Loading...
HomeMy WebLinkAboutSW1190801_65X-0079 (Leicester VFD) - Draft Report - Proposed Leicester Vol. Fire Stn., Alexander Road, Leicester, NC)_8/27/2019Draft Report of Geotechnical Study Proposed Leicester Volunteer Fire Station 1561 Alexander Road Leicester, North Carolina Prepared For: Leicester Fire and Rescue Department - Main Station 2852 New Leicester Highway Leicester, North Carolina By: FROEHLING & ROBERTSON, INC. 18 Woods Lake Road Greenville, South Carolina 29607 F&R Project No. 65X-0079 April 16, 2019 SINCE FROEHLING & ROBERTSON, INC. Engineering Stability Since 1881 34 Redmond Drive, Unit F Fletcher, North Carolina 28734 ® T 828.274.0742 1881 NC License #F-0266 April 16, 2019 F&R Project No. 65X-0079 Leicester Fire & Rescue Department 2852 New Leicester Highway Leicester, North Carolina 28748 Attn: Mr. Chris Brown (District 1 Fire Chief), Re: Draft Report of Subsurface Exploration and Geotechnical Engineering Study Proposed Leicester Volunteer Fire Station 1561 Alexander Road Leicester, North Carolina Dear Mr. Brown: The enclosed report presents the results of the subsurface exploration program and geotechnical engineering evaluation undertaken by Froehling & Robertson, Inc. (F&R), in connection with the proposed Leicester Volunteer Fire Station development located in the open grassy field west of 1561 Alexander Road in Leicester, North Carolina. Our services were performed in general accordance with F&R Proposal No. 1965-00415G dated March 15, 2019. The report presents our understanding of the project, reviews our exploration procedures, describes the general subsurface conditions at the boring locations, and presents our evaluations and recommendations. Corporate HQ: 3015 Dumbarton Road Richmond, Virginia 23228 T 804.264.2701 F 804.264.1202 www.fandr.com VIRGINIA • NORTH CAROLINA • SOUTH CAROLINA • MARYLAND • DISTRICT OF COLUMBIA A Minority -Owned Business We have enjoyed working with you on this project, and we are prepared to assist you with the recommended quality assurance monitoring and testing services during construction. Please contact us if you have any questions regarding this report or if we may be of further service. Sincerely, FROEHLING & ROBERTSON, INC. CAR �Essto•. -p $�. 2019 . cL SEAL � 046722 r GItdIE� Benedictus K. Azumah, P.E. "��°!� ag'` Geotechnical Services Manager r�11��i�101'\r BKA/RTT Ryne T. Turner, P.E. Branch Manager Ryne Turner Apr 16 2019 1:18 PM F:\Projects 65X\65X-0079 (Leicester Volunteer Fire Dept - Leicester Fire Dept)\Reports\Summary Reports\65X-0079 (Leicester VFD) - Final Report - Proposed Leicester Vol. Fire Stn., Alexander Road, Leicester, NC).docx Leicester Fire and Rescue Department F&R Project No. 65X-0079 Proposed Leicester Volunteer Fire Station 1561 Alexander Road Leicester, North Carolina April 16, 2019 Dncu5�t— 2 TABLE OF CONTENTS SECTION PAGE EXECUTIVE SUMMARY......................................................................................................... 1 1.0 PURPOSE & SCOPE OF SERVICE.................................................................................... 2 2.0 PROJECT INFORMATION............................................................................................... 3 2.1 SITE LOCATION AND DESCRIPTION..................................................................................... 3 2.2 PROJECT INFORMATION AND PROPOSED CONSTRUCTION........................................................ 3 3.0 EXPLORATION PROCEDURES........................................................................................ 4 3.1 SUBSURFACE EXPLORATION............................................................................................. 4 3.2 LABORATORY TESTING.................................................................................................... 5 4.0 REGIONAL GEOLOGY AND SUBSURFACE CONDITIONS .................................................. 6 4.1 GENERAL.....................................................................................................................6 4.2 REGIONAL GEOLOGY...................................................................................................... 6 4.3 GENERALIZED SUBSURFACE CONDITIONS............................................................................. 7 4.3.1 Surficial Material.................................................................................................. 7 4.3.2 Residual Soils........................................................................................................ 7 4.4 LABORATORY TEST RESULTS............................................................................................. 8 4.5 GROUNDWATER DATA.................................................................................................... 8 5.0 DESIGN RECOMMENDATIONS......................................................................................8 5.1 GENERAL.....................................................................................................................8 5.2 SHALLOW FOUNDATION DESIGN....................................................................................... 9 5.3 ESTIMATED FOUNDATION SETTLEMENT............................................................................... 9 5.4 SHRINK -SWELL, FROST DEPTH AND BEARING CONSIDERATIONS .............................................. 10 5.5 CONCRETE SLABS-ON-GRADE........................................................................................ 10 5.6 PAVEMENT DESIGN RECOMMENDATIONS.......................................................................... 11 5.7 SEISMIC SITE CLASSIFICATION......................................................................................... 13 6.0 CONSTRUCTION RECOMMENDATIONS....................................................................... 13 6.1 GENERAL...................................................................................................................13 6.2 SITE PREPARATION...................................................................................................... 14 6.3 CONTROLLED STRUCTURAL FILL PLACEMENT AND COMPACTION ............................................. 15 6.4 SHALLOW FOUNDATION CONSTRUCTION........................................................................... 16 6.5 SURFACE WATER CONTROL............................................................................................ 17 6.6 EXCAVATION CHARACTERISTICS....................................................................................... 17 6.7 GROUNDWATER CONDITIONS......................................................................................... 18 Leicester Fire and Rescue Department F&R Project No. 65X-0079 Proposed Leicester Volunteer Fire Station 1561 Alexander Road Leicester, North Carolina April 16, 2019 Page i of ii 6.8 EXCAVATIONS.............................................................................................................18 7.0 CONTINUATION OF SERVICES..................................................................................... 19 8.0 LIMITATIONS..............................................................................................................19 appFNnirFS APPENDIX I Site Vicinity Map (Figure No. 1) Test Location Plan (Figure No. 2) APPENDIX II Key to Soil Classification Soil Classification Chart Boring Logs B-01 through B-12 (12 Sheets) Subsurface Profiles: Figures 3A and 3B (2 Sheets) APPENDIX III Laboratory Test Summary Sheet (Not included) APPENDIX IV GBA Publication "Important Information About Your Geotechnical Engineering Report" Leicester Fire and Rescue Department F&R Project No. 65X-0079 Proposed Leicester Volunteer Fire Station IS61 Alexander Road Leicester, North Carolina April 16, 2019 Page ii of ii EXECUTIVE SUMMARY This Executive Summary is provided as a brief overview of our geotechnical engineering evaluation for the project and is not intended to replace more detailed information contained elsewhere in this report. As an overview, this summary inherently omits details that could be very important to the proper application of the provided geotechnical design recommendations. This report should be read in its entirety prior to implementation into design and construction. • The site is located in a grassy field west of existing Leicester Public Library at 1561 Alexander Road in Leicester, North Carolina. • Our subsurface exploration included twelve soil test borings to depths of 6 to 25 feet. The test borings indicated the presence of residual soils generally classifying as firm to very stiff Sandy Silt (ML), Sandy Lean Clay (CL), and loose to medium dense Silty Sand (SM) and Clayey Sand (SC). Groundwater was not encountered during our after our subsurface explorations and is therefore not anticipated during site grading and foundation excavation. • Based on the subsurface conditions at the site, we recommend that any shallow foundations can be designed for a maximum net allowable bearing pressure of 2,000 pounds per square foot (psf) for foundations bearing in approved subgrade soils. The recommended bearing pressure provides a factor of safety of at least 3 against general bearing capacity failure. With proper foundation sizing, we estimate that foundation settlement will be limited to less than 1-inch. • Based on the subsurface conditions at the site, we anticipate the near -surface soils within a depth of about 25 feet at the site can be excavated with backhoes, front-end loaders or other similar equipment using conventional means and methods. • Based on the available subsurface data from our exploration and in general accordance with the 2015 International Building Code, a Seismic Site Class "D" should be used for further evaluations relative to earthquake load design. Leicester Fire and Rescue Department F&R Project No. 65X-0079 Proposed Leicester Volunteer Fire Station 1561 Alexander Road Leicester, North Carolina April 16, 2019 Page 1 of 19 1.0 PURPOSE & SCOPE OF SERVICE The purpose of the subsurface exploration and geotechnical engineering evaluation is to explore the subsurface conditions in the area of the proposed Leicester Volunteer Fire Station development and to provide subsurface soil conditions and geotechnical engineering recommendations. Froehling & Robertson, Inc. (F&R) provided our Proposal No. 1965-00415G dated March 15, 2019, to Leicester Fire and Rescue Department in response to their proposal request and the provided project details. F&R's scope of services included the following: • A site reconnaissance to observe existing surface conditions and layout proposed boring locations. • Coordination of public underground utility location with NC811. • Review and summary of readily available geologic and subsurface information relative to the project site. • Completion of twelve SPT borings, designated as Borings B-01 through B-12, located within the footprint of the proposed fire station, driveway and parking areas of the development. The borings were advanced to termination depths of approximately 6 to 25 feet below the existing ground surface. The exploration included making observations for the presence of groundwater, dense soil strata, bedrock and obtaining their approximate depths