Geotechnical Engineering Study

Transcription

1 Geotechnical Engineering Study Proposed Escondido Creek Parkway Kenedy, Texas Arias Job No Prepared For Dunaway Associates November 28, 2017

2 , GEOPROFEIONALS 142 Chula Vista, San Antonio, Texas Phone: (210) Fax: (210) November 28, 2017 Arias Job No Via Mr. Bryan Kye Mask, ASLA Director-Landscape Architecture-San Antonio Dunaway Associates, LP 118 Broadway Street, Suite 201 San Antonio, Texas RE: Geotechnical Engineering Study Proposed Escondido Creek Parkway Kenedy, Texas Dear Mr. Mask: This Geotechnical Engineering Report presents the results of our geotechnical study for the proposed Escondido Creek Parkway to be located in Kenedy, Texas. This study was performed in general accordance with the terms and conditions outlined in the Subconsultant Agreement between Dunaway Associates, L.P. and Arias & Associates, Inc. (Arias) dated May 17, 2017 and was authorized in writing on June 28, The purpose of this geotechnical engineering study was to establish foundation and pavement engineering properties of the subsurface soil and groundwater conditions present at the site. The scope of the study is to provide geotechnical engineering criteria for use by design engineers in preparing the foundation and pavement designs. Our findings and recommendations should be incorporated into the design and construction documents for the proposed development. The long-term success of the project will be affected by the quality of materials used for construction and the adherence of the construction to the project plans and specifications. The quality of construction can be evaluated by implementing Quality Assurance (QA) testing. As the Geotechnical Engineer of Record (GER), we recommend that the earthwork and roadway construction be tested and observed by Arias in accordance with the report recommendations. A summary of our qualifications to provide QA testing is discussed in the Quality Assurance Testing section of this report. Furthermore, a message to the Owner with regard to QA testing is provided in the ASFE publication included in Appendix E. We appreciate the opportunity to serve you during this phase of design. further service, please call. If we may be of Sincerely, ARIAS & AOCIATES, INC. TBPE Registration No. F-32 G erry b.~e,p.e., D.GE~ JERRY DHEPHERD Senior Geotechnical Engineer ~ Senior I P.E. Engineer Arias & Associates, Inc. Arias Job No

3 TABLE OF CONTENTS Page INTRODUCTION... 1 PROJECT AND SITE DESCRIPTION... 1 SOIL BORING AND LABORATORY TESTS... 1 SUBSURFACE CONDITIONS... 2 Site Stratigraphy and Engineering Properties... 2 Groundwater Conditions... 3 ENGINEERING ANALYSIS AND DISCUION... 4 General... 4 Expansive Soils... 4 LOW WATER CROING STRUCTURES... 5 Lateral Earth Pressures for Headwalls, Box Culverts, and Retaining Walls... 6 Erosion Control... 8 Site Drainage... 8 PEDESTRIAN BRIDGE... 8 Pedestrian Bridge-Borings B-1 & B PAVILION AND AMPHITHEATER/SKATE PARK STRUCTURES...10 Recommended Building Pad Improvement for 1 PVR...10 Stiffened Beam and Slab-on-Grade...12 PAVEMENT RECOMMENDATIONS...14 Pavement Design Parameters and Assumptions...14 Rigid Concrete Pavement Joints...16 Performance Considerations...17 Pavements over Low Water Crossings...20 Performance Considerations...20 CONSTRUCTION CRITERIA...20 Site Preparation...20 Drilled Piers Construction Considerations...20 ADDITIONAL DESIGN CONSIDERATIONS...22 IBC Site Classification and Seismic Design Coefficients...22 Excavations...22 Earthwork...24 Groundwater Control...25 Arias & Associates, Inc. i Arias Job No

4 TABLE OF CONTENTS Page Quality Control...25 GENERAL COMMENTS...26 Review...26 Subsurface Variations...26 Standard of Care...26 APPENDIX A: FIGURES AND SITE PHOTOGRAPHS... A-1 APPENDIX B: SOIL BORING LOGS AND KEY TO TERMS... B-1 APPENDIX C: FIELD AND LABORATORY EXPLORATION... C-1 APPENDIX D: ASFE INFORMATION GEOTECHNICAL REPORT... D-1 APPENDIX E: PROJECT QUALITY AURANCE... E-1 Tables Table 1: Generalized Stratigraphic Conditions-Borings B-1 thru B Table 2: Generalized Stratigraphic Conditions-Borings B-8 & B Table 3: Ground Water Measurements... 3 Table 4: Box Culvert Allowable Bearing Pressure Information... 5 Table 5: Lateral Earth Pressures... 7 Table 6: Drilled Pier Design Parameters Axial Capacity-Pedestrian Bridge... 9 Table 7: Drilled Pier Geotechnical Input Parameters for LPILE Analyses-Pedestrian Bridge...10 Table 8: Building Pad Recommendations for 1-inch Design PVR...11 Table 9: BRAB and WRI Foundation Design Criteria...13 Table 10: PTI Slab-on-Grade Soil Design Criteria (3 rd Edition)...13 Table 11: Allowable Bearing Pressure and Beam Penetration...14 Table 12: Pavement Design Parameters and Assumptions...15 Table 13: Recommended Pavement Sections...15 Table 14: Pavement Subgrade Materials...17 Table 15: Fill Requirements and Subgrade Treatment Options...18 Table 16: Subgrade Treatment Option - Lime Treatment...18 Table 17: Flexible Pavement Requirements...19 Table 18: Rigid Pavement Section Materials...19 Table 19: Drilled Pier Installation Considerations...21 Table 20: Seismic Design Parameters...22 Table 21: OSHA Soil Classifications...23 Table 22: Project Compaction, Moisture and Testing Requirements...25 Arias & Associates, Inc. ii Arias Job No

5 INTRODUCTION This report presents the results of a geotechnical engineering study for the proposed Escondido Creek Parkway to be located in Kenedy, Texas. This study was performed in general accordance with the terms and conditions outlined in the Subconsultant Agreement between Dunaway Associates, L.P. and Arias & Associates, Inc. (Arias) dated May 17, 2017 and was authorized in writing on June 28, SCOPE OF SERVICES The purpose of this geotechnical engineering study was to conduct a subsurface exploration and perform laboratory testing to establish engineering properties of the subsurface soil and groundwater conditions present at the site. This information was used to develop geotechnical engineering criteria for use by design engineers in preparing the design for the planned structures and pavements. Global stability analyses or environmental studies were beyond our authorized scope of services for this project. PROJECT AND SITE DESCRIPTION The Escondido Creek Parkway will consist of two (2) low water crossings, one (1) pedestrian bridge, a small amphitheater/skate park, pavilion with restrooms, and new pavements. SOIL BORING AND LABORATORY TESTS A total of nine (9) borings were drilled for this project. Two (2) borings were drilled to a depth of 40 feet each at the two (2) low water crossings (4 borings total). Two (2) borings were drilled to 40 feet each at the pedestrian bridge, one (1) boring was drilled to 40 feet at the location of the pavilion, one (1) boing was drilled to 10 feet at the amphitheater/skate park, and one (1) boring was drilled to a depth of 10 feet in the area of proposed new pavements. The borings were drilled at the approximate locations shown on the Boring Location Plan provided as Figure 1 in Appendix A. The borings were sampled in accordance with ASTM D1586 for Split Spoon sampling techniques and ASTM D1587 for thin-walled tube sampling as described in Appendix C. A truck-mounted drill rig using continuous flight augers together with the sampling tools noted was used to secure the subsurface soil samples on July 18 and 19, Soil classifications and borehole logging were conducted during the exploration by our soil technician who is under the supervision of the Project Geotechnical Engineer. Final soil classifications, as seen on the attached boring logs (Appendix B), were determined by the Project Geotechnical engineer based on laboratory and field test results and applicable ASTM procedures. Arias & Associates, Inc. 1 Arias Job No

6 As a supplement to the field exploration, laboratory testing was conducted to determine soil water content, Atterberg Limits, and percent passing the US Standard No. 200 sieve. The laboratory results are reported in the attached boring logs included in Appendix B. A key to the terms and symbols used on the logs are also included in Appendix B. The soil laboratory testing for this project was done in accordance with applicable ASTM procedures with the specifications and definitions for these tests listed in the Appendix C. Remaining soil samples recovered from this exploration will be routinely discarded following submittal of this report. SUBSURFACE CONDITIONS Generalized stratigraphy and groundwater conditions at the project site are discussed in the following sections. The subsurface and groundwater conditions are based on conditions encountered at the boring locations and to the depths explored. Site Stratigraphy and Engineering Properties The generalized stratigraphic conditions at the boring locations are tabulated below: Table 1: Generalized Stratigraphic Conditions-Borings B-1 thru B-7 Stratum Depth (ft.) Description PI range #200 range PP range N range I IA II IIA 0 to to to to 40 Dark Brown & Tan CLAYEY SAND (SC), loose to very dense Brown CLAYEY SAND (SC), POORLY GRADED SAND with CLAY (SP-SC), loose to very dense Dark Brown SANDY LEAN CLAY (CL), FAT CLAY (CH), SANDY FAT CLAY (CH), FAT CLAY with SAND (CH), soft to stiff Brown SANDY LEAN CLAY (CL), stiff to very hard * / /10 Where: Depth Stratum depth from existing ground surface at the time of geotechnical study PI Plasticity Index, % #200 Percent passing the US Standard No. 200 sieve, % PP Pocket Penetrometer, tsf N Standard Penetration Test, blows per foot -- No sample selected for testing * Only one test Arias & Associates, Inc. 2 Arias Job No

7 Table 2: Generalized Stratigraphic Conditions-Borings B-8 & B-9 Stratum Depth (ft.) Description PI range #200 range PP range N range I IA II 0 to 8 6 to to 6-10 Dark Brown CLAYEY SAND (SC), loose (Encountered in Boring B-9 only) Brown CLAYEY SAND (SC), loose (Encountered in Boring B-8 only) Dark Brown SANDY Fat CLAY (CH), SANDY LEAN CLAY (CL), firm to stiff 23* 44* 4.5+* * 28* * 7-9 Where: Depth Stratum depth from existing ground surface at the time of geotechnical study PI Plasticity Index, % #200 Percent passing the US Standard No. 200 sieve, % PP Pocket Penetrometer, tsf N Standard Penetration Test, blows per foot -- No sample selected for testing * Only one test Groundwater Conditions A dry sampling method was used to obtain the samples at the project site. Groundwater was observed in some of the soil borings during drilling and sampling activities which were performed on July 18 and 19, Groundwater level measurements are shown in the table below. It should be noted that water levels may require several hours to several days to stabilize in open boreholes depending on the permeability of the soils. Table 3: Ground Water Measurements Boring Boring Depth, (ft.) Ground Water Reading (ft.) During Drilling After Completion None Encountered None Encountered 9 10 None Encountered None Encountered Arias & Associates, Inc. 3 Arias Job No

