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Home My WebLink AboutWPO201300021 Certified Engineer's Report 2018-12-20FROEHLING & ROBERTSON, INC. Q Engineering Stability Since 1881 �C 6185 Rockfish Gap Turnpike ® Crozet, Virginia 22932-3330 T 434.823.5154 1 F 434.823.4764 Mr. David Brockman December 20, 2018 Old Trail Village 1005 Heathercroft Circle. Suite 100 Crozet, Virginia 22932 Reference: Old Trail Pond Block 12 Albemarle County, Virginia F&R Project No. 71W0009 Dear Mr. Brockman: The purpose of this report is to present the results of the subsurface exploration program and geotechnical engineering analyses undertaken by Froehling & Robertson, Inc. (F&R) in connection with the above referenced project. Our services were performed in general accordance with our Project number 71W-0009 dated 11/29/2018, as authorized by you. The attached report presents our understanding of the project, reviews our exploration procedures, describes existing site and general subsurface conditions, and presents our evaluations, conclusions, and recommendations. PROJECT INFORMATION Our understanding of the proposed construction is based on project information provided by you. The site is located at the Old Trail subdivision along the east side of Old Trail Drive, to the south of Rowcross Street, in Albemarle County, Virginia, (see attached Site Vicinity Map, Drawing No. 1). F&R has been requested to verify the soil compaction for the embankment dam. This pond has been in use for several years in the Old Trail development and has been reconfigured numerous times. In its current configuration, the embankment has a height of approximately 10 feet, with the crest at El 649 and side slopes of 3H:1V. METHOD OF EXPLORATION F&R drilled three borings designated B-1 through B-3 at the planned locations on the existing dam. The soil borings were extended to their planned termination depths of 20 feet below existing grades. The test boring locations were staked in the field by F&R by measuring distances from existing site features.ln consideration of the methods used in their determination, the test boring locations shown on the attached Boring Location Plan should be considered approximate. 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 9 The test borings were performed in accordance with generally accepted practice using a track -mounted CME-55 rotary drill rig equipped with an automatic hammer. Our drill crew conducted standard penetration testing and representative split -spoon soil sampling at pre -selected depth intervals in general accordance with ASTM D 1586. A further explanation of standard test boring methods is attached. SUBSURFACE CONDITIONS Area Geology The project site is located in Virginia's Blue Ridge geologic province which is underlain by ancient igneous and metamorphic basement rock that are Mesoproterozoic in age. Information obtained from the Geology and Mineral Resources of Albemarle County, Virginia (1962) indicates that this area is located over the Virginia Blue Ridge Complex. The Virginia Blue Ridge Complex consists primarily of granodiorite, hypersthene granodiorite and the Marshall and Crozet granites. It is generally medium to coarsely grained, green to gray in color and generally has a greasy or waxy appearance. The virgin soils encountered in this area are the residual product of in -place chemical and mechanical weathering of the parent bedrock formation that underlies the site. These materials consist of CLAY soils near the surface where soil weathering is more advanced, underlain by sandy SILT. Soil Conditions Detailed descriptions of the sampled subsurface strata are presented on the attached boring logs. Strata breaks designated on the boring logs represent an approximate boundary between soil types; transition from one soil type to another may be gradual or occur abruptly between sampling intervals. Although the 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. Below the existing ground surface, the test borings generally