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HomeMy WebLinkAboutSW4240907_Soils/Geotechnical Report_20241015 (2) Cj ECS SOUTHEAST, LLC NC Engineering License No. F-1519 Geotechnical • Construction Materials • Environmental • Facilities August 13, 2024 Mr. Rick Ball Bradley& Ball Architects, PA 5921-H West Friendly Avenue Greensboro, North Carolina 27410 Reference: Seasonal High Water Table Determination Design Master Displays Expansion 5657 Prospect Street High Point, Guilford County, North Carolina ECS Project No:49:23793 Dear Mr. Ball: ECS Southeast, LLC (ECS) is pleased to submit this report of the Seasonal High Water Table Determination (SHWT)for the Design Master Displays Expansion site located in High Point, Guilford County, North Carolina. This report summarizes our findings for the site. PROJECT UNDERSTANDING The project site is the existing Design Master Displays facility located at 5657 Prospect Street in High Point, North Carolina. The majority of the proposed building and parking lot areas have been cleared of the natural vegetation and are improved with planted grass, and asphalt drive, and gravel parking area. Portions of the proposed parking lot,wet pond, and potential borrow areas are heavily wooded. We understand the proposed project will consist of constructing two single-story pre-engineered metal buildings with footprint areas of 9,000 and 12,000 square feet. The two buildings will share a common wall.The future parking lot area will consist of a flexible pavement section.A wet pond will be constructed north of the proposed parking lot area. ECS has been requested to explore a potential borrow area that may be used during grading operations for the proposed expansion. Traffic loading conditions were not available at the time of the proposal. The proposed Geotechnical Boring Plan was utilized as a background for the attached Figure 1. The soil investigation was conducted by reviewing split spoons during the Geotechnical drilling operations. SCOPE OF SERVICES ECS conducted a study/investigation of the soils to identify the depth of the seasonal high water table, if present.The properties and characteristics of the soils retrieved from the boring were observed and recorded in field notes.The properties include texture, depth, the presence of restrictive horizons, depth to seasonal high water table, coarse fragments, etc. The assessment was conducted in accordance with current soil science practices and technology. 1812 CENTER PARK DRIVE, SUITE D, CHARLOTTE, NC 28217 • T: 704-525-5152 • F: 704-357-0023 ECS Florida,LLC • ECS Mid-Atlantic, LLC • ECS Midwest,LLC • ECS Pacific, Inc. • ECS Southeast,LLC • ECS Southwest,LLP ECS New York Engineering, PLLC-An Associate of ECS Group of Companies • www.ecslimited.com "ONE FIRM.ONE MISSION." Design Master Displays Expansion August 13,2024 ECS Project No.49:23793 Page 2 SEASONAL HIGH WATER TABLE STUDY Below is a summary of the soils retrieved from the borings. SHWT B — 08 —The surface layer to a depth of approximately 2 inches Below Ground Surface (BGS) was grayish-brown sandy loam with weak, medium, granular structure. The consistence was very friable, non- sticky, and non-plastic. The sub-surface layer from approximately 2 inches to approximately 24 inches BGS was yellowish-brown clay loam (few gray mottles were present)with moderate,medium,sub-angular blocky structure. The consistence was firm, slightly sticky, and slightly plastic. The sub-surface layer from approximately 24 inches to approximately 48 inches BGS was brown clay loam (few gray mottles were present)with moderate, medium,sub-angular blocky structure.The consistence was firm,slightly sticky,and slightly plastic. The sub-surface layer from approximately 48 inches to approximately 72 inches BGS was reddish brown clay(few gray mottles and mixed saprolite colors were present)with moderate, medium,sub- angular blocky structure. The consistence was firm, sticky, and plastic. The sub-surface layer from approximately 72 inches to approximately 120 inches BGS was yellowish-red clay (many gray mottles, manganese oxides, and redox concentrations were present)with strong, medium, angular blocky structure. The consistence was very firm, very sticky, and very plastic. The sub-surface layer from approximately 120 inches to approximately 228 inches BGS was reddish-yellow clay (many gray mottles were present) with strong, medium, angular blocky structure. The consistence was very firm, very sticky, and very plastic. The sub-surface layer from approximately 228 inches to approximately 240 inches BGS was multi-colored loam saprolite(gray mottles were present). SHWT B — 09 — The surface layer to a depth of approximately 2 inches Below Ground Surface (BGS) was grayish-brown sandy loam with weak, medium, granular structure. The consistence was very friable, non- sticky, and non-plastic. The sub-surface layer from approximately 2 inches to approximately 24 inches BGS was yellowish-brown(gray mottles were present)with moderate,medium,sub-angular blocky structure.The consistence was firm,sticky,and plastic.The sub-surface layer from approximately 24 inches to approximately 72 inches BGS was red yellowish-brown clay (gray mottles were present) with moderate, medium, sub- angular blocky structure. The consistence was firm, sticky, and plastic. The sub-surface layer from approximately 72 inches to approximately 96 inches BGS was black clay loam(few gray mottles were present) with moderate, medium,sub-angular