T. Brian Williamson, P.E. Matthew B. Haston, P.E.

Transcription

1 September 22, 2017 Realty Link, LLC 550 South Main Street Greenville, South Carolina ATTENTION: Subject: Mr. Chris Swale REPORT OF GEOTECHNICAL EXPLORATION Oak Ridge Main Street Outparcel L Oak Ridge, Tennessee GEOServices Project No Dear Mr. Swale: We are submitting the results of the geotechnical exploration performed for the subject project. The geotechnical exploration was performed in accordance with our Proposal No R1, dated September 6, 2017, and as authorized by you. The following report presents our findings and recommendations for the proposed construction. Should you have any questions regarding this report, or if we can be of any further assistance, please contact us at your convenience. Sincerely, GEOServices, LLC T. Brian Williamson, P.E. Matthew B. Haston, P.E. Project Manager Senior Geotechnical Engineer TN 118,861 TN 109,269 TBW/MBH:tbw GEOServices, LLC; 2561 Willow Point Way; Knoxville, Tennessee 37931; Phone: (865) ; Fax: (865)

2 Submitted to: Realty Link, LLC 550 South Main Street Greenville, South Carolina ATTENTION: Mr. Chris Swale REPORT OF GEOTECHNICAL EXPLORATION Submitted by: GEOServices, LLC 2561 Willow Point Way Knoxville, Tennessee Oak Ridge Main Street Outparcel L OAK RIDGE, TENNEEE Phone (865) Fax (865) GEOSERVICES, LLC PROJECT NO

3 Contents TABLE OF CONTENTS Page 1.0 INTRODUCTION PURPOSE PROJECT INFORMATION AND SITE DESCRIPTION SCOPE OF STUDY EXPLORATION AND TESTING PROGRAMS FIELD EXPLORATION LABORATORY TEST PROGRAM SUBSURFACE CONDITIONS GEOLOGIC CONDITIONS SOIL STRATIGRAPHY CONCLUSIONS AND RECOMMENDATIONS SITE AEMENT SITE PREPARATION RECOMMENDATIONS Subgrade Structural Soil Fill Dense Graded Aggregate FOUNDATION RECOMMENDATIONS Shallow Foundations Slabs-on-Grade Settlement SEISMIC DESIGN CRITERIA PAVEMENT DESIGN RECOMMENDATIONS Flexible Pavement Design Rigid Pavement Design General CONSTRUCTION CONSIDERATIONS FOUNDATION CONSTRUCTION EXCAVATIONS Excavation Safety HIGH PLASTICITY SOIL CONSIDERATIONS MOISTURE SENSITIVE SOILS DRAINAGE AND SURFACE WATER CONCERNS SINKHOLE RISK REDUCTION AND CORRECTIVE ACTIONS LIMITATIONS...18 APPENDICES APPENDIX A APPENDIX B Figures and Test Boring Records Soil Laboratory Data

4 1.0 INTRODUCTION 1.1 PURPOSE The purpose of this geotechnical exploration was to explore the subsurface conditions of the proposed project sit and provide general recommendations for general site grading and for design and construction of the foundation system, including allowable bearing pressure. In addition, recommendations for light duty and heavy duty asphalt and concrete pavements are also provided. 1.2 PROJECT INFORMATION AND SITE DESCRIPTION Project information was provided by Mr. Chris Swale, which included a site plan for the proposed project. The project site is located directly northeast of the intersection of South Tulane Avenue and South Illinois Avenue in Oak Ridge, Tennessee. Although, detailed construction information is unavailable at this time, we understand that the proposed project is to consist of the construction of a new single-story retail building and associated pavements. Structural loading information has not been provided; however, we understand the foundations for the proposed structure have been designed with a maximum allowable bearing capacity of 1,500 psf. The site currently exists as a vacant property and ground cover general consists of short grass. The site has been filled with soil associated with the Oak Ridge Main Street Development. Detailed grading information has not been provided. However, we anticipate earthwork cuts and fill of up to 5 feet may be necessary to accommodate the proposed construction. 1.3 SCOPE OF STUDY The geotechnical explorations involved a site reconnaissance, field drilling, laboratory testing, and engineering analysis. The following sections of this report present discussions of the field exploration, laboratory testing programs, site conditions, and conclusions and recommendations. 1

5 The geotechnical scope of services did not include an environmental assessment for determining the presence or absence of wetlands, or hazardous or toxic materials in the soil, bedrock, surface water, groundwater, or air, on, or below, or around this site. Any statements in this report or on the boring logs regarding odors, colors, and unusual or suspicious items or conditions are strictly for informational purposes. 2.0 EXPLORATION AND TESTING PROGRAMS 2.1 FIELD EXPLORATION The existing subsurface conditions were explored with eight (8) soil test borings. Five (5) borings were performed in the footprint of the proposed building and the remaining three (3) borings were performed in the proposed parking and drive areas. The locations and depths were selected and staked in the field by GEOServices personnel using the provided site plan and a handheld GPS unit. Drilling was performed on September 13, The borings were advanced using 2.25-inch inside diameter hollow stem augers (HSA) with a Geoprobe tracked mounted drill rig. The approximate locations of the test borings performed on site are referenced in Figure 2. Detailed logs for soil test borings can be found in Appendix A of this report. Within each boring, SPT and split-spoon sampling were performed at approximately 2.5-foot intervals in the upper 10 feet and 5 feet intervals thereafter. The drill crew worked in accordance with ASTM D 6151 (hollow stem auger drilling). Standard Penetration Tests and split-spoon sampling were performed in accordance with ASTM D In split spoon sampling, a standard 2-inch O.D. split-spoon sampler is driven into the bottom of the boring with a 140-pound hammer falling a distance of 30 inches. The number of blows required to advance the sampler the last 12 inches of the standard 18 inches of total penetration is 2