below the existing ground surface. • Performing soil laboratory testing for classification purposes using wash No. 200 (ASTM D1140, Atterberg limits test (ASTM D4318), natural water content determinations (ASTM D2216), standard Proctor test (ASTM D698), and California Bearing Ratio (CBR) tests (ASTM D1883). • Evaluation of the Seismic Site Class in accordance with the 2015 International Building Code and based on subsurface exploration and testing data obtained from the site. • Preparation of this report summarizing our work on the project including recommendations for shallow foundation design, floor slab design parameters, site excavation characteristics, placement and compaction of load -bearing reusable on -site soils, and typical recommendations for heavy-duty flexible, heavy-duty rigid, and light -duty flexible pavement Leicester Fire and Rescue Department Proposed Leicester Volunteer Fire Station F&R Project No. 65X-0079 IS61 Alexander Road Leicester, North Carolina April 16, 2019 Page 2 of 19 sections for use on the project. Boring location plans, boring logs and subsurface profiles are also included in this report. F&R's geotechnical services did not include topographic or field surveying, development of quantity estimates, preparation of plans and specifications, or the identification and evaluation of wetlands or other environmental aspects of the project site. 2.0 PROJECT INFORMATION 2.1 Site Location and Description The project site is a 10.2-acre± tract located west of the existing Leicester Public Library at 1561 Alexander Road in Leicester, North Carolina. The site is an open grass -covered farmland with a rolling topography. Ground surface elevations range from approximately elevation (El.) 2,115 to 2,190 feet. The site location is shown on the attached Figure No. 1 - Site Vicinity Map, included in Appendix I. F&R obtained the site information from the project details including a Plat of Survey for Leicester Volunteer Fire Department, Inc., by Vaughn and Melton, which we received from your office on March 11, 2019. F&R also obtained site information through our review of available aerial photography and during our site visits. 2.2 Project Information and Proposed Construction A new fire station development is proposed at the site. Based on the provided information, the new fire station will have a total finished floor area of 15,350 square feet and will include several apparatus bays, sleeping quarters, office and training spaces, exercise rooms, mechanical, and bathrooms. The remaining areas to be developed will include landscaped areas, an access driveway with two parking areas for up to about 32 cars, and a stormwater retention pond area. Based on the provided project details, the finished floor elevation of the new fire station will be at El. 2,175. Complete construction drawings, building specifications and structural loading information were not available at the time of preparing this report. However, F&R has assumed that construction of the buildings will likely consist of concrete slab -on -grade, wood or metal framing, brick veneer, fiber cement or vinyl siding, and asphalt shingle roofs. Construction of the access driveway will be asphalt over a crushed stone base or concrete over a crushed stone base. Leicester Fire and Rescue Department F&R Project No. 65X-0079 Proposed Leicester Volunteer Fire Station IS61 Alexander Road Leicester, North Carolina April 16, 2019 Page 3 of 19 Specific site grading details for the proposed construction were also not available. However, we expect site grading to include less than 10 feet of cut and fill for the building, access roadway, and stormwater retention pond areas. We estimate column foundation loads to be on the order of 50 kips and less than 5 kips per linear foot for wall foundations. As part of the project planning requirements, F&R was asked to perform a geotechnical exploration at the site to evaluate the subsurface conditions within the planned building and pavement locations for the proposed development. 3.0 EXPLORATION PROCEDURES 3.1 Subsurface Exploration The subsurface exploration was conducted by F&R drillers on April 11, 2019. A field representative from F&R was onsite during drilling operations. The drill rig used for this project was an ATV -mounted CME 550X drill rig equipped with an automatic hammer. The test holes were advanced using 2.25" I.D. hollow stem augers. The Standard Penetration Test (SPT) was performed at the boring locations in general accordance with ASTM D1586. The subsurface exploration program consisted of twelve SPT borings, designated as Borings B-01 through B-12. The borings were located within the proposed building, pavement and stormwater retention areas as described in the project description and were in general accordance with the proposed boring location plan you submitted with your request for proposal. Five SPTs were performed in the upper 10 feet of the 15 to 25-foot deep borings starting from the ground surface. Thereafter, the boreholes were advanced further and SPT performed at approximate 5-foot intervals to their termination depths of 15 to 25 feet below the existing ground surface. Approximate boring locations are identified on Figure No. 2—Test Location Plan, which is included in Appendix I of this report. Boring locations were staked at the site by F&R personnel by measuring from existing site features. As such, the boring locations should be considered approximate. Ground surface elevations were estimated from the provided Plat of Survey for Leicester Volunteer Fire Department, Inc., as such, the ground surface elevations shown of our boring logs should be considered approximate. Leicester Fire and Rescue Department F&R Project No. 65X-0079 Proposed Leicester Volunteer Fire Station IS61 Alexander Road Leicester, North Carolina April 16, 2019 Page 4 of 19 Soil samples were obtained with a standard 2" O.D. and 30" long split -spoon sampler with each SPT being driven with a 140-lb automatic hammer falling 30 inches. The number of blows required to drive the sampler each 6-inch increment of penetration was recorded and are shown on the boring logs. The first six-inch increment is used to seat the sampler with the sum of the second and third penetration increments being termed the SPT value, "N." The fourth six-inch increment was obtained but not used. A representative portion of each disturbed split -spoon sample was collected with each SPT, placed in a glass jar, and returned to our laboratory for review. The recovered split -spoon samples were visually classified by F&R engineers in general accordance with the ASTM D2488. The boring logs and soil profiles provided in Appendix II show the subsurface conditions encountered on the date and at the approximate locations indicated. By the nature of the work performed, the drilling activities result in disturbances to the site. The completed boreholes performed were backfilled with drilling spoils upon completion for safety. The borehole backfill may subside at some time following our work. F&R assumes no responsibility for borehole subsidence after completion of the field exploration and departing the site. For continued safety, the boreholes should be occasionally observed by others with any needed additional backfilling then being performed. 3.2 Laboratory Testing For geotechnical considerations, select split -spoon and bulk soil samples from the soil test borings were subjected to laboratory classification testing. This testing included wash No. 200 (ASTM D1140), Atterberg limits test (ASTM D4318), natural water content determinations (ASTM D2216), standard Proctor test (ASTM D698), and California Bearing Ratio (CBR) tests (ASTM D1883). Based on the results of these tests, the soil samples were then classified in general accordance with Unified Soil Classification System (ASTM D2487). Laboratory test results, once they become available, will be provided in Appendix III of our final report. Leicester Fire and Rescue Department F&R Project No. 65X-0079 Proposed Leicester Volunteer Fire Station 1561 Alexander Road Leicester, North Carolina April 16, 2019 Page 5 of 19 4.0 REGIONAL GEOLOGY AND SUBSURFACE CONDITIONS 4.1 General The subsurface conditions discussed in the following paragraphs and those shown on the attached boring logs represent an estimate of the subsurface conditions based on interpretation of the field data using normally accepted geotechnical engineering judgments. Subsurface profiles for the project stratigraphy have been prepared for convenience only. Given the wide spacing between boring locations, it is anticipated that subsurface conditions may vary between each boring location. Strata breaks designated on the boring logs represent approximate boundaries between soil types. The transitions between different soil strata are usually less distinct than those shown on the boring logs. Although individual soil test borings are representative of the subsurface conditions at the boring locations on the dates shown, they are not necessarily indicative of subsurface conditions at other locations or at other times. Data from the specific soil test borings are shown on the individual boring logs included in Appendix II. Subsurface profiles in the area of the proposed building also included in Appendix II. 4.2 Regional Geology Based on our review of the Geologic Map of North Carolina (Brown, 1985), the project site is located in the Blue Ridge Physiographic Province of North Carolina. The Blue Ridge Belt is characterized by steep mountainous ridges and narrow valleys. Based upon available geologic literature and maps, the project site is underlain by Biotite muscovite gneiss (Zatm) that is described as being locally sulfidic; interlayered and gradational with mica schist, minor amphibolite, and hornblende gneiss. The Blue Ridge region is underlain by older crystalline (metamorphic and igneous) rock formations that trend northeast -southwest and vary greatly in their resistance to weathering and erosion. The major streams generally flow from northwest to southeast across these rock structures without regard to their northeast -southwest tending structures. The typical residual soil profile consists of fine-grained soils (clays/silts) near the surface, where soil weathering is more advanced, underlain by more coarse -grained soils (sandy silts/silty sands) with depth. The boundary between soil and rock is not sharply defined. This transitional zone, Leicester Fire and Rescue Department F&R Project No. 65X-0079 Proposed Leicester Volunteer Fire Station IS61 Alexander Road Leicester, North Carolina April 16, 2019 Page 6 of 19 termed "partially weathered rock", is normally found overlying the parent bedrock. The degree of weathering is facilitated by fractures, joints, and by the presence of less resistant rock types. Consequently, the profile of the "partially weathered rock" and hard rock is quite irregular and erratic, even over short, horizontal distances. 