blocky structure.The consistence was firm,sticky,and plastic.The sub- surface layer from approximately 96 inches to approximately 120 inches BGS was dark brown clay (gray mottles and mixed saprolite colors were present) with strong, medium, massive structure.The consistence was very firm, very sticky, and very plastic. The sub-surface layer from approximately 120 inches to approximately 240 inches BGS was multi-colored loam saprolite(gray mottles were present). FINDINGS *Indicators of SHWT commonly refer to the presence of soil mottling of chroma 2 or less,typically the result of reduced iron.Chroma 2 mottles also indicate horizons within the soil profile that are potentially restrictive (perched SHWT)with respect to water movement through the soil profile,which has resulted in subsequent reduction of iron. SHWT can be inconclusive in soils containing fill and/or having past disturbance.Saturated hydraulic conductivity or permeability testing may be required to determine conductivity rates of potentially restrictive or perched horizons. Installation of piezometers may be required for more accurate determination of actual SHWT. Design Master Displays Expansion August 13,2024 ECS Project No.49:23793 Page 3 SHWT B-08—Indicators of a SHWT were identified at a depth of approximately 24 inches BGS and continued until the termination of the boring. The restrictive characteristic observed in this soil profile was poor soil structure. Groundwater was observed at approximately 24 inches BGS and continued until the termination of the boring. SHWT B—09—Indicators of a SHWT were identified at a depth of approximately 6 inches BGS and continued until the termination of the boring. The restrictive characteristic observed in this soil profile was poor soil structure. Groundwater was observed at approximately 48 inches BGS and continued until the termination of the boring. The type of stormwater management facility designed is based on the depth of the SHWT or confining layer. The information above may be potentially utilized to determine the type of stormwater management facility best suited for this site according to the most recent version of the North Carolina Division of Water Quality Stormwater Best Management Practice Manual. CLOSING ECS is pleased to offer our professional services and look forward to assisting in any of your site analysis needs in the future. If you have any questions or require further assistance, please contact us at 704-525-5152. Respectfully, ECS SOUTHEAST, LLC Ak k. Alv,a,14;27 , W. ,c ..,...72-2 , Alex Thompson W. Brandon Fulton, LSS, PSC, PWS Project Manager Environmental Principal akthompson@ecslimited.com bfulton@ecslimited.com 984-344-6847 704-525-5152 Attachment: Figure 1—SHWT Boring Location Maps S i otPNDoi: � 4 o 1%", 1316 4,..m........000) .. _FieNtir-, 4 Legend . tole,' tit > °;.A. ; T..- . . .. ,. ,,,. - • - SHWT Boring Location Y .i,+,: Affs �; �- •7 d# ' :.A- " I,, :fir, ' .. :, - ,A1':-..iii ,4,.# 4, ..1,', I .itit -,.i. ,, ,. • .,/,„, ,,,- , i.. -`1'',ki ',r _ ',f �,i 1', , ,'%,$. No. . `gt • I ' Client: 'fit ' 6 �t2. ,+ ,� _ • �. ,j '• i ,. . ,, 4 l" a N BRADLEY&BALL ' • } i ARCHITECTS, PA • .fir . ' 'J y - •. Is' , + B-09 SHWT � '� . • , e. ' � �y ', •.' - .. �� 4 4, '4 ' 4 rr ,,8-t1'� �' " ti", `bi Project: ' +' '10 # t , 'l .fit ', , ,1 .k.. .. DESIGN MASTER (- '� • DISPLAYSEXPANON B-08SHWT ' ' ,.-,. �.s' •,',• '' $)* a - ' HIGH POINT, 1 BOq~' �r '' •+' .!+. ' I GUILFORD COUNTY, .----- OF . - pit,�- P n ^J y J NORTH CAROLINA 5 k. • , , , . 4 1. B 07 i, '4 'it -.4,,�.i• a ' ' Title: '►�1 .r t41 ' • B.0.8 � �� i �l� r ': SEASONAL HIGH 1 /@g��yi110,--__- : I\ ,. ••41, • � R • ,,• WATER TABLE - • ./ s [43 B-0 STUDY 'v .10 L t'_ r,-1mE�', -1�_ ,t,Ca'o -rriNC. 'v i 4. ^ •- ♦. t. f.....,40 0.411..0 diletAtie) -,tri .*: , '4* At Afr. 4..- -_-, ,,,-6) 0 * .I., . . ,....fall ang n M Of#14*," •Ci. -Mtn . L ),1 .� ! c O ' /'` DaV6 r. I �1 GUILFORD COUNTY, '► it' ' ,. , , y • ~ c A !Design aste Displays ' NORTH CAROLINA Alp Carolina mart Vorks _ 'r �. • I i ill DrawnBy: Checked By: �, BLM WBF 0 ,, i •r .- , 'N Approved By: Date: �"� - . - WBF 08/02/2024 illf air. ` - ',,, ECS Project No: American re 'Storag- o Archda'C , 49:23793 ' V'-,/:- FIGURE 1 Appendix E — Other Information GBA- Geotechnical Engineering Report Information Sheet Important Information about This Geotecbnical-[ngineering Subsurface problems are a principal cause of construction delays, cost overruns, claims, and disputes. While you cannot eliminate all such risks, you can manage them. The following information is provided to help. The Geoprofessional Business Association (GBA) will not likely meet the needs of a civil-works constructor or even a has prepared this advisory to help you—assumedly different civil engineer.Because each geotechnical-engineering study a client representative—interpret and apply this is unique,each geotechnical-engineering report is unique,prepared geotechnical-engineering report as effectively as solely for the client. possible. In that way, you can benefit from a lowered Likewise,geotechnical-engineering services are performed for a specific exposure to problems associated with subsurface project and purpose.For example,it is unlikely that a geotechnical conditions at project sites and development of engineering study for a refrigerated warehouse will be the same as them that,for decades, have been a principal cause one prepared for a parking garage;and a few borings drilled