6 recorded as the Standard Penetration Resistance (N-value). These N-values are indicated on the boring logs at the testing depth, and provide an indication of strength of cohesive materials. 2.2 LABORATORY TEST PROGRAM After completion of the field drilling and sampling phase of this project, the soil samples were returned to our laboratory where they were visually classified in general accordance with the Unified Soil Classification System (USCS ASTM D 2487) by a GEOServices geotechnical professional. Select samples were then tested for moisture content (ASTM D 2216) and Atterberg limits (ASTM D 4318). The laboratory test results are further discussed in the following sections of this report and a summary is provided in Appendix B. 3.0 SUBSURFACE CONDITIONS 3.1 GEOLOGIC CONDITIONS The site lies within the Appalachian Valley and Ridge Physiographic Province of East Tennessee. This Province is characterized by elongated, northeasterly-trending ridges formed on highly resistant sandstone and shale. Between ridges, broad valleys and rolling hills are formed primarily on less resistant limestone, dolomite, and shale. Published geologic information indicates that the proposed construction area is underlain by limestones of the Chickamauga Group. The Chickamauga Group is comprised mostly of limestone with minor amounts of shale. Weathering of the Chickamauga Group generally produces a medium to high plasticity clay soil with minor amounts of chert gravel. Since the underlying bedrock formation contains limestone, the site is susceptible to the typical carbonate hazards of irregular weathering, cave and cavern conditions, and overburden sinkholes. Carbonate rock, while appearing very hard and resistant, is soluble in slightly acidic water. This 3

7 characteristic, plus differential weathering of the bedrock mass, is responsible for the hazards. Of these hazards, the occurrence of sinkholes is potentially the most damaging. In East Tennessee, sinkholes occur primarily due to differential weathering of the bedrock and flushing or raveling of overburden soils into the cavities in the bedrock. The loss of solids creates a cavity or dome in the overburden. Growth of the dome over time or excavation over the dome can create a condition in which rapid, local subsidence or collapse of the roof of the dome occurs. While a rigorous effort to assess the potential for sinkhole formation was beyond the scope of this evaluation, our borings did not encounter obvious indications of sinkhole development at the locations explored. A certain degree of risk with respect to sinkhole formation and subsidence should be considered with any site located within geologic areas underlain by potentially soluble rock units. A review of the United States Geologic Survey (USGS Windrock, TN) topographic and geologic quadrangle maps of the area did reveal one closed contour depression, which indicate past sinkhole activity within the general vicinity of the site. We consider that this site has a low to moderate potential for future sinkhole development. Based on this information, it is our opinion that the risk of sinkhole development at this site is no greater than at other sites located within similar geologic settings which have been developed successfully. However, the owner must be willing to accept a slight to moderate risk of sinkhole development at this site. The risk of sinkhole development can be reduced by following the recommendations provided in the Sinkhole Risk Reduction and Corrective Actions section of this report. 3.2 SOIL STRATIGRAPHY The following subsurface description is of a generalized nature to highlight the subsurface stratification features and material characteristics at the boring locations. The boring logs included in Appendix A of this report should be reviewed for specific information at each boring location. Information on actual subsurface conditions exists only at the specific boring locations 4

8 and is relevant only to the time that this exploration was performed. Variations may occur and should be expected at the site. Fill Soils Existing fill soil was encountered in each of the eight borings from the ground surface to depths ranging from 8 to 11 feet beneath the existing ground surface. We note that the existing fill was not penetrated in boring B-8, prior to termination at 10 feet. Fill is classified as soils that have been transported and placed by man. The fill soils generally consisted of reddish brown and brown fat clay (CH) with varying amounts of rock fragments. The SPT N-values used to evaluate the consistency of the fill soil encountered ranged from 4 to 16 blows per foot (bpf), indicating a consistency of soft to very stiff. However, the N-values indicating very stiff soils were likely elevated due to rock fragments. The natural moisture content of the fill soil samples tested ranged from approximately 12.7 to 33.8 percent. Moreover, the fill soils were typically judged to be moist to wet during visual classification. Additionally, the Atterberg limits testing resulted a liquid limits (LL) and plasticity index of 64 and 42 percent, respectively. Residual Soil Beneath the existing fill soils in each boring except B-8, residual soils were encountered to depths ranging from 10 of 16 feet beneath the existing ground surface. The residual soil encountered generally consisted of reddish brown and brown fat clay (CH) with varying amounts of chert fragments. SPT N-values used to evaluate the consistency of the residual soil ranged from 6 to 32 bpf, indicating a fine-grained soil consistency of firm to hard. The natural moisture content of the residual soil samples tested ranged from approximately 18.7 to 34.9 percent. Auger Refusal Auger refusal conditions were encountered in five borings (B-1 through B-5) at depths ranging from 11.5 to 16 feet below existing ground surface. Auger refusal is a designation applied to 5