8 Groundwater levels at the time of construction may differ from those observed during the field exploration since the presence of perched groundwater is subject to seasonal conditions, recent rainfall, drought or temperature affects. Clay soils are generally not conducive to readily transmit groundwater; however, gravels, sands, silts or open fractures and joints can store and readily transmit perched groundwater flow or seepage. Perched groundwater seepage can also occur at strata interfaces. The borings were performed at the time of an extended drought in the San Antonio area. Seasonal weather conditions or other factors may dictate actual shallow groundwater conditions at the time of construction. Upon completion of the sampling activities, the soil borings were backfilled with soil cuttings generated from the augering process. The Contractor should be prepared with appropriate measures to control surface water and groundwater at the site as necessary to allow for the proposed construction. Should dewatering become required, it is considered means and methods and is solely the responsibility of the contractor. General ENGINEERING ANALYSIS AND DISCUION Geotechnical soil design parameters for the proposed low water crossings, pedestrian bridge, amphitheater/skate park, pavilion, and pavements are provided in the following sections. We understand that the low water crossings will consist of multiple box concrete culverts. The pedestrian bridge will a typical structure manufactured by Con-Tech company. The proposed Pavilion and Amphitheater/Skate Park will be prone to shrink/swell movements associated with the clay soils encountered at this site. Low water crossing culverts and the pedestrian bridge structure will be subject to potential erosion. Reductions of potential movement and distress can be accomplished by following our recommendations presented in this report. Expansive Soils The site soils beneath in the area of the Amphitheater/Skate Park and Pavilion have a moderate to relatively high expansion potential. Expansive clays shrink when they lose water and swell or grow in volume when they gain water content. The potential of expansive clays to shrink and swell is generally related to the Plasticity Index (PI). Clays with a higher PI typically have a greater potential for soil volume changes due to moisture content variations. Change in soil moisture is the single most important factor affecting the shrinking and swelling of clays. The most pronounced movements are commonly observed when soils are exposed to extreme moisture fluctuations that occur during wet weather following Arias & Associates, Inc. 4 Arias Job No

9 prolonged drought conditions. As noted previously, the San Antonio area has experienced a significant drought period. We have estimated potential vertical movement for the Amphitheater/Skate Park and Pavilion sites using the Tex-124-E method outlined by the Texas Department of Transportation (TxDOT). This method provides an estimate of potential vertical rise (PVR) using the liquid limits, plasticity indices, and possible moisture conditions (i.e. existing, dry, and wet) for the expansive clay soils. The PVR is estimated in the seasonally active zone, which for this site is estimated to be about 15 feet. Using the TxDOT method, we estimated that the PVR is about 2½ to 3½ inches at the Amphitheater and Pavilion locations. Estimated PVRs are based upon assumed changes in soil moisture content from a dry to a wet condition; however, soil movements in the field depend on the actual changes in moisture content. Thus, actual soil movements could be less than that calculated if little soil moisture variations occur or the actual movement could exceed the estimated values if actual soil moisture content changes exceed the assumed dry and wet limits outlined by the PVR method. Such moisture conditions that exceed the limits of the PVR method may be the result of extended droughts, flooding, perched groundwater infiltration, poor surface drainage, and/or leaking underground water/sewer piping and irrigation lines. LOW WATER CROING STRUCTURES We understand the reinforced concrete box culvert structures will be used for the low-water crossings. Excavations for the box culverts should preferably be neat-excavated. The excavations may need to be over-excavated to allow for the placement of bedding material that may be required by the project civil engineer. The anticipated bearing depth of the planned culverts is not known. Based on the results of our borings, the table below outlines the allowable bearing pressures for each of the planned box culvert structures. Table 4: Box Culvert Allowable Bearing Pressure Information Low Water Crossing Depth, ft (below existing ground surface) Anticipated Bearing Soils Allowable Bearing Pressure, psf South of Pedestrian Bridge 0 to 40 CLAYEY SAND (SC), loose to very dense 1,800 South End of Project 0 to 9 FAT CLAY (CH), dark brown, soft to stiff 1,500 South End of Project 9 to 40 CLAYEY SAND (SC), loose to dense 1,800 Arias & Associates, Inc. 5 Arias Job No

10 Using these allowable bearing pressures, total and differential settlement of the box culvert structures should be less than 1 inch and ½ inch, respectively, provided that the subgrade at each site is prepared as discussed subsequently. Depending on seasonal weather conditions, excavations may encounter free groundwater. Groundwater was observed during the sampling activities and may be present in the clayey sand layers observed in the soil borings. If groundwater is encountered, depending on the volume, conventional sump and pump methods may be utilized to temporarily dewater the base of the excavation to remain sufficiently dry to allow for concrete placement. The means and methods for dewatering the site are solely the responsibility of the contractor. Excavation equipment may disturb the bearing soils and loose pockets can occur at the culvert s bearing elevation. Accordingly, we recommend that the upper 6 inches of the base of the excavations be compacted to achieve a density of at least 95 percent of the maximum dry density as determined by TEX 114-E. A common bedding material for culverts consists of 1-inch clean TXDOT concrete gravel Grade #5 (ASTM C-33 #67). Soil backfill above bedding materials and on top of the culverts (below the roadway section) should consist of select fill material meeting the following criteria: (1) free and clean of organic or other deleterious material, (2) have a plasticity index (PI) between 7 and 20, and (3) not contain particles exceeding 3 inches in maximum dimension. A filter fabric should be provided between any free-draining gravel and soil backfill to aid in preventing finer-grained soils from infiltrating into the free-draining gravel, which could lead to ground loss and distress to the overlying roadway. Onsite soils, bedding materials, and select fill should be placed in lifts not to exceed 8 inches in loose measure and should be moisture conditioned to between -1 and +3 percentage points of optimum moisture content, and compacted to at least 95 percent of the maximum dry density determined by TEX 114-E. A representative of Arias & Associates should observe the backfill and compaction processes. A lean concrete mud-mat may also be used as an alternative to providing a layer of drainage gravel. The excavation may need to be over-excavated to: (a) remove soft mucky soils from the bearing surface, or (2) allow for the placement of the mud-mat and bedding material that may be required by the project civil engineer. Soft mucky soils, if encountered beneath the box culvert structure, should be replaced with select fill meeting the requirements in this report or flowable fill. Lateral Earth Pressures for Headwalls, Box Culverts, and Retaining Walls Lateral earth pressures that may act on the box culvert structures, stem walls, headwalls, and retaining walls can be evaluated by using the following equivalent fluid unit weights provided in Table 5 for the corresponding type of backfill. The equivalent fluid unit weights Arias & Associates, Inc. 6 Arias Job No

11 are based on at-rest earth pressure conditions. Table 5 values can also be used for planned retaining walls to be located near the pedestrian bridge and the Amphitheater. Table 5: Lateral Earth Pressures Backfill Type Select Fill (7 PI 20) Clean Gravel (Bedding Material) On-site Lean Clay Soils Estimated Total Soil Unit Weight, (pcf) Effective Soil Unit Weight, (pcf) At-Rest Earth Pressure Coefficient, (k o) Equivalent Fluid Unit Weight Dry Condition, (pcf) Submerged Condition, (pcf) Note: 1. The above equivalent fluid unit weights do not consider surcharge loads. 2. Soil and hydrostatic water pressures behind walls will impose a triangular stress distribution on the walls; surcharge loads will impose a rectangular stress distribution on the walls. The equivalent fluid unit weight submerged condition values in the above table should be used if there is a chance for hydrostatic forces to develop. If hydrostatic water pressures are not expected to develop, the equivalent fluid unit weight dry condition values can be used. Surcharge loads including equipment loads, traffic, and soil stockpiles should also be considered in the analysis of the box culvert structure and headwalls. Measures should be taken to design against buoyancy forces. These methods may include reducing the potential for water to migrate beneath and around the sides of the box culvert structure and headwalls and/or by designing for the use of adequate overburden pressure. The weight of the box culvert structure and headwalls and soil backfill will aid in resisting potential buoyancy forces. The following design measures can be considered to reduce the risk of water entering backfill or becoming trapped under the box culverts: If granular soils are encountered in box culvert excavation bottoms, they can be undercut down to clay and replaced with lean clay select fill or flowable fill. Select fill consisting of the excavated clayey sand and lean clay can be used to backfill behind and above the box culverts and behind stem walls and wing walls. Concrete riprap aprons can be placed upstream and downstream of the box culverts, and turn-down reinforced concrete beams can be constructed to depths of at least 2 feet at Arias & Associates, Inc. 7 Arias Job No

12 the toes of the concrete aprons. The concrete beams and aprons are expected to be cast monolithically, so that there are not joints that water could possibly migrate through. Stone riprap, or other designed energy dissipator, can be placed upstream of the concrete apron to reduce flow velocities. Erosion Control The performance of the outfall system will be directly related to the control of erosion; thus, protection against scour should be provided. Some potential erosion control methods are presented below: Rock Riprap Gabions and Slope Mattresses Concrete Lining Erosion Control Mats Care should be taken to provide adequate anchorage for the erosion control materials. Actual measures for erosion and scour control should be determined by the project civil engineer. Based on the results of the soil borings, we recommend that turn-down grade beams used for the planned box culvert and headwall structures extend a minimum of 24 inches below the lowest adjacent grade and bear within the on-site clay soils. Additional depth may be required by the designers based on the results of the site-specific scour analysis. Site Drainage The favorable performance of any structure is dependent on positive site drainage. Careful consideration should be provided by the designers and contractor to ensure positive drainage of all storm waters away from the planned improvements both during and after construction. PEDESTRIAN BRIDGE Pedestrian Bridge-Borings B-1 & B-2 Straight shaft drilled piers are recommended for the Pedestrian Bridge Structure due to the possibility of scour and overturning of the bridge headwall. Recommendations for axial capacity and lateral capacity are presented in the following tables. Pier capacities for axial loading were evaluated based on design methodologies included in FHWA-IF Drilled Shafts: Construction Procedures and Design Methods. Both end bearing and side friction resistance may be used in evaluating the allowable bearing capacity of the pier shafts. Arias & Associates, Inc. 8 Arias Job No

13 Table 6: Drilled Pier Design Parameters Axial Capacity-Pedestrian Bridge Recommended Design Parameters Depth Material Allowable Skin Friction, psf Allowable End Bearing, psf Uplift Force, kips 0 to 5 FAT CLAY (CH) Neglect Contribution 5 to 30 CLAYEY SAND (SC) and LEAN CLAY (CL) 400 4,000 NA 30 to 40 CLAYEY SAND (SC) 1,200 12,000 Constraints to be Imposed During Pier Design Minimum embedment depth Minimum shaft diameter At least 25 feet below existing grade, deeper depths may be required to resist compressive, lateral, uplift or pullout loads or to get an effective casing seal 18 inches Notes: 1. For straight shaft piers, the contribution of the soils for the top 5 feet of soil embedment and for a length equal to at least 1 pier diameter from the bottom of the shaft should be neglected in determination of friction capacity for compression loading. The recommended design parameters include a factor of safety of 2 for skin friction and of 3 for end bearing. 2. Total and differential settlement of piers is expected to be less than 1 inch and ½ inch, respectively. Estimated settlements are based on performance of properly installed piers in the South Texas areas. A detailed settlement estimate is outside of the scope of this service. 3. Sufficient reinforcing steel should be placed within the pier to account for tension and lateral loading as applicable. Pier vertical reinforcing steel should be designed to resist the uplift forces from swelling soils and uplift and lateral forces from wind loading. The final reinforcing requirements should be determined by the project structural engineer. Tensile rebar steel should be designed in accordance with ACI Code Requirements. 4. A minimum shaft diameter of 18 inches is recommended. Larger shaft diameters may be required. Straight-shaft piers should be spaced at least 3 diameters apart center-to-center. If the recommended pier spacing cannot be maintained, Arias should be consulted to consider the group effect of closelyspaced piers. Lateral pile analyses including capacity, maximum shear, and maximum bending moment will be evaluated by the project structural engineer using LPILE or similar software. In the following table, Arias presents geotechnical input parameters for the encountered soils for the Pedestrian Bridge. Please note that the depths to the top and bottom of each layer were interpreted using approximate elevation data at the explored boring locations and layer boundaries as shown on the boring logs. Arias & Associates, Inc. 9 Arias Job No