during of construction delays, cost overruns, claims, a preliminary study to evaluate site feasibility will not be adequate to and disputes. If you have questions or want more develop geotechnical design recommendations for the project. information about any of the issues discussed herein, contact your GBA-member geotechnical engineer. Do not rely on this report if your geotechnical engineer prepared it: Active engagement in GBA exposes geotechnical . for a different client; engineers to a wide array of risk-confrontation • for a different project or purpose; techniques that can be of genuine benefit for • for a different site(that may or may not include all or a portion of everyone involved with a construction project. the original site);or • before important events occurred at the site or adjacent to it; e.g.,man-made events like construction or environmental Understand the Geotechnical-Engineering Services remediation,or natural events like floods,droughts,earthquakes, Provided for this Report or groundwater fluctuations. Geotechnical-engineering services typically include the planning, collection,interpretation,and analysis of exploratory data from Note,too,the reliability of a geotechnical-engineering report can widely spaced borings and/or test pits.Field data are combined be affected by the passage of time,because of factors like changed with results from laboratory tests of soil and rock samples obtained subsurface conditions;new or modified codes,standards,or from field exploration(if applicable),observations made during site regulations;or new techniques or tools.If you are the least bit uncertain reconnaissance,and historical information to form one or more models about the continued reliability of this report,contact your geotechnical of the expected subsurface conditions beneath the site.Local geology engineer before applying the recommendations in it.A minor amount and alterations of the site surface and subsurface by previous and of additional testing or analysis after the passage of time-if any is proposed construction are also important considerations.Geotechnical required at all-could prevent major problems. engineers apply their engineering training,experience,and judgment to adapt the requirements of the prospective project to the subsurface Read this Report in Full model(s). Estimates are made of the subsurface conditions that Costly problems have occurred because those relying on a geotechnical- will likely be exposed during construction as well as the expected engineering report did not read the report in its entirety.Do not rely on performance of foundations and other structures being planned and/or an executive summary.Do not read selective elements only.Read and affected by construction activities. refer to the report in full. The culmination of these geotechnical-engineering services is typically a You Need to Inform Your Geotechnical Engineer geotechnical-engineering report providing the data obtained,a discussion About Change of the subsurface model(s),the engineering and geologic engineering Your geotechnical engineer considered unique,project-specific factors assessments and analyses made,and the recommendations developed when developing the scope of study behind this report and developing to satisfy the given requirements of the project.These reports may be the confirmation-dependent recommendations the report conveys. titled investigations,explorations,studies,assessments,or evaluations. Typical changes that could erode the reliability of this report include Regardless of the title used,the geotechnical-engineering report is an those that affect: engineering interpretation of the subsurface conditions within the context • the site's size or shape; of the project and does not represent a close examination,systematic inquiry,or thorough investigation of all site and subsurface conditions. • the elevation,configuration,location,orientation, function or weight of the proposed structure and Geotechnical-Engineering Services are Performed the desired performance criteria; • the composition of the design team;or for Specific Purposes, Persons, and Projects, • project ownership. and At Specific Times Geotechnical engineers structure their services to meet the specific As a general rule,always inform your geotechnical engineer of project needs,goals,and risk management preferences of their clients.A or site changes-even minor ones-and request an assessment of their eotechnical-engineering study conducted for a given civil engineer impact.The geotechnical engineer who prepared this report cannot accept -, responsibility or liability for problems that arise because the geotechnical conspicuously that you've included the material for information purposes engineer was not informed about developments the engineer otherwise only.To avoid misunderstanding,you may also want to note that would have considered. "informational purposes"means constructors have no right to rely on the interpretations,opinions,conclusions,or recommendations in the Most of the "Findings" Related in This Report report.Be certain that constructors know they may learn about specific Are Professional Opinions project requirements,including options selected from the report,only Before construction begins,geotechnical engineers explore a site's from the design drawings and specifications.Remind constructors subsurface using various sampling and testing procedures.Geotechnical that they may perform their own studies if