SUBSURFACE EXPLORATION, LABORATORY TESTING PROGRAM, AND FOUNDATION AND PAVEMENT RECOMMENDATIONS

Transcription

1 GEOTECHNICAL ENGINEERING CONSTRUCTION MATERIALS ENGINEERING & TESTING SOILS ASPHALT CONCRETE Elsasser Architectural Inc. P.O. Box 833 Georgetown, Texas Attention: Richard Elsasser SUBJECT: SUBSURFACE EXPLORATION, LABORATORY TESTING PROGRAM, AND FOUNDATION AND PAVEMENT RECOMMENDATIONS CLAY COOLEY NISSAN OF AUSTIN 4914 IH-35 FRONTAGE ROAD AUSTIN, TEXAS U Dear Mr. Elsasser, In accordance with our agreement, Rock Engineering & Testing Laboratory, Inc. (RETL) has conducted a subsurface exploration, laboratory testing program, and foundation and pavement evaluation for the above referenced project. The results of this exploration, together with our recommendations, are presented in this electronic copy. RETL will provide up to two (2) versions of this report in hard copy at the request of the client. Often, because of design and construction details that occur on a project, questions arise concerning soil conditions. RETL would be pleased to continue its role as the Geotechnical Engineer during project implementation. RETL also has great interest in providing materials testing and observation services during the construction of the project. If you will advise us of the appropriate time to discuss these engineering services, we will be pleased to meet with you at your convenience. Sincerely, Arnie K. Hammock, P.E. Principal Engineer - Round Rock ROCK ENGINEERING & TESTING LABORATORY, INC. (TBPE FIRM NO. 2101) No. 1 Roundville Lane Round Rock, Texas, Office: (512) Fax: (512)

2

3 TABLE OF CONTENTS Page INTRODUCTION... 1 Authorization... 1 Purpose and Scope... 1 General... 1 DESCRIPTION OF SITE... 2 FIELD EXPLORATION... 3 Scope... 3 Drilling and Sampling Procedures... 3 Field Tests and Measurements... 4 LABORATORY TESTING PROGRAM... 4 SUBSURFACE CONDITIONS... 5 General... 5 Soil Conditions... 5 Seismic Site Class... 6 Groundwater Observations... 6 FOUNDATION DISCUSSION AND RECOMMENDATIONS... 6 Project Description... 6 PVR Discussion... 7 Drilled Pier Recommendations... 7 Drilled, Cast-in-Place, Pier Construction Considerations... 8 Floor Slabs... 9 PAVEMENT CONSIDERATIONS Flexible Pavement Rigid Concrete Pavements Pavement Material Recommendations SITE IMPROVEMENT METHODS General Considerations Concrete Flatwork CONSTRUCTION CONSIDERATIONS General Site Preparation Subgrade Preparation Select Fill Materials Earthwork and Foundation Acceptance Vapor Retarder Expansion Joints GENERAL COMMENTS APPENDIX Boring Location Plan Logs of Boring B-1 and B-2 Key to Soil Classifications

4 INTRODUCTION This report presents the results of a soils exploration and foundation and pavement evaluation for the proposed Site Improvements Project Phase II to be constructed at the existing Clay Cooley Nissan of Austin dealership located at 4914 IH-35 Frontage Road in. This study was conducted for Elsasser Architectural, Inc. Authorization The work for this project was performed in accordance with RETL Proposal No. P022916A dated February 29, The proposal contained a scope of work, fee, and limitations. The proposal was approved and signed by Richard Elsasser representing Elsasser Architectural, Inc. and returned to RETL via . Purpose and Scope The purpose of this exploration was to evaluate the soil, rock, and groundwater conditions at the subject site and to provide foundation and pavement recommendations suitable for the proposed project. The scope of the exploration and evaluation included the following: Subsurface exploration Field and laboratory testing Engineering analysis and evaluation of the subsurface materials Provision of foundation recommendations Preparation of this report Our scope of services did not include an environmental assessment. Any statements in this report, or on the Logs of Boring, regarding odors, colors, unusual or suspicious items or conditions are strictly for the information of the client. General The exploration and analysis of the subsurface conditions reported herein are considered sufficient in detail and scope to form a reasonable basis for the foundation and pavement designs. The recommendations submitted for the proposed project are based on the available soil information and the preliminary design details provided in dated February 22, 2016 prepared by James Drake, representing Elsasser Architectural, Inc., which included a plan titled A NEW AUTOMOTIVE FACILITY FOR: NISSAN AUSTIN (Sheet A1.0) as well as a project description. If the civil or structural engineers require additional soil parameters to complete the foundation design, and this information can be obtained from the soil data and laboratory tests performed within the scope of work included in our proposal for the project, RETL will provide the requested information as a supplement to this report. 1 of 17

5 The Geotechnical Engineer states that the findings, recommendations, specifications or professional advice contained herein, have been presented after being prepared in a manner consistent with the level of care and skill ordinarily exercised by reputable members of the Geotechnical Engineer s profession practicing contemporaneously under similar conditions in the locality of the project. RETL operates in general accordance with Standard Practice for Minimum Requirements for Agencies Engaged in the Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction (ASTM D3740). No other representations are expressed or implied, and no warranty or guarantee is included or intended. This report has been prepared for the exclusive use of Elsasser Architectural, Inc. for the specific application towards the proposed Site Improvements Project Phase II to be completed in. DESCRIPTION OF SITE The subject site is located 4914 IH-35 Frontage Road in. The site is located on the west side of IH-35, north of Colonial Park Boulevard, as depicted in the aerial imagery below: 2 of 17