4.3 Generalized Subsurface Conditions Subsurface data obtained from the soil borings are presented in the following paragraphs. Complete boring logs are presented in Appendix II. 4.3.1 Surficial Material The borings generally encountered approximately 6 inches of Surficial Soil at the ground surface. Surficial Soil is typically a dark -colored soil material containing roots, fibrous matter, and or other organic components, and is generally unsuitable for engineering purposes. F&R has not performed any laboratory testing to determine the organic content or other horticultural properties of the observed Surficial Soil materials. Therefore, the term Surficial Soil is not intended to indicate suitability for landscaping and or other purposes. The Surficial Soil depths provided in this report are based on driller observations and should be considered approximate. We note that the transition from Surficial Soil to underlying materials may be gradual, and therefore the observation and measurement of Surficial Soil depths is subjective. Actual Surficial Soil depths should be expected to vary. 4.3.2 Residual Soils Residual soils, formed by in -place weathering of the parent rock, were encountered in the borings from below the surficial materials to depths of approximately 6 to 25 feet. Sampled fine-grained residual soils were generally classified as firm to very stiff Sandy Lean Clay (CL) and Sandy Silt (ML) containing varying amounts of root, mica and rock fragments. Sampled coarse -grained residual soils were generally classified as loose to medium dense Silty Sand (SM) and Clayey Sand (SC) containing varying amounts of mica and rock fragments. Standard penetration resistance (N-value) in the residual soils generally ranged from 5 to 18 blows per foot (bpf). Leicester Fire and Rescue Department F&R Project No. 65X-0079 Proposed Leicester Volunteer Fire Station 1S61 Alexander Road Leicester, North Carolina April 16, 2019 Page 7 of 19 4.4 Laboratory Test Results Laboratory tests results were not available at the time of submitting this draft report. Once laboratory test results become available, we will include them in the final version of this report. 4.5 Groundwater Data Groundwater was generally not observed during drilling. However, most of the recovered soil samples were moist. The boring cave-in depths, after removal of drilling augers, ranged from approximately 4 to 17.5 feet below the existing ground surface. After removal of drilling augers, the boreholes were backfilled with drilling spoils for safety except for Boring B-01 were we installed a 1.25-inch diameter hand -slotted PVC pipe to a depth of 15 feet below the ground surface. We returned to the site to measure stabilized groundwater in the pipe, approximately 3.5 hours after pipe installation. The bottom of borehole was dry. The presence of groundwater was evaluated at each boring location by visually judging the moisture content of the recovered split -spoon soil samples and by dropping a weighted tape measure down the borehole. Groundwater levels fluctuate with seasonal changes, periods of heavy or little rainfall, stream levels and other factors. Therefore, our evaluations of the groundwater level do not reveal the actual year-round groundwater conditions. 5.0 DESIGN RECOMMENDATIONS 5.1 General The following findings and recommendations are based on our observations at the site, interpretation of the field and laboratory data obtained during our subsurface exploration, and our experience with similar subsurface conditions and projects. Soil penetration data has been used to evaluate the subsurface conditions based on established correlations. Subsurface conditions in unexplored locations may vary from those encountered. If the proposed Leicester Volunteer Fire Station development footprint and anticipated grading plans are changed, F&R requests that we be advised so that our recommendations can be re-evaluated. Leicester Fire and Rescue Department F&R Project No. 65X-0079 Proposed Leicester Volunteer Fire Station 1561 Alexander Road Leicester, North Carolina April 16, 2019 Page 8 of 19 5.2 Shallow Foundation Design The existing ground surface elevations at the fire station area ranges from about El. 2,173 feet to about 2,182 feet. We anticipate site grading will include less than 10 feet of cut and or fill. Therefore, we expect proposed foundation subgrade soils to consist of residual soils or new compacted structural fill soils. The proposed fire station may be supported on shallow foundation systems bearing on approved natural soils, or newly placed controlled structural fill subgrades. Based on our assumed structural loading and the encountered subsurface conditions, we recommend that the fire station building foundations be designed for a net allowable bearing pressure of 2,000 pounds per square foot (psf) for foundations bearing on approved subgrades. To reduce the possibility of localized shear failures, spread and strip foundations should be a minimum of 2 feet and 1.5 feet wide, respectively. We recommend the use of a friction factor of 0.30 between bearing elevations and foundations. This factor considers that concrete foundation elements will be placed in direct contact with suitable on -site soils. 5.3 Estimated Foundation Settlement Based on the subsurface data, anticipated site grading and assumed structural loading conditions, we estimate total foundation settlement would be less than 1-inch, with differential settlement of of the estimated total settlement. The magnitude of differential settlements will be influenced by the variability of underlying soils across the footprint of the structure and the variation of foundation loads. Our settlement analysis was performed based on an anticipated maximum structural column load of 50 kips and maximum wall load of 5 kips per linear foot. The settlement analysis was based on a conventional shallow foundation bearing at a depth of at least 2 feet below the anticipated finished floor elevations and designed for an allowable soil bearing pressure of 2,000 psf. Actual settlements experienced by the fire station building and the time required for these soils to settle will be influenced by undetected variations in subsurface conditions, final structural loads, and the quality of fill placement and foundation construction. Leicester Fire and Rescue Department F&R Project No. 65X-0079 Proposed Leicester Volunteer Fire Station IS61 Alexander Road Leicester, North Carolina April 16, 2019 Page 9 of 19 5.4 Shrink -Swell, Frost Depth and Bearing Considerations Based on our exploration, most of the residual soils encountered within foundation bearing grades consist of coarse -grained and some fine-grained soils. We also anticipate that fill obtained from on -site sources will meet the requirements for controlled structural fill specified in Section 6 of this report. We recommend any near surface unsuitable soils at foundation bearing grades be removed and replaced with suitable new controlled structural fill. Based on our general experience in the project vicinity, we anticipate the fine-grained soils present in foundation bearing grades to have a medium to high potential for moisture -related volume change (shrink -swell behavior). Accordingly, we recommend that exterior foundations be constructed at least 36 inches below adjacent grades in order to reduce the effect of shrink -swell, frosting, and shear puncture. Alternatively, exterior foundation subgrades consisting of high plasticity fine-grained soils may be undercut 2 feet and replaced with flowable fill, or lean concrete. In order to further reduce the potential of shrink -swell soil behavior, we recommend the ground surface near the fire station building foundations be graded such that surface water does not accumulate near the foundations. Roof drainage downspouts should be routed into appropriate drainage channels directed away from the building. 5.5 Concrete Slabs -On -Grade The floor slabs may be designed as a slab -on -grade supported on suitable undisturbed natural soil or new controlled structural fill subgrades. Slab -on -grade support is contingent upon successful completion of the subgrade evaluation process as described in the Site Preparation section of this report (Section 6.2). A modulus of subgrade reaction (k) of 100 pounds per square inch per inch (psi/inch) may be used for design of the floor slab bearing on an approved subgrade. A six-inch thick layer of North Carolina Department of Transportation (NCDOT) open graded coarse aggregate No. 57 or No. 67 should be placed beneath the floor slab. This granular base would function as a leveling and load distributing material as well as a capillary break beneath the slab. Leicester Fire and Rescue Department F&R Project No. 65X-0079 Proposed Leicester Volunteer Fire Station IS61 Alexander Road Leicester, North Carolina April 16, 2019 Page 10 of 19 A vapor retarder should be used beneath slabs that will be covered by tile, wood, carpet, impermeable coatings, and or if other moisture -sensitive equipment or materials will be in contact with the slab. However, the use of vapor retarders may result in excessive curling of concrete slabs during curing. We refer the concrete slab designer to ACI 302.1R-15, Section 5.2, for further discussion on vapor retarders, curling, and the means to lessen potential concrete shrinkage and curling. Proper jointing of the concrete slabs -on -grade is also essential to reduce cracking. ACI suggests that unreinforced plain concrete slabs may be jointed at spacing of 24 to 36 times the slab thickness, up to a maximum spacing of 15 feet. Slab construction should incorporate isolation joints along walls and column locations (if applicable) to allow minor movements to occur without damage. Utility or other construction excavations in the prepared subgrade should be backfilled to a controlled structural fill criterion to provide uniform support. 