Geotechnical Engineering Report Proposed Communications Tower Spain Park Site Hoover, Alabama

Transcription

1 Geotechnical Engineering Report Proposed Communications Tower Spain Park Site Hoover, Alabama July 24, 2014 Terracon Project No. E Prepared for: The City Of Hoover Hoover, Alabama Prepared by: Terracon Consultants, Inc. Birmingham, Alabama

2 July 24, 2014 City of Hoover, Valleydale Road Hoover, Al Attn: Re: Mr. Michael Cornwell E: Geotechnical Engineering Report Proposed Communications Tower Spain Park Site Hoover, Alabama Terracon Project No: E Dear Mr. Cornwell: Terracon Consultants, Inc. (Terracon) has completed the geotechnical engineering services for the above referenced project. This study was performed in general accordance with our proposal PE dated April 02, This report presents the findings of the subsurface exploration and provides the seismic considerations for the design of the proposed foundation. We appreciate the opportunity to be of service to you on this project. If you have any questions concerning this report, or if we may be of further service, please contact us. Sincerely, Terracon Consultants, Inc. Bryan C. Ritenour, P.E. Jerome A. Smith, P.E. Senior Project Engineer Manager, Geotechnical Services Alabama P. E. No Alabama P. E. No Terracon Consultants, Inc TH Street North Birmingham, Alabama P [205] F [205] terracon.com

3 TABLE OF CONTENTS Page 1.0 INTRODUCTION PROJECT INFORMATION Site Location and Description Project Description SUBSURFACE CONDITIONS Geology Typical Profile Groundwater Geotechnical Considerations Earthwork Structural Fill Material Requirements Structural Fill Placement and Compaction Requirements Earthwork Construction Considerations Foundations Design Recommendations for Mat Foundation Design Recommendations for Drilled Pier Foundation Foundation Construction Considerations Seismic Considerations GENERAL COMMENTS... 9 APPENDIX A FIELD EXPLORATION Exhibit A-1 Site Location Plan Exhibit A-2 Boring Location Plan Exhibit A-3 Field Exploration Description Exhibit A-4 and A-6 Boring Logs B-1, B-1A and B-2 APPENDIX B SUPPORTING DOCUMENTS Exhibit B-1 General Notes Exhibit B-2 Unified Soil Classification Responsive Resourceful Reliable

4 GEOTECHNICAL ENGINEERING REPORT PROPOSED COMMUNICATIONS TOWER SPAIN PARK SITE HOOVER, ALABAMA Terracon Project No. E July 24, INTRODUCTION A geotechnical investigation has been performed for the proposed City of Hoover communications tower to be located along the northwest flank of Hew Hope Mountain on the southeast side of Valleydale Road near Spain Park in Hoover, Alabama. A total of three (3) borings were drilled at, or near, the location of the new tower as identified in the field by Mr. Cornwell. Exhibit A-2 shows the approximate location of the borings. Logs of the borings are also included in Appendix A. The purpose of these services is to provide information and geotechnical engineering recommendations relative to: subsurface soil conditions groundwater conditions seismic considerations earthwork foundation design and construction 2.0 PROJECT INFORMATION 2.1 Site Location and Description ITEM Location Existing improvements Current ground cover Existing topography DESCRIPTION The project site is located on the southeast side of Valleydale Road near Veterans Park. The site is currently undeveloped, and has been recently cleared with a steep access road, extending up the northwest flank of New Hope Mountain from Valleydale Road. A relatively level pad has been graded for the tower pad. Bare soils Relatively steeply sloping access road leading to a relatively level pad Responsive Resourceful Reliable