14 Table 7: Drilled Pier Geotechnical Input Parameters for LPILE Analyses-Pedestrian Bridge Depth (ft) Material γ e C u φ K (static loading) K (cyclic loading) e 50 0 to 5 CLAYEY SAND (SC) NEGLECT 5 to 30 CLAYEY SAND (SC) and LEAN CLAY (CL) to 40 CLAYEY SAND (SC) , Where: γe = effective soil unit weight, pcf cu = undrained soil shear strength, psf φ = undrained angle of internal friction, degrees K = modulus of subgrade reaction, pci e50 = 50% strain value PAVILION AND AMPHITHEATER/SKATE PARK STRUCTURES Recommended Building Pad Improvement for 1 PVR Building pad preparation requirements on expansive clay sites are dependent upon the soil moisture condition at the time of construction. Typically, the geotechnical engineer does not know the climate conditions that will exist at the time of construction since he does not know when the structure will be built. Therefore, having the geotechnical engineer retained to review site preparation recommendations and be an active participant in Team Meetings near the time of construction can often result in project cost savings since soil moisture conditions at the time of construction could be more accurately assessed. Additionally, it has been our experience that retaining the same firm for both geotechnical engineering services and construction materials testing is prudent since the geotechnical engineer is most familiar with site conditions and can quickly respond to field challenges. Grade-supported foundation elements for the proposed Pavilion and Amphitheater/Skate Park will require additional site improvement recommendations in order to reduce the PVR or soil shrink-swell potential of the expansive clays. In this area, a PVR of 1-inch is typically an acceptable amount of movement for structures of this type and the recommendations provided in this report are based on this assumption. Although this is a typically acceptable magnitude of movement in this area, it should be understood that a 1-inch PVR can result in some cracking requiring periodic maintenance; but the structural integrity of the building should be maintained. If project requirements dictate a different magnitude of PVR, we should be informed so that modifications to our recommendations may be made. Arias & Associates, Inc. 10 Arias Job No

15 Recommendations are presented in the Table below and are valid only for a 1-inch design PVR. Table 8: Building Pad Recommendations for 1-inch Design PVR Recommended Foundation Type: Site Improvement Method: Improved Site Condition (PVR): Minimum Undercut Depth: Exposed Subgrade Preparation (See Note 3): Pumping/Rutting Areas Discovered During Proof rolling: Scarify, Moisten & Compact Exposed Subgrade: Select Fill Type: Stiffened Beam and Slab on Grade Undercut and Replace with Compacted Select Fill in Moisture Controlled Lifts 1-inch Minimum of 5 feet Proof roll with rubber tired vehicle weighing at least 20 tons such as a loaded dump truck. See Note 3 Remove to firmer materials and replace with compacted select fill under direction of Geotechnical Engineer s representative 18 inches LEAN CLAY (CL) with LL 40, PI = 8 20, #200 50%, 3 Maximum Particle Size. Working Surface: Top 6 to be Crushed Limestone Base Meeting Requirements of TxDOT Item 247 Type A, Grade 1 or 2 Moisture Barrier: See Note 8 Notes: 1. The building pad improvements will be used with a stiffened beam and slab on grade. 2. Following stripping operations, undercut the existing soils from beneath the slab areas to at least the depth provided above. Undercutting should extend laterally to provide at least a 5-foot overbuild beyond the building perimeter and to the width of any adjacent sidewalks wider than five (5) feet. 3. The exposed subgrade should be thoroughly rolled with a heavily loaded dump truck weighing at least 20 tons. A minimum of 20 passes should be performed with passes alternating in directions perpendicular to each other. Any area that yields under the roller loading should be undercut to the depth specified by the geotechnical engineer and replaced with compacted fill as specified by the Geotechnical Engineer and outlined in Table 22. If deleterious material, rubble, or debris is encountered, they should be removed to firmer materials and disposed of properly. The void should then be replaced with properly compacted select fill. It is important that the site preparation operations be observed and tested by one of our representatives to verify that these recommendations are followed. 4. The exposed subgrade should be scarified to a depth of at least 18 inches, moisture conditioned and compacted in maximum 6-inch compacted lifts as specified in SECTION I, Table 22 (Project Compaction, Moisture and Testing Requirements). 5. The building pad should be constructed using select fill. The select fill should be placed within 48 hours of completion of the subgrade compaction and should be placed in maximum 8-inch loose lifts as specified in SECTION I, Table 22 (Project Compaction, Moisture and Testing Requirements). 6. For construction equipment access, and to help in providing a more all-weather working surface, we recommend placing 6 inches of compacted crushed limestone base meeting the requirements of 2004 TXDOT Item 247, Type A, Grade 1 or 2 on top of the select fill. 7. If additional select fill thickness is necessary to achieve final design grade, fill should consist of material meeting the requirements in Table 8 above. Arias & Associates, Inc. 11 Arias Job No

16 8. A horizontal barrier should extend at least 10 feet horizontally beyond the perimeter of the foundation. The barrier can consist of concrete or asphalt paving, concrete flatwork or at least 24 of compacted onsite or import clay (PI between 20 and 40). All joints within the pavement, flatwork, and at pavement/flatwork interfaces should be sealed. Any landscaping located within 10 feet of the structure foundation should be placed in watertight above-grade planter boxes with drainage discharge on top of adjacent flatwork/paving. We recommend that the perimeter grade beam be constructed to a depth of at least 30 inches to aid in reducing the potential for moisture fluctuation beneath the building pad. The final grade beam depth and recommended construction should be determined by the structural engineer. The slab vapor retarder plastic should be extended from beneath the slab down the inside face (building pad side) of the grade beam trench. In unpaved areas at the perimeter of the planned structures, a 2-foot thick clay cap (see Note 8, Table 8) should be constructed over the select fill overbuild. This clay cap should aid in reducing the chances for surface water from infiltrating into the more previous select fill and pond on top of the underlying, less permeable clay subgrade. A PVR exceeding 1-inch can occur if water is allowed to readily pond on top of the clay subgrade beneath the select fill body. Clean onsite soils (PI of 20 to 40, if present) can be used to construct the clay cap. The clay cap should be moisture conditioned to between 0 and +4 percentage points of optimum moisture content and then compacted to at least 95 percent of the maximum dry density determined by ASTM D 698. Stiffened Beam and Slab-on-Grade A grid type beam and slab-on-grade is generally used to support relatively light structures upon expansive soils where soil conditions are relatively uniform, and where uplift and settlement can be tolerated. The intent of a stiffened beam and slab-on-grade foundation is to allow the structure and foundation to move up and down with soil movements while providing sufficient stiffness to limit differential movements within the superstructure to an acceptable magnitude. A stiffened grid type beam and slab-on-grade foundation may be utilized for the proposed structure provided it is designed specifically for these soil conditions. Also, the building pad for a stiffened beam and slab on grade must be improved as outlined in Table 8. There are various design methods for use by the structural engineer to select the grade beams depths and beam spacings for this project. The foundation may be designed using the Building Research Board No. 33 (BRAB Report) as a guideline. Alternatively, the foundation may be designed based on the Design of Slab-On-Ground Foundations published by the Wire Reinforcement Institute, Inc. (WRI-August 1981). Provided in the following table are design criteria for both methods. Arias & Associates, Inc. 12 Arias Job No

17 Table 9: BRAB and WRI Foundation Design Criteria Design Method BRAB WRI Design PVR 1 1 Climatic Rating (Cw) Kenedy, Texas Effective Plasticity Index Support Index (C) Soil/Climatic Rating Factor (1-C) Unconfined Compressive Strength (tsf) Note: The above design values assume that the building pads havd been improved as outlined in this report for an approximate 1-inch design PVR. A stiffened beam and slab type foundation may also be designed for the structures using the 3 rd Edition of the Design of Post-Tensioned Slabs-on-Ground published by the Post- Tensioning Institute. These values were estimated from the Volflo computer program in consideration of the soil conditions in the area of the borings. Provided in the following table are design criteria for this method for design PVR values of 1-inch. Table 10: PTI Slab-on-Grade Soil Design Criteria (3 rd Edition) Design PVR Depth to Constant Soil Suction Constant Soil Suction Edge Moisture Variation Distance Center Lift, e m Edge Lift, e m Differential Soil Movement Center Lift, y m Edge Lift, y m About 1 inch 15 Feet 3.8 pf 9.0 feet 4.9 feet 1.2 inches 2.0 inches Coefficient of Slab-Subgrade Friction, µ 0.75 Note: The above design values assume that the building pads have been improved as outlined in this report for an approximate 1-inch design PVR. Arias is providing design values for BRAB, WRI, and PTI methods for the Structural Engineer s consideration and possible use. Arias recommends the final design methodology for the planned foundation be selected by the project Structural Engineer based on his knowledge and experience with similar foundation conditions. Arias & Associates, Inc. 13 Arias Job No

18 Table 11: Allowable Bearing Pressure and Beam Penetration Allowable Bearing Pressure Bearing Stratum at Bottom of Grade Beams/Footings Min. Penetration of Beams/Footings Below Final Grade for Bearing Pressure Requirements 2,000 psf Compacted Select Fill 30 inches Note: Actual beam depth should be determined by structural engineer. Minimum penetration below final grade is necessary to reduce scour potential and the potential for water penetration under the foundation Grade beams/footings based at the recommended depth, and founded within the compacted select fill, should be designed for the allowable soil bearing capacity provided above. Grade beams may be thickened and widened at concentrated loads to serve as spread footings. The beams and widened columns should be a minimum of 10 and 12 inches wide, respectively, for shear resistance. The grade beams should extend at least 30 inches below final grade within the compacted select fill. We recommend that at least a 10-mil vapor retarder be used under the slab. The vapor retarder should conform to ASTM E1745, Class C or better and shall have a maximum water vapor permeance of perms when tested in accordance with ASTM E96. A 10 mil Stego Wrap by Stego Industries LLC or other similar products meeting these requirements would be acceptable. PAVEMENT RECOMMENDATIONS Pavement Design Parameters and Assumptions Accumulation of water beneath the asphaltic surface course can cause progressive and rapid deterioration of the pavement section. Similarly, pavement surfaces should be well drained to eliminate ponding with a two-percent minimum slope, as possible. The pavement recommendations were prepared in accordance with the 1993 AASHTO Guide for the Design of Pavement Structures for asphalt and the ACI Design Guide 330R for concrete parking lots. Traffic volumes and types were not provided to us at the time of this Report. Therefore, the following design parameters and assumptions were used in our analysis: Arias & Associates, Inc. 14 Arias Job No

19 Table 12: Pavement Design Parameters and Assumptions Traffic Load for Light Duty Pavement Traffic Load for Medium Duty Pavement Concrete Compressive Strength Raw Subgrade California Bearing Ratio (CBR) Raw Subgrade Modulus of Subgrade Reaction, k in pci 7,500 equivalent single axle loads (ESALs) 25,000 ESALS 4,000 psi 2 for high plasticity compacted clay (CH) subgrade 75 for high plasticity compacted clay (CH) subgrade It should be noted that the conditions and recommendations contained herein are based on the materials encountered at the time of field exploration. These conditions may differ once the earthwork operations are performed. We recommend that a representative of Arias be retained to observe that our recommendations are followed and to assist in determining the actual subgrade material classification at a particular location. Options for section thickness for flexible and rigid pavements are provided in the table below: Table 13: Recommended Pavement Sections Flexible Asphaltic Concrete Rigid Concrete Layer Material Parking Area & Light Duty Access Drive, Truck Lane & Medium Duty Parking Area & Light Duty Access Drive, Truck Lane & Medium Duty Surface HMAC/PCC 2½ Base Flexible Base Subgrade Moisture conditioned *Moisture conditioned flexible asphalt sections should also have Tensar TX-140 geogrid installed over the 6-inch moisture conditioned subgrade *6 -- * Lime Treated Notes: 1. Asphaltic concrete pavements founded on top of expansive soils will be subjected to PVR soil movements estimated and presented in this report (i.e., approximately 2 to 3 inches). These potential soil movements are typically activated to some degree during the life of the pavement. Consequently, pavements can be expected to crack and require periodic maintenance. Periodic/preventative maintenance should be planned for to reduce deterioration of the pavement structure while aiding to preserve the investment. Arias & Associates, Inc. 15 Arias Job No