5.6 Pavement Design Recommendations The pavement design for the proposed access driveway, building apron, and parking lot areas should consider whether the pavements will be subjected to light -duty or heavy-duty traffic. A light -duty pavement section should be used where traffic is expected to primarily consist of autos and occasional light service vehicles such as in parking spaces. A heavy-duty pavement section should be used where the traffic will also consist of light and numerous heavy service vehicles such as in access driveway and building apron areas. We understand that the parking lot and driveways will be paved with asphalt and the building apron will be paved with concrete. Pavement designs are normally based on a Design CBR (DCBR) value that may be calculated as Z/ of the soaked CBR value. The results of our laboratory CBR testing for this project were not available at the time of submitting this draft report, however, based on the soils encountered and our experience with similar type soils, we assume a CBR value of 5 for the site soils and therefore the DCBR used for this project would be 3. We also considered a modulus of subgrade reaction (k) of 100 psi/inch and an ADT loading of up to 500 cars including up to about 50 heavy-duty fire service trucks or other heavy vehicles. Our asphalt pavement design considers a design period of 20 years. Please note that flexible pavement designed for a period of about 20 years should consider that periodic maintenance and repairs of cracks are performed on a regular basis. Leicester Fire and Rescue Department F&R Project No. 65X-0079 Proposed Leicester Volunteer Fire Station IS61 Alexander Road Leicester, North Carolina April 16, 2019 Page 11 of 19 We established our asphalt pavement design recommendations based on the AASHTO layer coefficient method and our concrete pavement design using methods as outlined in the Guide for Design and Construction of Concrete Parking Lots reported by ACI Committee 330 (ACI 330R-1). Using the above referenced traffic loading conditions and the design CBR value, the following light -duty and heavy-duty asphalt and heavy-duty concrete pavement sections are recommended for the project: Table 5.6.1: Pavement Section Design Light -Duty Heavy -Duty Heavy -Duty Asphalt Asphalt Concrete Pavement Section Pavement Pavement Pavement (inches) (inches) (inches) S9.513 Bituminous Concrete Surface Mix 2 1.5 - 119.013 Bituminous Concrete Intermediate Mix - 2.5 - 1325.013 Bituminous Concrete Intermediate Mix - 3.0 - Welded Wire Fabric Reinforced Concrete (PCC) - - 8 NCDOT ABC Stone Subbase 6 8.0 At least 6 Construction of the pavements should be performed in accordance with the latest edition of the North Carolina Department of Transportation Standard Specifications for Roads and Structures. Concrete pavements are recommended to be reinforced with welded wire fabric (WWF). Long-term performance of pavements is highly dependent on maintaining suitable drainage conditions and preventing deterioration of the underlying subgrade materials. If the base material remains saturated over an extended period of time, pavement distresses are much more likely to occur. Subsurface drains are typically utilized beneath a pavement where water may enter the pavement from below or above. Based on the results of the soil test borings, we do not anticipate that sub drains will be required for this site. However, site drainage problems revealed during construction may indicate a requirement for sub drainage installation. Leicester Fire and Rescue Department F&R Project No. 65X-0079 Proposed Leicester Volunteer Fire Station IS61 Alexander Road Leicester, North Carolina April 16, 2019 Page 12 of 19 Proper drainage may be aided by grading the site such that surface water is directed away from pavements and by construction of swales adjacent to the pavements. This will be required in areas of this site were pavement subgrades will be in cut areas or areas where the ground surface slopes towards the pavement. All pavements should be graded such that surface water is directed towards the outer limits of the paved area or to catch basins located such that surface water does not remain on the pavement. It is recommended that any dumpsters be supported on a minimum 6-inch thick concrete pad on a minimum 6-inch thick NCDOT ABC stone subbase. The pad should project horizontally in front of the dumpster such that the front wheels of any service truck are supported by the concrete pad during loading and unloading of the dumpster. Concrete pavements should have a minimum 4,000-psi compressive strength and be air entrained. 5.7 Seismic Site Classification The seismic site class evaluations presented herein reference the International Building Code (IBC) 2015, which entails an evaluation of the top 100 feet of the subsurface soil profile in order to determine the seismic site class. The deepest soil borings for this project were terminated at a depth of 25 feet for foundation considerations. Based on the data we collected from our subsurface exploration and on our experience in the area, a Soil Seismic Site Class D is recommended for this project site. F&R notes that the recommended Site Class is based on information available at the time this report was written. If this classification should be so onerous to the project cost that further study is warranted, we can perform a site -specific geo-physical survey to attain sufficient detail to further define the project's seismic Site Class definition. This additional testing would be beyond the currently authorized scope of services for this project. 6.0 CONSTRUCTION RECOMMENDATIONS 6.1 General The principal purpose of this section is to comment in general on the items related to earthwork and associated geotechnical engineering aspects of construction that should be expected for this Leicester Fire and Rescue Department F&R Project No. 65X-0079 Proposed Leicester Volunteer Fire Station IS61 Alexander Road Leicester, North Carolina April 16, 2019 Page 13 of 19 project. It is recommended that F&R's geotechnical engineer be retained to provide soil -engineering services during the construction phases of the project and perform appropriate evaluations to help assure that conditions encountered during construction are similar to conditions encountered in the borings. The geotechnical engineer can also assist in interpretation of differing subsurface conditions that may be encountered and recommend remedial work, if needed. 6.2 Site Preparation The entire construction area should be stripped of existing vegetation, surficial organic soils, debris or any other deleterious materials to a minimum of 5 feet outside the proposed building construction areas and 2 feet behind the curb lines for paved areas. Depressions or low areas resulting from stripping operations should be backfilled with approved soil and compacted in accordance with the recommendations presented in this report. Existing buried utilities and deleterious materials should be completely removed from within the footprint of the proposed new structures and replaced with approved soil. During grading operations, hidden features in the substratum, such as organic laden soils, or other deleterious materials may be encountered within the proposed construction area. Generally, such features will require removal. Details regarding the removal of deleterious materials should be determined on a case -by -case basis and; therefore, contract documents should include a contingency cost for the removal of such subsurface features. We recommend site preparation be monitored by the geotechnical engineer or his representative to verify that the recommendations presented herein are implemented. Prior to fill placement and or at -grade construction, areas to provide support for foundations, floor slabs, pavements and structural fills should be proofrolled under the supervision of the geotechnical engineer or his representative. Proofrolling should be performed with a fully loaded tandem -axle dump truck or similar piece of rubber -tired equipment with a minimum loaded weight of 20 tons. The purpose of the proofrolling is to detect the existence of any soft, very loose, or wet, near -surface materials or unsuitable soils that may require undercutting. Areas that deflect, rut, or pump excessively during proofrolling, and which cannot be densified in -place by further rolling, should be Leicester Fire and Rescue Department F&R Project No. 65X-0079 Proposed Leicester Volunteer Fire Station 1S61 Alexander Road Leicester, North Carolina April 16, 2019 Page 14 of 19 remediated as directed by the geotechnical engineer or his representative and approved by the Owner. Some localized undercutting and or recompaction should be anticipated and; therefore, contract documents should include a contingency cost for localized undercutting and recompaction. 6.3 Controlled Structural Fill Placement and Compaction Prior to fill placement, representative samples of each engineered fill material should be collected and tested by F&R to determine the material's moisture -density characteristics (including, the maximum dry density, optimum water content, gradation and Atterberg limits). These tests are needed for quality control of the controlled structural fill and to determine if the fill material meets project specification requirements. Controlled structural fill in structural areas should be free of organics, roots, or other deleterious materials; should not contain more than five percent (by weight) organic material; should not have a plasticity index (PI) greater than 25; or have a maximum dry density less than 90 pounds per cubic foot. Soils not meeting these criteria may be used in landscaped or non-structural areas. Compacted structural fill should consist of material classified as CL, ML, SC or SM per ASTM D2487, or others as approved by the geotechnical engineer. CH and MH materials are generally not recommended for use as structural fill due to their low strength characteristics and moisture sensitivity, but may be approved on a case -by -case basis. Soils imported from off -site sources should also meet similar classification requirements and be approved by the geotechnical engineer prior to use. Successful reuse of the excavated, on -site soils as controlled structural fill will depend on the water content and the plasticity of the soils encountered during excavation. Once fill placement begins, a qualified soils technician should perform field density tests to document the degree of compaction being obtained in the field. Structural fills should be placed in thin (8- to 10-inch) loose lifts and compacted to the following recommendations: • Upper 18 inches below the final subgrade elevation: ■ 100% of the soil's standard Proctor maximum dry density (ASTM Test Method D698) at or near optimum water content: maximum deviation of ±3 percentage points of optimum water content. • Depths below 18 inches: Leicester Fire and Rescue Department F&R Project No. 65X-0079 Proposed Leicester Volunteer Fire Station 1561 Alexander Road Leicester, North Carolina April 16, 2019 Page 15 of 19 ■ 95% of the soil's standard Proctor maximum dry density (ASTM Test Method D698) at or near optimum water content: maximum deviation of ±3 percentage points of optimum water content. Some manipulation of the water content (such as wetting or drying) may be required during the filling operation to obtain the required degree of compaction. The manipulation of the water content is highly dependent on weather conditions and site drainage conditions. Therefore, the grading contractor should be prepared to both dry and wet the fill materials to obtain the specified compaction during grading. Regular one -point Proctor tests should be conducted in an attempt to verify that the most representative Proctor curve is being selected. Sufficient density tests should be performed to confirm the required compaction of the fill material. The contractor should exercise care after these soils have been compacted. If water is allowed to stand on the surface, these soils may become saturated. Movement of construction traffic on saturated subgrades can cause rutting that may destroy the fill's integrity. Once the integrity of the subgrade is destroyed, mobility of construction traffic becomes difficult or impossible. Therefore, the fill surface should be sloped to achieve positive drainage and to minimize water from ponding on the surface. If the surface becomes excessively wet, fill operations should be halted and our geotechnical engineer consulted for guidance. Testing of the fill material and compaction monitoring by our engineering technician is recommended during fill placement operations. 