5 Geotechnical Engineering Report Proposed Communication Tower- Spain Park Site Hoover, Alabama July 24, 2014 Terracon Project No. E Project Description ITEM Structures Foundation Grading DESCRIPTION A planned 100-foot monopole tower Mat or drilled pier foundation It appears that up to about 12 feet of cut and fill was performed to create the pad Should any of the above information or assumptions be inconsistent with the planned construction, please let us know so that we may make any necessary modifications to this report. 3.0 SUBSURFACE CONDITIONS 3.1 Geology Published maps from the Geological Survey of Alabama indicate that the site is underlain by the Chepultepec and Copper Ridge Dolomites undifferentiated. The Chepultepec and Copper Ridge Dolomites undifferentiated consist of light-gray to dark-bluish-gray thick-bedded dolomite and interbedded light-gray limestone. The bedrock weathers to a cherty clay soil containing isolated dense chert beds and boulders. The bedrock surface is often highly irregular and often lies in excess of 100 feet below the ground surface. However, large hard chert boulders are commonly encountered even in shallow excavations. The proposed site is underlain by carbonate rocks. Over long periods of geologic time (i.e., thousands of years) carbonate rocks are susceptible to dissolution as groundwater moves through cracks and fissures in the rock. As dissolution progresses, cavities are formed within the rock mass. Sinkholes are formed as overburden soils filter into the solution cavities. During our field reconnaissance we looked for visual signs of surface subsidence indicative of sinkhole activity. We did not observe evidence of sinkhole activity on the tower site. It should be noted that this study does not preclude the possibility of future sinkhole occurrence within the area. Even an extensive drilling or geophysical exploration program could not rule out the possibility of future sinkhole formation at the site. The owner must accept that there is some degree of risk in developing over carbonate rock geology. 3.2 Typical Profile A total of three (3) borings were drilled. Our field program planned to drill one (1) SPT boring at, or near, the tower location. In the initial attempt, the boring encountered auger refusal at a depth Responsive Resourceful Reliable 2

6 Geotechnical Engineering Report Proposed Communication Tower- Spain Park Site Hoover, Alabama July 24, 2014 Terracon Project No. E of 5 feet below the ground surface. An offset boring (Boring B-1A) was drilled about 2 feet away from the initial boring. The offset boring encountered auger refusal at about 17 feet below the ground surface. In an attempt to reach greater depths, a third boring (Boring B-2) was drilled about 10 feet north of boring B-1A. Boring B-2 encountered auger refusal at a depth of about 10 feet. Shallow auger refusal in the Chepultepec and Copper Ridge Dolomites undifferentiated is commonly caused by dense chert boulders and seams in the native soil overburden. Above the auger refusal depth at Boring B-1A, native soils were encountered at the ground surface. The native soils were generally classified as orange brown lean clay (CL) with chert gravel. The consistency of the native soils was generally very stiff to hard with N-values ranged from 13 to over 50 blows per foot. At Boring B-2, existing fill soils placed to grade the pad were encountered at the ground surface and extended to a depth of about 6 feet. The existing fill soils were generally classified as red brown lean clay with chert gravel. N-values recorded in the fill ranged from 5 to 10 blows per foot. Native soils were encountered beneath the existing fill. The native soils were generally classified as red brown lean clay (CL) with chert gravel. The consistency of the native soils was generally stiff to hard with N-values ranged from 16 to over 50 blows per foot. Conditions encountered at the boring location are indicated on the individual boring log. Stratification boundaries on the boring log represent the approximate location of changes in soil types; in-situ, the transition between materials may be gradual. Details for the boring can be found on the boring log in Appendix A. 3.3 Groundwater The boreholes were observed during SPT drilling for the presence and level of groundwater. No groundwater was observed in the boring at the time of SPT. However, this does not necessarily mean that the boring was terminated above groundwater. 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 log. Groundwater seepage is common in the porous cherty soils. Responsive Resourceful Reliable 3