20 2. Light duty areas include parking and drive lanes that are subjected to passenger vehicle traffic only. Light duty areas exclude entrance aprons and drives to the site and single access route drive lanes to parking areas. 3. Medium duty areas include entrance aprons and drives into the site, single access route drive lanes to parking areas, and areas where paving will be subjected to truck traffic. Medium duty areas exclude areas where tractor trailers may travel or park, dock areas, areas where trash collection vehicles may travel and load or unload. 4. Heavy duty areas include areas subjected to 18-wheel tractor trailers, trash collection vehicles, dumpster pads including loading and unloading areas, and areas where truck turning and maneuvering may occur. Eight (8)-inch thick concrete pavement is recommended for heavy duty areas and is not shown in Table During the paving life, maintenance to seal surface cracks within concrete or asphalt paving and to reseal joints within concrete pavement should be undertaken to achieve the desired paving life. Perimeter drainage should be controlled to reduce the influx of surface water from areas surrounding the paving. Water penetration into base or subgrade materials, sometimes due to irrigation or surface water infiltration leads to pre-mature paving degradation. Curbs should be used in conjunction with paving to reduce potential for infiltration of moisture into the base course. Curbs should extend the full depth of the base course and should extend at least 3 inches into the underlying clayey subgrade. The base layer should be tied into the area inlets to drain water that may collect in the base. 6. For flexible pavements only where the moisture conditioned subgrade option will be utilized, Tensar TX-140 geogrid should be installed over the 6-inch moisture conditioned subgrade. 7. Material specifications, construction considerations, and section requirements are presented under Pavement Subgrade and Section Materials included in this report. Rigid Concrete Pavement Joints Placement of expansion joints in concrete paving on potentially expansive subgrade or on granular subgrade subject to piping often results in horizontal and vertical movement at the joint. Many times, concrete spalls adjacent to the joint and eventually a failed concrete area results. This problem is primarily related to water infiltration through the joint. One method to mitigate the problem of water infiltration through the joints is to eliminate all expansion joints that are not absolutely necessary. It is our opinion that expansion or isolation joints are needed only adjacent where the pavement abuts intersecting drive lanes and other structures. Elimination of all expansion joints within the main body of the pavement area would significantly reduce access of moisture into the subgrade. Regardless of the type of expansion joint sealant used, eventually openings in the sealant occur resulting in water infiltration into the subgrade. The use of sawed and sealed joints should be designed in accordance with current Portland Cement Association (PCA) or American Concrete Institute (ACI) guidelines. Research has proven that joint design and layout can have a significant effect on the overall performance of concrete pavement. Recommendations presented herein are based on the use of reinforced concrete pavement. Local experience has shown that the use of distributed steel placed at a distance of 1/3 slab thickness from the top is of benefit in crack control for concrete pavements. Improved crack control also reduces the potential for water infiltration. Arias & Associates, Inc. 16 Arias Job No

21 Performance Considerations Our pavement recommendations have been developed to provide an adequate structural thickness to support the anticipated traffic volumes. Some shrink/swell movements due to moisture variations in the underlying soils, or potential movement from settling utility backfill material, should be anticipated over the life of the pavements. The owner should recognize that over a period of time, pavements may crack and undergo some deterioration and loss of serviceability. We recommend the project budgets include an allowance for maintenance such as patching of cracks or occasional overlays over the life of the pavement. Recommendations for subgrade preparation in the planned pavement areas, as well as for the pavement section materials, are provided in the following five (5) tables shown below. Table 14: Pavement Subgrade Materials Subgrade Preparation Prior to Paving Section Construction 6 inches or as needed to remove organics and existing Minimum undercut depth pavement/foundations Provided they are free of roots and debris and meet the Reuse excavated soils material requirements for their intended use Horizontal extent for undercut 2 feet beyond the paving limits The exposed subgrade should be thoroughly rolled with a heavily loaded dump truck weighing at least 20 tons. A minimum of 20 passes should be performed with passes alternating in directions perpendicular to each other. Any area that yields under the roller loading should be undercut to the depth specified by the geotechnical Exposed subgrade treatment engineer and replaced with compacted fill as specified by (before moisture conditioning or lime the Geotechnical Engineer and outlined in Table 22. If treatment) deleterious material, rubble, or debris is encountered, they should be removed to firmer materials and disposed of properly. The void should then be replaced with properly compacted select fill. It is important that the site preparation operations be observed and tested by one of our representatives Pumping and/rutting should be expected and then remove Pumping/rutting areas discovered during to firmer materials and replace with compacted general or proof rolling select fill under direction of Geotechnical Engineer s representative Arias & Associates, Inc. 17 Arias Job No

22 Table 15: Fill Requirements and Subgrade Treatment Options Fill Requirements for Grade Increases Material free of roots, debris and other deleterious General fill type material with a maximum rock size of 3 inches; onsite clays having CBR > 2.0 may be used Minimum general fill thickness As required to achieve grade Maximum general fill loose lift thickness 8 inches General fill compaction and moisture ASTM D 698 criteria 95% compaction at 0 to +4 from optimum Subgrade Treatment Option - Moisture Conditioning Depth of moisture conditioning 9 inches (disk in place and moisture condition) ASTM D 698 Compaction and moisture criteria 95% compaction at 0 to +4 from optimum In-Place Density and Moisture Verification Testing Testing frequency (Subgrade) 1 test per 5,000 square feet with minimum of 3 tests Table 16: Subgrade Treatment Option - Lime Treatment Treatment depth Treatment type Application rate (estimated) Subgrade Treatment Option - Lime Treatment 6 inches Hydrated lime 6-8% by dry weight Soil dry unit weight (estimated) 105 pcf but may be variable The actual application rate should be determined by laboratory testing of soil samples taken after the pavement subgrade elevation has been achieved. The quantity of lime should be sufficient to result in a ph of at least 12.4 when tested in accordance with ASTM C 977, Determination of application rate Appendix XI. Alternately, the optimum lime content may be determined through Atterberg limits testing on treated samples with varying percentages of lime. Sulfate testing of the exposed subgrade should be performed prior to the use of lime, cement or other calcium-based treatment agents. Treatment procedure TxDOT Item 260 and 264 Treatment layer compaction and moisture criteria Test frequency (all materials) ASTM D % compaction at 0 to +4 from optimum In-Place Density and Moisture Verification Frequency 1 test per 5,000 square feet (min. 3 tests) Arias & Associates, Inc. 18 Arias Job No

23 Table 17: Flexible Pavement Requirements Flexible Pavement Section Requirements Flexible Base Material Type 2004 TxDOT Item 247, Type A, Grade 1 or 2 Maximum Flexible Base Loose Lift 9 inches Thickness Compact to > 95% maximum dry density at +3 Flexible Base Placement Criteria percentage points of optimum moisture content (ASTM D 1557) Hot Mix Asphaltic Concrete (HMAC) Type 2004 TxDOT Item 340, Type D 91% to 95% Theoretical Lab Density HMAC Placement Criteria (TEX 207 F) Minimum compressive strength at 28 days Desired slump during placement Reinforced Steel Table 18: Rigid Pavement Section Materials Portland Cement Concrete Section Requirements 4,000 psi at 28 days 5 ± 1 inch 18 each way placed D/3 from top of slab Light duty 5, 6-inch section: 5/8 diameter, on center and lubricated both sides, dowel embedment of 5. Construction Joint Dowels Expansion Joints Contraction Joints transverse and longitudinal Placement Medium duty 6, 7 -inch section: 3/4 diameter, on center and lubricated both sides, dowel embedment of 6. Heavy duty 8-inch section: 1 diameter, on center and lubricated both sides, dowel embedment of 6. May be eliminated except at tie-ins with existing concrete and structures Meet spacing and sawing requirements of ACI 330R (Guide for Design and Construction of Concrete Parking Lots) In accordance with ACI 304R (guide for measuring, mixing, transporting, and placing), ACI 305R (hot weather concreting, and ACI 306R (cold weather concreting) To help reduce degradation of the prepared subgrade, paving preferably should be placed within 14 days. If pavement placement is delayed, protection of the subgrade surface with an emulsion-based sealer should be considered. Alternately, the paving section could be slightly overbuilt so blading performed to remove distressed sections does not reduce the treated subgrade thickness. Arias & Associates, Inc. 19 Arias Job No

24 Pavements over Low Water Crossings At the locations where the pavement extends across a low water crossing, we would recommend that the pavement section chosen be continued over the low water crossing (i.e., same base and asphalt thicknesses as for the roadway). If crushed limestone base is placed over the low water crossing (either as fill or as part of the base course), we recommend that a non-woven 4 oz/yd 2 minimum fabric, such as Mirafi 140N, be installed over all gravel backfill, and over the top of the concrete boxes. All fill should be placed and compacted as outlined below. Hot mix asphalt or base course should not be placed directly over the fabric. Performance Considerations Our pavement recommendations have been developed to provide an adequate structural thickness to support the anticipated traffic volumes. Some shrink/swell movements due to moisture variations in the underlying soils should be anticipated over the life of the pavements. The owner should recognize that over a period of time, pavements may crack and undergo some deterioration and loss of serviceability. We recommend the project budgets include an allowance for maintenance such as patching of cracks or occasional overlays over the life of the pavement. Site Preparation CONSTRUCTION CRITERIA Topsoil stripping should be performed as needed to remove organic materials, soft/very soft mucky soils, vegetation, roots, and stumps. The exposed subgrade should then be scarified to a depth of at least 8 inches and moisture conditioned to between minus one (-1) and plus three (+3) percentage points of optimum moisture content and compacted to at least 95 percent of the Standard Proctor Method. We recommend that one of our representatives be scheduled to observe that the site preparation operations are performed in accordance with our recommendations. Drilled Piers Construction Considerations The contractor should verify groundwater conditions before production pier installation begins. Comments pertaining to high-torque drilling equipment, groundwater, slurry, and temporary casing are based on generalized conditions encountered at the explored locations. Conditions at individual pier locations may differ from those presented and may require that these issues be implemented to successfully install piers. Construction considerations for drilled pier foundations are outlined in the following table. Arias & Associates, Inc. 20 Arias Job No