6.4 Shallow Foundation Construction To document suitable bearing within the actual foundation excavation, we recommend that the near -surface bearing soils be evaluated by performing hand auger borings with DCP testing equipment or other suitable methods prior to foundation installation. Any unsuitable soils detected during this evaluation should be undercut and remediated as directed by the geotechnical engineer. Depending on final design grades, some localized undercutting and or recompaction should be anticipated. We recommend that individual foundations be concreted as soon after the evaluation as possible to minimize the potential disturbance of the bearing soils. If the foundation excavation subgrade soils must remain exposed overnight or during inclement weather, we recommend that a 2- to Leicester Fire and Rescue Department F&R Project No. 65X-0079 Proposed Leicester Volunteer Fire Station IS61 Alexander Road Leicester, North Carolina April 16, 2019 Page 16 of 19 4-inch thick "mud -mat" of lean concrete be placed on the bearing soils, taking care to maintain the required thickness of foundation concrete and the design top of footing elevation. The foundation bearing area should be free of any very loose or soft material, standing water, and debris at the time of concrete placement. Concrete should not be placed on soils that have been softened by precipitation or frost heave. Exposure of the subgrade materials to the environment may weaken these soils at the foundation bearing level. If the foundation excavations remain open for long periods of time, or during inclement weather, re-evaluation of the subgrade materials by the geotechnical engineer or his representative should be performed prior to steel, concrete, or stone placement. 6.5 Surface Water Control If free water is allowed to stand on stable subgrade soils, these soils can absorb water, swell, and experience a reduction in their support capability. As a result, we recommend that the subgrade surface be graded to provide positive drainage away from the construction areas and towards suitable drainage handling areas, such as a perimeter ditch, French drain, culvert, or retention pond. Due to the presence of moisture -sensitive soils, trapped or perched water conditions could develop during periods of inclement weather and during seasonally wet periods. Such conditions could cause seepage into excavations and deeper cuts. Therefore, grading of the project should be performed in such a manner to prevent ponding of water and promote runoff away from construction areas. In addition, if site grading is performed during the seasonally wet months or after extended periods of inclement weather, wet and water softened near surface soil conditions should be expected. 6.6 Excavation Characteristics We anticipate the near -surface soils at the site can be excavated with backhoes, front-end loaders or other similar equipment using conventional means and methods. Typically, material with an N-value of 50 blows per 3 to 6 inches of penetration can be excavated with moderate to heavy effort using appropriately sized equipment, such as a large track -hoe (e.g., Caterpillar 330 with rock teeth). Leicester Fire and Rescue Department F&R Project No. 65X-0079 Proposed Leicester Volunteer Fire Station 1S61 Alexander Road Leicester, North Carolina April 16, 2019 Page 17 of 19 6.7 Groundwater Conditions Groundwater for the purposes of this report is defined as water encountered below the existing ground surface. Based on the data obtained during our exploration program, groundwater was not encountered in our soil test borings. Therefore, it is unlikely that groundwater would be encountered during site grading and foundation excavation; however, a perched groundwater condition may be encountered. The contractor should be prepared to dewater locations where surface water or a perched water condition is encountered. The contractor should be responsible for the design and installation of any dewatering systems required for this project. Groundwater levels tend to fluctuate with seasonal and climatic variations as well as with some types of construction operations. Generally, the highest groundwater levels occur in late winter and early spring and the lowest levels occur in late summer and early fall. Depending on time of construction, groundwater may be encountered at shallower depths and locations not explored during this study. If encountered during construction, engineering personnel from our office should be notified immediately. 6.8 Excavations Mass excavations and other excavations required for construction of this project must be performed in accordance with the United States Department of Labor, Occupational Safety and Health Administration (OSHA) guidelines (29 CFR 1926, Subpart P, Excavations) or other applicable jurisdictional codes for permissible temporary side -slope ratios and or shoring requirements. The OSHA guidelines require daily inspections of excavations, adjacent areas and protective systems by a "competent person" for evidence of situations that could result in cave-ins, indications of failure of a protective system, or other hazardous conditions. Excavated soils, equipment, building supplies, etc., should be placed away from the edges of the excavation at a distance equaling or exceeding the depth of the excavation. F&R cautions that the actual excavation slopes will need to be evaluated frequently each day by the "competent person" and flatter slopes or the use of shoring may be required to maintain a safe excavation depending upon excavation specific circumstances. The contractor is responsible for providing the "competent person" and all aspects of site excavation safety. F&R can evaluate specific excavation slope situations if we are informed and requested by the owner, designer or contractor's "competent person." Leicester Fire and Rescue Department F&R Project No. 65X-0079 Proposed Leicester Volunteer Fire Station IS61 Alexander Road Leicester, North Carolina April 16, 2019 Page 18 of 19 7.0 CONTINUATION OF SERVICES F&R recommends that we be retained for professional and construction materials testing services during construction of the project. Our continued involvement on the project helps provide continuity for proper implementation of the recommendations discussed herein. Additionally, we request the opportunity to review the final grading plans, foundation plans and project specifications when these construction documents approach completion. This review evaluates whether the recommendations and comments provided herein have been understood and properly implemented. The above listed services are not part of the currently authorized scope of services. 8.0 LIMITATIONS There are important limitations to this and all geotechnical studies. Some of these limitations are discussed in the information prepared by the Geoprofessional Business Association (GBA), which is included in Appendix IV. We recommend that you review the GBA information. This report has been prepared for the exclusive use by Leicester Fire and Rescue Department or their agents, for specific application to the proposed Leicester Volunteer Fire Station development near 1561 Alexander Road in Leicester, North Carolina, in accordance with generally accepted soil and foundation engineering practices. No other warranty, express or implied, is made. Our conclusions and recommendations are based on project information furnished to us at the time the work was performed, and generally accepted geotechnical engineering practices. The findings and recommendations do not reflect variations in subsurface conditions, which could exist in unexplored areas of the site. In areas where variations from the available subsurface data become apparent during construction, it will be necessary to re-evaluate our conclusions and recommendations based upon on -site observations of the conditions. In the event that changes are made in the design or location of the proposed cuts at the proposed development, the recommendations presented in this report shall not be considered valid unless the changes are reviewed by our firm and conclusions of this report modified and or verified in writing. If this report is copied or transmitted to a third party, it must be copied or transmitted in its entirety, including text, attachments, and enclosures. Interpretations based on only a part of this report may not be valid. Leicester Fire and Rescue Department F&R Project No. 65X-0079 Proposed Leicester Volunteer Fire Station IS61 Alexander Road Leicester, North Carolina April 16, 2019 Page 19 of 19 Site Vicinity Map (Figure No. 1) Test Location Plan (Figure No. 2) »41 rasa 707 z63 Site Location u 18d9 751 s Alexander f7ln lam laa� 1 rat lazz ,�z5 ,g�4 ,sTg '4%,M561 Alexander Road Leicester Z 91 �► lsa� r � tb5z 1-7 1377 14C2 1 , 0 83 r 75 •' F '.1' 1769� 0' 1 mi. 2 mi. L31� 1338 Image obtained from Google Maps F R O E H L I N G & R O B E RTS O N, INC. Site Vicinity Map Job No.: 65X-0079 Scale: 1" = 1 mil Fgc R Engineering Stability Since 1881 Proposed Leicester Volunteer Fire Station Date: 04/09/2019 Drawn By: R. French v 18 Woods Lake Road, Greenville, SC 29607 1 USA Near Alexander Road SINCE 1881 T 864.271.2840 1 F 864.271.8124 Leicester, North Carolina Figure No.: 1 Checked By: B. Azumah Drawing Legend: Approx. Boring Loc. J +� } III Ff w _ • `, � B-02 a ..a -}004� uM r13 B-05 B `BJ07 A m Proposed Fire Station a lw'%f oln i3'I-ce-vta� .'rr _---__---- Rsw V Pane Oil -- ------ ---- ----------------- +ti °�� ��`t} ri''�• \�•i�. M y-- ��. =� ``--`----- ---r� s- ,. _ �'ar rr�'yr'. �rrf rrrrrr,rri•-rt� ��. k `�'�'e :r+ +- -_-..'�- r�rr • r r�r �-��.•`�11~a Z s; •�. � � .. •^r �_��tititi_+r�__rr^���.^-.--:�-�� rr -.+r- r��r`+��:rr�fr ..:�1 - '..�y��•.r•rrr; �_-.-+. ►__.r-�r ter':-r--'r y.-�-.y`�^a`.• ',l z • r r r-- ,j '..��... rr .--+ r r �_....^ rrr .��_-\' ,.i'• r rr r `�rii +rri rr' -. �--r• ••��--ram'-r^\vim«-^rr r--'"-�errr � r - !'-,' .. rri �•��� r..r,,. - ,� s �'a+o `._ �=���"`-_•..--:,••ter--_-- ,� . ,, rr—�` . ' � �■ r-'rrrr�rr':rffrrffi rrr•• .^s Sti �\.�t--_---�_•_'-���..��:��=�.•���..- 9rs'414-7lra - r i:!�ir%fffr rrrr•r+ii r� ��.� ��`• ��� ``,`a ''s ^-"����r•�-r.o---'���-^` T el/Io r�frr/r'Fr/vr�•�.. • i ,,y �� ''—n—�.