7 Geotechnical Engineering Report Proposed Communication Tower- Spain Park Site Hoover, Alabama July 24, 2014 Terracon Project No. E RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION 4.1 Geotechnical Considerations The results of our field program indicate that the subsurface conditions beneath the prepared pad generally consists of stiff to hard native soils from the ground surface over a portion of the pad. Another portion of the pad has existing fill underlain by stiff to hard native soils. Shallow auger refusal in the Chepultepec and Copper Ridge Dolomites undifferentiated is commonly caused by dense chert boulders and seams in the native soil overburden. Therefore, it is likely that the auger refusal material encountered in our borings consists of dense chert seams or large chert boulders. Mat foundation excavations encountering dense chert seams and large chert boulders will require the use of heavy-duty excavation equipment or a track hoe equipped with a pneumatic hammering device. Drilled pier excavations encountering dense chert seams and large chert boulders will require rock removal techniques to advance the drilled pier. The existing fill, such as encountered at boring B-2, is not suitable to support the proposed tower foundation. Therefore, any foundation member should extend through the existing fill and be brought to bear on the underlying stiff to hard native soils. 4.2 Earthwork The development of the site will include excavation for a mat foundation or drilling a pier foundation. We recommend that the exposed foundation bearing material be thoroughly evaluated by our engineer prior to reinforcement steel placement. Mat foundations typically bear at a minimum depth of about 5 to 6 feet below the ground surface. Deeper excavations may be required to penetrate the existing fill. Therefore, if a mat foundation is used to support the tower, engineered fill will likely be placed over the mat foundation to resist uplift forces. Subsurface conditions, as identified by the field testing program, have been reviewed and evaluated with respect to the proposed tower foundation plans known to us at this time Structural Fill Material Requirements Engineered fill should not be placed below the proposed tower foundation. However, we understand that engineered fill will be placed above the concrete foundation to resist uplift forces. Responsive Resourceful Reliable 4

8 Geotechnical Engineering Report Proposed Communication Tower- Spain Park Site Hoover, Alabama July 24, 2014 Terracon Project No. E Structural fill should meet the following material property requirements: Fill Type 1 USCS Classification Acceptable Location for Placement Lean clay Silt CL (LL<50 and PI<30) ML (LL<50 and PI<30) All locations and elevations All locations and elevations Sand SW, SC, SM All locations and elevations Fat clay Elastic Silt On-Site Soils CH (LL>50 or PI>30) MH (LL>50 or PI>30) Varies Not acceptable for use as Structural Fill Not acceptable for use as Structural Fill The on-site soils to be excavated for the foundation installation appear suitable for use as fill provided they are free of topsoil, organics or other deleterious materials. 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 Structural Fill Placement and Compaction Requirements Fill Lift Thickness ITEM Compaction Requirements 1 Moisture Content Cohesive Soil Moisture Content Granular Material 2 DESCRIPTION 8-inches or less in loose thickness when heavy, self-propelled compaction equipment is used 4 to 6 inches in loose thickness when handguided equipment (i.e. jumping jack or plate compactor) is used. 98% of the materials maximum standard Proctor dry density (ASTM D 698). Within 2 percentage points of the optimum moisture content value as determined by the standard Proctor test at the time of placement and compaction. Within 3 percentage points of the optimum moisture content value as determined by the standard Proctor test at the time of placement and compaction. Responsive Resourceful Reliable 5

9 Geotechnical Engineering Report Proposed Communication Tower- Spain Park Site Hoover, Alabama July 24, 2014 Terracon Project No. E ITEM DESCRIPTION 1. We recommend that engineered fill be tested for moisture content and compaction during placement. Should the results of the in-place density tests indicate the specified moisture or compaction limits have not been met, the area represented by the test should be reworked and retested as required until the specified moisture and compaction requirements are achieved. 2. Specifically, moisture levels should be maintained low enough to allow for satisfactory compaction to be achieved without the cohesionless fill material pumping when proofrolled Earthwork Construction Considerations 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. All excavations should comply with applicable local, state and federal safety regulations, including the current OSHA Excavation and Trench Safety Standards. An evaluation of the cut slope made to grade the tower site is beyond the scope of our investigation. Terracon should be retained during the construction phase of the project to observe earthwork and to perform necessary tests and observations during subgrade preparation; foundation excavation observations; placement and compaction of controlled compacted fills and backfilling of excavations into the completed subgrade. 4.3 Foundations The new tower can be supported by a mat foundation system. If a mat foundation is used, the mat foundation should bear on the stiff to hard native soils such as encountered near the surface at boring B-1A and 6 feet deep at boring B-2. The mat foundation should extend through any existing fill and be brought to bear on the underlying stiff to hard native soil. The tower could also be supported by a drilled pier foundation bearing in the stiff to hard native soils. The drill pier should not be located in an area of the pad having existing fill to a depth greater than 3 feet below the ground surface. The bearing elevation of the mat foundation or drilled pier should be determined by the structural engineer. Design recommendations for the mat foundation are presented in the following paragraphs. Responsive Resourceful Reliable 6

