of the field log and include modifications based on laboratory observation and tests of the samples. Responsive Resourceful Reliable Exhibit A-3

16 PROJECT: Skiatook City Substation BORING LOG NO. B-1 CLIENT: GRDA Tulsa, OK Page 1 of 2 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL BORE LOGS.GPJ TERRACON_DATATEMPLATE.GDT 10/5/17 SITE: GRAPHIC LOG South Lombard Lane Skiatook, OK LOCATION See Exhibit A-2 DEPTH 4" Topsoil LEAN CLAY (CL), brown, medium stiff LEAN CLAY (CL), with sand, brown with yellowish-brown, stiff LEAN CLAY/FAT CLAY (CL/CH), with sand and iron nodules, yellowish-brown with gray, very stiff HIGHLY WEATHERED SANDY SHALE+, light olive-brown with gray and trace rusty brown, soft WEATHERED SANDY SHALE+, olive-brown with trace rusty brown, soft SHALEY LEAN TO FAT CLAY (CL/CH), olive-gray with trace rusty brown, very stiff SHALE+, with well-cemented sandstone layers, olive-gray, hard to moderately hard - gray below about 23.5 feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: Power Auger Abandonment Method: Boring backfilled with soil cuttings and bentonite chips upon completion. WATER LEVEL OBSERVATIONS 14 ft While drilling 14 ft After boring DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE See Exhibit A-3 for description of field procedures. See Appendix B for description of laboratory procedures and additional data (if any). See Appendix D for explanation of symbols and abbreviations E 47th Pl Ste D Tulsa, OK RECOVERY (In.) FIELD TEST RESULTS N= N= N= N=78 50/3" 50/5" N=34 50/2" 50/1" UNCONFINED COMPRESSIVE STRENGTH (tsf) WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI Hammer Type: Automatic +Classification estimated from disturbed samples. Core samples and petrographic analysis may reveal other rock types. Notes: Boring Started: Drill Rig: RIG-5/850 Project No.: Driller: DW PERCENT FINES Boring Completed: Exhibit: A-4

17 PROJECT: Skiatook City Substation BORING LOG NO. B-1 CLIENT: GRDA Tulsa, OK Page 2 of 2 SITE: GRAPHIC LOG 1001 South Lombard Lane Skiatook, OK LOCATION See Exhibit A-2 DEPTH SHALE+, with well-cemented sandstone layers, olive-gray, hard to moderately hard (continued) DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE RECOVERY (In.) FIELD TEST RESULTS UNCONFINED COMPRESSIVE STRENGTH (tsf) WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI PERCENT FINES 50/2" 15 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL BORE LOGS.GPJ TERRACON_DATATEMPLATE.GDT 10/5/ Boring Terminated at 30 Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: Power Auger Abandonment Method: Boring backfilled with soil cuttings and bentonite chips upon completion. WATER LEVEL OBSERVATIONS 14 ft While drilling 14 ft After boring 30 See Exhibit A-3 for description of field procedures. See Appendix B for description of laboratory procedures and additional data (if any). See Appendix D for explanation of symbols and abbreviations E 47th Pl Ste D Tulsa, OK Hammer Type: Automatic +Classification estimated from disturbed samples. Core samples and petrographic analysis may reveal other rock types. Notes: Boring Started: Drill Rig: RIG-5/850 Project No.: Boring Completed: Driller: DW Exhibit: A-4

18 APPENDIX B LABORATORY TESTING

19 Geotechnical Engineering Report Skiatook City Substation Skiatook, Oklahoma October 05, 2017 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 D. Bedrock materials were classified according to the General Notes and described using commonly accepted geotechnical terminology. The field descriptions were modified as necessary and an applicable laboratory testing program was formulated to determine engineering properties of the subsurface materials. Laboratory tests were conducted on select soil and rock samples. The laboratory test results are presented on the boring logs next to the respective samples. Laboratory tests were performed in general accordance with the applicable ASTM, local or other accepted standards. Selected soil and rock samples obtained from the site were tested for the following engineering properties: Visual Classification (ASTM D2488) Water Content (ASTM D 2216) Atterberg Limits (ASTM D 4318) Procedural standards noted above are for reference to methodology in general. In some cases variations to methods are applied as a result of local practices or professional judgment. Responsive Resourceful Reliable Exhibit B-1

20 APPENDIX C FOUNDATION DESIGN TABLES

21 TABLE A.1 BORING B-1 AXIAL AND LATERAL CAPACITY ANALYSES SOIL/ROCK PARAMETERS Skiatook City Substation Terracon Project No Skiatook, Oklahoma Depth of Soil/Rock Layer (feet) Effective Unit Weight (pcf) Net Allowable Bearing Pressure (psf) Allowable Side Friction Initial Value (psf) Increase per Foot of Depth (psf) Allowable Passive Pressure Initial Value (psf) Increase per Foot of Depth (psf) Undrained Shear Strength (psf) Friction Angle (degrees) Ignore --- Ignore --- Ignore , , , , , , , , , , , , ,000 3, , ,400 0 Notes: 1. Design depth to groundwater is about 14 feet. 2. The net allowable bearing pressure refers to the pressure at the foundation bearing level in excess of the minimum surrounding overburden pressure. The net allowable bearing pressure has a safety factor on the order of 3. A minimum penetration of 2 feet or one pier diameter, whichever is greater, into the desired bearing strata should be achieved to use the recommended allowable end bearing pressure. 3. The allowable side friction and passive pressure in cohesive soils and bedrock are based on a rectangular pressure distribution. The allowable side friction and passive pressure values have a safety factor of approximately Allowable bearing pressure represents a reduced value due to presence of underlying shaley clay layer. Responsive Resourceful Reliable Exhibit C-1