25 Table 19: Drilled Pier Installation Considerations Recommended installation procedure FHWA-NHI , May 2010 High-torque drilling equipment anticipated Groundwater anticipated Temporary casing anticipated Slurry installation anticipated Concrete placement Maximum water accumulation in excavation Concrete installation method needed if water accumulates Quality assurance monitoring Yes; dense and hard soils Yes, encountered in most borings. Yes, due to the groundwater and the clayey sand encountered in the borings. See Table 3. Possible if subsurface soil and groundwater conditions dictate. Same day as drilling. If a pier excavation cannot be drilled and filled with concrete on the same day, temporary casing or slurry may be needed to maintain an open excavation. The concrete should be placed using a tremie or pump and not allow the concrete to ricochet off the reinforcing cage or side pier side walls. 2 inches - MAXIMUM Tremie or pump to displace water. Geotechnical engineer s representative should be present during drilling of all piers, should observe drilling and verify the installed depth and diameter, should verify material type at the base of excavation and cleanliness of base, should observe placement of reinforcing Notes: 1. The contractor should verify groundwater conditions before production pier installation begins. Temporary casing will be needed due to groundwater conditions, quanity will be dependent on seasonal conditions. Payment provisions for temporary casing and for placement of concrete by the tremie method are recommended for inclusion in the Contract Documents. 2. Comments pertaining to high-torque drilling equipment, groundwater, temporary casing, and slurry drilling methods are based on generalized conditions encountered at the explored locations. Importantly, these are considered means and methods and are the sole responsibility of the contractor. Conditions at individual pier locations may differ from those presented and may require that these techniques be implemented to successfully install piers. 3. The following installation techniques will aid in successful construction of the shafts: o o o o The clear spacing between rebar or behind the rebar cage should be at least 3 times the maximum size of coarse aggregate. Centralizers on the rebar cage should be installed to keep the cage properly positioned. Cross-bracing of a reinforcing cage may be used when fabricating, transporting, and/or lifting. However, experience has shown that cross-bracing can contribute to the development of voids in a concrete shaft. Therefore, we recommend the removal of the cross-bracing prior to lowering the cage in the open shaft. The use of a tremie should be employed so that concrete is directed in a controlled manner down the center of the shaft to the pier bottom. The concrete should not be allowed to ricochet off the pier reinforcing steel nor off the pier side walls. Arias & Associates, Inc. 21 Arias Job No

26 o The pier concrete should be designed to achieve the desired design strength when placed at a 7- inch slump, plus or minus 1-inch tolerance. Adding water to a mix designed for a lower slump does not meet these recommendations. ADDITIONAL DESIGN CONSIDERATIONS IBC Site Classification and Seismic Design Coefficients Section 1613 of the International Building Code (2015) requires that every structure be designed and constructed to resist the effects of earthquake motions, with the seismic design category to be determined in accordance with Section 1613 or ASCE 7. Site classification according to the International Building Code (2015) is based on the soil profile encountered to the 100-foot depth. The stratigraphy at the site location was explored to a maximum 40- foot depth. Soils having similar consistency were extrapolated to be present between the 40 and 100- foot depths. On the basis of the site class definitions included in the 2015 Code and the encountered generalized stratigraphy, we characterize the site as Site Class D. Seismic design coefficients were determined using the on-line software, Seismic Hazard Curves and Uniform Response Spectra, version 5.1.0, dated February 10, 2011 accessed at ( Analyses were performed considering the 2015 International Building Code. Input included GPS coordinates and Site Class D. Seismic design parameters for the site are summarized in the following table. Table 20: Seismic Design Parameters Site Classification F a F v S s S 1 D g 0.029g Where: Fa = Site coefficient Fv = Site coefficient Ss = Mapped spectral response acceleration for short periods S1 = Mapped spectral response acceleration for a 1-second period Excavations The contractor should be aware that slope height, slope inclination, or excavation depths (including utility trench excavations) should in no case exceed those specified in local, state, or federal safety regulations, e.g., OSHA Health and Safety Standards for Excavations, 29 CFR Part 1926, dated October 31, Such regulations are strictly enforced and, if not followed, the Owner, Contractor, and/or earthwork and utility subcontractors could be liable for substantial penalties. The soils encountered at this site were classified as to type in accordance with this publication and are shown in the table below: Arias & Associates, Inc. 22 Arias Job No

27 Table 21: OSHA Soil Classifications Stratum Description OSHA Classification I CLAYEY SAND (SC) Dark Brown Loose C I LEAN CLAY (CL) Dark brown, stiff B/C II LEAN CLAY (CL), FAT CLAY (CH), Dark Brown and Brown, soft to very hard **It must be noted that layered slopes cannot be steeper at the top than the underlying slope and that all materials below the water table must be classified as Type C soils. The OSHA publication should be referenced for layered soil conditions, benching, etc. B/C For excavations less than 20 feet deep, the maximum allowable slope for Type C soils is 1.5H:1V (34 ), and for Type B soils is 1H:1V (45º). It should be noted that the table and allowable slopes above are for temporary slopes. Permanent slopes at this site should be sloped no steeper than 4H:1V and flatter slopes may be required. Flatter slopes may also be desired for mowing purposes. Appropriate trench excavation methods will depend on the various soil and groundwater conditions encountered. We emphasize that undisclosed soil conditions may be present at locations and depths other than those encountered in our borings. Consequently, flatter slopes and dewatering techniques may be required in these areas. The soils to be penetrated by excavations may vary significantly across the site. Our preliminary soil classification is based solely on the materials encountered in the nine (9) borings widely spaced though out the site. The contractor should verify that similar conditions exist throughout the proposed area of excavation. If different subsurface conditions are encountered at the time of construction, we recommend that Arias be contacted immediately to evaluate the conditions encountered. Trenches less than 5 feet deep are generally not required to be sloped back or braced following federal OSHA requirements for excavations. Sides of temporarily vertical excavations less than 5 feet deep may stay open for short periods of time; however, the granular soils that are expected to be encountered in trench excavations are subject to random caving and sloughing. If side slopes begin to slough, the sides should be either braced or be sloped back as needed. If any excavation is extended to a depth of more than twenty (20) feet, it will be necessary to have the side slopes designed by a professional engineer registered in Texas. As a safety measure, it is recommended that all vehicles and soil piles be kept a minimum lateral distance from the crest of the slope equal to no less than the slope height. Arias & Associates, Inc. 23 Arias Job No

28 Specific surcharge loads such as traffic, heavy cranes, earth stockpiles, pipe stacks, etc., should be considered by the Trench Safety Engineer. It is also important to consider any vibratory loads such as heavy truck traffic. It is required by OSHA that the excavations be carefully monitored by a competent person making daily construction inspections. These inspections are required to verify that the excavations are constructed in accordance with the intent of OSHA regulations and the Trench Safety Design. If deeper excavations are necessary or if actual soil conditions vary from the borings, the trench safety design may have to be revised. It is especially important for the inspector to observe the effects of changed weather conditions, surcharge loadings, and cuts into adjacent backfills of existing utilities. The flow of water into the base and sides of the excavation and the presence of any surface slope cracks should also be carefully monitored by the Trench Safety Engineer. The bottoms of trench excavations should expose strong competent soils, and should be dry and free of loose, soft, or disturbed soil. If fill soils are encountered at the base of trench excavations, their competency should be verified through proof-rolling, probing and density testing. Soft, wet, weak, or deleterious materials should be over-excavated to expose strong competent soils. If soft or weak soils are unexpectedly encountered to great depth, overexcavation to stronger soils may not be feasible and/or economical. In the event of encountering these areas of deep soft or weak soils, we recommend that the bottom of the trench be evaluated by the contractor s Trench Safety Engineer and the project Geotechnical Engineer. Earthwork Exposure to the environment may weaken the soils at the bearing level if the excavation remains open for long periods of time. Therefore, it is recommended that all excavations be extended to final grade and constructed as soon as possible in order to reduce the potential damage to bearing materials. If bearing materials are exposed to severe drying or wetting, the unsuitable material must be re-conditioned or removed as appropriate. The bearing level should be free of loose or soft soil, ponded water or debris, and should be observed by the Geotechnical Engineer or his representative. If excavations are expected to be open for extended time periods, a working platform consisting of a lean concrete mud-mat can be placed after removing any soft or loose soils as previously discussed. Subgrade preparation and fill placement operations should be monitored by the Geotechnical Engineer or his representative. In-place density tests should be performed as noted in the Quality Control section of this report. Any areas not meeting the required compaction should be recompacted and retested until compliance is met. Arias & Associates, Inc. 24 Arias Job No

29 Table 22: Project Compaction, Moisture and Testing Requirements Description Material Percent Compaction Optimum Moisture Content According to Standard Proctor ASTM D 698 Testing Requirement Building Pads Scarified On-site Soil (Subgrade) Select Fill: (Material Meeting Requirements Outlined previously in Table 8) 95% 0 to +4% 98% -1% to +3% 1 per 5,000 SF; min. 3 tests per structure 1 per 5,000 SF; min. 3 per lift per structure Scarified On-site Soil (Subgrade) 95% 0 to +4% 1 per 5,000 SF; min. 3 tests General Fill (Onsite Material) 95% 0 to +4% 1 per 5,000 SF; min. 3 per lift Pavement Areas Base Material 95% (ASTM D 1557) +3% 1 per 5,000 SF; min. 3 per lift Hot-mix asphaltic concrete 91% to 95% Theoretical Lab Density (TEX 207 F) Not applicable 1 per 5,000 SF; min. 3 per lift Non-Structural Areas (Outside Building Pads) General Fill (On-site Material) 95% -2% to +3% General Fill On-Site or Imported Material 95% 0 to +4% 1 per 5,000 SF; min. 3 per lift 1 per 5,000 SF; min. 3 per lift Groundwater Control The contractor should be prepared with appropriate dewatering measures to dewater the site as necessary to allow for the proposed construction. Open sump and pump methods may be a possible method for use. We should note that the means, methods and designs of dewatering systems are solely the responsibility of the Contractor. Quality Control As Geotechnical Engineer of Record, we should be engaged to: (1) observe and evaluate earthwork for site subgrade improvement activities to determine that the actual bearing materials are consistent with those encountered during the field exploration, and (2) observe and test subgrade preparation and fill placement. It is also important that we be given the opportunity to review the design and construction documents. The purpose of this review is to check to see if our recommendations are properly interpreted into the project plans and specifications. Arias & Associates, Inc. 25 Arias Job No

30 Subgrade preparation and fill placement operations should be monitored by the Geotechnical Engineer or his representative. As a guideline, at least three (3) in-place density tests should be performed for the prepared subgrade and each subsequent lift of fill as previously presented in Table 22. Any areas not meeting the required compaction should be recompacted and retested until compliance is met. In the event that Arias is not retained to provide quality assurance testing, we should be immediately contacted if differing subsurface conditions are encountered during construction. Differing materials may require modification to the recommendations that we provided herein. GENERAL COMMENTS This report was prepared as an instrument of service for this project exclusively for the use of Dunaway Associates and the project design team. If the development plans change relative to layout, anticipated traffic loads, or if different subsurface conditions are encountered during construction, we should be informed and retained to ascertain the impact of these changes on our recommendations. We cannot be responsible for the potential impact of these changes if we are not informed. Important information about this geotechnical report is provided in the ASFE publication given in Appendix D. Review Arias should be given the opportunity to review the design and construction documents. The purpose of this review is to check to see if our recommendations are properly interpreted into the project plans and specifications. Please note that design review was not included in the authorized scope and additional fees may apply. Subsurface Variations Soil and groundwater conditions may vary away from the sample boring locations. Transition boundaries or contacts, noted on the boring logs to separate soil types, are approximate. Actual contacts may be gradual and vary at different locations. The Contractor should verify that similar conditions exist throughout the proposed area of excavation. If different subsurface conditions or highly variable subsurface conditions are encountered during construction, we should be contacted to evaluate the significance of the changed conditions relative to our recommendations. Standard of Care This report has been prepared in accordance with generally accepted geotechnical engineering practice with a degree of care and skill ordinarily exercised by reputable geotechnical engineers practicing in this area and the area of the site. Arias & Associates, Inc. 26 Arias Job No