±�r ~^ A.M1— _ 0' 100, nwe,as rr Cid! ��[,IYF7Ti '36 E�]$rlltl! a A d r nry aea 416�-A% F F R O E H L I N G & R O B E RTS O N, INC. Test Location Plan Job No.: 65X-0079 Scale: 1": 100' Engineering Stability Since 1881 Proposed Leicester Volunteer Fire Station 18 Woods Lake Road, Greenville, SC 29607 1 USA Near Alexander Road Date: 04/09/2019 Drawn By: R. French SINCE 1881 T 864.271.2840 1 F 864.271.8124 Leicester, North Carolina Figure No.: 2 Checked By: B. Azumah APPENDIX II Key to Soil Classification Soil Classification Chart Boring Logs B-01 through B-12 Subsurface Soil Profiles — Building and Pavement Areas (Figure Nos. 3A and 3B) SINCE 186i KEY TO SOIL CLASSIFICATION Correlation of Penetration Resistance with Relative Density and Consistency Sands and Gravels Silts and Clays No. of Relative No. of Relative Blows, N DMLity Blows, N Densi 0 - 4 Very loose 0 - 2 Very soft 5 - 10 Loose 3- 4 Soft 11 - 30 Medium dense 5 - 8 Firm 31 -50 Dense 9 - 15 Stiff Over 50 Very dense 16 - 30 Very stiff 31 - 50 Hard Over 50 Very hard Particle Size Identification (Unified Classification System) Boulders: Diameter exceeds 8 inches Cobbles: 3 to 8 inches diameter Gravel: Coarse - 3/4 to 3 inches diameter Fine - 4.76 mm to 3/4 inch diameter Sand: Coarse - 2.0 mm to 4.76 mm diameter Medium - 0.42 mm to 2.0 mm diameter Fine - 0.074 mm to 0.42 mm diameter Silt and Clay: Less than 0.07 mm (particles cannot be seen with naked eye) Modifiers The modifiers provide our estimate of the amount of silt, clay or sand size particles in the soil sample. Approximate Content Modifiers <_ 5%: Trace 5% to 12%: Slightly silty, slightly clayey, slightly sandy 12% to 30%: Silty, clayey, sandy 30% to 50%: Very silty, very clayey, very sand Field Moisture Description Saturated: Usually liquid; very wet, usually from below the groundwater table Wet: Semisolid; requires drying to attain optimum moisture Moist: Solid; at or near optimum moisture Dry: Requires additional water to attain optimum moisture SOIL CLASSIFICATION CHART MAJOR DIVISIONS SYMBOLS TYPICAL DESCRIPTIONS GRAPH LETTER GRAVEL AND CLEAN GRAVELS �•� I. r k GW WELL —GRADED GRAVELS, GRAVEL — SAND MIXTURES, LITTLE OR NO FINES �'. ,'. �•� �. •�. GP POORLY —GRADED GRAVELS, GRAVEL — SAND MIXTURES, LITTLE OR NO FINES GRAVELLY SOILS (LITTLE OR NO FINES) COARSE GRAINED SOILS MORE THAN 50% OF COARSE GRAVELS WITH FINES • '' �' • ' GM SILTY GRAVELS, GRAVEL — SAND — SILT MIXTURES FRACTION RETAINED ON NO. 4 SIEVE (APPRECIABLE AMOUNT OF FINES) r±�+ GC CLAYEY GRAVELS, GRAVEL — SAND — CLAY MIXTURES SAND AND CLEAN SANDS eeeeeeeee SW WELL —GRADED SANDS, GRAVELLY SANDS, LITTLE OR NO FINES MORE THAN 50% OF MATERIAL IS LARGER THAN SANDY NO. 200 SIEVE SIZE SOILS (LITTLE OR NO FINES) Sp POORLY —GRADED SANDS, GRAVELLY SAND, LITTLE OR NO FINES SANDS WITH FINES - — — — - `SM SILTY SANDS, SAND — SILT MIXTURES MORE THAN 50% OF COARSE FRACTION _ — PASSING ON NO. 4 SIEVE (APPRECIABLE AMOUNT OF FINES) _ — — — — �r sc CLAYEY SANDS, SAND — CLAY MIXTURES INORGANIC SILTS AND VERY FINE M L SANDS, ROCK FLOUR, SILTY OR CLAYEY FINE SANDS OR CLAYEY SILTS WITH SLIGHT PLASTICITY CL INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY, GRAVELLY CLAYS, SANDY CLAYS, SILTY CLAYS, LEAN CLAYS FINE GRAINED SOILS SILTS AND LIQUID LIMIT LESS THAN 50 CLAYS OL ORGANIC SILTS AND ORGANIC SILTY CLAYS OF LOW PLASTICITY MORE THAN 50% OF MATERIAL IS SMALLER THAN NO. 200 SIEVE M H INORGANIC SILTS, MICACEOUS OR DIATOMACEOUS FINE SAND OR SILTY SOILS SIZE SILTS AND LIQUID LIMIT CLAYS GREATER THAN 50 CH INORGANIC CLAYS OF HIGH PLASTICITY OH ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY, ORGANIC SILTS HIGHLY ORGANIC SOILS L ` i`', PT PEAT, HUMUS, SWAMP SOILS WITH HIGH ORGANIC CONTENTS NOTE: DUAL SYMBOLS ARE USED TO INDICATE BORDERLINE SOIL CLASSIFICATIONS c c c SINCE �& Froehling & Robertson, Inc. BORING LOG Boring: B 01 (1 of 1) 1861 Project No: 65X-0079 Elevation: 2167.5 ± Drilling Method: HSA Client: Leicester Fire and Rescue Department Total Depth: 15.0' Hammer Type: Automatic Project: Leicester Volunteer Fire Station Boring Location: See Test Location Plan Date Drilled: 4/11/19 City/State: 1561 Alexander Road, Leicester, NC Driller: F&R, Inc. Elevation Depth Description of Materials * Sample Sample et N-Value Remarks (Classification) Blows eeth (blows/ft) 2167.0 0.5 6 inches SURFICIAL SOIL 2-4-5 U Groundwater was not RESIDUUM: Loose, Reddish -Brown, Coarse to -7 9 encountered during Fine Clayey SAND (SC), moist drilling 2165.5 2.0 2.0 Medium Dense, Reddish -Brown, Coarse to Fine 5-6-7 Silty SAND (SM), moist -11 13 4.0 5-5-6 -7 11 2161.5 6.0 Medium Dense to Loose, Red, Yellowish -Black, 6.0 4-6-5 Coarse to Fine Silty SAND (SM), moist -6 11 8.0 10-4-5 -6 9 10.0 13.0 3-3-4 7 2152.5 15.0 Boring terminated at 15 feet and temporary water observation well installed for stabilized groundwater measurement. ivumDer oT Diows requires Tor a 14u io nammer aropping su to arive L u.u., i.u. sampler a toiai oT iu incnes in inree o increments. The sum of the second and third increments of penetration is termed the standard penetration resistance, N-Value. c c c SINCE �& Froehling & Robertson, Inc. BORING LOG Boring: B 02 (1 of 1) 1861 Project No: 65X-0079 Elevation: 2180 ± Drilling Method: HSA Client: Leicester Fire and Rescue Department Total Depth: 10.0' Hammer Type: Automatic Project: Leicester Volunteer Fire Station Boring Location: See Test Location Plan Date Drilled: 4/11/19 City/State: 1561 Alexander Road, Leicester, NC Driller: F&R, Inc. Elevation Depth Description of Materials * Sample Sample et N-Value (blows/ft) Remarks (Classification) Blows eeth 2179.5 0.5 6 inches SURFICIAL SOIL 3-3-5 Groundwater was not RESIDUUM: Loose, Reddish -Brown, Coarse to -7 8 encountered during Fine Clayey SAND (SC), moist drilling 2178.0 2.0 2.0 Medium Dense, Reddish -Brown, Coarse to Fine 3-5-9 Silty SAND with some Clay (SM) , moist -6 14 2176.0 4.0 Medium Dense, Reddish -Brown, Coarse to Fine 4.0 3-5-8 Silty SAND with some Clay (SM) , moist -10 13 6.0 3-6-7 -10 13 8.0 3-4-8 -10 12 2170.0 10.0 Boring terminated at 10 feet and backfilled with auger cuttings (soil) after completion. ivumDer oT Diows requires Tor a lvu iD nammer aropping ju to arive L u.u., i.u. sampler a toiai oT iu incnes in inree o increments. The sum of the second and third increments of penetration is termed the standard penetration resistance, N-Value. c c c SINCE �& Froehling & Robertson, Inc. BORING LOG Boring: B 03 (1 of 1) 1861 Project No: 65X-0079 Elevation: 2175 ± Drilling Method: HSA Client: Leicester Fire and Rescue Department Total Depth: 6.0' Hammer Type: Automatic Project: Leicester Volunteer Fire Station Boring Location: See Test Location Plan Date Drilled: 4/11/19 City/State: 1561 Alexander Road, Leicester, NC Driller: F&R, Inc. Elevation Depth Description of Materials * Sample Sample et N-Value (blows/ft) Remarks (Classification) Blows eeth 2174.5 0.5 6 inches SURFICIAL SOIL 3.63-5 Groundwater was not 8 encountered during RESIDUUM: Firm to very Stiff, Reddish -Brown, Sandy SILT with some Clay (ML), moist drilling. 2.0 3-7-11 -13 18 2171.0 4.0 11 4.0 Loose, Reddish -Brown, Coarse to Fine Silty SAND 3-4-6 (SM), moist -9 10 2169.0 6.0 6.0 Boring terminated at 6 feet and backfilled with auger cuttings (soil) after completion. ivumDer oT Diows requires Tor a lvu iD nammer aropping ju to arive L u.u., i.u. sampler a toiai oT iu incnes in inree o increments. The sum of the second and third increments of penetration is termed the standard penetration resistance, N-Value. c c c SINCE �& Froehling & Robertson, Inc. BORING LOG Boring: B 04 (1 of 1) 1861 Project No: 65X-0079 Elevation: 2178 ± Drilling Method: HSA Client: Leicester Fire and Rescue Department Total Depth: 10.0' Hammer Type: Automatic Project: Leicester Volunteer Fire Station Boring Location: See Test Location Plan Date Drilled: 4/11/19 City/State: 1561 Alexander Road, Leicester, NC Driller: F&R, Inc. Elevation Depth Description of Materials * Sample Sample et N-Value (blows/ft) Remarks (Classification) Blows eeth 2177.5 0.5 6 inches SURFICIAL SOIL 2-4-5 6 5 Groundwater was not 9 encountered during RESIDUUM: Stiff, Dark Reddish -Brown, Sandy SILT with some Clay (ML), moist drilling 2.0 3-3-6 -9 9 2174.0 4.0 Stiff, Reddish -Brown, Sandy SILT with some Clay 4.0 4-6-7 (ML), moist -10 13 6.0 4-4-5 -7 9 8.0 4-5-7 -9 12 2168.0 10.0 Boring terminated at 10 feet and backfilled with auger cuttings (soil) after completion. ivumDer oT Diows requires Tor a lvu iD nammer aropping ju to arive L u.u., i.u. sampler a toiai oT iu incnes in inree o increments. The sum of the second and third increments of penetration is termed the standard penetration resistance, N-Value. c c c SINCE �& Froehling & Robertson, Inc. BORING LOG Boring: B 05 (1 of 1) 1861 Project No: 65X-0079 Elevation: 2179 ± Drilling Method: HSA Client: Leicester Fire and Rescue Department Total Depth: 20.0' Hammer Type: Automatic Project: Leicester Volunteer Fire Station Boring Location: See Test Location Plan Date Drilled: 4/11/19 City/State: 1561 Alexander Road, Leicester, NC Driller: F&R, Inc. Elevation Depth Description of Materials * Sample Sample et N-Value Remarks (Classification) Blows eeth (blows/ft) 2178.5 0.5 6 inches SURFICIAL SOIL 2 -65 Groundwater was not RESIDUUM: Loose to Medium Dense, 9 encountered during Reddish -Brown, Coarse to Fine Clayey SAND (SC), drilling moist 2.0 2-5-6 -10 11 2175.0 4.0 4.0 Medium Dense, Reddish -Brown, Coarse to Fine 3-5-6 Silty SAND (SM), moist -8 11 2173.0 6.0 Loose, Red and Gray, Coarse to Fine Silty SAND 6.0 3-4-6 (SM), moist -8 10 2171.0 8.0 Medium Dense, Red, Yellow and Black, Coarse to 8.0 3-5-7 Fine Silty SAND (SM), moist -10 12 10.0 13.5 4-6-8 14 15.0 18.5 3-5-8 13 2159.0 20.0 Boring terminated at 20 feet and backfilled with auger cuttings (soil) after completion. ivumDer oT Diows requires Tor a 14u iD nammer aropping su to arive L u.u., i.u. sampler a toiai oT iu incnes in inree o increments. The sum of the second and third increments of penetration is termed the standard penetration resistance, N-Value. c c c SINCE �& Froehling & Robertson, Inc. BORING LOG Boring: B 06 (1 of 1) 1861 Project No: 65X-0079 Elevation: 2172.5 ± Drilling Method: HSA Client: Leicester Fire and Rescue Department Total Depth: 10.0' Hammer Type: Automatic Project: Leicester Volunteer Fire Station Boring Location: See Test Location Plan Date Drilled: 4/11/19 City/State: 1561 Alexander Road, Leicester, NC Driller: F&R, Inc. Elevation Depth Description of Materials * Sample Sample et N-Value Remarks (Classification) Blows eeth (blows/ft) 2172.0 0.5 6 inches SURFICIAL SOIL 2 -53 Groundwater was not RESIDUUM: Loose to Medium Dense, 5 encountered during Reddish -Brown, Coarse to Fine Clayey SAND (SC), drilling moist 2.0 4-6-9 -14 15 4.0 3-6-10 -11 16 6.0 3-5-8 -10 13 2164.5 8.0 8.0 Medium Dense, Reddish -Brown, Coarse to Fine 3-4-7 Silty SAND (SM), moist -9 11 2162.5 10.0 Boring terminated at 10 feet and backfilled with auger cuttings (soil) after completion. ivumDer oT Diows requires Tor a lvu iD nammer aropping ju to arive L u.u., i.u. sampler a toiai oT iu incnes in inree o increments. The sum of the second and third increments of penetration is termed the standard penetration resistance, N-Value. c c c SINCE �& Froehling & Robertson, Inc. BORING LOG Boring: B 07 (1 of 1) 1861 Project No: 65X-0079 Elevation: 2171.5 ± Drilling Method: HSA Client: Leicester Fire and Rescue Department Total Depth: 25.0' Hammer Type: Automatic Project: Leicester Volunteer Fire Station Boring Location: See Test Location Plan Date Drilled: 4/11/19 City/State: 1561 Alexander Road, Leicester, NC Driller: F&R, Inc. Elevation Depth Description of Materials * Sample Sample et N-Value Remarks (Classification) Blows eeth (blows/ft) 2171.0 0.5 6 inches SURFICIAL SOIL 2-2-3 Groundwater was not RESIDUUM: Loose, Reddish -Brown, Coarse to -4 5 encountered during Fine Clayey SAND (SC), moist drilling 2.0 2-4-6 -7 10 2167.5 4.0 4.0 Loose, Reddish -Brown, Coarse to Fine Silty SAND 2-5-5 (SM), moist -6 10 2165.5 6.0 Loose, Red, Yellow and White, Coarse to Fine 6.0 2-4-4 Silty SAND (SM), moist -4 8 8.0 4-3-3 -5 6 10.0 2158.0 13.5 13.5 Stiff, Grayish -Brown, Sandy SILT (ML), contains 4-9-6 mica, moist 