22 LPILE LPILE Soil Effective Undrained Internal Soil Modulus Unit Shear Friction Strain Soil Top Bottom k 2 Weight Strength 3 Angle RQD 4 Factor Layer Soil Type (feet) (feet) (pci) (pcf) (psf) (degrees) (%) e 50/ k rm NOTES: LPILE TABLE B.1 BORING B-1 L-PILE LATERAL CAPACITY ANALYSES DESIGN SOIL/ROCK PARAMETERS FOR UNDRAINED CONDITIONS Skiatook City Substation Terracon Project No Skiatook, Oklahoma Depth to Soil Layer 1 Stiff Clay without Free Water (3) Stiff Clay without Free Water (3) Stiff Clay without Free Water (3) , Weak Rock (9) , Stiff Clay without Free Water (3) , Weak Rock (9) , Design depth to subsurface water is about 14 feet. 2. Value given for Weak Rock is E ri in psi. 3. Uniaxial compressive strength for rock, in psi 4. Value given for RQD estimated from field data and sample examination. Responsive Resourceful Reliable Exhibit C-2

23 TABLE C.1 BORING B-1 MFAD 5.0/HFAD 5.0 ANALYSES SOIL/ROCK PARAMETERS Skiatook City Substation Terracon Project No Skiatook, Oklahoma Soil/Rock Layer Number Notes: Layer Type Depth to Bottom of Layer (feet) Effective Unit Weight 1 (pcf) Deformation Modulus 2 (ksi) Effective Friction Angle (degrees) Undrained Shear Strength or Rock Effective Cohesion (ksf) Allowable Rock/Concrete Bond Strength 3 1 Soil Soil Soil Soil Soil Soil Design depth to groundwater is about 14 feet. 2. Deformation modulus determined based on the data in the following papers: (A) DiGioia, A.M., Donovan, T.D., and Cortese, F.J., A Multi- Layered/Pressuremeter Approach to Laterally Loaded Rigid Caisson Design, presented at the seminar on Lateral Pressures Related to Large Diameter Pipes, Piles, Tunnels, and Caissons, Dayton, Ohio, February 1975, ASCE. (B) Schmertmann, J.H., Static Cone to Compute Static Settlement over Sand, Journal of the Soil Mechanics and Foundation Division, ASCE, Vol. 96, No. SM3, May 1970, pp Allowable rock/concrete bond strength has a factor of safety of about 2. (ksf) Responsive Resourceful Reliable Exhibit C-3

24 APPENDIX D SUPPORTING DOCUMENTS

25 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

26 UNIFIED SOIL CLASSIFICATION SYSTEM Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests A Coarse Grained Soils: More than 50% retained on No. 200 sieve Fine-Grained Soils: 50% or more passes the No. 200 sieve Gravels: More than 50% of coarse fraction retained on No. 4 sieve Sands: 50% or more of coarse fraction passes No. 4 sieve Silts and Clays: Liquid limit less than 50 Silts and Clays: Liquid limit 50 or more Group Symbol Soil Classification Group Name B Clean Gravels: Cu 4 and 1 Cc 3 E GW Well-graded gravel F Less than 5% fines C Cu 4 and/or 1 Cc 3 E GP Poorly graded gravel F Gravels with Fines: Fines classify as ML or MH GM Silty gravel F,G,H More than 12% fines C Fines classify as CL or CH GC Clayey gravel F,G,H Clean Sands: Cu 6 and 1 Cc 3 E SW Well-graded sand I Less than 5% fines D Cu 6 and/or 1 Cc 3 E SP Poorly graded sand I Sands with Fines: Fines classify as ML or MH SM Silty sand G,H,I More than 12% fines D Fines classify as CL or CH SC Clayey sand G,H,I Inorganic: Organic: Inorganic: Organic: PI 7 and plots on or above A line J CL Lean clay K,L,M PI 4 or plots below A line J ML Silt K,L,M Liquid limit - oven dried Liquid limit - not dried 0.75 OL Organic clay K,L,M,N Organic silt K,L,M,O PI plots on or above A line CH Fat clay K,L,M PI plots below A line MH Elastic Silt K,L,M Liquid limit - oven dried Liquid limit - not dried Highly organic soils: Primarily organic matter, dark in color, and organic odor PT Peat 0.75 OH Organic clay K,L,M,P Organic silt K,L,M,Q A Based on the material passing the 3-inch (75-mm) sieve B If field sample contained cobbles or boulders, or both, add with cobbles or boulders, or both to group name. C Gravels with 5 to 12% fines require dual symbols: GW-GM well-graded gravel with silt, GW-GC well-graded gravel with clay, GP-GM poorly graded gravel with silt, GP-GC poorly graded gravel with clay. D Sands with 5 to 12% fines require dual symbols: SW-SM well-graded sand with silt, SW-SC well-graded sand with clay, SP-SM poorly graded sand with silt, SP-SC poorly graded sand with clay E Cu = D 60 /D 10 Cc = D (D 10 2 ) 30 x D 60 F If soil contains 15% sand, add with sand to group name. G If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM. H If fines are organic, add with organic fines to group name. I If soil contains 15% gravel, add with gravel to group name. J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay. K If soil contains 15 to 29% plus No. 200, add with sand or with gravel, whichever is predominant. L If soil contains 30% plus No. 200 predominantly sand, add sandy to group name. M If soil contains 30% plus No. 200, predominantly gravel, add gravelly to group name. N PI 4 and plots on or above A line. O PI 4 or plots below A line. P PI plots on or above A line. Q PI plots below A line. Exhibit C-2

27 Exhibit D-3