6 At the time of our subsurface exploration, the subject site was developed with a multi-story structure surrounded by paving areas and drive through lanes; the surface of the site was predominantly covered with asphaltic concrete paving. Based on visual observations, the overall site appeared to slope down from the northwest towards the southeast. The paved areas were firm and the drilling crew experienced little difficulty moving about the site. Scope FIELD EXPLORATION The subsurface exploration, completed in order to evaluate the engineering characteristics of the foundation and pavement materials, included a reconnaissance of the project site, drilling the test borings, and recovering disturbed split spoon samples. A total of two (2) test borings were performed at the site within the proposed building expansion area. Each test boring was completed to a depth of approximately 40-feet below the existing ground surface. RETL determined the number, depth, and location of the test borings, as well as located the test borings at the subject site using the referenced site plan. The test borings were located where on-site obstructions and marked underground utilities would allow. The drilling operations were performed by the RETL drilling crew. A Boring Location Plan, which is a reproduction of the referenced site plan provided to RETL, is provided in the Appendix of this report. Upon completion of the drilling operations and after obtaining groundwater observations, the bore holes were backfilled with excavated soil and rock, asphalt surface patches applied, and the site cleaned as required. Drilling and Sampling Procedures The test borings were performed using a drilling rig equipped with a rotary head and air rotary drilling methods were used to advance the boreholes to the desired termination depths. Disturbed samples were obtained employing split-barrel sampling procedures in general accordance with the procedures for Penetration Test and Split-Barrel Sampling of Soils (ASTM D1586). The soil and rock samples were placed in plastic bags, marked according to test boring number, depth and any other pertinent field data, and stored in special containers. At the completion of the drilling operations, the samples were delivered to RETL s laboratory for testing. 3 of 17

7 Field Tests and Measurements Penetration Tests - During the sampling procedures, standard penetration tests (SPT) were performed to obtain the standard penetration value of the soil. The standard penetration value (N) is defined as the number of blows of a 140-pound hammer, falling 30-inches, required to advance the split-barrel sampler 1-foot into the soil. The sampler is lowered to the bottom of the previously cleaned drill hole and advanced by blows from the hammer. The number of blows is recorded for each of three successive 6-inch penetrations. The N value is obtained by adding the second and third 6-inch increment number of blows. The results of standard penetration tests indicate the relative density of cohesionless soils and comparative consistency of cohesive soils, thereby providing a basis for estimating the relative strength and compressibility of the soil profile components. Water Level Observations - Water level observations were obtained during the test boring operations and are noted on the Logs of Boring provided in the Appendix. The amount of water in open boreholes largely depends on the permeability of the soils encountered at the boring locations. In relatively pervious soils, such as sandy soils, the indicated depths are usually reliable groundwater levels. In relatively impervious soils, a suitable estimate of the groundwater depth may not be possible, even after several days of observation. Seasonal variations, temperature, land-use, proximity to a body of water, and recent rainfall conditions may influence the depth to the groundwater. Ground Surface Elevations - The ground surface elevation at the test boring locations was estimated based on the topographic information presented on a plan titled Grading Plan prepared by kbge. The depths referred to in this report are measured from the ground surface at the test boring locations during the time of our field investigation. LABORATORY TESTING PROGRAM In addition to the field investigation, a laboratory-testing program was conducted to determine additional pertinent engineering characteristics of the subsurface materials necessary in analyzing the behavior of the foundation and pavement systems for the proposed project. The laboratory-testing program included performing supplementary visual classification (ASTM D2487) on the samples obtained. In addition, selected samples were subjected to water content tests (ASTM D2216), Atterberg limits tests (ASTM D4318), and percent material finer than the #200 sieve tests (ASTM D1140). The laboratory-testing program was conducted in general accordance with applicable ASTM Specifications. The results of the testing are presented on the accompanying Logs of Boring provided in the Appendix. 4 of 17

8 General SUBSURFACE CONDITIONS The types of foundation bearing materials encountered in the test borings have been visually classified and are described in detail on the Logs of Boring. The results of the standard penetration tests, water level observations, and laboratory tests are presented on the Logs of Boring in numerical form. Representative samples of the subsurface materials were placed in polyethylene bags and are now stored in the laboratory for further analysis, if desired. Unless notified to the contrary, the samples will be disposed of three (3) months after issuance of this report. The stratification of the soil and rock, as shown on the Logs of Boring, represents the subsurface conditions at the actual test boring locations. Variations may occur between, or beyond, the boring locations. Lines of demarcation represent the approximate boundary between different soil and rock types, but the transition may be gradual, or not clearly defined. It should be noted that, whereby the test borings were drilled and sampled by experienced drillers, it is sometimes difficult to record changes in stratification within narrow limits. In the absence of foreign substances, it is also difficult to distinguish between discolored soils and clean soil fill. Soil Conditions The subsurface conditions encountered in the test borings drilled at the subject site have been summarized and soil and rock properties including classification, strength, plasticity, and grain size are provided in the following tables: SUMMARY OF SOIL CONDITIONS D Description LL PI C θ e -#200 N 0-1 ASPHALT / BASE ½ Fat Clayey Sand / Gravel FILL* , N= ½-8 Sandy Fat CLAY , N=10 to 6-50/ Weathered CHALK / CHALK * Denotes encountered in Test Boring B-2 to a depth of 4-feet , N=26-50/3 to 50/0 Where: D = Depth in feet below existing grade LL = Liquid Limit (%) PI = Plasticity Index C = Average Soil Cohesion, psf (undrained) θ = Angle of Internal Friction, deg. (undrained) e = Effective Soil Unit Weight, pcf -#200= Percent Material Finer than a #200 Sieve N = Standard Penetration Value range, blows per foot 5 of 17