15 15.0 2153.0 18.5 17 Firm, Grayish -Brown with white, Sandy SILT (ML), 18.5 3-2-4 contains mica, moist 6 20.0 2148.0 23.5 23.5 Loose, Light Grayish -Brown, Coarse to Fine Silty 2-2-5 SAND (SM), moist 7 2146.5 25.0 Boring terminated at 25 feet and backfilled with auger cuttings (soil) after completion. ivumDer oT Diows requires Tor a lvu io nammer aropping su to arive L u.u., i.u. sampler a toiai oT iu incnes in inree o increments. The sum of the second and third increments of penetration is termed the standard penetration resistance, N-Value. c c c SINCE �& Froehling & Robertson, Inc. BORING LOG Boring: B 08 (1 of 1) 1861 Project No: 65X-0079 Elevation: 2177.5 ± Drilling Method: HSA Client: Leicester Fire and Rescue Department Total Depth: 20.0' Hammer Type: Automatic Project: Leicester Volunteer Fire Station Boring Location: See Test Location Plan Date Drilled: 4/11/19 City/State: 1561 Alexander Road, Leicester, NC Driller: F&R, Inc. Elevation Depth Description of Materials * Sample Sample et N-Value Remarks (Classification) Blows eeth (blows/ft) 2177.0 0.5 6 inches SURFICIAL SOIL 2-3-5 6 5 Groundwater was not - 8 encountered during RESIDUUM: Firm, Reddish -Brown, Sandy SILT with some Clay (MIL), moist drilling 2175.5 2.0 2.0 Loose to Medium Dense, Reddish -Brown, Coarse 3-3-7 to Fine Silty SAND (SM), moist -8 10 4.0 3-5-7 -9 12 2171.5 6.0 Loose to Medium Dense, Light Reddish -Brown, 6.0 3-4-6 Coarse to Fine Silty SAND (SM), moist -7 10 8.0 3-4-5 -6 9 10.0 13.5 3-4-7 11 15.0 2159.0 18.5 Loose, Grayish -Brown, Coarse to Fine Silty SAND 18.5 2-4-4 (SM), moist 8 2157.5 20.0 Boring terminated at 20 feet and backfilled with auger cuttings (soil) after completion. ivumDer oT Diows requires Tor a 14u io nammer aropping su to arive L u.u., i.u. sampler a toiai oT iu incnes in inree o increments. The sum of the second and third increments of penetration is termed the standard penetration resistance, N-Value. c c c SINCE �& Froehling & Robertson, Inc. BORING LOG Boring: B 09 (1 of 1) 1861 Project No: 65X-0079 Elevation: 2175 ± Drilling Method: HSA Client: Leicester Fire and Rescue Department Total Depth: 25.0' Hammer Type: Automatic Project: Leicester Volunteer Fire Station Boring Location: See Test Location Plan Date Drilled: 4/11/19 City/State: 1561 Alexander Road, Leicester, NC Driller: F&R, Inc. Elevation Depth Description of Materials * Sample Sample et N-Value (blows/ft) Remarks (Classification) Blows eeth 2174.5 0.5 6 inches SURFICIAL SOIL 2 6 Groundwater was not RESIDUUM: Loose to Medium Dense, -8 9 encountered during Reddish -Brown, Coarse to Fine Clayey SAND (SC), drilling moist 2.0 2-5-6 -10 11 2171.0 4.0 Medium Dense, Reddish -Brown, Coarse to Fine 4.0 3-6-6 Clayey SAND (SC) with rock fragments, moist -8 12 2169.0 6.0 6.0 Loose, Reddish -Brown, Coarse to Fine Silty SAND 3-4-6 (SM), moist -7 10 2167.0 8.0 Medium Dense, Yellowish -Brown, Black and 8.0 3-4-8 White, Coarse to Fine Silty SAND (SM), moist -10 12 10.0 2161.5 13.5 Medium Dense to Loose, Yellowish -Brown, 13.5 3-5-9 Coarse to Fine Silty SAND (SM) with rock 14 fragments, moist 15.0 18.5 3-5-5 10 20.0 2151.5 23.5 Medium Dense, Red, Black and Yellow, Coarse to 23.5 5-8-10 Fine Silty SAND (SM), moist 18 2150.0 25.0 Boring terminated at 25 feet and backfilled with auger cuttings (soil) after completion. ivumDer oT Diows requires Tor a lvu iD nammer aropping su to arive L u.u., i.u. sampler a toiai oT iu incnes in inree o increments. The sum of the second and third increments of penetration is termed the standard penetration resistance, N-Value. c c c SINCE �& Froehling & Robertson, Inc. BORING LOG Boring: B 10 (1 of 1) 1861 Project No: 65X-0079 Elevation: 2165 ± Drilling Method: HSA Client: Leicester Fire and Rescue Department Total Depth: 10.0' Hammer Type: Automatic Project: Leicester Volunteer Fire Station Boring Location: See Test Location Plan Date Drilled: 4/11/19 City/State: 1561 Alexander Road, Leicester, NC Driller: F&R, Inc. Elevation Depth Description of Materials * Sample Sample et N-Value (blows/ft) Remarks (Classification) Blows eeth 2164.5 0.5 6 inches SURFICIAL SOIL 2.4 2 Groundwater was not RESIDUUM: Very Loose to Loose, 4 encountered during Reddish -Brown, Coarse to Fine Clayey SAND (SC), drilling moist 2.0 2-4-5 -7 9 2161.0 4.0 4.0 Medium Dense, Reddish -Brown, Coarse to Fine 4-6-7 Silty SAND (SM), moist -8 13 2159.0 6.0 J. Medium Dense, Reddish -Brown, Yellow and 6.0 3-5-7 Black, Coarse to Fine Silty SAND (SM), moist -10 12 8.0 4-6-8 -10 14 2155.0 10.0 Boring terminated at 10 feet and backfilled with auger cuttings (soil) after completion. ivumDer oT Diows requires Tor a lvu iD nammer aropping ju to arive L u.u., i.u. sampler a toiai oT iu incnes in inree o increments. The sum of the second and third increments of penetration is termed the standard penetration resistance, N-Value. c c c SINCE �& Froehling & Robertson, Inc. BORING LOG Boring: B 11 (1 of 1) 1861 Project No: 65X-0079 Elevation: 2180 ± Drilling Method: HSA Client: Leicester Fire and Rescue Department Total Depth: 6.0' Hammer Type: Automatic Project: Leicester Volunteer Fire Station Boring Location: See Test Location Plan Date Drilled: 4/11/19 City/State: 1561 Alexander Road, Leicester, NC Driller: F&R, Inc. Elevation Depth Description of Materials * Sample Sample et N-Value Remarks (Classification) Blows eeth (blows/ft) 2179.5 0.5 6 inches SURFICIAL SOIL 2-2-4 Groundwater was not RESIDUUM: Firm to Stiff, Reddish -Brown, Sandy -7 6 encountered during Lean CLAY (CL), moist drilling 2.0 2-5-8 -10 13 4.0 4-7-8 -10 15 2174.0 6.0 6.0 Boring terminated at 6.1 feet and backfilled with auger cuttings (soil) after completion. ivumDer oT Diows requires Tor a lvu iD nammer aropping ju to arive L u.u., i.u. sampler a toiai oT iu incnes in inree o increments. The sum of the second and third increments of penetration is termed the standard penetration resistance, N-Value. c c c SINCE �& Froehling & Robertson, Inc. BORING LOG Boring: B 12 (1 of 1) 1861 Project No: 65X-0079 Elevation: 2172.5 ± Drilling Method: HSA Client: Leicester Fire and Rescue Department Total Depth: 10.0' Hammer Type: Automatic Project: Leicester Volunteer Fire Station Boring Location: See Test Location Plan Date Drilled: 4/11/19 City/State: 1561 Alexander Road, Leicester, NC Driller: F&R, Inc. Elevation Depth Description of Materials * Sample Sample et N-Value (blows/ft) Remarks (Classification) Blows eeth 2172.0 0.5 6 inches SURFICIAL SOIL 2 -65 Groundwater was not RESIDUUM: Firm to Very Stiff, Reddish -Brown, 7 encountered during Sandy Lean CLAY (CL), moist drilling 2.0 2-5-7 -10 12 4.0 3-7-11 -16 18 2166.5 6.0 6.0 Medium Dense, Red and Yellow, Coarse to Fine 4-6-8 Silty SAND (SM), moist -10 14 8.0 4-5-7 -10 12 2162.5 10.0 Boring terminated at 10 feet and backfilled with auger cuttings (soil) after completion. ivumDer oT Diows requires Tor a lvu iD nammer aropping ju to arive L u.u., i.u. sampler a toiai oT iu incnes in inree o increments. The sum of the second and third increments of penetration is termed the standard penetration resistance, N-Value. SINCE �& Froehl ing & Robertson, Inc. Project No: 65X-0079 Client: Leicester Fire and Rescue Department Project: Leicester Volunteer Fire Station City/State: 1561 Alexander Road, Leicester, NC SUBSURFACE PROFILE Plot Based on Elevation Profile Name: Building and Pavement Areas 2,180 B-05 B-04 9 9 11 B 03 B-09 2,175 ............ \a .......... ............... ................... .9 .......... :...............:...............:............... :.......... .\` 8 11 9 13 18 10 B 07 11 9 2,170 ............ ,::10 .......:...............:................... ............ ..:..1.2..; ............... :.............. . ............ ...............:......... ... 12........................... ........... ............ 12 10 0 10 10 12 B.1....... o 2,165 ............ :............................... :............... :................ .... ........... 14 :. .......... ... ............................ g ........ ............ ............ ........... I @ 4 o > w 6 z 9 0 0 14 w 2,160 .............................................................................. ........... 13 .......... ......... ........... ........ ............ ............ ........... 1.3..... 12 z 15 1............. 1 4... 2,155 ............ :............... :............... :............... :................ :............... :............. :. .......... ......... ........... :.. ........ ............ ........... U 0 0 6 18 2,150 X W ..........................................:...............:................:...............:. ........... ............ ........... ............ a 0 7 Z a 2,145 SINCE �& Froehl ing & Robertson, Inc. Project No: 65X-0079 Client: Leicester Fire and Rescue Department Project: Leicester Volunteer Fire Station City/State: 1561 Alexander Road, Leicester, NC SUBSURFACE PROFILE Plot Based on Elevation Profile Name: Building and Pavement Areas 2,185 B-02 B*11 2,180 ............. . . ................. ................................ ....................................................... ...................................................... .A 7. ........................ 8 6 9 - B08 ....14 8 13 11 2,175 1.3................... ...................... ........................... .................. . .7 ..... ........................... ........................... ............. 15 .............. 11 10: 13 ..10 B-07 12: 12 A I 5 10 2,170 ...... ......................• 12 .................................... ....... .................. ........................... ...................................................... ........................... 10 .9 0 o > 2,165 ............ ........................... . . ...................................... .............. .................. ........................... ........................... ........................... ........................... 14 8 -.6 2,160 ........................................ .... ....... .................. .. ........................... ....................................................... ........................... LJJJ 13....................................... > 15 2,155 ............ ........................... ........................... ................ .... ........................... ........................... ........................... ........................... 6 2,150 ....................................... . ...................... ........................................... ...................................... ........................... 