10 Geotechnical Engineering Report Proposed Communication Tower- Spain Park Site Hoover, Alabama July 24, 2014 Terracon Project No. E Design Recommendations for Mat Foundation DESCRIPTION PARAMETER Net allowable bearing pressure for the stiff to hard native soils 1 3,500 psf Minimum embedment below finished grade Approximate total settlement 2 Estimated differential settlement Ultimate Passive pressure for lateral resistance 3 At least three (3) feet where stiff to hard native soils are encountered at the ground surface; Where existing fill is present, the mat should extend through any existing fill and be brought to bear on the underlying stiff to hard native soil. <¾ inch <¾ inch 330 pcf equivalent fluid pressure Ultimate coefficient of sliding friction The recommended net allowable bearing pressure is the pressure in excess of the minimum surrounding overburden pressure at the footing base elevation. 2. The above settlement estimates have assumed that the maximum mat foundation size is 20 feet (or less) square. 3. 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. Final surrounding grades should be sloped away from the tower foundation on all sides to prevent ponding of water Design Recommendations for Drilled Pier Foundation It may be desirable to support the proposed tower on a deep foundation. The following parameters can be used to dimension a drilled pier foundation bearing in the stiff to hard lean clays containing chert gravel, cobbles, and boulders. The drill pier should not be located in an area of the pad having existing fill to a depth greater than 3 feet below the ground surface. Responsive Resourceful Reliable 7

11 Geotechnical Engineering Report Proposed Communication Tower- Spain Park Site Hoover, Alabama July 24, 2014 Terracon Project No. E Depth Below Existing Grade (ft) Material Description Net Allowable End Bearing Pressure (psf) Allowable Side Friction (psf) Effective Unit Weight (pcf) Cohesion (pcf) Friction Angle (degrees) Strain at 50% (E 50) Horizontal Subgrade Modulus (k) (pci) Drilled Pier Termination Native soil or existing fill material Lean clay with chert gravel and cobbles Stiff to hard lean clay with chert gravel, cobbles, and boulders Ignore Ignore Ignore Ignore Ignore Ignore Ignore Not recommended for drilled pier end bearing ,000 1, The above indicated cohesion, friction angle, horizontal subgrade modulus and strain values have no applied factors of safety, and the allowable skin friction and the passive resistances have factors of safety of 2 to 3. The cohesion, internal friction angle, lateral subgrade modulus and strain values given in the above table are based on the results of our boring, published values and our past experience with similar soil types. These values should, therefore, be considered approximate. The allowable end bearing pressure provided in the table has an approximate factor of safety of at least 3. If the drilled pier is designed using the above parameters, settlements are not anticipated to exceed 1/2 inch. The upper 3 feet of clay should be ignored due to the potential affects of frost action and construction disturbance. To avoid a reduction in lateral and uplift resistance caused by variable subsurface conditions, we recommend that drawings instruct the contractor to notify the engineer if subsurface conditions significantly different than encountered in our boring are disclosed during drilled pier installation. Under these circumstances, it may be necessary to adjust the overall length of the pier. To facilitate these adjustments and assure that the pier is embedded in suitable materials, it is recommended that a Terracon representative observe the drilled pier excavation. A drilled pier foundation should be designed with a minimum shaft diameter of 30 inches to facilitate clean out and possible dewatering of the pier excavation. Temporary casing may be required during the pier excavation in order to control possible groundwater seepage and support the sides of the excavation in weak soil zones. Care should be taken so that the sides and bottom of the excavations are not disturbed during construction. The bottom of the shaft should be free of loose soil or debris prior to reinforcing steel and concrete placement. Responsive Resourceful Reliable 8