encountered fill soils, residual soils and soft weathered rock. These strata are discussed in the following paragraphs. Existing Fill Materials Existing Fill Materials include any materials deposited by man and were encountered in each of the borings, and extended to depths of 10 to 12 feet below existing grades. Sampled fill materials were visually classified as red brown, moist, sandy SILT (ML), and lean CLAY (CL), with trace gravel and organics, with standard penetration resistances (N-values) of 5 bpf to 23 bpf, with a majority of the N-values being 9 bpf or higher. Residual Soils Residual soils, formed by in -place weathering of the parent rock, were encountered in each of the borings except B-2 below the fill materials and extended to SWR or boring termination. The sampled residual soils were described as brown, and gray brown, moist, silty SAND (SM) with standard penetration resistances (N-values) ranging from 17 bpf to 77 bpf. Old Trail Village Old Trail Block 12 Pond F&R Project No. 71W0009 2 December 20, 2018 9 Soft Weathered Rock Soft weathered rock (SWR), is a transitional material between soil and rock which contains the relic structure of the rock. SWR materials were encountered in the borings below the fill materials or residual soils and extended to boring termination at depth of 20 feet. The sampled SWR soils were described as brown and gray brown, moist, silty SAND (SM) with standard penetration resistances (N-values) ranging from 50/1 bpf to 50/5 bpf. Subsurface Water Subsurface water for the purposes of this report is defined as water encountered below the existing ground surface. Subsurface water was not encountered during drilling. Fluctuations in subsurface water levels and soil moisture can be anticipated with changes in precipitation, run- off, and season. ENGINEERING EVALUATION AND RECOMMENDATIONS Dam Fill Evaluation As previously indicated, the majority of the N-values recorded in the fill were recorded at 9 bpf or higher. While N-values are not a direct measure of the degree of compaction of the soil sample, they do provide a good indication of the relative density or consistency of the soil. It is F&R's judgement that the recorded N-values are consistent with what would be expected from fill materials which were placed in a controlled and compacted manner. Further, the embankment appeared to be in good condition, with no evidence of water seepage or soil sloughing. LIMITATIONS This report has been prepared for the exclusive use of Old Trail Village and/or their agents, for specific application to the Old Trail Block 12 Pond project located in Albemarle County, Virginia, in accordance with generally accepted soil and foundation engineering practices. No other warranty, express or implied, is made. These conclusions and recommendations do not reflect variations in subsurface conditions, which could exist in unexplored areas of the site. Regardless of the thoroughness of a subsurface exploration, there is the possibility that conditions will differ from those at the boring locations, that conditions are not as anticipated by the designers, or that the construction process has altered the soil conditions. Therefore, experienced geotechnical engineers should evaluate earthwork and foundation construction to verify that the conditions anticipated in design actually exist. Otherwise, we assume no responsibility for construction compliance with the design concepts, specifications, or recommendations. Old Trail Village Old Trail Block 12 Pond F&R Project No. 71W0009 3 December 20, 2018 In the event changes are made in the proposed construction plans, the recommendations presented in this report shall not be considered valid unless reviewed by our firm and conclusions of this report modified 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 and attachments. Interpretations based on only a part of this report may not be valid. This report contains 4 pages of text and the listed attachments. ACKNOWLEDGMENT Froehling & Robertson, Inc. appreciates