9 Based on the results obtained during the field investigation program, it should be noted that the chalk materials encountered at this site are very hard in consistency and that high powered rock excavation equipment and other comparable heavy duty earth moving equipment will be necessary to excavate these materials. Seismic Site Class The field investigation did not include a 100-foot deep test boring, therefore, the soil/rock properties are not known in sufficient detail to determine the Site Class per IBC. This site has surficial layers of stiff to very stiff fat clayey fill soils underlain by stiff to very hard sandy fat clay to the 8-foot depth; the sandy fat clay soils are underlain very hard chalk materials which extend to the boring termination depths of 40-feet. Table Site Class Definitions, indicates that Site Class C materials should have soil undrained shear strengths greater than 2,000 psf and standard penetration resistances greater than 50 blows per foot. The subsurface materials extending to a depth of 40-feet at this site generally have strengths similar to Site Class C materials; therefore, RETL recommends that Site Class C, very dense soil and soft rock profile be assumed. Groundwater Observations Groundwater was not encountered during the drilling operations nor measured in the test borings upon completion of the drilling. Based on observations made in the field and moisture contents obtained in the laboratory, it appears that groundwater at this site during the time of our field investigation is greater than the 40-foot depth, the deepest test boring termination depths. It should be noted that water levels in open boreholes may require anywhere from several hours to several days to stabilize depending on the permeability of the soils and that groundwater levels at this site may be subject to seasonal conditions, recent rainfall, drought or temperature effects. Project Description FOUNDATION DISCUSSION AND RECOMMENDATIONS Based on the project information provided in the referenced , RETL understands that Phase II of the project will consist of the following: Construction of a New Showroom structure (Finish Floor Elevation = El ) o Expansion of the existing building at the referenced address o Demolition of existing service porte-cochere and paving surface areas to accommodate new construction o Installation of rigid concrete pavement and parking areas Based on similar type projects completed in the vicinity of the subject site, it is anticipated that the proposed structure will be supported by a deep foundation system with a soil-supported concrete floor slab. 6 of 17

10 PVR Discussion The laboratory test results indicate the upper fat clayey Fill and sandy fat clay soils located within the active zone at this site are high to very high in plasticity; the underlying chalk materials are low to moderate in plasticity. The maximum calculated total potential vertical rise (PVR), based on the subsurface materials encountered at the subject site, ranges from 1½-inch to 2-inches. These PVR values were calculated using the Texas Department of Transportation Method TEX-124E and took into account the depth of the active zone, estimated to extend to a maximum depth of approximately 8-feet, or the depth to chalk, and the Atterberg limits test results of the soils encountered within the active zone. The estimated PVR values provided are based on a concrete floor or flatwork system applying a sustained surcharge load of approximately 1.0 pound per square inch on the subgrade soils. The values represent the vertical rise that can be experienced by dry subsoils if they are subjected to conditions that allow them to become saturated, such as poor drainage. Using dry soil conditions to calculate the PVR is generally considered the worst case scenario. The actual movement of the subsoils is dependent upon their change in moisture content. Differential vertical movements can potentially be equal to the expected total movements. Differential vertical movements associated with the soils at this site may occur over a distance on the order of 8-feet, or approximately the maximum depth of the active zone. Drilled Pier Recommendations Based on the subsurface materials at this site, a straight shaft drilled pier foundation system may be used to provide support of the structural loads for the proposed structure. The structural designer can utilize an allowable end bearing value of 25,000 pounds per square foot for straight shaft drilled piers bearing at least two (2) pier diameters into competent chalk materials. Competent chalk materials were encountered an approximate elevation of El 603 feet at Test Boring B-1 and at an approximate elevation of El 595 feet at Test Boring B-2. In addition, an allowable unit skin friction value of 1,500 pounds per square foot may be used for that portion of the pier shaft in contact with the chalk materials below an elevation of approximately El 605 feet. The recommended allowable end bearing and unit skin friction values utilize a safety factor of 3 and 2, respectively to prevent shear failure. Resistance to uplift can be calculated by taking 70-percent of the friction capacity of a straight shaft drilled pier. 7 of 17