9 material that cannot be penetrated by the power auger. Auger refusal may indicate dense gravel or cobble layers, boulders, rock ledges or pinnacles, or the top of continuous bedrock. Although rock coring was beyond the scope of our services, we anticipate the refusal conditions encountered likely corresponds with top of pinnacled bedrock. Subsurface Water Subsurface water was encountered in five of the borings at the completion of drilling. Borings B- 1 through B-5 encountered subsurface water at depths ranging from 9 to 14 feet below existing ground surface. Subsurface water levels may fluctuate due to seasonal changes in precipitation amounts. However, areas of perched water may exist in the overburden and/or near the contact with bedrock. The groundwater information presented is based on results of this exploration only. 4.0 CONCLUSIONS AND RECOMMENDATIONS 4.1 SITE AEMENT The results of the subsurface exploration indicate that the site is generally underlain by approximately 8 to 11 feet of existing fill material overlying residual soil. The fill soils encountered were generally soft to firm in consistency and were generally free of deleterious material. The residual soil encountered was generally firm to stiff consistency. Information pertaining to the age, placement, and compaction of the existing fill was unavailable at the time of this report. There are risks associated with construction on undocumented fill material. The owner should be aware of these risks if the existing fill will be utilized for support of the structure or pavement. These risks include soft compressible zones not disclosed by our soil test borings. Also, fill material may be encountered in areas not explored that could contain abundant organic matter, compressible zones, debris, and other deleterious materials. These materials, if present, could lead to differential settlement of the proposed structure, potentially causing structural distress. Due to the variable consistency of the fill material, GEOServices recommends that the existing fill material encountered on-site not be utilized for direct foundation support. 6

10 A full depth undercut and replacement of the existing fill soils may not be cost effective to reduce the risk associated with the undocumented fill material given that a significant portion of the existing fill material will likely be unsuitable for re-use as structural soil fill without significant moisture conditioning (i.e. drying). Therefore, GEOServices recommends that the owner pursue the option of remediating the existing fill soils by supporting the proposed structure on a rammed aggregate pier remediated subgrade. A rammed aggregate pier reinforced subgrade is a viable alternative and would provide sufficient remediation to support the proposed construction and significantly reduce the risk associated with settlement of the fill material. In addition, rammed aggregate piers will reduce the amount of soil haul-off / replacement and can be used to support the proposed structure and concrete slab, if required. While a full-depth undercut and replacement approach in the proposed parking areas and driveways at this site would eliminate the risk associated with the existing fill in these areas, such an approach may not be economically feasible. If the owner is willing to accept some risk associated with the existing fill material, it is our opinion that the risk associated with the fill can be significantly reduced by maintaining a minimum of 2 feet of newly placed, properly compacted structural soil fill between a stable existing fill subgrade and the bottom of pavement subgrade. We note based on results of our field exploration, it may be necessary to utilize subgrade stabilizing geogrid in the pavement areas prior to the placement of new fill. However, if the owner is not willing to accept the risk associated with the fill material, the existing fill should be completely removed and replaced with structural soil fill to reach planned subgrade elevation. Upon removal of surficial layers, existing fill (as required), or low consistency residual soil (if encountered), we recommend that the exposed subgrade be thoroughly proofrolled with a fully loaded (with soil or rock), tandem-axle dump truck or other pneumatic tired construction equipment of similar weight. A GEOServices geotechnical engineer, or qualified representative, should observe proofrolling of all structural soil fill subgrade and concrete slab on grade 7

11 subgrade prior to placement of fill or basestone. Areas observed to be unsuitable for use as subgrade should be remediated at the geotechnical engineer s direction. Remediation of these areas would likely consist of an undercut and replacement with structural soil fill or compacted dense graded aggregate. Based on the conditions encountered in the geotechnical exploration and provided the recommendations set forth in the following sections of this report are followed, the proposed structure can be supported using conventional shallow foundations and/or concrete slabs-ongrade bearing in newly placed structural soil fill, and/or a rammed aggregate pier remediated subgrade. 4.2 SITE PREPARATION RECOMMENDATIONS Subgrade All vegetation, unsuitable soil, loose rock fragments greater than 6 inches, and other debris should be removed from the proposed construction areas. After completion of stripping operations and any required excavations to reach planned subgrade elevation, we recommend that the subgrade be proofrolled with a fully-loaded, tandem-axle dump truck or other pneumatic-tired construction equipment of similar weight. The geotechnical engineer or his representative should observe proofrolling. Areas judged to perform unsatisfactorily by the engineer should be undercut and replaced with structural soil fill or remediated at the geotechnical engineer's recommendation. Areas to receive structural soil fill should also be proofrolled prior to the placement of any fill Structural Soil Fill Material considered suitable for use as structural fill should be clean soil free of organics, trash, and other deleterious material, containing no rock fragments greater than 6 inches in any one dimension. Preferably, structural soil fill material should have a standard Proctor maximum dry density of 90 pcf or greater and a plasticity index (PI) of 35 percent or less. All material to be used as structural fill should be tested by the geotechnical engineer to confirm that it meets the project requirements 8

12 before being placed. Based on the results of our subsurface exploration, we expect the onsite soils will NOT be suitable to be reused as structural fill. Structural fill should be placed in loose, horizontal lifts not exceeding 8 inches in thickness. Each lift should be compacted to at least 98 percent of the soil s maximum dry density per the standard Proctor method (ASTM D 698) and within the range of minus (-) 2 percent to plus (+) 3 percent of the optimum moisture content. Each lift should be tested by geotechnical personnel to confirm that the contractors method is capable of achieving the project requirements before placing any subsequent lifts. Any areas which have become soft or frozen should be removed before additional structural fill is placed Dense Graded Aggregate Dense graded aggregate (DGA) fill may be required as backfill, to reach finished floor elevation. The dense graded aggregate used should be Type A and Grading D or E in accordance with Section of the Tennessee Department of Transportation (TDOT) specifications, or an engineer approved equivalent material. The DGA fill should be placed in loose, horizontal lifts not exceeding 8 inches in loose thickness. Each lift should be compacted to at least 98 percent of maximum dry density per the standard Proctor method (ASTM D 698) and within the range of minus (-) 2 to plus (+) 3 percent of the optimum moisture content. Each lift should be compacted, tested by geotechnical personnel and approved before placing any subsequent lifts. 4.3 FOUNDATION RECOMMENDATIONS Shallow Foundations Foundations for the proposed construction are anticipated to bear on soils improved using rammed aggregate piers. The rammed aggregate piers should be designed to improve the existing soils to be capable of withstanding the designed bearing pressures. Even if design loads would allow smaller sizes, we recommend that continuous footings be a minimum of 18 inches wide and isolated spread footings be a minimum of 24 inches wide to reduce the possibility of a localized punching shear 9