the opportunity to be a member of your team for this project and is prepared to assist with the recommended engineering evaluations and testing services during construction. Please call if you have questions or if we can be of additional service. Sincerely, FROEHLING & ROBERTSON, INC. 1, Matthew H spodar, G.I.T. Staff Geologist rH °P� Ne� qarrm-/�': o UNTEA. SIMMONS, III � Lic. No. 037906 SIV 4.NAL Clyde A. Simmons III, P.E. Senior Engineer/Branch Manager Attachments: GBA Important Information about Your Geotechnical Report Site Vicinity Map (Drawing No. 1) Unified Soil Classification System Key to Boring Log Soil Classification Boring Location Plan (Drawing No. 2) Boring Logs F:\Projects 71W\71W0009 (Old Trail Block 12 Pond)\Geo\Report\Old Trail Block 12 Pond Report.doc Old Trail Village Old Trail Block 12 Pond F&R Project No. 71W0009 4 December 20, 2018 -- 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 To;' St M1 LoLust Ln L r� a m m 34 u QJ +i+ SITE i D $ d� xso- Rockfish Gap Tpke b ion � 'o 0 pOtter$ C i { 64 _ 1.64 ems` Sk��u`1 0� FROEHLING & ROBERTSON, INC. F& Engineering Stability Since 1881 6185 Rockfish Gap Turnpike Crozet, Virginia 22932-3330 T 434.823.5154 1 F 434.823.4764 Site Location Plan Client: Old Trail Village Project: Old Trail Block 12 Pond F&R Project No. 71W0009 Date: Dec, 2018 Scale: No Scale Drawing No.: 1 UNIFIED SOIL CLASSIFICATION SYSTEM (ASTM D-2487) Major Divisions Group Symbols Typical Names Laboratory Classification Criteria GW Well -graded gravels, gravel -sand Cu D6o/Dlo greater than 4; rowy mixtures, little or no fines p C�=(D3o) /(Diox D60) between 1 and 3 o � Poorly graded gravels, gravel- "4 1 y V GP sand mixtures, little or no fines o to Not meeting all gradation requirements for GW N N1�i V V N �y '�• Silty -sand -silt Atterberg limits below "A" o w Z GM gravels, gravel U cv Y 7, w mixtures 't line or PI less than 4 Above "A" line with PI z Y 3 o ,�, ° ,�, between 4 and 7 are border- line cases requiring use of o o > o GC Clayey gravels, gravel -sand -clay Atterberg limits below "A" dual symbols b i lu mixtures c o C7 L7 CG line or PI greater than 7 o yU SW Well -graded sands, gravelly Cu D6�io greater than 6; o y b sands, little or no fines A C= (D3o) /(D1ox D60) between I and 3 U � SP Poorlygraded sands, gravelly gr g y Not meeting all gradation requirements for SW O > .�' °' U sands, little or no fines 41 .o .�+ o v •� V O O cd Atterberg limits above "A" g � � � ° `�' � ep SM Silty sands, sand -silt mixtures 2 w 7o ; line or PI less than 4 Above "A" line with PI between 4 and 7 are border- "A" 0 3 ¢ ro ¢ Y line cases requiring use of d� o SC Clayey sands, sand -clay mixtures ,, 2 2 o Atterberg limits above line or PI greater than 7 dual symbols ��-jrr A iL V a/v V1 Inorganic silts and very fine o ML sands, rock flour, silty or clayey Plasticity Chart � fine sands, or clayey silts with 60 slight plasticity Inorganic clays of low to medium ti 50 o ro ' CL plasticity, gravelly clays, sandy Y ' clays, silty clays, lean clays o 'b CH OL Organic silts and organic silty 40 a clays of low plasticity xX o c 30 Inorganic silts, micaceous or p\\ MH diatomaceous fine sandy or silty Z5 °Q o`h soils, elastic silts ig a 20 MH & OH w Inorganic clays of high plasticity, CL X 4 :E CH fat claysI 10 in r c Organic clays of medium to high C -ML ML & OH plasticity o OL 0 0 10 20 30 40 50 60 70 80 90 100 'o Liquid Limit, LL ~won Pt Peat and other highly organic soils tin 0 KEY TO BORING LOG SOIL CLASSIFICATION Particle Size and Proportion Verbal descriptions are assigned to each soil sample or stratum based on estimates of the particle size of each component of the soil and the percentage of each component of the soil. Particle Size Proportion Descriptive Terms Descriptive Terms Soil Component Particle Size Component Term Percentage Boulder > 12 inch Major Uppercase Letters >50% Cobble 3 — 12 inch (e.g., SAND, CLAY) Gravel -Coarse 3/4 - 3 inch -Fine #4 - 3/4 inch Secondary Adjective 20%-50% Sand -Coarse #10 - #4 (e.g. sandy, clayey) -Medium #40 - # 10 -Fine #200 - #40 Minor Some 15%-25% Silt (non -cohesive) < #200 Little 5%-15% Clay (cohesive) < #200 Trace 0%-5% Notes: 1. Particle size is designated by U.S. Standard Sieve Sizes 2. Because of the small size of the split spoon sampler relative to the size of gravel, the true percentage of gravel may not be accurately estimated. Density or Consistency The standard penetration resistance values (N-values are used to describe the density of coarse -grained soils (GRAVEL, SAND) or the consistency of fine-grained soils (SILT, CLAY). Sandy silts of very low plasticity may be assigned a density instead of a consistency. DENSITY CONSISTENCY Term N-Value Term N-Value Very Loose 0-4 Very Soft 0-1 Loose 5 — 10 Soft 2-4 Medium -Dense 11 — 30 Medium Stiff 5-8 Dense 31 — 50 Stiff 9 — 15 Very Dense > 50 Very Stiff 16 — 30 Hard >30 Notes: 1. The N-value is the number of blows of a 140 lb. hammer freely falling 30 inches required to drive a standard split - spoon sampler (2.0 in. O.D., 1-3/8 in. I.D.) 12 inches into the soil after properly seating the sampler 6 inches. 2. When encountered, gravel may increase the N-value of the standard penetration test and may not accurately represent the in -situ density or consistency of the soil sampled. 115, Ilk W. 1 5� - - 6► 6' - �65Ct;EX. ACSA X ESFA'T 0e 4257 317 - 1.,� t I� `�%- ACSA UTIL- ESM'T 4704 PG 379 0.=64 17 14 3 (ASBUILT)► 4 _ _ _ _ Ill� � /'/ �°a.0.= 44ss� 1 1 � I ► M A _660- 6y� : "/ AS -BUILT � .� REB in B / '1.1=fi45.14 lh / fjy2 1.0.=646.14 1 3 -BUILT) i► , 6r / 1 4 I t it l I lpl 640 , � 5 q t I } vsOA i 3 3 ► ► y ` I 1 1fl 3y r1 , i WET POND i w0 T lb b / i 7 P 4 0 / I � � 0. - - - 63e �tyG / / �• III 4 B P�J R /B / LN IJ � III '� � = 38 - pQ� / / �4 / / � � ► I .-f�I 0. r!r ,� �• `� - -- - -- 646 ice'- _-� ,� � 3' 1 II I zo_ , lip J! 11 605 r _ \�6' r s s e2 1l I ri ❑ �I O rx Ln ❑ i QJ %u Z J w W N M N N Q q > n Cl) N M N O 00 U � M �5 LL i? LL c — i r-- O Lf) D m � N L 00 Lq .4 M U 0 cr Ln 00 C O fB V O � V) z m U N J � O O 0 .i u 00 O CIOm o o N cv O i v ~ Z U v � � V 41 0 4, U- c� a 0 Drawing No. 0) SINCE nro Froehl ing & Robertson, Inc. BORING LOG 1881 Project No: 71W0009 Elevation: 649 ± Client: Old Trail Village Total Depth: 20.0' Project: Old Trail Block 12 Pond Boring Location: See Boring Location Plan City/State: Albemarle County, Virginia Boring: B-1 (1 of 1) Drilling Method: HSA Hammer Type: Automatic Date Drilled: 12/7/18 Driller: J. Monroe Elevation Depth Description of Materials * Sample Sample N Value Remarks (Classification) Blows (fepteet) (blows/ft) 648.7 0.3 SurficialOrganics 1-3-4 0.0 -4 7 Red Brown, Moist, Medium Stiff, Sandy Lean CLAY (CL),Trace Organics and Gravel 2.0 1-2-3 FILL -3 5 4.0 4-4-6 -14 10 Subsurface Water Not 6.0 Encountered During 2-5-8 -7 13 Drilling or Upon Removal of the Augers 8 4-5-7 -8 12 10.0 4-4-7 -8 11 637.0 12.0 12.0 Brown, Moist, Medium Dense, Fine, Silty SAND 5-8-15 (SM), Trace Gravel -17 23 RESIDUUM 14.0 5-11-15 -22 26 633.0 16.0 16.0 Soft Weathered Rock Sampled as Brown, Moist, 13-50/5 Very Dense, Fine, Silty SAND (SM), Trace Gravel 16•9 100+ SOFT WEATHERED ROCK 18.0 40-50/4 18.8 100+ 629.0 20.0 Boring Terminated at 20 Feet 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. SINCE nro Froehl ing & Robertson, Inc. BORING LOG 1881 Project No: 71W0009 Elevation: 649 ± Client: Old Trail Village Total Depth: 20.0' Project: Old Trail Block 12 Pond Boring Location: See Boring Location Plan City/State: Albemarle County, Virginia Boring: B-2 (1 of 1) Drilling Method: HSA Hammer Type: Automatic Date Drilled: 12/7/18 Driller: J. Monroe Elevation Depth Description of Materials (Classification) * Sample Blows Sample (fepteet) N Value (blows/ft) Remarks Surficial Organics 1-4-6 -8 0.0 10 Brown Red, Moist, Stiff to Very Stiff, Sandy SILT (ML) FILL 2.0 23 8-13-10 -5 645.0 4.0 4.0 6.0 8 6 11 Subsurface Water Not Encountered During Drilling or Upon Removal of the Augers Red Brown, Moist, Medium Stiff to Very Stiff, Sandy SILT (ML), Trace Gravel FILL 