12 Geotechnical Engineering Report Proposed Communication Tower- Spain Park Site Hoover, Alabama July 24, 2014 Terracon Project No. E Foundation Construction Considerations The base of the foundation excavation should be free of water and loose soil prior to placing concrete. Concrete should be placed soon after excavating to reduce bearing soil disturbance. Should the soils at bearing level become excessively dry, disturbed, saturated, or frozen, the affected soil should be removed prior to placing concrete. A lean concrete mud-mat should be placed over the bearing soils if the excavations must remain open over night or for an extended period of time. It is recommended that the geotechnical engineer be retained to observe and test the soil foundation bearing materials. If unsuitable bearing soils are encountered, the excavation should be extended deeper to suitable soils and the footing could bear directly on these soils at the lower level or on lean concrete backfill placed in the excavations. 4.4 Seismic Considerations Code Used Site Classification 2009 International Building Code (IBC) 1 C 2 1. In general accordance with the 2009 International Building Code, Table The 2009 International Building Code requires a site soil profile determination extending a depth of 100 feet for seismic site classification. The current scope requested does not include the required 100 foot soil profile determination. The boring for the sign foundation extended to a depth of approximately 17 feet. A geophysical exploration could be utilized in order to attempt to justify a higher seismic site class. 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 away from the boring, 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. Responsive Resourceful Reliable 9

13 Geotechnical Engineering Report Proposed Communication Tower- Spain Park Site Hoover, Alabama July 24, 2014 Terracon Project No. E 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 expressed 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 10

14 APPENDIX A FIELD EXPLORATION

15 Site Location DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES Project Manager: BCR Drawn by: BCR Checked by: JAS Approved by: JAS Project No. E Scale: NTS File Name: Date: th Street North Birmingham, Alabama PH. (205) FAX. (205) SITE LOCATION PLAN Communications Tower Spain Park Site Hoover, Alabama Exhibit A-1

16 Fill Slope B-2 B-1/B-1A Boring Location DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES Project Manager: BCR Drawn by: BCR Checked by: JAS Approved by: JAS Project No. E Scale: NTS File Name: Date: th Street North Birmingham, Alabama PH. (205) FAX. (205) BORING LOCATION PLAN Communications Tower Spain Park Site Hoover, Alabama Exhibit A-2

17 Geotechnical Engineering Report Proposed Communication Tower- Spain Park Site Hoover, Alabama July 24, 2014 Terracon Project No. E Field Exploration Description The boring was marked in the field by the City of Hoover representatives. The boring was drilled with an ATV-mounted Mobile B-47 rotary drill rig with a rope and cathead configuration using hollow stem augers to advance the boreholes. Samples of the soil encountered in the borings were obtained using the split-barrel sampling procedures (general accordance with ASTM D1586). 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 Test N-value (SPT-N). This value is used to estimate the in situ relative density of cohesionless soils and consistency of cohesive soils. The soil samples were placed in containers to reduce moisture loss, tagged for identification, and taken to our laboratory (general accordance with ASTM D4220) for further examination, testing, and classification. Information provided on the boring logs attached to this report includes soil descriptions, consistency evaluations, boring depths, sampling intervals, and groundwater conditions. A field log of the boring was prepared by the Terracon engineer. The log included visual classifications (general accordance with ASTM D5434) of the materials encountered during drilling as well as the engineer s interpretation of the subsurface conditions between samples. Final boring log included with this report represent the engineer's interpretation of the field log and include modifications based on laboratory observation of the samples. Exhibit A-3