31 APPENDIX A: FIGURES AND SITE PHOTOGRAPHS Arias & Associates, Inc. A-1 Arias Job No

32 Approximate Site Location 142 Chula Vista, San Antonio, Texas Phone: (210) Fax: (210) Date: September 11, 2017 Job No.: Drawn By: RWL Checked By: JDS Approved By: CMS Scale: N.T.S. VICINITY MAP Escondido Linear Park Kenedy, Texas Figure 1 1 of 1

33 BORING LOCATION PLAN Escondido Linear Park Kenedy, Texas 142 Chula Vista, San Antonio, Texas Phone: (210) Fax: (210) Date: September 11, 2017 Job No.: REVISIONS: Drawn By: RWL Checked By: JDS No.: Date: Description: Approved By: CMS Scale: N.T.S. Figure 2 1 of 1

34 Photo 1 View looking at Boring 1 drilling operations. Photo 2 View looking at Boring 4 drilling operations. SITE PHOTOS Escondido Linear Park Kenedy, Texas 142 Chula Vista, San Antonio, Texas Phone: (210) Fax: (210) Date: September 11, 2017 Drawn By: RWL Approved By: CMS Job No.: Checked By: JDS Scale: N.T.S. Appendix A 1 of 2

35 Photo 3 View looking at Boring 5 drilling operations. Photo 4 View looking at Boring 7 drilling operations. SITE PHOTOS Escondido Linear Park Kenedy, Texas 142 Chula Vista, San Antonio, Texas Phone: (210) Fax: (210) Date: September 11, 2017 Drawn By: RWL Approved By: CMS Job No.: Checked By: JDS Scale: N.T.S. Appendix A 2 of 2

36 APPENDIX B: SOIL BORING LOGS AND KEY TO TERMS Arias & Associates, Inc. B-1 Arias Job No

37 Project: Escondido Creek Parkway Pedestrian Bridge Kenedy, Texas Location: See Boring Location Plan Soil Description CLAYEY SAND (SC), loose, dark brown STRATUM I Boring Log No. B-1 Sampling Date: 7/18/17 Coordinates: N28 o 49'17.5'' W97 o 51'40.3'' Backfill: Cuttings Depth (ft) SN WC PL LL PI PP N medium dense from 4'-13' brown below 8' 10 T T loose from 13'-28' T GPJ 11/21/17 (BORING LOG SA12-02,ARIAA12-01.GDT,LIBRARY GLB) -medium dense from 28'-33' -dense from 33'-38' -very dense from 38'-40' Borehole terminated at 40 feet Groundwater Data: First encountered during drilling: 18-ft depth After 15 minutes: 18.5-ft depth (20-ft open borehole depth) Field Drilling Data: Coordinates: Hand-held GPS Unit Logged By: J. Ramos Driller: Eagle Drilling, Inc. Equipment: Truck-mounted drill rig Single flight auger: 0-40 ft Nomenclature Used on Boring Log Split Spoon () WC = Water Content (%) PL = Plastic Limit LL = Liquid Limit PI = Plasticity Index PP = Pocket Penetrometer (tsf) Thin-walled tube (T) N = SPT Blow Count -200 = % Passing #200 Sieve Arias Geoprofessionals Water encountered during drilling Delayed water reading Job No.:

38 Project: Escondido Creek Parkway Pedestrian Bridge Kenedy, Texas Location: See Boring Location Plan Soil Description CLAYEY SAND (SC), loose, brown STRATUM I Boring Log No. B-2 Sampling Date: 7/19/17 Coordinates: N28 o 49'16.4'' W97 o 51'40.7'' Backfill: Cuttings Depth (ft) SN WC PL LL PI PP N SANDY LEAN CLAY (CL), firm, dark brown STRATUM II 10 T T CLAYEY SAND (SC), loose, brown STRATUM IA medium dense from 18'-28' GPJ 11/21/17 (BORING LOG SA12-02,ARIAA12-01.GDT,LIBRARY GLB) -dense from 28'-33' -very dense from 33'-38' -dense from 38'-40' Borehole terminated at 40 feet Groundwater Data: First encountered during drilling: 12.5-ft depth After 15 minutes: ft depth Field Drilling Data: Coordinates: Hand-held GPS Unit Logged By: J. Ramos Driller: Eagle Drilling, Inc. Equipment: Truck-mounted drill rig Single flight auger: 0-40 ft Nomenclature Used on Boring Log Split Spoon () WC = Water Content (%) PL = Plastic Limit LL = Liquid Limit PI = Plasticity Index PP = Pocket Penetrometer (tsf) Thin-walled tube (T) N = SPT Blow Count -200 = % Passing #200 Sieve Arias Geoprofessionals /11" Water encountered during drilling Delayed water reading Job No.:

39 Project: Escondido Creek Parkway Low Water Crossing Kenedy, Texas Location: See Boring Location Plan Soil Description SANDY FAT CLAY (CH), firm, dark brown STRATUM II -stiff from 2'-4' Boring Log No. B-3 Sampling Date: 7/18/17 Coordinates: N28 o 49'11.6'' W97 o 51'34.3'' Backfill: Cuttings Depth (ft) SN WC PL LL PI PP N -200 T FAT CLAY (CH), stiff, dark brown STRATUM II 5 T Poorly-graded SAND with Clay (SP-SC), loose, brown STRATUM IA 10 T CLAYEY SAND (SC), very loose, brown STRATUM IA loose from 18'-28' GPJ 11/21/17 (BORING LOG SA12-02,ARIAA12-01.GDT,LIBRARY GLB) -medium dense from 28'-33' -dense from 33'-40' Borehole terminated at 40 feet Groundwater Data: First encountered during drilling: 8-ft depth After 15 minutes: 8.5-ft depth (12-ft open borehole depth) Field Drilling Data: Coordinates: Hand-held GPS Unit Logged By: J. Ramos Driller: Eagle Drilling, Inc. Equipment: Truck-mounted drill rig Single flight auger: 0-40 ft Nomenclature Used on Boring Log Split Spoon () WC = Water Content (%) PL = Plastic Limit LL = Liquid Limit PI = Plasticity Index PP = Pocket Penetrometer (tsf) Thin-walled tube (T) N = SPT Blow Count -200 = % Passing #200 Sieve Arias Geoprofessionals Water encountered during drilling Delayed water reading Job No.:

40 Project: Escondido Creek Parkway Low Water Crossing Kenedy, Texas Location: See Boring Location Plan Soil Description FAT CLAY with Sand (CH), stiff, dark brown STRATUM II Boring Log No. B-4 Sampling Date: 7/18/17 Coordinates: N28 o 49'11.4'' W97 o 51'34.7'' Backfill: Cuttings Depth (ft) SN WC PL LL PI PP N -200 T firm from 4'-6' soft from 6'-10' T SANDY LEAN CLAY (CL), firm, brown STRATUM II 10 T very stiff from 13'-18' CLAYEY SAND (SC), medium dense, brown STRATUM IA 20 T GPJ 11/21/17 (BORING LOG SA12-02,ARIAA12-01.GDT,LIBRARY GLB) -dense from 33'-40' Borehole terminated at 40 feet Groundwater Data: First encountered during drilling: 10-ft depth After 15 minutes: 9.5-ft depth (10.3-ft open borehole depth) Field Drilling Data: Coordinates: Hand-held GPS Unit Logged By: J. Ramos Driller: Eagle Drilling, Inc. Equipment: Truck-mounted drill rig Single flight auger: 0-40 ft Nomenclature Used on Boring Log Split Spoon () WC = Water Content (%) PL = Plastic Limit LL = Liquid Limit PI = Plasticity Index PP = Pocket Penetrometer (tsf) Thin-walled tube (T) N = SPT Blow Count -200 = % Passing #200 Sieve Arias Geoprofessionals Water encountered during drilling Delayed water reading Job No.:

41 Project: Escondido Creek Parkway Pavilion Kenedy, Texas Location: See Boring Location Plan Soil Description SANDY FAT CLAY (CH), firm, dark brown STRATUM II Boring Log No. B-5 Sampling Date: 7/18/17 Coordinates: N28 o 49'13.3'' W97 o 51'30.4'' Backfill: Cuttings Depth (ft) SN WC PL LL PI PP N -200 T T CLAYEY SAND (SC), medium dense, brown STRATUM IA 10 T loose from 13'-18' medium dense from 18'-33' GPJ 11/21/17 (BORING LOG SA12-02,ARIAA12-01.GDT,LIBRARY GLB) -dense from 33'-38' -medium dense from 38'-40' Borehole terminated at 40 feet Groundwater Data: First encountered during drilling: 7-ft depth After 15 minutes: 7.5-ft depth Field Drilling Data: Coordinates: Hand-held GPS Unit Logged By: J. Ramos Driller: Eagle Drilling, Inc. Equipment: Truck-mounted drill rig Single flight auger: 0-40 ft Nomenclature Used on Boring Log Split Spoon () WC = Water Content (%) PL = Plastic Limit LL = Liquid Limit PI = Plasticity Index PP = Pocket Penetrometer (tsf) Thin-walled tube (T) N = SPT Blow Count -200 = % Passing #200 Sieve Arias Geoprofessionals Water encountered during drilling Delayed water reading Job No.:

42 Project: Escondido Creek Parkway Pavilion Kenedy, Texas Location: See Boring Location Plan Soil Description SANDY FAT CLAY (CH), stiff, dark brown STRATUM II Boring Log No. B-6 Sampling Date: 7/18/17 Coordinates: N28 o 49'12.5'' W97 o 51'29.2'' Backfill: Cuttings Depth (ft) SN WC PL LL PI PP N -200 T T CLAYEY SAND (SC), loose, brown STRATUM IA T T medium dense from 18'-23' dense from 23'-28' GPJ 11/21/17 (BORING LOG SA12-02,ARIAA12-01.GDT,LIBRARY GLB) -medium dense from 28'-33' Poorly-graded SAND with Clay (SP-SC), medium dense, tan STRATUM IA -very dense from 38'-40' Borehole terminated at 40 feet Groundwater Data: First encountered during drilling: 13-ft depth After 15 minutes: 12.5-ft depth Field Drilling Data: Coordinates: Hand-held GPS Unit Logged By: J. Ramos Driller: Eagle Drilling, Inc. Equipment: Truck-mounted drill rig Single flight auger: 0-40 ft Nomenclature Used on Boring Log Split Spoon () WC = Water Content (%) PL = Plastic Limit LL = Liquid Limit PI = Plasticity Index PP = Pocket Penetrometer (tsf) Thin-walled tube (T) N = SPT Blow Count -200 = % Passing #200 Sieve Arias Geoprofessionals /11" Water encountered during drilling Delayed water reading Job No.:

43 Project: Escondido Creek Parkway Amphitheater and Skate Park Kenedy, Texas Location: See Boring Location Plan Soil Description FAT CLAY (CH), stiff, dark brown STRATUM II Boring Log No. B-7 Sampling Date: 7/18/17 Coordinates: N28 o 49'15.5'' W97 o 51'26.1'' Backfill: Cuttings Depth (ft) SN WC PL LL PI PP N -200 T CLAYEY SAND (SC), medium dense, brown STRATUM IA 5 T T T SANDY LEAN CLAY (CL), stiff, brown STRATUM IIA very stiff from 18'-33' GPJ 11/21/17 (BORING LOG SA12-02,ARIAA12-01.GDT,LIBRARY GLB) -very hard from 33'-40' Borehole terminated at 40 feet Groundwater Data: First encountered during drilling: 16-ft depth After 15 minutes: 11.2-ft depth (19-ft open borehole depth) Field Drilling Data: Coordinates: Hand-held GPS Unit Logged By: J. Ramos Driller: Eagle Drilling, Inc. Equipment: Truck-mounted drill rig Single flight auger: 0-40 ft Nomenclature Used on Boring Log Split Spoon () WC = Water Content (%) PL = Plastic Limit LL = Liquid Limit PI = Plasticity Index PP = Pocket Penetrometer (tsf) Thin-walled tube (T) N = SPT Blow Count -200 = % Passing #200 Sieve Arias Geoprofessionals /10" Water encountered during drilling Delayed water reading Job No.:

44 Project: Escondido Creek Parkway Amphitheater and Pavement Kenedy, Texas Location: See Boring Location Plan Soil Description SANDY FAT CLAY (CH), stiff, dark brown Boring Log No. B-8 Sampling Date: 7/18/17 Coordinates: N28 o 49'21.5'' W97 o 51'23'' Backfill: Cuttings Depth (ft) SN WC PL LL PI PP N -200 STRATUM II firm from 2'-6' T CLAYEY SAND (SC), very loose, brown 6 STRATUM IA GPJ 11/21/17 (BORING LOG SA12-02,ARIAA12-01.GDT,LIBRARY GLB) Borehole terminated at 10 feet Groundwater Data: During drilling: Not encountered Field Drilling Data: Coordinates: Hand-held GPS Unit Logged By: J. Ramos Driller: Eagle Drilling, Inc. Equipment: Truck-mounted drill rig Single flight auger: 0-10 ft Nomenclature Used on Boring Log Split Spoon () WC = Water Content (%) PL = Plastic Limit LL = Liquid Limit PI = Plasticity Index PP = Pocket Penetrometer (tsf) 10 Thin-walled tube (T) 25 N = SPT Blow Count -200 = % Passing #200 Sieve Arias Geoprofessionals 2 Job No.:

45 Project: Escondido Creek Parkway Pavement Kenedy, Texas Location: See Boring Location Plan Soil Description CLAYEY SAND (SC), loose, dark brown Boring Log No. B-9 Sampling Date: 7/18/17 Coordinates: N28 o 49'14.6'' W97 o 51'34.9'' Backfill: Cuttings Depth (ft) SN WC PL LL PI PP N -200 STRATUM I T SANDY LEAN CLAY (CL), firm, dark brown GPJ 11/21/17 (BORING LOG SA12-02,ARIAA12-01.GDT,LIBRARY GLB) STRATUM II Borehole terminated at 10 feet Groundwater Data: During drilling: Not encountered Field Drilling Data: Coordinates: Hand-held GPS Unit Logged By: J. Ramos Driller: Eagle Drilling, Inc. Equipment: Truck-mounted drill rig Single flight auger: 0-10 ft Nomenclature Used on Boring Log Split Spoon () WC = Water Content (%) PL = Plastic Limit LL = Liquid Limit PI = Plasticity Index PP = Pocket Penetrometer (tsf) 10 Thin-walled tube (T) 13 N = SPT Blow Count -200 = % Passing #200 Sieve Arias Geoprofessionals Job No.:

46 KEY TO TERMS AND SYMBOLS USED ON BORING LOGS MAJOR DIVISIONS GROUP SYMBOLS DESCRIPTIONS COARSE-GRAINED SOILS More than half of material LARGER than No. 200 Sieve size GRAVELS SANDS More than Half of Coarse fraction is LARGER than No. 4 Sieve size More than half of Coarse fraction is SMALLER than No. 4 Sieve size Clean Gravels (little or no Fines) Gravels with Fines (Appreciable amount of Fines) Clean Sands (little or no Fines) Sands with Fines (Appreciable amount of Fines) GW GP GM GC SW SP SM SC Well-Graded Gravels, Gravel-Sand Mixtures, Little or no Fines Poorly-Graded Gravels, Gravel-Sand Mixtures, Little or no Fines Silty Gravels, Gravel-Sand-Silt Mixtures Clayey Gravels, Gravel-Sand-Clay Mixtures Well-Graded Sands, Gravelly Sands, Little or no Fines Poorly-Graded Sands, Gravelly Sands, Little or no Fines Silty Sands, Sand-Silt Mixtures Clayey Sands, Sand-Clay Mixtures FINE-GRAINED SOILS More than half of material SMALLER than No. 200 Sieve size SILTS & CLAYS SILTS & CLAYS Liquid Limit less than 50 Liquid Limit greater than 50 ML CL MH CH Inorganic Silts & Very Fine Sands, Rock Flour, Silty or Clayey Fine Sands or Clayey Silts with Slight Plasticity Inorganic Clays of Low to Medium Plasticity, Gravelly Clays, Sandy Clays, Silty Clays, Lean Clays Inorganic Silts, Micaceous or Diatomaceous Fine Sand or Silty Soils, Elastic Silts Inorganic Clays of High Plasticity, Fat Clays SANDSTONE Massive Sandstones, Sandstones with Gravel Clasts FORMATIONAL MATERIALS MARLSTONE LIMESTONE CLAYSTONE CHALK Indurated Argillaceous Limestones Massive or Weakly Bedded Limestones Mudstone or Massive Claystones Massive or Poorly Bedded Chalk Deposits MARINE CLAYS Cretaceous Clay Deposits GROUNDWATER Indicates Final Observed Groundwater Level Indicates Initial Observed Groundwater Location Density of Granular Soils Number of Blows per ft., N Over 50 Very Dense Consistency and Strength of Cohesive Soils Number of Blows per ft., N Relative Density Very Loose 4-10 Loose Below 2 Medium Dense Consistency Very Soft 2-4 Soft Medium (Firm) Stiff Very Stiff Unconfined Compressive Strength, qᵤ (tsf) Less than Over 30 Hard Over 4.0 Arias Geoprofessionals

47 Gravels Clean Gravels Cu 4 and 1 Cc 3 D (More than 50% of (Less than 5% fines C ) coarse fraction retained Cu < 4 and/or GP on No. 4 sieve) [Cc < 1 or Cc > 3] D Gravels with Fines Fines classify as ML or GM (More than 12% fines C ) MH Fines classify as CL or GC CH Sands Clean Sands Cu 6 and 1 Cc 3 D SW (50% or more of coarse (Less than 5% fines H ) Cu < 6 and/or SP fraction passes No. 4 [Cc < 1 or Cc > 3] D sieve) Sands with Fines SM organic Liquid limit - oven dried <0.75 Liquid limit - not dried HIGHLY ORGANIC SOILS Primarily organic matter, dark in color, and organic odor A Based on the material passing the 3-inch (75mm) 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 Cu = D 60 /D 10 Cc = (D 30 ) 2 E F G H I J K L M N O P Q KEY TO TERMS AND SYMBOLS USED ON BORING LOGS TABLE 1 Soil Classification Chart (ASTM D ) Criteria of 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 Fines classify as ML or (More than 12% fines H ) MH Fines classify as CL or SC CH Silts and Clays inorganic PI > 7 and plots on or CL above "A" line J Liquid limit less than 50 PI < 4 or plots below "A" ML line J organic Liquid limit - oven dried OL <0.75 Liquid limit - not dried Silts and Clays inorganic PI plots on or above "A" CH line Liquid limit 50 or more PI plots on or below "A" line D 10 x D 60 If soil contains 15% sand, add "with sand" to group name If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM If fines are organic, add "with organic fines" to group name Sand 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 If soil contains 15% gravel, add "with gravel" to group name If Atterberg limits plot in hatched area, soil is a CL-ML, silty clay If soil contains 15% to < 30% plus No. 200, add "with sand" or "with gravel," whichever is predominant If soil contains 30% plus No. 200, predominantly sand, add "sandy" to group name If soil contains 30% plus No. 200, predominantly gravel, add "gravelly" to group name PI 4 and plots on or above "A" line PI < 4 or plots below "A" line PI plots on or above "A" line PI plots below "A" line Soil Classification Group Group Name B Symbol GW Well-Graded Gravel E MH OH PT Poorly-Graded Gravel E Silty Gravel E,F,G Clayey Gravel E,F,G Well-Graded Sand I Poorly-Graded Sand I Silty Sand F,G,I Clayey Sand F,G,I Lean Clay K,L,M Silt K,L,M Organic Clay K,L,M,N Organi Silt K,L,M,O Fat Clay K,L,M Elastic Silt K,L,M Organic Clay K,L,M,P Organic Silt K,L,M,Q Peat TERMINOLOGY Boulders Over 12-inches (300mm) Parting Inclusion < 1/8-inch thick extending through samples Cobbles 12-inches to 3-inches (300mm to 75mm) Seam Inclusion 1/8-inch to 3-inches thick extending through sample Gravel 3-inches to No. 4 sieve (75mm to 4.75mm) Layer Inclusion > 3-inches thick extending through sample Sand No. 4 sieve to No. 200 sieve (4.75mm to 0.075mm) Silt or Clay Passing No. 200 sieve (0.075mm) Calcareous Containing appreciable quantities of calcium carbonate, generally nodular Stratified Laminated Fissured Slickensided Blocky Lensed Homogeneous Alternating layers of varying material or color with layers at least 6mm thick Alternating layers of varying material or color with the layers less than 6mm thick Breaks along definite planes of fracture with little resistance to fracturing Fracture planes appear polished or glossy sometimes striated Cohesive soil that can be broken down into small angular lumps which resist further breakdown Inclusion of small pockets of different soils, such as small lenses of sand scattered through a mass of clay Same color and appearance throughout Arias Geoprofessionals

48 KEY TO TERMS AND SYMBOLS USED ON BORING LOGS Hardness Classification of Intact Rock Class Hardness Field Test Approximate Range of Uniaxial Compression Strength kg/cm² (tons/ft²) I Extremely hard Many blows with geologic hammer required to break intact specimen. > 2,000 II Very hard Hand held specimen breaks with hammer end of pick under more than one blow. 2,000 1,000 III Hard Cannot be scraped or pealed with knife, hand held specimen can be broken with single moderate blow with pick. 1, IV Soft Can just be scraped or peeled with knife. Indentations 1mm to 3mm show in specimen with moderate blow with pick V Very soft Material crumbles under moderate blow with sharp end of pick and can be peeled with a knife, but is too hard to hand-trim for triaxial test specimen Rock Weathering Classifications Grade Symbol Diagnostic Features Fresh F No visible sign of Decomposition or discoloration. Rings under hammer impact. Slightly Weathered WS Slight discoloration inwards from open fractures, otherwise similar to F. Moderately Weathered Highly Weathered Completely Weathered Residual Soil WM WH WC RS Discoloration throughout. Weaker minerals such as feldspar decomposed. Strength somewhat less than fresh rock, but cores cannot be broken by hand or scraped by knife. Texture preserved. Most minerals somewhat decomposed. Specimens can be broken by hand with effort or shaved with knife. Core stones present in rock mass. Texture becoming indistinct, but fabric preserved. Minerals decomposed to soil, but fabric and structure preserved (Saprolite). Specimens easily crumbled or penetrated. Advanced state of decomposition resulting in plastic soils. Rock fabric and structure completely destroyed. Large volume change. Rock Discontinuity Spacing Description for Structural Features: Bedding, Foliation, or Flow Banding Very thickly (bedded, foliated, or banded) Thickly Medium Thinly Very thinly Description for Micro-Structural Features: Lamination, Foliation, or Cleavage Intensely (laminated, foliated, or cleaved) Very intensely Spacing More than 6 feet 2 6 feet 8 24 inches 2½ 8 inches ¾ 2½ inches Spacing ¼ ¾ inch Less than ¼ inch Description for Joints, Faults or Other Fractures Very widely (fractured or jointed) Widely Medium Closely Very closely Descriptions for Joints, Faults, or Other Fractures Extremely close RQD % Engineering Classification for in Situ Rock Quality Velocity Index Rock Mass Quality Excellent Good Fair Poor Very Poor Arias Geoprofessionals