13 failure. Exterior footings should be designed to bear at least 18 inches below finished exterior grade to protect against frost heave. Detailed foundation subgrade observations should be performed by a GEOServices geotechnical engineer, or his qualified representative so that the recommendations provided in this report are consistent with the site conditions encountered. A dynamic cone penetrometer (DCP) is commonly utilized to provide information that is compared to the data obtained in the geotechnical report. Where unacceptable materials are encountered, the material should be excavated to stiff, suitable soils or remediated at the geotechnical engineer s direction. Typical remedial measures consist of undercutting, overexcavation, or combinations thereof Slabs-on-Grade For slab-on-grade construction, the site should be prepared as previously described. We recommend that the subgrade be topped with a minimum 4-inch layer of crushed stone to act as a capillary moisture block. The subgrade should be proofrolled and approved prior to the placement of the crushed stone. Based on the conditions encountered on this site, we recommend that the floor slabs be designed using a subgrade modulus of 90 pounds per cubic inch (pci). This modulus is appropriate for small diameter loads (i.e. a 1ft x 1ft plate) and should be adjusted for wider loads. Additionally, if rammed aggregate piers are installed beneath slabs-on-grade the subgrade modulus will be improved. The increase in subgrade modulus will be dependent on rammed aggregate pier parameters (e.g. size, spacing, etc.). Therefore, the rammed aggregate pier designer will provide a new subgrade modulus. Partial undercutting and replacement of the existing soft fill will likely be required to correction slab subgrade support conditions if rammed aggregate piers are not used for soil improvement Settlement Based on the results of our geotechnical exploration, anticipated structural loads, and under the assumption that the existing soil is remediated with rammed aggregate piers, we anticipate total settlements of less than 1 inch and differential settlements of less than 0.5 inch could be 10

14 experienced by the proposed structure. GEOServices should be retained to observe and document the installation of the rammed aggregate piers to ensure that the recommendations provided in this report are properly implemented in the field. 4.4 SEISMIC DESIGN CRITERIA International Building Code, 2012 In accordance with the International Building Code, 2012, we have provided the following table of seismic design information. After evaluating the subsurface conditions, it was determined that the Seismic Site Class D would be most appropriate of the provided classes. A table follows, showing the calculated spectral response accelerations for both a short and 1-second period. Structure Table 1: Seismic Design Parameters Ss S1 SDS SD1 g g g g Commercial Building PAVEMENT DESIGN RECOMMENDATIONS Flexible Pavement Design AASHTO flexible pavement design methods have been utilized for pavement recommendations. Our recommendations are based on the assumptions that the subgrade has been properly prepared as described previously. At this site, undercutting and replacement possibly in conjunction with the use of geogrid reinforcement will be required to correction subgrade support conditions. Based on our experience with similar developments, we recommend the following light and heavy-duty flexible pavement sections: 11

15 Table 2: Flexible Pavement Recommendations Pavement Materials Light-Duty Heavy-Duty Bituminous Asphalt Surface Mix Bituminous Asphalt Base Mix Compacted Crushed Aggregate Base We recommend a base stone equivalent to a Type A and Grading D in accordance with Section of the TDOT specifications. The bituminous asphalt pavement should be Grading "E" as per Section 411 for the surface mix and Grading BM as per section 307 for the binder mix. Compaction requirements for the crushed aggregate base and the bituminous asphalt pavement should generally follow TDOT specifications Rigid Pavement Design AASHTO rigid pavement design methods have been utilized for pavement recommendations. In areas of trash dumpster pads or areas where large trucks will be parked on the pavement, we recommend the use of a concrete paving section. Our recommendations are based on the assumptions that the subgrade has been properly prepared which will likely require undercutting and replacement possibly in conjunction with geogrid reinforcement. Based on our experience with similar developments, we recommend the following rigid pavement section: Table 3: Rigid Pavement Recommendations Pavement Materials Light-Duty Heavy-Duty 4,000 psi Type I Concrete Compacted Crushed Aggregate Base Concrete should be reinforced with welded wire fabric or reinforcing bars to assist in controlling cracking from drying shrinkage and thermal changes. Sawed or formed control joints should be included for each 225 square feet of area or less (15 feet by 15 feet). Saw cuts should not cut 12

16 through the welded wire fabric or reinforcing steel and dowels should be utilized at formed and/or cold joints General Our recommendations are based upon the assumption that the subgrade has been properly prepared as described in previous sections and that if used, off-site soil borrow to be used to backfill to the final subgrade meets the requirements of the structural fill section. Given the soft existing fill encountered in the borings, it is likely undercutting and replacement or other alternative will be required to correct foundation support conditions. The paved areas should be constructed with positive drainage to direct water off-site and to minimize surface water seeping into the pavement subgrade. The subgrade should have a minimum slope of 1 percent. In down grade areas, the basestone should extend through the slope to allow any water entering the basestone to exit. For rigid pavements, water-tight seals should also be provided at formed construction and expansion joints. We understand that budgetary considerations sometimes warrant thinner pavement sections than those presented. However, the client, owner, and project designers should be aware that thinner pavement sections may result in increased maintenance costs and lower than anticipated pavement life. If thinner pavement sections are warranted, alternate reinforced pavement sections can be considered, including the use of geo-grid reinforcement. 5.0 CONSTRUCTION CONSIDERATIONS 5.1 FOUNDATION CONSTRUCTION Foundation excavations should be opened, the subgrade evaluated, remedial work performed (if required), and concrete placed in an expeditious manner. Exposure to weather often reduces foundation support capabilities, thus necessitating remedial measures prior to concrete placement. It 13