11 The following LPILE parameters may be used to evaluate the lateral capacity of the piers: Description C θ e K E50 Weathered CHALK / CHALK 5, , Where: D = Depth in feet below existing grade LL = Liquid Limit (%) PI = Plasticity Index C = Average Soil Cohesion, psf (undrained) θ = Angle of Internal Friction, deg. (undrained) e = Effective Soil Unit Weight, pcf K = modulus of subgrade reaction (pci) E50 = 50% strain value E50 values were estimated from known correlations. Straight shaft drilled piers should have a minimum diameter of 18-inches and should be spaced no closer than three (3) pier diameters apart measured center to center. Drilled piers at this site should be adequately reinforced with a minimum of 1-percent of the cross-sectional area of the pier shaft throughout the depth of the pier to withstand uplift forces. Straight shaft drilled piers designed using the parameters provided and bearing into the recommended chalk materials should undergo very little permanent settlement. Drilled, Cast-in-Place, Pier Construction Considerations Based on subsurface conditions encountered in the test borings drilled at the subject site, temporary steel casing will likely not be required to successfully install the straight shaft drilled piers at this site. Temporary steel casing, to be paid for by the linear foot, should be included in the bid documents as an add-on. Temporary steel casing is typically used as a method to control soil sloughing and groundwater inflow. Concrete should be placed in the pier excavations as soon as possible after loose material has been removed, the pier excavation inspected and reinforcing steel installed. Pier concrete shall be placed within 8-hours of completion of the drilling of any given pier; pier excavations shall not be left open overnight. A relatively high slump concrete mix (6 to 7-inches) is suggested to minimize aggregate segregation caused by the reinforcing steel. Free fall of concrete into the pier excavation is permitted provided the concrete can be placed into the pier excavation without striking the sides of the excavation or hitting the rebar. It should be noted that research has shown that free fall concrete guided at the top of the excavation to avoid contact with the sides of the pier excavation and reinforcing steel can drop more than 80-feet without any measurable segregation. In addition, the research has shown that as long as the concrete drop is in air, the strength of the concrete was not adversely affected. 8 of 17

12 In situations where it is impossible for the concrete to fall freely without striking the rebar cage or sides of the pier excavation the free fall should be limited to 10-feet, or placed with a tremie. Pier excavations should not be allowed to stay open overnight. The successful placement of a drilled pier foundation system is dependent on the expertise of the drilled pier foundation contractor. A test pier excavation should be performed at the site to verify the contractor s construction methods and to identify any potential groundwater infiltration and soil sloughing problems. The Geotechnical Engineer, or his designated representative, should be present to witness the installation of all the drilled piers, including the test pier excavation. Floor Slabs Soil supported floor slabs may be used in conjunction with the drilled pier foundation system. Soil supported floor slabs may be subject to vertical movements, as discussed earlier in this report. Even slight differential movements may cause distress to interior wall partitions supported by a soil supported floor slab system resulting in cosmetic damage. This amount of movement should be understood and addressed during the design phase of the proposed structure planned for construction at this site. Utilities which project through soil supported floor slabs should be designed with either some degree of flexibility, or with sleeves, in order to prevent damage to these lines should movement occur. It is recommended that the guidelines provided in the Site Preparation section of this report be performed in areas where soil supported floor slab systems are selected. Appropriate structural design details are usually required to account for differential movements that could occur between the relatively fixed foundation elements and a soil supported floor slab. Since the PVR condition at this site will be approximately 1-inch or less after the recommendations in the Site Preparation section of the report have been performed in the building areas, differential movements between the floor slab and foundation elements should be minimal. Soil supported floor slabs may be attached to the pier supported foundation elements. However, a hinge crack in the slab located approximately 5-feet away from the perimeter should be expected. The slabs should therefore be sufficiently reinforced to resist distress at the crack locations and control joints in the slab installed. A minimum 6-inch void space should be constructed beneath grade beams spanning between the piers and beneath pier caps. Grade beams spanning between piers should be structurally connected to the piers. A structurally suspended floor slab should be utilized in conjunction with the drilled piers if relatively no floor slab movements can be tolerated and a high level of performance is desired from the floor slab system. It is recommended that the structural slab be constructed with a minimum 6-inch void space between the slab and the soil at the site. A vapor barrier should be placed beneath the floor slab in order to break the rise of capillary moisture. 9 of 17

13 A building pad constructed with properly compacted Engineered Fill soils as recommended in this report will result in a subgrade modulus (k) of 150 pci. The k value presented in this report is based on empirical equations that estimate the results of plate load tests. For design purposes, the following friction factors should be used: Slab over Base Layer: 0.35 Slab over Moisture Barrier: 0.20 Adequate reinforcement and control joints shall be provided to limit cracking of the floor slab resulting from any differential movement or shrinkage. Rolled mesh welded wire reinforcement shall not be used due to curling and difficulty in handling. Sawed joints for un-reinforced concrete shall be no more than three (3) times (in feet) the slab thickness in inches. For example, for a 5-inch thick slab, use a center-to-center spacing of 15-feet or less. Depth of the sawed joints shall be at least ¼ the slab thickness. The surface of the building pad shall be proofrolled with at least a 15-ton pneumatic roller or equivalent then followed with a smooth drum roller just prior to concrete slab-on-grade construction. The finished surface of the building pad shall be deemed acceptable if there is no vertical surface deviation greater than one-quarter ¼-inch. PAVEMENT CONSIDERATIONS In designing the proposed automobile access driveways and parking areas, the existing subgrade conditions must be considered together with the expected traffic use and loading conditions. The conditions that influence pavement design can be summarized as follows: 1. Bearing values of the subgrade. These values can be represented by a California Bearing Ratio (CBR) for the design of flexible asphalt pavements, or a Modulus of Subgrade Reaction (K) for rigid concrete pavements. 2. Vehicular traffic, in terms of the number and frequency of vehicles and their range of axle loads. 3. Probable increase in vehicular use over the life of the pavement. 4. The availability of suitable materials to be used in the construction of the pavement and their relative costs. Specific laboratory testing to define the subgrade strength (i.e. CBR/K values) have not been performed for this analysis. Based upon local experience and the plasticity indices of the subgrade soils, the CBR and K value for design has been selected as 3 and 150 pci, respectively. 10 of 17