27 2,145 APPENDIX III Laboratory Test Summary Sheet (Not Included) APPENDIX IV GBA Publication "Important Information About Your Geotechnical Engineering Report" -- Geotechnical- Engineering Report ---) The Geoprofessional Business Association (GBA) has prepared this advisory to help you — assumedly a client representative — interpret and apply this geotechnical-engineering report as effectively as possible. In that way, clients can benefit from a lowered exposure to the subsurface problems that, for decades, have been a principal cause of construction delays, cost overruns, claims, and disputes. If you have questions or want more information about any of the issues discussed below, contact your GBA-member geotechnical engineer. Active involvement in the Geoprofessional Business Association exposes geotechnical engineers to a wide array of risk -confrontation techniques that can be of genuine benefit for everyone involved with a construction project. Geotechnical-Engineering Services Are Performed for Specific Purposes, Persons, and Projects Geotechnical engineers structure their services to meet the specific needs of their clients. A geotechnical-engineering study conducted for a given civil engineer will not likely meet the needs of a civil - works constructor or even a different civil engineer. Because each geotechnical-engineering study is unique, each geotechnical- engineering report is unique, prepared solely for the client. Those who rely on a geotechnical-engineering report prepared for a different client can be seriously misled. No one except authorized client representatives should rely on this geotechnical-engineering report without first conferring with the geotechnical engineer who prepared it. And no one - not even you - should apply this report for any purpose or project except the one originally contemplated. Read this Report in Full Costly problems have occurred because those relying on a geotechnical- engineering report did not read it in its entirety. Do not rely on an executive summary. Do not read selected elements only. Read this report in full. You Need to Inform Your Geotechnical Engineer about Change Your geotechnical engineer considered unique, project -specific factors when designing the study behind this report and developing the confirmation -dependent recommendations the report conveys. A few typical factors include: • the client's goals, objectives, budget, schedule, and risk -management preferences; • the general nature of the structure involved, its size, configuration, and performance criteria; • the structure's location and orientation on the site; and • other planned or existing site improvements, such as retaining walls, access roads, parking lots, and underground utilities. Typical changes that could erode the reliability of this report include those that affect: • the site's size or shape; • the function of the proposed structure, as when it's changed from a parking garage to an office building, or from a light -industrial plant to a refrigerated warehouse; • the elevation, configuration, location, orientation, or weight of the proposed structure; • the composition of the design team; or • project ownership. As a general rule, always inform your geotechnical engineer of project changes - even minor ones - and request an assessment of their impact. The geotechnical engineer who prepared this report cannot accept responsibility or liability for problems that arise because the geotechnical engineer was not informed about developments the engineer otherwise would have considered. This Report May Not Be Reliable Do not rely on this report if your geotechnical engineer prepared it: • for a different client; • for a different project; • for a different site (that may or may not include all or a portion of the original site); or • before important events occurred at the site or adjacent to it; e.g., man-made events like construction or environmental remediation, or natural events like floods, droughts, earthquakes, or groundwater fluctuations. Note, too, that it could be unwise to rely on a geotechnical-engineering report whose reliability may have been affected by the passage of time, because of factors like changed subsurface conditions; new or modified codes, standards, or regulations; or new techniques or tools. If your geotechnical engineer has not indicated an `apply -by" date on the report, ask what it should be, and, in general, if you are the least bit uncertain about the continued reliability of this report, contact your geotechnical engineer before applying it. A minor amount of additional testing or analysis - if any is required at all - could prevent major problems. Most of the "Findings" Related in This Report Are Professional Opinions Before construction begins, geotechnical engineers explore a site's subsurface through various sampling and testing procedures. Geotechnical engineers can observe actual subsurface conditions only at those specific locations where sampling and testing were performed. The data derived from that sampling and testing were reviewed by your geotechnical engineer, who then applied professional judgment to form opinions about subsurface conditions throughout the site. Actual sitewide-subsurface conditions may differ - maybe significantly - from those indicated in this report. Confront that risk by retaining your geotechnical engineer to serve on the design team from project start to project finish, so the individual can provide informed guidance quickly, whenever needed. This Report's Recommendations Are Confirmation -Dependent The recommendations included in this report - including any options or alternatives - are confirmation -dependent. In other words, they are not final, because the geotechnical engineer who developed them relied heavily on judgment and opinion to do so. Your geotechnical engineer can finalize the recommendations only after observing actual subsurface conditions revealed during construction. If through observation your geotechnical engineer confirms that the conditions assumed to exist actually do exist, the recommendations can be relied upon, assuming no other changes have occurred. The geotechnical engineer who prepared this report cannot assume responsibility or liability for confirmation - dependent recommendations if you fail to retain that engineer to perform construction observation. This Report Could Be Misinterpreted Other design professionals' misinterpretation of geotechnical- engineering reports has resulted in costly problems. Confront that risk by having your geotechnical engineer serve as a full-time member of the design team, to: • confer with other design -team members, • help develop specifications, • review pertinent elements of other design professionals' plans and specifications, and • be on hand quickly whenever geotechnical-engineering guidance is needed. You should also confront the risk of constructors misinterpreting this report. Do so by retaining your geotechnical engineer to participate in prebid and preconstruction conferences and to perform construction observation. Give Constructors a Complete Report and Guidance Some owners and design professionals mistakenly believe they can shift unanticipated -subsurface -conditions liability to constructors by limiting the information they provide for bid preparation. To help prevent the costly, contentious problems this practice has caused, include the complete geotechnical-engineering report, along with any attachments or appendices, with your contract documents, but be certain to note conspicuously that you've included the material for informational purposes only. To avoid misunderstanding, you may also want to note that "informational purposes" means constructors have no right to rely on the interpretations, opinions, conclusions, or recommendations in the report, but they may rely on the factual data relative to the specific times, locations, and depths/elevations referenced. Be certain that constructors know they may learn about specific project requirements, including options selected from the report, only from the design drawings and specifications. Remind constructors that they may perform their own studies if they want to, and be sure to allow enough time to permit them to do so. Only then might you be in a position to give constructors the information available to you, while requiring them to at least share some of the financial responsibilities stemming from unanticipated conditions. Conducting prebid and preconstruction conferences can also be valuable in this respect. Read Responsibility Provisions Closely Some client representatives, design professionals, and constructors do not realize that geotechnical engineering is far less exact than other engineering disciplines. That lack of understanding has nurtured unrealistic expectations that have resulted in disappointments, delays, cost overruns, claims, and disputes. To confront that risk, geotechnical engineers commonly include explanatory provisions in their reports. Sometimes labeled "limitations;' many of these provisions indicate where geotechnical engineers' responsibilities begin and end, to help others recognize their own responsibilities and risks. Read these provisions closely. Ask questions. Your geotechnical engineer should respond fully and frankly. Geoenvironmental Concerns Are Not Covered The personnel, equipment, and techniques used to perform an environmental study - e.g., a "phase -one" or "phase -two" environmental site assessment - differ significantly from those used to perform a geotechnical-engineering study. For that reason, a geotechnical- engineering report does not usually relate any environmental findings, conclusions, or recommendations; e.g., about the likelihood of encountering underground storage tanks or regulated contaminants. Unanticipated subsurface environmental problems have led to project failures. If you have not yet obtained your own environmental information, ask your geotechnical consultant for risk -management guidance. As a general rule, do not rely on an environmental report prepared for a different client, site, or project, or that is more than six months old. Obtain Professional Assistance to Deal with Moisture Infiltration and Mold While your geotechnical engineer may have addressed groundwater, water infiltration, or similar issues in this report, none of the engineer's services were designed, conducted, or intended to prevent uncontrolled migration of moisture - including water vapor - from the soil through building slabs and walls and into the building interior, where it can cause mold growth and material -performance deficiencies. Accordingly, proper implementation of the geotechnical engineer's recommendations will not of itself be sufficient to prevent moisture infiltration. Confront the risk of moisture infiltration by including building -envelope or mold specialists on the design team. Geotechnical engineers are not building - envelope or mold specialists. GEOPROFESSIONAL BUSINESS SEA ASSOCIATION Telephone: 301 /565-2733 e-mail: info@geoprofessional.org wwwgeoprofessional.org Copyright 2016 by Geoprofessional Business Association (GBA). Duplication, reproduction, or copying of this document, in whole or in part, by any means whatsoever, is strictly prohibited, except with GBAs specific written permission. Excerpting, quoting, or otherwise extracting wording from this document is permitted only with the express written permission of GBA, and only for purposes of scholarly research or book review. Only members of GBA may use this document or its wording as a complement to or as an element of a report of any kind. Any other firm, individual, or other entity that so uses this document without being a GBA member could be committing negligent SINCE Im HQ: 3015 DUMBARTON ROAD RICHMOND, VIRGINIA 23228 T 804.264.2701 F 804.264.1202 www.fandr.com VIRGINIA • NORTH CAROLINA • SOUTH CAROLINA • MARYLAND • DISTRICT OF COLUMBIA