49 APPENDIX C: FIELD AND LABORATORY EXPLORATION Arias & Associates, Inc. C-1 Arias Job No

50 FIELD AND LABORATORY EXPLORATION The field exploration program included drilling at selected locations within the site and intermittently sampling the encountered materials. The boreholes were drilled using single flight auger (ASTM D 1452). Samples of encountered materials were obtained using a splitbarrel sampler while performing the Standard Penetration Test (ASTM D 1586), or by taking material from the auger as it was advanced (ASTM D 1452). The sample depth interval and type of sampler used is included on the soil boring log. Arias field representative visually logged each recovered sample and placed a portion of the recovered sampled into a plastic bag for transport to our laboratory. SPT N-values and blow counts for those intervals where the sampler could not be advanced for the required 18-inch penetration are shown on the soil boring logs. If the test was terminated during the 6-inch seating interval or after 10 hammer blows were applied used and no advancement of the sampler was noted, the log denotes this condition as blow count during seating penetration. Pocket penetrometer values were determined on the undisturbed tube samples and the values are recorded on the boring logs. Arias performed soil mechanics laboratory tests on selected samples to aid in soil classification and to determine engineering properties. Tests commonly used in geotechnical exploration, the method used to perform the test, and the column designation on the boring logs where data are reported are summarized as follows: Test Name Test Method Log Designation Water (moisture) content of soil and rock by mass ASTM D 2216 Wc Liquid limit, plastic limit, and plasticity index of soils ASTM D 4318 LL, PL, PI Amount of material in soils finer than the No. 200 sieve ASTM D The laboratory results are reported on the soil boring logs. Arias & Associates, Inc. C-2 Arias Job No

51 APPENDIX D: ASFE INFORMATION GEOTECHNICAL REPORT Arias & Associates, Inc. D-1 Arias Job No

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54 APPENDIX E: PROJECT QUALITY AURANCE Arias & Associates, Inc. E-1 Arias Job No

55 PROJECT QUALITY AURANCE A Message to Owners Construction materials engineering and testing (CoMET) consultants perform qualityassurance (QA) services to evaluate the degree to which constructors are achieving the specified conditions they re contractually obligated to achieve. Done right, QA can save you time and money; prevent unanticipatedconditions claims, change orders, and disputes; and reduce short-term and long-term risks, especially by detecting molehills before they grow into mountains. Fact: Most CoMET firms are not accredited, and the quality of those that are varies significantly. Accreditation which is important nonetheless means that a facility met an accrediting body s minimum criteria. Some firms practice at a much higher level; others just barely scrape by. And what an accrediting body typically evaluates management, staff, facilities, and equipment can change substantially before the next review, two, three, or more years from now. Done right, QA can save you time and money; prevent claims and disputes; and reduce risks. Many owners don t do QA right because they follow bad advice. Many owners don t do QA right because they follow bad advice; e.g., CoMET consultants are all the same. They all have accredited facilities and certified personnel. Go with the low bidder. But there s no such thing as a standard QA scope of service, meaning that to bid low each interested firms must propose the cheapest QA service it can live with, jeopardizing service quality and aggravating risk for the entire project team. Besides, the advice is based on misinformation. Most CoMET firms are not accredited. It s dangerous to assume CoMET personnel are certified. Fact: It s dangerous to assume CoMET personnel are certified. Many have no credentials at all; some are certified by organizations of questionable merit, while others have a valid certification, but not for the services they re assigned. Some CoMET firms the low-cost providers want you to believe that price is the only difference between QA providers. It s not, of course. Firms that sell low price typically lack the facilities, equipment, personnel, and insurance quality-oriented firms invest in to achieve the reliability concerned owners need to achieve quality in quality assurance Colesville Road Suite G106 Silver Spring, Maryland Voice: Fax: info@asfe.org Internet: 1

56 PROJECT QUALITY AURANCE Firms that sell low price typically lack the facilities, equipment, personnel, and insurance quality-oriented firms invest in to achieve the reliability concerned owners need to achieve quality in quality assurance. To derive maximum value from your investment in QA, require the CoMET firm s project manager to serve actively on the project team from beginning to end, a level of service that s relatively inexpensive and can pay huge dividends. During the project s planning and design stages, experienced CoMET professionals can help the design team develop uniform technical specifications and establish appropriate observation, testing, and instrumentation procedures and protocols. They can also analyze plans and specs much as constructors do, looking for the little errors, omissions, conflicts, and ambiguities that often become the basis for big extras and big claims. They can provide guidance about operations that need closer review than others, because of their criticality or potential for error or abuse. They can also relate their experience with the various constructors that have expressed interest in your project. To derive maximum value, require the project manager to serve actively on the project team from beginning to end. CoMET consultants construction-phase QA services focus on two distinct issues: those that relate to geotechnical engineering and those that relate to the other elements of construction. The geotechnical issues are critically important because they are essential to the observational method geotechnical engineers use to significantly reduce the amount of sampling they d otherwise require. They apply the observational method by developing a sampling plan for a project, and then assigning field representatives to ensure samples are properly obtained, packaged, and transported. The engineers review the samples and, typically, have them tested in their own laboratories. They use the information they derive to characterize the site s subsurface and develop preliminary recommendations for the structure s foundations and for the specifications of various geo elements, like excavations, site grading, foundationbearing grades, and roadway and parking-lot preparation and surfacing. Geotechnical engineers cannot finalize their recommendations until they or their field representatives are on site to observe what s excavated to verify that the subsurface conditions the engineers predicted are those that actually exist. When unanticipated conditions are observed, recommendations and/or specifications should be modified. Responding to client requests, many geotechnical-engineering firms have expanded their field-services mix, so they re able to perform overall construction QA, encompassing in addition to geotechnical issues reinforced concrete, structural steel, welds, fireproofing, and so on. Unfortunately, that s caused some confusion. Believing that all CoMET consultants are alike, some owners take bids for the overall CoMET package, including the geotechnical field observation. Entrusting geotechnical field observation to someone other than the geotechnical engineer of record (GER) creates a significant risk. 2

57 PROJECT QUALITY AURANCE Geotechnical engineers cannot finalize their recommendations until they are on site to verify that the subsurface conditions they predicted are those that actually exist. Entrusting geotechnical field observation to someone other than the geotechnical engineer of record (GER) creates a significant risk. GERs have developed a variety of protocols to optimize the quality of their field-observation procedures. Quality-focused GERs meet with their field representatives before they leave for a project site, to brief them on what to look for and where, when, and how to look. (No one can duplicate this briefing, because no one else knows as much about a project s geotechnical issues.) And once they arrive at a project site, the field representatives know to maintain timely, effective communication with the GER, because that s what the GER has trained them to do. By contrast, it s extremely rare for a different firm s field personnel to contact the GER, even when they re concerned or confused about what they observe, because they regard the GER s firm as the competition. Divorcing the GER from geotechnical field operations is almost always penny-wise and pound-foolish. Still, because owners are given bad advice, it s commonly done, helping to explain why geo issues are the number-one source of construction-industry claims and disputes. Divorcing the GER from geotechnical field operations is almost always penny-wise and pound-foolish, helping to explain why geo issues are the number-one source of constructionindustry claims and disputes. To derive the biggest bang for the QA buck, identify three or even four quality-focused CoMET consultants. (If you don t know any, use the Find a Geoprofessional service available free at Ask about the firms ongoing and recent projects and the clients and client representatives involved; insist upon receiving verification of all claimed accreditations, certifications, licenses, and insurance coverages. Insist upon receiving verification of all claimed accreditations, certifications, licenses, and insurance coverages. Once you identify the two or three most qualified firms, meet with their representatives, preferably at their own facility, so you can inspect their laboratory, speak with management and technical staff, and form an opinion about the firm s capabilities and attitude. Insist that each firm s designated project manager participate in the meeting. You will benefit when that individual is a seasoned QA professional familiar with construction s rough-and-tumble. Ask about others the firm will assign, too. There s no substitute for experienced personnel who are familiar with the codes and standards involved and know how to: read and interpret plans and specifications; perform the necessary observation, inspection, and testing; document their observations and findings; interact with constructors personnel; and respond to the unexpected. Important: Many of the services CoMET QA field representatives perform like observing operations and outcomes require the good judgment afforded by extensive training and experience, especially in situations where standard operating procedures do not apply. You need to know who will be exercising that judgment: a 15-year veteran or a rookie? 3

58 PROJECT QUALITY AURANCE Many of the services CoMET QA field representatives perform require good judgment. Also consider the tools CoMET personnel use. Some firms are passionate about proper calibration; others, less so. Passion is a good thing! Ask to see the firm s calibration records. If the firm doesn t have any, or if they are not current, be cautious. You cannot trust test results derived using equipment that may be out of calibration. Also ask a firm s representatives about their reporting practices, including report distribution, how they handle notifications of nonconformance, and how they resolve complaints. Scope flexibility is needed to deal promptly with the unanticipated. For financing purposes, some owners require the constructor to pay for CoMET services. Consider an alternative approach so you don t convert the constructor into the CoMET consultant s client. If it s essential for you to fund QA via the constructor, have the CoMET fee included as an allowance in the bid documents. This arrangement ensures that you remain the CoMET consultant s client, and it prevents the CoMET fee from becoming part of the constructor s bid-price competition. (Note that the International Building Code (IBC) requires the owner to pay for Special Inspection (SI) services commonly performed by the CoMET consultant as a service separate from QA, to help ensure the SI services integrity. Because failure to comply could result in denial of an occupancy or use permit, having a contractual agreement that conforms to the IBC mandate is essential.) If it s essential for you to fund QA via the constructor, have the CoMET fee included as an allowance in the bid documents. Note, too, that the International Building Code (IBC) requires the owner to pay for Special Inspection (SI) services. CoMET consultants can usually quote their fees as unit fees, unit fees with estimated total (invoiced on a unit-fee basis), or lumpsum (invoiced on a percent-completion basis referenced to a schedule of values). No matter which method is used, estimated quantities need to be realistic. Some CoMET firms lower their total-fee estimates by using quantities they know are too low and then request change orders long before QA is complete. Once you and the CoMET consultant settle on the scope of service and fee, enter into a written contract. Established CoMET firms have their own contracts; most owners sign them. Some owners prefer to use different contracts, but that can be a mistake when the contract was prepared for construction services. Professional services are different. Wholly avoidable problems occur when a contract includes provisions that don t apply to the services involved and fail to include those that do. Some owners create wholly avoidable problems by using a contract prepared for construction services. 4

59 PROJECT QUALITY AURANCE This final note: CoMET consultants perform QA for owners, not constructors. While constructors are commonly allowed to review QA reports as a courtesy, you need to make it clear that constructors do not have a legal right to rely on those reports; i.e., if constructors want to forgo their own observation and testing and rely on results derived from a scope created to meet only the needs of the owner, they must do so at their own risk. In all too many cases where owners have not made that clear, some constructors have alleged that they did have a legal right to rely on QA reports and, as a result, the CoMET consultant not they are responsible for their failure to deliver what they contractually promised to provide. The outcome can be delays and disputes that entangle you and all other principal project participants. Avoid that. Rely on a CoMET firm that possesses the resources and attitude needed to manage this and other risks as an element of a quality-focused service. Involve the firm early. Keep it engaged. And listen to what the CoMET consultant says. A good CoMET consultant can provide great value. For more information, speak with your ASFE-Member CoMET consultant or contact ASFE directly Colesville Road Suite G106 Silver Spring, Maryland Voice: Fax: info@asfe.org Internet: 5