4-3-3 -4 9-7-4 -5 4-7-12 -10 19 639.0 10.0 10.0 Soft Weathered Rock Sampled as Gray Brown, 8-33-50/5 Moist, Very Dense, Medium, Silty SAND (SM), Trace Gravel SOFT WEATHERED ROCK 12.4 12.9 100+ 100+ 28-50/5 25-37-50/4 14.0 15.3 100+ 16.0 39-50/1 100+ 18.0 50/2 100+ 629.0 20.0 Boring Terminated at 20 Feet 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. SINCE nro Froehl ing & Robertson, Inc. BORING LOG 1881 Project No: 71W0009 Elevation: 649 ± Client: Old Trail Village Total Depth: 20.0' Project: Old Trail Block 12 Pond Boring Location: See Boring Location Plan City/State: Albemarle County, Virginia Boring: B-3 (1 of 1) Drilling Method: HSA Hammer Type: Automatic Date Drilled: 12/7/18 Driller: J. Monroe Elevation Depth Description of Materials * Sample Sample N Value Remarks (Classification) Blows (fepteet) (blows/ft) 648.7 0.3 SurficialOrganics 4-6-8 0.0 -9 14 Red Brown, Moist, Stiff, Sandy SILT (ML) FILL 2.0 8-4-5 -6 9 4.0 4-6-5 -6 11 Subsurface Water Not 6.0 Encountered During 4-4-5 _5 9 Drilling or Upon Removal of the Augers 8 0 4-5-8 -8 13 639.0 10.0 10.0 Gray Brown, Moist, Medium Dense to Very 6-7-10 Dense, Medium, Silty SAND (SM), Trace Gravel -16 17 RESIDUUM 12.0 8-16-33 -40 49 16-19-21 14.0 -45 40 25-30-36 16.0 -50/5 66 1$'0 17-32-45 -50/3 77 629.0 20.0 Boring Terminated at 20 Feet ivumDer oT Diows requires Tor a 14u iD nammer aropping su to arive L u.u., i.u. sampler a ioiai oT iu incnes in mree o increments. The sum of the second and third increments of penetration is termed the standard penetration resistance, N-Value. SINCE nrQD Fr oehl ing & Robertson, Inc. 1881 Project No: 71W0009 Client: Old Trail Village Project: Old Trail Block 12 Pond City/State: Albemarle County, Virginia SUBSURFACE PROFILE Plot Based on Elevation Profile Name: Subsurface Profile 650 .B-1 B-2 B-3 7 ;A�;; 10 14 648 ............ >C< >c< xx .............. .............. .............. .............. .............. .............. XX )0< ........ .............. .............. .............. .............. .............. .............. <x <- X. . <X ....... *< KX >0< >0< 5 >0< ><�)< >0< 23 <x <x <X9 <x 646 ............ >0( *< ................................ ........... .............. ............................... Xx )<D.< ><Cx ><D< ........ ............................. .............. .............. ............... .............. <x . ........ KX >0< >0< 10 ><�x 6 <x <x 11 644 ............ >0( >0< >0( >0< ........... ......... <x >0( >0< >0( 13 11 01C <X9 <X 642 ............ >0< >4X >0< >0( ......... .............. .............. .............. .............. .............. .............. . ........ .............. .............. .............. .............. .............. .............. <x 0C . <x 01C ....... >0< >0( 12 19 <x <x 13 0 -640 M ............ >0< *< KX ......... ........... ... ............................. .............. ............................. . . ........ ............................. .............. ............................ .............. . <x Z . . ....... > w >0< KX LU >0< >0< 11 50/5 :17 638 ............ xx xx ......... ........... ............................. .............. ............................. . . . . . . . . . ........ ........................................... .............................. ...... ....... ...23 SO/5 49 636 ......... .. ......... .............. .............. .............. .............. .............. .............. ...... .............. ......... .26 50/4 40 634 ............ .......... .............. .............. .............. .............. ............ . ........ .............. .............. .............. .............. .............. .............. . .. . . ....... 50/5 50/1 66 632 ti ............ ......... .............. ............................ .............. ............................. .. ........ ............................. ............................................ .............. ........ ti 50/4 50/2 1.1-177 630 ... ......... ......... ............ . ........ ......... . ........ 6281