they want to,and be sure to engineers can observe actual subsurface conditions only at those specific allow enough time to permit them to do so.Only then might you be in locations where sampling and testing is performed.The data derived from a position to give constructors the information available to you,while that sampling and testing were reviewed by your geotechnical engineer, requiring them to at least share some of the financial responsibilities who then applied professional judgement to form opinions about stemming from unanticipated conditions.Conducting prebid and subsurface conditions throughout the site.Actual sitewide-subsurface preconstruction conferences can also be valuable in this respect. conditions may differ-maybe significantly-from those indicated in this report.Confront that risk by retaining your geotechnical engineer Read Responsibility Provisions Closely to serve on the design team through project completion to obtain Some client representatives,design professionals,and constructors do informed guidance quickly,whenever needed. not realize that geotechnical engineering is far less exact than other engineering disciplines.This happens in part because soil and rock on This Report's Recommendations Are project sites are typically heterogeneous and not manufactured materials Confirmation-Dependent with well-defined engineering properties like steel and concrete.That The recommendations included in this report-including any options or lack of understanding has nurtured unrealistic expectations that have resulted in disappointments,delays,cost overruns,claims,and disputes. alternatives-are confirmation-dependent.In other words,they are not final,because the geotechnical engineer who developed them relied heavily To confront that risk,geotechnical engineers commonly include on judgement and opinion to do so.Your geotechnical engineer can finalize explanatory provisions in their reports.Sometimes labeled"limitations:' the recommendations only after observing actual subsurface conditions many of these provisions indicate where geotechnical engineers' exposed during construction.If through observation your geotechnical responsibilities begin and end,to help others recognize their own responsibilities and risks.Read these provisions closely.Ask questions. engineer confirms that the conditions assumed to exist actually do exist, the recommendations can be relied upon,assuming no other changes have Your geotechnical engineer should respond fully and frankly. occurred.The geotechnical engineer who prepared this report cannot assume responsibility or liability for confirmation-dependent recommendations if you Geoenvironmental Concerns Are Not Covered fail to retain that engineer to perform construction observation. The personnel,equipment,and techniques used to perform an environmental study-e.g.,a"phase-one"or"phase-two"environmental This Report Could Be Misinterpreted site assessment-differ significantly from those used to perform a geotechnical-engineering study.For that reason,a geotechnical-engineering Other design professionals'misinterpretation of geotechnical engineering reports has resulted in costly problems.Confront that risk report does not usually provide environmental findings,conclusions,or recommendations;e.g.,about the likelihood of encountering underground by having your geotechnical engineer serve as a continuing member of the design team,to: storage tanks or regulated contaminants.Unanticipated subsurface • confer with other design-team members; environmental problems have led to project failures.If you have not • help develop specifications; obtained your own environmental information about the project site, • review pertinent elements of other design professionals'plans and ask your geotechnical consultant for a recommendation on how to find specifications;and environmental risk-management guidance. • be available whenever geotechnical-engineering guidance is needed. Obtain Professional Assistance to Deal with You should also confront the risk of constructors misinterpreting this Moisture Infiltration and Mold report.Do so by retaining your geotechnical engineer to participate in While your geotechnical engineer may have addressed groundwater, prebid and preconstruction conferences and to perform construction- water infiltration,or similar issues in this report,the engineer's phase observations. services were not designed,conducted,or intended to prevent migration of moisture-including water vapor-from the soil Give Constructors a Complete Report and Guidance through building slabs and walls and into the building interior,where Some owners and design professionals mistakenly believe they can shift it can cause mold growth and material-performance deficiencies. unanticipated-subsurface-conditions liability to constructors by limiting Accordingly,proper implementation of the geotechnical engineer's the information they provide for bid preparation.To help prevent recommendations will not of itself be sufficient to prevent the costly,contentious problems this practice has caused,include the moisture infiltration.Confront the risk of moisture infiltration by complete geotechnical-engineering report,along with any attachments including building-envelope or mold specialists on the design team. or appendices,with your contract documents,but be certain to note Geotechnical engineers are not building-envelope or mold specialists. 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