17 is also important that proper surface drainage be maintained both during construction (especially in terms of maintaining dry footing trenches) and after construction. Soil backfill for footings should be placed in accordance with the recommendations for structural fill presented herein. 5.2 EXCAVATIONS As previously mentioned, auger refusal materials were encountered at depths ranging from 11.5 to 16 feet. Auger refusal conditions generally correspond to materials which require difficult excavation techniques for removal. Typically, soils penetrated by augers can be removed with conventional earthmoving equipment. However, excavation equipment varies, and field refusal conditions may vary. Generally, the weathering process is erratic and variations in the rock profile can occur in small lateral distances. Based on our subsurface exploration and the anticipated maximum excavation depth of about 5 feet, we do not anticipate that difficult excavation will present a significant challenge at this site. However, in this geologic setting, it is possible that some partially weathered rock and/or rock pinnacles or ledges requiring difficult excavation techniques may be encountered in site areas between our boring locations Excavation Safety Excavations should be sloped or shored in accordance with local, state, and federal regulations, including OSHA (29 CFR Part 1926) excavation trench safety standards. The contractor is usually solely responsible for site safety. This information is provided only as a service, and under no circumstances should GEOServices be assumed responsible for construction site safety. 5.3 HIGH PLASTICITY SOIL CONSIDERATIONS Based on our experience in the East Tennessee area, soils with plasticity indices (PI) less than 30 percent have a slight potential for volume changes with changes in moisture content, and soils with a PI greater than 50 percent are highly susceptible to volume changes. Between these values, we consider the soils to be moderately susceptible to volume changes. With plastic indices of 14

18 from 42 percent, the onsite soils have a moderate potential for volume change with significant moisture changes. Highly plastic soils have the potential to shrink or swell with significant changes in moisture content. Unlike other areas of the country where high plasticity soils cause considerable foundation problems, this region does not typically endure long periods of severe drought or wet weather. However, in recent years drought conditions have been sufficient to cause soil shrinkage and related structural distress of buildings, floor slabs and pavements at sites underlain by high plasticity soils. At sites that have high plasticity soils, certain precautions should be considered to minimize or eliminate the potential for volume changes. The most effective way to eliminate the potential for volume changes is to remove highly plastic soils and replace them with compacted fill of nonexpansive material. Testing and recommendations for the required depth of removal can be provided, if needed. If removal of the highly plastic soils is not desirable, then measures should be taken to protect the soils from excessive amounts of wetting or drying. In addition, modification of the soils by lime or cement treatment can be utilized to reduce the soil plasticity. Several construction considerations may reduce the potential for volume changes in the subgrade soils. Foundations should be excavated, checked, and concreted in the same day to prevent excessive wetting or drying of the foundation soils. The floor subgrade should be protected from excessive drying and wetting by covering the subgrade prior to slab construction. The site should be graded in order to drain surface water away from the building both during and after construction. Installing moisture barriers around the perimeter of the slab will help limit the moisture variation of the soil and reduce the potential for shrinking or swelling. In addition, roof drains should discharge water away from the building area and foundations. Heat sources should be isolated from foundation soils to minimize drying of the foundation soils. Trees and large shrubs can draw large amounts of moisture from the soil during dry weather and should be kept 15

19 well away from the building to prevent excessive drying of the foundation soils. Watering of lawns or landscaped areas should be performed to maintain moisture levels during dry weather. Structural details to make the building flexible should be considered to accommodate potential volume changes in the subgrade. Floor slabs should be liberally jointed to control cracking, and the floor slab should not be structurally connected to the walls. Walls should incorporate sufficient expansion/contraction joints to allow for differential movement. 5.4 MOISTURE SENSITIVE SOILS The moderately plastic fine-grained soils encountered at this site will be sensitive to disturbances caused by construction traffic and changes in moisture content. During wet weather periods, increases in the moisture content of the soil can cause significant reduction in the soil strength and support capabilities. Construction traffic patterns should be varied to prevent the degradation of previously stable subgrade. In addition, the soils at this site which become wet may be slow to dry and thus significantly retard the progress of grading and compaction activities. We caution if site grading is performed during the wet weather season increases in the undercut volume required due to the marginal fills should be expected. Further for site fills, methods such as discing and allowing the material to dry will be required to meet the required compaction recommendations. It will, therefore, be advantageous to perform earthwork and foundation construction activities during dry weather. However, November through March is typically the difficult grading period due to the limited drying conditions that exist. 5.5 DRAINAGE AND SURFACE WATER CONCERNS To reduce the potential for undercut and construction induced sinkholes, water should not be allowed to collect in the foundation excavations, on floor slab areas, or on prepared subgrades of the construction area either during or after construction. Undercut or excavated areas should be sloped toward one corner to facilitate removal of any collected rainwater, subsurface water, or 16