14 Since traffic counts and design vehicles have not been provided, it is possible to provide a non-engineered pavement section suitable for light, medium, and heavy-duty service based on pavement sections that have provided adequate serviceability for similar type applications. Allowances for proper drainage and proper material selection of base materials are most important for performance of asphaltic pavements. Ruts and birdbaths in asphalt pavements allow for quick deterioration of the pavement primarily due to saturation of the underlying base materials and subgrade soils. Automobile access driveways and parking areas can be designed with either a flexible or rigid pavement. It is important that the exposed subgrade is properly prepared prior to pavement installation. Flexible Pavement The following flexible pavement sections were determined using the above information and assumptions in conjunction with Chart 3.1 included in the Guide for Design of Pavement Structures, published by AASHTO in The recommended light, medium, and heavy-duty flexible pavement section, using the locally available base material, are provided in the following tables: Flexible Pavement (Automobile Parking Areas) Pavement Constituent Light Duty Medium Duty Heavy Duty HMAC Type D 1½ 2 2½ Crushed Limestone Base Material 8 10" 12 Compacted Subgrade Rigid Concrete Pavements The use of concrete for paving has become more prevalent in recent years due to the long term maintenance cost benefits of concrete pavement compared to asphalt pavements. Concrete pavement is recommended in areas that receive continuous repetitive traffic such as the parking lot entrances, loading areas, and trash dump areas. The recommended light, medium, and heavy-duty rigid concrete pavement sections are provided in the following table: Rigid Pavement Light Duty Medium Duty Heavy Duty Reinforced Concrete 5½" 6" 7 Compacted Subgrade 8" 8" 8 11 of 17

15 The heavy-duty concrete at the location of the trash dumpster should be 7-inches in thickness and be large enough to accommodate both the front and rear wheels of the vehicles used to pick up the trash dumpsters. Maintenance or operations managers need to stress the importance of placing the trash dumpsters in their proper locations to reduce the distress trash pickup operations place on the pavement. Pavement Material Recommendations Compacted Subgrade - After surface organics and deleterious materials have been removed and the desired subgrade elevation has been achieved, the upper 8-inches of exposed subgrade soils should be compacted to at least 92-percent of the maximum dry density as determined by the modified Proctor test (ASTM D1557). The moisture content of the subgrade soils should be maintained between 1-percent below to 3-percent above the optimum moisture content. Compacted Fill - After subgrade preparation is complete, the placement of properly compacted Fill soils may begin in the paved areas to raise the grades, where required. Fill soils may consist of on-site soils free of organics and other deleterious materials, or imported soils with plasticity indices similar to the on-site soils. The Fill used to raise the grade in the proposed parking and driveway areas should be placed in no greater than 8-inch thick loose lifts. Each lift should be compacted to at least 92-percent of the maximum dry density as determined by the modified Proctor test (ASTM D1557). The moisture content of the fill soils should be maintained between 1-percent below to 3-percent above the optimum moisture content. Fill slopes, with a 2-percent drainage gradient, shall extend beyond the edge of pavement sections at least 10-feet prior to sloping. Long-term slopes of FILL material shall not be steeper than 3H:1V. Base Material - Base materials in flexible pavement areas should meet the requirements set forth in the Texas Department of Transportation (TxDOT) 2014 Standard Specifications for Construction of Highways, Streets and Bridges; Item 247, Type A, Grade 2 or better. The base material should be placed in maximum 8-inch thick loose lifts and compacted to at least 95-percent of the maximum dry density as determined by the modified Proctor test (ASTM D1557). The moisture content of the base materials should be maintained within 2-percent of the optimum moisture content. Hot Mix Asphaltic Concrete - Hot mix asphaltic concrete should meet the requirements set forth in TxDOT Item 340; Type D surface course. The asphaltic concrete should be compacted to between 92 and 96-percent of the laboratory density. Rigid Concrete - The concrete pavement should be properly reinforced and jointed, as per ACI, and should have a minimum 28-day compressive strength of 3,500 psi. Expansion joints should be spaced no greater than 60-feet and should be sealed with an appropriate sealant so that moisture infiltration into the subgrade soils and resultant concrete deterioration at the joints is minimized. 12 of 17

16 Control joint spacing should not exceed 15-feet and preferably less to adequately control cracking. The joints should be thoroughly cleaned and sealant should be installed without overfilling before the pavement is opened to traffic. Based on past experience with concrete pavements supported on similar subgrade soils, RETL recommends that reinforcement for concrete pavement consist of #4 bars (½-inch diameter) spaced at 14, 16, and 18-inches on center each way for heavy, medium, and light-duty pavement options, respectively. The splice length for #4 bars should not be less than 20-inches. General Considerations SITE IMPROVEMENT METHODS A majority of foundation related problems are attributable, at least in part, to poor drainage. Cohesive soils can expand or shrink by absorbing or losing water, respectively. Reducing the variation in moisture content can potentially reduce the variation in volume. A number of measures may be used to attain a reduction in subsoil moisture content variations, thus reducing the soil's volume change potential. Some of these measures are outlined as follows: During construction, a positive drainage scheme should be implemented to prevent ponding of water on the subgrade in the foundation areas. Positive drainage should be maintained around the proposed structure through a roof/gutter system connected to piping or directed to paved surfaces, transmitting water away from the foundation perimeters. In addition, positive grades sloping away from the foundations should be designed and implemented for the area extending at least 10-feet away from the foundation perimeters. Utility trenches should not be backfilled with sand or gravel to assure the trenches do not serve as aqueducts that could transport water beneath the proposed structure due to excessive surface water infiltration. Vegetation placed in landscape beds that are adjacent to the proposed structure should be limited to plants and shrubs that will not exceed a mature height of 3-feet. Large bushes and trees should be planted away from the foundation at a distance that will exceed their full mature height and canopy width. Project features beyond the scope of those discussed above should be planned and designed similarly to attain a region of relatively uniform moisture content within the foundation areas. Poor drainage schemes resulting in soil moisture and volume changes are generally the primary cause of foundation problems. 13 of 17

