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HomeMy WebLinkAbout20110089 Ver 3_More Info Received_20170721SOUTHERN ENGINEERING Consulting • Engineering • Construction Testing • Special Inspections July 20, 2017 Mr. David Lutz, P.E. CES Group Engineers 274 N Highway 16 Suite 300 Denver, NC 28037 Re: Airlie Park Spec Building Seasonal High Ground Water Determination Denver, North Carolina SE&T Project No.: 17-108 Dear Mr. Lutz, SOUTHERN ENGINEERING is pleased to provide geotechnical engineering services for the Airlie Park Spec Building in Denver, NC. Our services included a subsurface exploration to observe the site soils for indicators of seasonal high ground water, ground water and other impermeable strata. Our service was provided in accordance with the scope of service defined in our proposal number 17-10222. Authorization to provide this service was in the form of a signed proposal agreement. A rubber -tracked hydraulic excavator (Takeuchi TB 250) was mobilized to the site on June 14, 2017. Three observation pits were located and excavated at this site in the vicinity of the planned ponds. The test pits were located using a handheld Garmin GPS device (reported accuracy ±30 feet). The approximate locations of the test pits are indicated on the Test Pit Location Plan included with this letter report. The observation pits were excavated to depths ranging from approximately 56 to 108 inches below the existing ground surface. The encountered soils were classified using the USDA Classification System (Textural) and Unified Soil Classification System (USCS) for soil. The test pits were observed and logged by an experienced registered professional engineer licensed in the State of North Carolina. Our interpretation of the soil horizon, depth, color (Munsell) and textural classification are presented on the attached test pit logs. Additionally, groundwater and seasonal high ground water table (SHWT) indicators were noted, if encountered. The results of the subsurface exploration did not reveal the presence of ground water, seasonal high ground water table indications nor other impermeable strata within the observation pits. The site appears suitable for the planned usage as stormwater management ponds. Respectfully submitted, TESTING, P.C. tority 5297 Test Pit Logs SouTHERNENGINEERING AND TESTING, P.C. 6120 Q Brookshire Boulevard, Charlotte, NC 28216 Office (704) 557-0070 Main (828) 468-8300 Facsimile (704) 910-3516 r— 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. Geoenviron mental 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 SAYA 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 GBNs 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. 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BORING NUMBER 108-1 SourHERd1T ENGLNEEREVG 6120 Brookshire Blvd, Suite Q PAGE 1 OF 1 -4-W Charlotte, NC 28016 Telephone: 7045570070 Fax: 7049103516 CLIENT CES Group Engineers PROJECT NAME Airlie Park Spec Building SHWT Study PROJECT NUMBER 17-108 PROJECT LOCATION Denver, NC DATE STARTED 6/14/17 COMPLETED 6/14/17 GROUND ELEVATION 767 ft HOLE SIZE inches DRILLING CONTRACTOR Takeuchi TB250 w/thumb & 24 -inch bucket GROUND WATER LEVELS: DRILLING METHOD Observation Pit AT TIME OF DRILLING --- LOGGED BY RF CHECKED BY RF AT END OF DRILLING --- NOTES Surface Elevation is approximate. AFTER DRILLING --- (SM) 6 to 24 -inches, Dark brown (7.5YR3/4) sandy loam, Horizon B SM SP - SMI (SP -SM) 24 to 56 -inches, Light brown (7.5YR6/4) loamy sand, Horizon C; Cr near 56 -inches (dense) Refusal at 4.7 feet. Bottom of borehole at 4.7 feet. w U _ Fa} w 2 p a~ w W J 0 U C/5D a- MATERIAL DESCRIPTION J a -Z C7 Q U) 0.0 (OL) 0 to 6 -inches, Brown (7.5YR4/4) loamy sand, Horizon A OL (SM) 6 to 24 -inches, Dark brown (7.5YR3/4) sandy loam, Horizon B SM SP - SMI (SP -SM) 24 to 56 -inches, Light brown (7.5YR6/4) loamy sand, Horizon C; Cr near 56 -inches (dense) Refusal at 4.7 feet. Bottom of borehole at 4.7 feet. Southern Engineering and Testing, P.C. BORING NUMBER 108-2 SC7LTI'HERd1T ENGL4 EREVG 6120 Brookshire Blvd, Suite Q PAGE 1 OF 1 Charlotte, NC 28016 -4-W Telephone: 7045570070 Fax: 7049103516 CLIENT CES Group Engineers PROJECT NAME Airlie Park Spec Building SHWT Study PROJECT NUMBER 17-108 PROJECT LOCATION Denver, NC DATE STARTED 6/14/17 COMPLETED 6/14/17 GROUND ELEVATION 779 ft HOLE SIZE inches DRILLING CONTRACTOR Takeuchi TB250 w/thumb & 24 -inch bucket GROUND WATER LEVELS: DRILLING METHOD Observation Pit AT TIME OF DRILLING --- LOGGED BY RF CHECKED BY RF AT END OF DRILLING --- NOTES Surface Elevation is approximate. AFTER DRILLING --- w U _ a~ w Fa} w a- J U p MATERIAL DESCRIPTION W J a- Z C7 Q U) 0.0 (OL) 0 to 13 -inches, Strong brown (7.5YR4/6) silt loam, Horizon Ap OL 1.1 777.9 (SM) 13 to 35 -inches, Strong brown (7.5YR5/6) silt loam, Horizon B SM 2.5 2.9 776.1 (SP -SM) 35 to 75 -inches, Brown (7.5YR5/4) loamy sand, Horizon B/C SP - SM 5.0 6.3 772.8 (SP -SM) 75 to 108 -inches, Brown (7.5YR4/4) sandy clay loam, Horizon C 7.5 SP - SM 9.0 770.0 Bottom of borehole at 9.0 feet. Southern Engineering and Testing, P.C. BORING NUMBER 108-3 sot,THERZVENCE4WXPC 6120 Brookshire Blvd, Suite Q PAGE 1 OF 1 Charlotte, NC 28016 t�r����P�L Telephone: 7045570070 Fax: 7049103516 CLIENT CES Group Engineers PROJECT NAME Airlie Park Spec Building SHWT Study PROJECT NUMBER 17-108 PROJECT LOCATION Denver, NC DATE STARTED 6/14/17 COMPLETED 6/14/17 GROUND ELEVATION 777 ft HOLE SIZE inches DRILLING CONTRACTOR Takeuchi TB250 w/thumb & 24 -inch bucket GROUND WATER LEVELS: DRILLING METHOD Observation Pit AT TIME OF DRILLING --- LOGGED BY RF CHECKED BY RF AT END OF DRILLING --- NOTES Surface Elevation is approximate. AFTER DRILLING --- w U _ a~ w Fa} w a- J U p MATERIAL DESCRIPTION W J a- Z C7 Q U) 0.0 =' (OL) 0 to 8 -inches, Strong brown (7.5YR4/4) sandy loam, Horizon Ap OL 2 0.7 776.3 (SM) 8 to 32 -inches, Strong brown (7.5YR4/6) silt loam, Horizon B SM 2.5 2.7 774.3 (SP -SM) 32 to 79 -inches, Reddish brown (5YR4/4) loamy sand, Horizon B/C SP - SM 5.0 :. 6.6 770.4 (SP -SM) 79 to 108 -inches, Yellowish red (5YR5/6) sandy loam, Horizon C 7.5 SP - SM 9.0 768.0 Bottom of borehole at 9.0 feet.