20 surface runoff. Positive site surface drainage should be provided to reduce infiltration of surface water around the perimeter of the building and beneath the floor slab. The grades should be sloped away from the building and surface drainage should be collected and discharged such that water is not permitted to infiltrate the backfill and floor slab areas of the building. 5.6 SINKHOLE RISK REDUCTION AND CORRECTIVE ACTIONS Based on our experience, corrective actions can also be performed to reduce the potential for sinkhole development at this site. These corrective actions would decrease but not eliminate the potential for sinkhole development. Much can be accomplished to decrease the potential of future sinkhole activity by proper grade selection and positive site drainage. In general, the portions of a site that are excavated to achieve the desired grades will have a higher risk of sinkhole development than the areas that are filled, because of the exposure of relic fractures in the soil to rainfall and runoff. On the other hand, those portions of a site that receive a modest amount of fill (or that have been filled in the past) will have a decreased risk of sinkhole development caused by rainfall or runoff because the placement of a cohesive soil fill over these areas effectively caps the area with a relatively impervious blanket of remolded soil. Therefore, the recommendations that follow incorporate a modest remedial treatment program designed to make the surface of the soil in excavated areas less permeable. Although it is our opinion that the risk of ground subsidence associated with sinkhole formation cannot be eliminated, however, we have found that several measures are useful in site design and development to reduce this potential risk. These measures include: Maintaining positive site drainage to route surface waters well away from structural areas both during construction and for the life of the structure. The scarification and re-compaction of the upper 6 to 10 inches of soil in earthwork cut areas. Verifying that subsurface piping beneath structures is carefully constructed and pressure tested prior to its placement in service. 17

21 The use of pavement or lined ditches, particularly in cut areas, to collect and transport surface water to areas away from structures. Considerations when building within a sinkhole prone area are to provide positive surface drainage away from any proposed building or parking area both during and after construction. Backfill in utility trenches of other excavations should consist of compacted, well-graded material such as dense graded aggregate or compacted on site soils. The use of an open graded stone such as No. 57 stone is not recommended unless the stone backfill is provided an exit path and not allowed to pond. If sinkhole conditions are observed, the type of corrective action is most appropriately determined by a geotechnical engineer on a case-by-case basis. 6.0 LIMITATIONS This report has been prepared in accordance with generally accepted geotechnical engineering practice for specific application to this project. This report is for our geotechnical work only, and no environmental assessment efforts have been performed. The conclusions and recommendations contained in this report are based upon applicable standards of our practice in this geographic area at the time this report was prepared. No other warranty, express or implied, is made. The analyses and recommendations submitted herein are based, in part, upon the data obtained from the exploration. The nature and extent of variations between the borings will not become evident until construction. We recommend that GEOServices be retained to observe the project construction in the field. GEOServices cannot accept responsibility for conditions which deviate from those described in this report if not retained to perform construction observation and testing. If variations appear evident, then we will re-evaluate the recommendations of this report. In the event that any changes in the nature, design, or location of the structures are planned, the conclusions and recommendations contained in this report will not be considered valid unless the changes are reviewed and conclusions modified or verified in writing. Also, if the scope of the project should change significantly from that described herein, these recommendations may need to be reevaluated. 18

22 APPENDIX A Figures and Test Boring Records

23 N NOTES: 1.) BASE MAP: USGS Qaud Map (Windrock MAPS) SITE LOCATION PLAN Oak Ridge Main Street Outparcel L Oak Ridge, TN TBW TBW N.T.S /22/17 FIGURE

24 N B-1 B-2 B-6 B-3 B-4 B-5 B-8 B-7 NOTES: 1.) BORING LOCATIONS ARE SHOWN IN GENERAL ARRANGMENT ONLY. 2.) DO NOT USE BORING LOCATIONS FOR DETERMINATIONS OF DISTANCES OR QUANTITIES. 3.) BASE MAP PROVIDED BY: Realty Link LLC & GOOGLE EARTH, INC. LOCATION OF SOIL TEST BORING BORING LOCATION PLAN Oak Ridge Main Street Outparcel L Oak Ridge, TN TBW TBW N.T.S /22/17 FIGURE

25

26 BORING NO. / LOCATION Oak Ridge Main Street - Outparcel L LOG OF BORING B-1 Oak Ridge, TN SHEET 1 OF 1 GEOServices Project # DRILLER ON-SITE REP. M&W Drilling B-1 DRY ON COMPLETION? No DATE September 13, 2017 SURFACE ELEV. FT. WATER LEVEL DATA (IF APPLICABLE) REFUSAL: Yes DEPTH 16.0 FT. ELEV FT. COMPLETION: DEPTH 14.0 FT. SAMPLED 16.0 FT. 4.9 M ELEV FT. TOP OF ROCK DEPTH FT. ELEV. FT. AFTER 1 HRS: DEPTH TNP FT. BEGAN CORING DEPTH FT. ELEV. FT. ELEV. FT. FOOTAGE CORED (LF) FT. AFTER 24 HRS. DEPTH TNP FT. BOTTOM OF HOLE DEPTH 16.0 FT. ELEV FT. ELEV. FT. BORING ADVANCED BY:. POWER AUGERING X PROPOSED FFE: FT. STRATUM SAMPLE DEPTH SAMPLE FIELD LABORATORY DEPTH FROM TO OR SAMPLE RESULTS RESULTS STRATUM DESCRIPTION FT. ELEV. FT. FT. RUN NO. TYPE N-Value Qu LL PI %M Fat CLAY (CH) - with rock fragments - reddish brown and brown - moist (FILL) Fat CLAY (CH) - with trace chert fragmentsbrown and light brown - moist - stiff to hard (RESIDUUM) Auger Refusal at 16 feet REMARKS:

27 BORING NO. / LOCATION Oak Ridge Main Street - Outparcel L LOG OF BORING B-2 Oak Ridge, TN SHEET 1 OF 1 GEOServices Project # DRILLER ON-SITE REP. M&W Drilling B-2 DRY ON COMPLETION? No DATE September 13, 2017 SURFACE ELEV. FT. WATER LEVEL DATA (IF APPLICABLE) REFUSAL: Yes DEPTH 16.0 FT. ELEV FT. COMPLETION: DEPTH 13.0 FT. SAMPLED 16.0 FT. 4.9 M ELEV. FT. TOP OF ROCK DEPTH FT. ELEV. FT. AFTER 1 HRS: DEPTH TNP FT. BEGAN CORING DEPTH FT. ELEV. FT. ELEV. FT. FOOTAGE CORED (LF) FT. AFTER 24 HRS. DEPTH TNP FT. BOTTOM OF HOLE DEPTH 16.0 FT. ELEV FT. ELEV. FT. BORING ADVANCED BY:. POWER AUGERING X PROPOSED FFE: FT. STRATUM SAMPLE DEPTH SAMPLE FIELD LABORATORY DEPTH FROM TO OR SAMPLE RESULTS RESULTS STRATUM DESCRIPTION FT. ELEV. FT. FT. RUN NO. TYPE N-Value Qu LL PI %M Fat CLAY (CH) - with rock fragments - reddish brown and brown - moist (FILL) Fat CLAY (CH) - with trace chert fragmentsbrown and light brown - moist - stiff to firm (RESIDUUM) Auger Refusal at 16 feet REMARKS:

28 BORING NO. / LOCATION Oak Ridge Main Street - Outparcel L LOG OF BORING B-3 Oak Ridge, TN SHEET 1 OF 1 GEOServices Project # DRILLER ON-SITE REP. M&W Drilling B-3 DRY ON COMPLETION? No DATE September 13, 2017 SURFACE ELEV. FT. WATER LEVEL DATA (IF APPLICABLE) REFUSAL: Yes DEPTH 11.5 FT. ELEV FT. COMPLETION: DEPTH 9.0 FT. SAMPLED 11.5 FT. 3.5 M ELEV FT. TOP OF ROCK DEPTH FT. ELEV. FT. AFTER 1 HRS: DEPTH TNP FT. BEGAN CORING DEPTH FT. ELEV. FT. ELEV. FT. FOOTAGE CORED (LF) FT. AFTER 24 HRS. DEPTH TNP FT. BOTTOM OF HOLE DEPTH 11.5 FT. ELEV FT. ELEV. FT. BORING ADVANCED BY:. POWER AUGERING X PROPOSED FFE: FT. STRATUM SAMPLE DEPTH SAMPLE FIELD LABORATORY DEPTH FROM TO OR SAMPLE RESULTS RESULTS STRATUM DESCRIPTION FT. ELEV. FT. FT. RUN NO. TYPE N-Value Qu LL PI %M Fat CLAY (CH) - with rock fragments - reddish brown and brown - moist (FILL) Fat CLAY (CH) - with trace chert fragmentsbrown and light brown - moist - firm (RESIDUUM) Auger refusal at 11.5 feet REMARKS:

29 BORING NO. / LOCATION Oak Ridge Main Street - Outparcel L LOG OF BORING B-4 Oak Ridge, TN SHEET 1 OF 1 GEOServices Project # DRILLER ON-SITE REP. M&W Drilling B-4 DRY ON COMPLETION? No DATE September 13, 2017 SURFACE ELEV. FT. WATER LEVEL DATA (IF APPLICABLE) REFUSAL: Yes DEPTH 13.0 FT. ELEV FT. COMPLETION: DEPTH 12.0 FT. SAMPLED 13.0 FT. 4.0 M ELEV FT. TOP OF ROCK DEPTH FT. ELEV. FT. AFTER 1 HRS: DEPTH TNP FT. BEGAN CORING DEPTH FT. ELEV. FT. ELEV. FT. FOOTAGE CORED (LF) FT. AFTER 24 HRS. DEPTH TNP FT. BOTTOM OF HOLE DEPTH 13.0 FT. ELEV FT. ELEV. FT. BORING ADVANCED BY:. POWER AUGERING X PROPOSED FFE: FT. STRATUM SAMPLE DEPTH SAMPLE FIELD LABORATORY DEPTH FROM TO OR SAMPLE RESULTS RESULTS STRATUM DESCRIPTION FT. ELEV. FT. FT. RUN NO. TYPE N-Value Qu LL PI %M Fat CLAY (CH) - with rock fragments - reddish brown and brown - moist (FILL) Fat CLAY (CH) - with trace chert fragmentsbrown and light brown - moist - stiff (RESIDUUM) Auger refusal at 13 feet REMARKS:

30 BORING NO. / LOCATION Oak Ridge Main Street - Outparcel L LOG OF BORING B-5 Oak Ridge, TN SHEET 1 OF 1 GEOServices Project # DRILLER ON-SITE REP. M&W Drilling B-5 DRY ON COMPLETION? no DATE September 13, 2017 SURFACE ELEV. FT. WATER LEVEL DATA (IF APPLICABLE) REFUSAL: Yes DEPTH 13.0 FT. ELEV FT. COMPLETION: DEPTH 9.0 FT. SAMPLED 13.0 FT. 4.0 M ELEV FT. TOP OF ROCK DEPTH FT. ELEV. FT. AFTER 1 HRS: DEPTH TNP FT. BEGAN CORING DEPTH FT. ELEV. FT. ELEV. FT. FOOTAGE CORED (LF) FT. AFTER 24 HRS. DEPTH TNP FT. BOTTOM OF HOLE DEPTH 13.0 FT. ELEV FT. ELEV. FT. BORING ADVANCED BY:. POWER AUGERING X PROPOSED FFE: FT. STRATUM SAMPLE DEPTH SAMPLE FIELD LABORATORY DEPTH FROM TO OR SAMPLE RESULTS RESULTS STRATUM DESCRIPTION FT. ELEV. FT. FT. RUN NO. TYPE N-Value Qu LL PI %M Fat CLAY (CH) - with rock fragments - reddish brown and brown - moist (FILL) Fat CLAY (CH) - with trace chert fragmentsbrown and light brown - moist - stiff (RESIDUUM) Auger refusal at 13 feet REMARKS:

31 BORING NO. / LOCATION Oak Ridge Main Street - Outparcel L LOG OF BORING B-6 Oak Ridge, TN SHEET 1 OF 1 GEOServices Project # DRILLER ON-SITE REP. M&W Drilling B-6 DRY ON COMPLETION? Yes DATE September 13, 2017 SURFACE ELEV. FT. WATER LEVEL DATA (IF APPLICABLE) REFUSAL: no DEPTH FT. ELEV. FT. COMPLETION: DEPTH Dry FT. SAMPLED 10.0 FT. 3.0 M ELEV. FT. TOP OF ROCK DEPTH FT. ELEV. FT. AFTER 1 HRS: DEPTH TNP FT. BEGAN CORING DEPTH FT. ELEV. FT. ELEV. FT. FOOTAGE CORED (LF) FT. AFTER 24 HRS. DEPTH TNP FT. BOTTOM OF HOLE DEPTH 10.0 FT. ELEV FT. ELEV. FT. BORING ADVANCED BY:. POWER AUGERING X PROPOSED FFE: FT. STRATUM SAMPLE DEPTH SAMPLE FIELD LABORATORY DEPTH FROM TO OR SAMPLE RESULTS RESULTS STRATUM DESCRIPTION FT. ELEV. FT. FT. RUN NO. TYPE N-Value Qu LL PI %M Fat CLAY (CH) - with rock fragments - reddish brown and brown - moist (FILL) Fat CLAY (CH) - with trace chert fragmentsbrown and light brown - dry to moist - firm (RESIDUUM) Boring Terminated at 10 feet REMARKS:

32 BORING NO. / LOCATION Oak Ridge Main Street - Outparcel L LOG OF BORING B-7 Oak Ridge, TN SHEET 1 OF 1 GEOServices Project # DRILLER ON-SITE REP. M&W Drilling B-7 DRY ON COMPLETION? Yes DATE September 13, 2017 SURFACE ELEV. FT. WATER LEVEL DATA (IF APPLICABLE) REFUSAL: no DEPTH FT. ELEV. FT. COMPLETION: DEPTH Dry FT. SAMPLED 10.0 FT. 3.0 M ELEV. FT. TOP OF ROCK DEPTH FT. ELEV. FT. AFTER 1 HRS: DEPTH TNP FT. BEGAN CORING DEPTH FT. ELEV. FT. ELEV. FT. FOOTAGE CORED (LF) FT. AFTER 24 HRS. DEPTH TNP FT. BOTTOM OF HOLE DEPTH 10.0 FT. ELEV FT. ELEV. FT. BORING ADVANCED BY:. POWER AUGERING X PROPOSED FFE: FT. STRATUM SAMPLE DEPTH SAMPLE FIELD LABORATORY DEPTH FROM TO OR SAMPLE RESULTS RESULTS STRATUM DESCRIPTION FT. ELEV. FT. FT. RUN NO. TYPE N-Value Qu LL PI %M Fat CLAY (CH) - with rock fragments - reddish brown and brown - moist (FILL) Fat CLAY (CH) - with trace chert fragmentsbrown and light brown - dry to moist - firm (RESIDUUM) Boring Terminated at 10 feet REMARKS:

33 BORING NO. / LOCATION Oak Ridge Main Street - Outparcel L LOG OF BORING B-8 Oak Ridge, TN SHEET 1 OF 1 GEOServices Project # DRILLER ON-SITE REP. M&W Drilling B-8 DRY ON COMPLETION? Yes DATE September 13, 2017 SURFACE ELEV. FT. WATER LEVEL DATA (IF APPLICABLE) REFUSAL: no DEPTH FT. ELEV. FT. COMPLETION: DEPTH Dry FT. SAMPLED 10.0 FT. 3.0 M ELEV. FT. TOP OF ROCK DEPTH FT. ELEV. FT. AFTER 1 HRS: DEPTH TNP FT. BEGAN CORING DEPTH FT. ELEV. FT. ELEV. FT. FOOTAGE CORED (LF) FT. AFTER 24 HRS. DEPTH TNP FT. BOTTOM OF HOLE DEPTH 10.0 FT. ELEV FT. ELEV. FT. BORING ADVANCED BY:. POWER AUGERING X PROPOSED FFE: FT. STRATUM SAMPLE DEPTH SAMPLE FIELD LABORATORY DEPTH FROM TO OR SAMPLE RESULTS RESULTS STRATUM DESCRIPTION FT. ELEV. FT. FT. RUN NO. TYPE N-Value Qu LL PI %M Fat CLAY (CH) - with rock fragments - reddish brown and brown - moist (FILL) Boring Terminated at 10 feet REMARKS:

34 APPENDIX B Soil Laboratory Testing Results

35 Natural Percent Boring Sample Depth Moisture Soil Organic Number Number (feet) Content LL PL PI Type Content B ' 22.1% ' 17.7% CH ' 28.9% ' 32.5% ' 34.9% B ' 19.4% ' 20.7% ' 21.5% ' 21.2% ' 28.4% B ' 16.7% ' 17.8% ' 16.6% ' 18.7% B ' 23.3% ' 27.9% ' 33.8% ' 31.7% B ' 12.7% ' 20.7% ' 20.6% ' 22.2% B ' 18.3% ' 22.3% ' 23.1% ' 27.0% Oak Ridge Main Street "L" GEOServices Project No September 21, 2017 SOIL DATA SUMMARY Atterberg Limits GEOServices, LLC Willow Point Way Knoxville. Tennessee, Phone: (865) Fax: (865)