17 Concrete Flatwork Concrete flatwork such as sidewalks may be subject to PVR movements when constructed over plastic soils. Changes in the moisture content of the supporting plastic soils causes volumetric changes, resulting in differential movements of the flatwork. Provisions in the site development should be made in order to maintain relative uniform moisture contents of the supporting soils. Individual panels of concrete flatwork should be dowelled together to minimize trip hazards as a result of differential movements within the flatwork. Efforts should be made to avoid having situations where site flatwork panels are partially supported on compacted select fill soils and partially supported on plastic soils. This may result in differential movement and may also result in a negative slope back towards the proposed structure causing ponding of water next to the foundation perimeter. General Discussion CONSTRUCTION CONSIDERATIONS General Discussion - Based on a review of the referenced Grading Plan, the Finish Floor Elevation (FFE) of the proposed New Showroom has been set at Elevation feet. The existing site grades within the proposed building area range from a high of approximately El 618 feet to a low of approximately El 615 feet. Minor cut and fill grading operations will be required to raise the building pad area to the design subgrade elevation. The recommendations presented in the following sections are applicable if the proposed FFE of the structure will be constructed at El feet. Site Preparation Within the areas of the subject site where engineered improvements are planned, existing pavement constituents, vegetation, roots, and objectionable materials should be stripped from the surface. The stripped material should either be stockpiled for use in non-structural / landscaped areas or removed from the site. Building Areas - Within the proposed building area where soil supported floor slabs are planned and any appurtenances including porches, patios and stoops, and extending at least 5-feet beyond the perimeter of the foundations, additional excavation should be performed to allow the placement of select fill soils below the concrete floor system as follows, to achieve the desired PVR condition: PVR CONDITIONS PVR (in) +/- 1 +/- ¾ +/- ½ Minimum Undercut Depth (ft) Minimum Select Fill Thickness (ft) of 17

18 After excavating as recommended, the exposed subgrade materials should be proofrolled with a minimum 15-ton rubber tire dump truck or loader under the supervision of RETL to detect any soft areas prior to select fill placement. If any soft pockets or pumping areas are identified, the soft materials should be removed to expose firm materials and the excavation replaced with compacted Select Fill. The RETL Geotechnical Engineer must approve the subgrade condition prior to the placement of engineered select fill materials. Subgrade Preparation After proofrolling operations are completed, the exposed subgrade soils should be scarified to a depth of 8-inches, moisture conditioned if necessary, and compacted. The subgrade soils should be compacted to at least 92-percent of the maximum dry density as determined by the modified Proctor test (ASTM D1557). The moisture content of the subgrade soils should be maintain between 1-percent below to 3-percent above the optimum moisture content. Select Fill Materials Select fill material used at this site to raise the building areas to the design subgrade elevations should consist of imported crushed limestone. Imported limestone Select Fill should meet the gradation and plasticity requirements set forth in Texas Department of Transportation (TxDOT) Standard Specifications 2014; Item 247, Type A, Grade 3 or better. Select Fill soils should be placed in no greater than 8-inch thick loose lifts and shall be compacted to at least 95-percent of the maximum dry density as determined by the modified Proctor test (ASTM D1557). The moisture content of the select fill soils should be maintained within 1-percent below to 3-percent above the optimum moisture content. Earthwork and Foundation Acceptance Exposure to the environment may weaken the soils at the foundation bearing level if excavations remain open for long periods of time. Therefore, it is recommended that the foundation excavations be extended to the required grade and the foundations be constructed as soon as possible to minimize potential damage to the bearing soils. The foundation bearing level in the drilled pier excavations should be free of loose or soft soil, ponded water or debris and should be observed prior to concreting by the Geotechnical Engineer, or his designated representative. Foundation concrete should not be placed on soils that have been disturbed by seepage. If the bearing soils are softened by water intrusion, the unsuitable soils must be removed from the foundation excavations and be replaced with properly compacted select fill prior to placement of concrete. 15 of 17