18 BORING LOG NO. B-1 PROJECT: Communications Tower Spain Park Site CLIENT: City of Hoover, AL Page 1 of 1 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL E COMMUNICATIONS TOWER SPAIN PARK SITE.GPJ TEMPLATE UPDATE GPJ 7/24/14 SITE: GRAPHIC LOG LOCATION DEPTH LEAN CLAY (CL), with chert gravel, orange-brown, very stiff 5.0 Hoover, Alabama See Exhibit A-2 Auger Refusal at 5 Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: Hollow stem auger Abandonment Method: Backfilled with cuttings WATER LEVEL OBSERVATIONS No water observed during drilling 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 th Street North Birmingham, Alabama Notes: DEPTH (Ft.) 5 WATER LEVEL OBSERVATIONS N= N=22 Boring B-1 met auger refusal at 5 feet. Boring B-1A was drilled as an offset boring. Boring Started: 7/23/2014 Drill Rig: Mobile B-47 Project No.: E SAMPLE TYPE FIELD TEST RESULTS Boring Completed: 7/23/2014 Driller: Chambers Exhibit: A-4 WATER CONTENT (%) ATTERBERG LIMITS LL-PL-PI

19 BORING LOG NO. B-1A PROJECT: Communications Tower Spain Park Site CLIENT: City of Hoover, AL Page 1 of 1 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL E COMMUNICATIONS TOWER SPAIN PARK SITE.GPJ TEMPLATE UPDATE GPJ 7/24/14 SITE: GRAPHIC LOG LOCATION Hoover, Alabama See Exhibit A-2 DEPTH LEAN CLAY (CL), with chert gravel, orange-brown, very stiff chert content increases and becomes hard 17.0 Auger Refusal at 17 Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: Hollow stem auger Abandonment Method: Backfilled with cuttings WATER LEVEL OBSERVATIONS No water observed during drilling 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 th Street North Birmingham, Alabama Notes: DEPTH (Ft.) WATER LEVEL OBSERVATIONS Boring Started: 7/23/2014 Drill Rig: Mobile B-47 Project No.: E SAMPLE TYPE FIELD TEST RESULTS See B-1 See B N= N= /5" N=50+ Boring Completed: 7/23/2014 Driller: Chambers Exhibit: A-5 WATER CONTENT (%) ATTERBERG LIMITS LL-PL-PI

20 BORING LOG NO. B-2 PROJECT: Communications Tower Spain Park Site CLIENT: City of Hoover, AL Page 1 of 1 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL E COMMUNICATIONS TOWER SPAIN PARK SITE.GPJ TEMPLATE UPDATE GPJ 7/24/14 SITE: GRAPHIC LOG LOCATION DEPTH LEAN CLAY, FILL, with chert gravel, red-brown Hoover, Alabama LEAN CLAY (CL), with chert gravel, red-brown, stiff becomes hard See Exhibit A-2 Auger Refusal at 10 Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: Hollow stem auger Abandonment Method: Backfilled with cuttings WATER LEVEL OBSERVATIONS No water observed during drilling 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 th Street North Birmingham, Alabama Notes: DEPTH (Ft.) 5 10 WATER LEVEL OBSERVATIONS Boring Started: 7/23/2014 Drill Rig: Mobile B-47 Project No.: E SAMPLE TYPE FIELD TEST RESULTS N= N= N= /2" N=50+ Boring Completed: 7/23/2014 Driller: Chambers Exhibit: A-6 WATER CONTENT (%) ATTERBERG LIMITS LL-PL-PI

21 APPENDIX B SUPPORTING DOCUMENTS

22 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 Ring Sampler Grab Sample Macro Core 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) Standard Penetration Test (blows per foot) Photo-Ionization Detector Organic Vapor Analyzer 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) Unconfined Compressive Strength, Qu, tsf Very Loose Very Soft less than 0.25 Loose Medium Dense Dense Standard Penetration or N-Value Blows/Ft Soft 0.25 to Medium-Stiff 0.50 to Ring Sampler Blows/Ft. Descriptive Term (Consistency) Stiff 1.00 to 2.00 Standard Penetration or N-Value Blows/Ft. Ring Sampler Blows/Ft. 0-1 < Very Dense > 50 > _ 99 Very Stiff 2.00 to Hard > 4.00 > 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

23 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 Organic clay K,L,M,N 0.75 OL Liquid limit - not dried 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 ) 2 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 B-2