19 The Geotechnical Engineer, or his designated representative, should approve the condition of the exposed subgrade and monitor the placement of select fill. As a guideline, a minimum of one (1) in-place density test should be performed on the subgrade and each lift of select fill for each 3,000 SF or a minimum of three (3) in-place densities per testing interval. Any areas not meeting the required compaction should be recompacted and retested until compliance is met. Vapor Retarder A vapor retarder with a permeance of less than 0.3 US perms (ASTM E96) should be placed under the concrete floor slab on the ground to reduce the transmission of water vapor from the supporting soil through the concrete slab and to function as a slip sheet to reduce subgrade drag friction. Polyethylene film with a minimum thickness of 10 mils (0.25 mm) is typically used for reduced vapor transmission and durability during and after its installation. The vapor retarder should be installed according to ASTM E1643, Standard Practice for Installation of Water Vapor Retarders Used in Contact with Earth or Granular Fill Under Concrete Slabs. Penetrations through the vapor retarder should be sealed to ensure its integrity. The vapor retarder should be taped around all openings to ensure the effectiveness of the barrier. Grade stakes should not be driven through the barrier and care should be taken to avoid punctures during reinforcement and concrete placement. Placement of slab concrete directly on the vapor retarder increases the risks of surface dusting, blistering and slab curling making good concrete practice critical. A low water to cement ratio concrete mix design combined with proper and adequate curing procedures will help ensure a good quality slab. Expansion Joints Expansion or control joints should be designed and placed in various portions of the structure. Properly planned placement of these joints will assist in controlling the degree and location of material cracking that normally occurs due to material shrinkage, thermal affects, soil movements and other related structural conditions. 16 of 17

20 GENERAL COMMENTS If significant changes are made in the character or location of the proposed project, a consultation should be arranged to review any changes with respect to the prevailing soil conditions. At that time, it may be necessary to submit supplementary recommendations. It is recommended that the services of RETL be engaged to test and evaluate the soils in the foundation excavations and pavement areas prior to concreting or placing pavement section materials in order to verify that the bearing soils are consistent with those encountered in the test borings. RETL cannot accept any responsibility for any conditions that deviate from those described in this report, nor for the performance of the foundation if not engaged to also provide construction observation and testing. If it is required for RETL to accept any liability, then RETL must agree with the plans and perform such observation during construction as we recommend. Sheeting, shoring, and bracing of trenches, pits and excavations should be made the responsibility of the contractor and should comply with all current and applicable local, state and federal safety codes, regulations and practices, including the Occupational Safety and Health Administration. 17 of 17

21 APPENDIX

22 BORING LOCATION PLAN NO SCALE BORING LOCATIONS ARE APPROXIMATE Elsasser Architectural, Inc. ROCK ENGINEERING AND TESTING LABORATORY, INC. (TBPE FIRM NO. 2101) No. 1 ROUNDVILLE LANE ROUND ROCK, TEXAS (512)

23 SOIL SYMBOL FIELD DATA DEPTH (FT) 5 10 SAMPLE NUMBER SPT S-1 SPT S-2 SPT S-3 SPT S-4 SPT S-5 SAMPLES N: BLOWS/FT P: TONS/SQ FT T: TONS/SQ FT PERCENT RECOVERY/ ROCK QUALITY DESIGNATION N=20 N=13 N=12 N=6-50/5" N=50/2" Rock Engineering & Testing Laboratory, Inc. No. 1 Roundville Lane Round Rock, TX Telephone: (512) Fax: (512) MOISTURE CONTENT (%) LABORATORY DATA LIQUID LIMIT LL ATTERBERG LIMITS PLASTIC LIMIT PL PLASTICITY INDEX PI LOG OF BORING B-1 DRY DENSITY POUNDS/CU.FT COMPRESSIVE STRENGTH (TONS/SQ FT) MINUS NO. 200 SIEVE (%) CLIENT: PROJECT: LOCATION: NUMBER: SURFACE ELEVATION: DESCRIPTION OF STRATUM ASPHALT = 1-INCH, BASE = 9 3/4-INCHES FAT CLAYEY GRAVEL FILL, with calcareous material, grayish-brown and light reddish-brown, moist, very stiff. (GC) SANDY FAT CLAY, reddish-gray brown, moist, very stiff. (CH) Same as above. (CH) SHEET 1 of 1 Elsasser Architectural, Inc. Site Improvements Project - Phase II 4914 IH-35 Frontage Road - Austin, TX G DATE(S) DRILLED: 03/06/ /06/2016 DRILLING METHOD(S): Air-Rotary GROUNDWATER INFORMATION: Groundwater was not encountered during drilling, nor measured in the borehole upon the completion of the drilling. Same as above, light reddish-brown with light gray seams, very hard. (CH) WEATHERED CHALK, pale brown with light gray seams, slightly moist, very hard. 15 GRAB S-6 N=50/1" CHALK, light gray, slightly moist, very hard. 20 GRAB S-7 N=50/1" Same as above, dry. LOG_OF_BORING G316119_LOGS_OF_BORING_WITH_LITHO.GPJ ROCK_ETL.GDT 3/10/ GRAB S-8 GRAB S-9 GRAB S-10 GRAB S-11 N=50/0" N=50/0" N=50/0" N=50/0" N - STANDARD PENETRATION TEST RESISTANCE P - POCKET PENETROMETER RESISTANCE T - POCKET TORVANE SHEAR STRENGTH Same as above. CHALK, light gray, dry, very hard. Same as above. Same as above. Test boring terminated at a depth of 40-feet. REMARKS: Test boring location determined by RETL; drilling operations performed by RETL. GPS Coordinates: N 30 o ', W 97 o '

24 SOIL SYMBOL FIELD DATA DEPTH (FT) 5 10 SAMPLE NUMBER SPT S-1 SPT S-2 SPT S-3 SPT S-4 SPT S-5 SAMPLES N: BLOWS/FT P: TONS/SQ FT T: TONS/SQ FT PERCENT RECOVERY/ ROCK QUALITY DESIGNATION N=7 N=9 N=10 N=18 N=26-50/3" Rock Engineering & Testing Laboratory, Inc. No. 1 Roundville Lane Round Rock, TX Telephone: (512) Fax: (512) MOISTURE CONTENT (%) LABORATORY DATA LIQUID LIMIT LL ATTERBERG LIMITS PLASTIC LIMIT PL PLASTICITY INDEX PI LOG OF BORING B-2 DRY DENSITY POUNDS/CU.FT COMPRESSIVE STRENGTH (TONS/SQ FT) MINUS NO. 200 SIEVE (%) CLIENT: PROJECT: LOCATION: NUMBER: SURFACE ELEVATION: DESCRIPTION OF STRATUM ASPHALT = 1 1/2-INCH, BASE = 11 1/2-INCHES CLAYEY GRAVEL FILL, grayish-brown, moist, very stiff. (GC) FAT CLAYEY SAND FILL, pale brown, moist, stiff. (SC) SANDY FAT CLAY, black, moist, stiff. Same as above, very hard. (CH) SHEET 1 of 1 Elsasser Architectural, Inc. Site Improvements Project - Phase II 4914 IH-35 Frontage Road - Austin, TX G DATE(S) DRILLED: 03/06/ /06/2016 DRILLING METHOD(S): Air-Rotary GROUNDWATER INFORMATION: Groundwater was not encountered during drilling, nor measured in the borehole upon the completion of the drilling. WEATHERED CHALK, pale brown with light gray seams, moist, very hard. 15 SPT S-6 N=50/2" Same as above. 20 GRAB S-7 N=50/1" CHALK, light gray, dry, very hard. LOG_OF_BORING G316119_LOGS_OF_BORING_WITH_LITHO.GPJ ROCK_ETL.GDT 3/10/ GRAB S-8 GRAB S-9 GRAB S-10 GRAB S-11 N=50/1" N=50/0" N=50/0" N=50/0" 6 N - STANDARD PENETRATION TEST RESISTANCE P - POCKET PENETROMETER RESISTANCE T - POCKET TORVANE SHEAR STRENGTH Same as above. Same as above. CHALK, light gray, dry, very hard. Same as above. Test boring terminated at a depth of 40-feet. REMARKS: Test boring location determined by RETL; drilling operations performed by RETL. GPS Coordinates: N 30 o ', W 97 o '

25 Engineering & Testing Laboratory, Inc. Rock Engineering & Testing Laboratory 1 Roundville Lane Round Rock, TX Telephone: Fax: KEY TO SOIL CLASSIFICATION AND SYMBOLS UNIFIED SOIL CLASSIFICATION SYSTEM MAJOR DIVISIONS SYMBOL NAME TERMS CHARACTERIZING SOIL STRUCTURE COARSE GRAINED SOILS GRAVEL AND GRAVELLY SOILS GW GP GM GC SW Well Graded Gravels or Gravel-Sand mixtures, little or no fines Poorly Graded Gravels or Gravel-Sand mixtures, little or no fines Silty Gravels, Gravel-Sand-Silt mixtures Clayey Gravels, Gravel-Sand-Clay Mixtures Well Graded Sands or Gravelly Sands, little or no fines SLICKENSIDED - having inclined planes of weakness that are slick and glossy in appearance FISSURED - containing shrinkage cracks, frequently filled with fine sand or silt; usually more or less vertical LAMINATED (VARVED) - composed of thin layers of varying color and texture, usually grading from sand or silt at the bottom to clay at the top CRUMBLY - cohesive soils which break into small blocks or crumbs on drying SAND AND SANDY SOILS SP SM Poorly Graded Sands or Gravelly Sands, little or no fines Silty Sands, Sand-Silt Mixtures CALCAREOUS - containing appreciable quantities of calcium carbonate, generally nodular WELL GRADED - having wide range in grain sizes and substantial amounts of all intermediate particle sizes FINE GRAINED SOILS SILTS AND CLAYS LL < 50 SILTS AND CLAYS LL > 50 SC ML CL OL MH CH OH Clayey Sands, Sand-Clay mixtures Inorganic Silts and very fine Sands, Rock Flour, Silty or Clayey fine Sands or Clayey Silts Inorganic Clays of low to medium plasticity, Gravelly Clays, Sandy Clays, Silty Clays, Lean Clays Organic Silts and Organic Silt-Clays of low plasticity Inorganic Silts, Micaceous or Diatomaceous fine Sandy or Silty soils, Elastic Silts Inorganic Clays of high plasticity, Fat Clays Organic Clays of medium to high plasticity, Organic Silts POORLY GRADED - predominantly of one grain size uniformly graded) or having a range of sizes with some intermediate size missing (gap or skip graded) SYMBOLS FOR TEST DATA Groundwater Level (Initial Reading) Groundwater Level (Final Reading) Shelby Tube Sample SPT Samples Auger Sample HIGHLY ORGANIC SOILS PT Peat and other Highly Organic soils Rock Core DESCRIPTIVE TERM Very Loose Loose Medium Dense Very Dense COARSE GRAINED SOILS NO. BLOWS/FT. STANDARD PEN. TEST over 50 TERMS DESCRIBING CONSISTENCY OF SOIL Very Soft Soft Firm Stiff Very Stiff Hard DESCRIPTIVE TERM FINE GRAINED SOILS NO. BLOWS/FT. STANDARD PEN. TEST < over 30 UNCONFINED COMPRESSION TONS PER SQ. FT. < over 4.00 Field Classification for "Consistency" is determined with a 0.25" diameter penetrometer