ALBEMARLE COUNTY OFFICE OF FACILITIES DEVELOPMENT Hydraulic Road and Barracks Road Sidewalks Improvement Project IFB# ADDENDUM NUMBER 1

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1 ALBEMARLE COUNTY OFFICE OF FACILITIES DEVELOPMENT Hydraulic Road and Barracks Road Sidewalks Improvement Project IFB# ADDENDUM NUMBER 1 This Addendum dated the 17th of April 2017, modifies the above project manual and contract documents dated March 30, Where this Addendum modifies changes, corrects or conflicts with the original contract documents, this Addendum shall govern. Where no modification, change, correction or conflict occurs, the original documents shall remain in force. Modification to the Project Manual, Special Provision Copied Notes, Supplemental Specifications and Special Provisions 1. County Special Provision Copied Notes, REPORTS OF EXPLORATION AND TESTS OF SUBSURFACE CONDITIONS CLARIFICATION. The geotechnical investigation report entitled Report of Geotechnical Study Barracks Road Sidewalks and Addendum No. 1 to Report of Geotechnical Study are now posted to the same folder with the Contract Documents on the Albemarle County Purchasing website. Responses to Pre-Bid Questions 1. Is the Contractor required to provide a field office for inspectors? The Contractor WILL NOT be required to provide a field office for the inspectors. Should the Contractor desire to acquire a laydown/staging area or site for a field office, the laydown/staging area of field office SHALL conform to the current Albemarle County Code entitled Temporary Construction Headquarters as stated in the County Special Provision Copied Notes. 2. I would like to obtain a copy of the Geotech report for the Barracks Road portion of the project? See clarification above. 1 of 1

2 Report of Geotechnical Study Barracks Road Sidewalks Albemarle County, Virginia F&R Project No. 71S0272 Prepared For: Kimley-Horn and Associates, Inc Willow Lawn Drive, Suite 200 Richmond, Virginia Prepared By: Froehling & Robertson, Inc Rockfish Gap Turnpike Crozet, Virginia April 27, 2015 Corporate HQ: 3015 Dumbarton Road Richmond, Virginia T F VIRGINIA NORTH CAROLINA SOUTH CAROLINA MARYLAND DISTRICT OF COLUMBIA A Minority-Owned Business

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4 SECTION TABLE OF CONTENTS 1.0 PURPOSE & SCOPE OF SERVICES PROJECT INFORMATION SITE DESCRIPTION PROPOSED CONSTRUCTION EXPLORATION PROCEDURES SOIL BORINGS LABORATORY TESTING REGIONAL GEOLOGY & SUBSURFACE CONDITIONS REGIONAL GEOLOGY SUBSURFACE CONDITIONS General Pavement Surficial Materials Existing Fill Materials Residual Soils Soft Weathered Rock Auger Refusal Materials SUBSURFACE WATER GEOTECHNICAL DESIGN RECOMMENDATIONS GENERAL RETAINING WALL STORMWATER MANAGEMENT SIDEWALK/CURB SUBGRADES GEOTECHNICAL CONSTRUCTION RECOMMENDATIONS SUBGRADE PREPARATION EXCAVATION CONDITIONS STRUCTURAL FILL PLACEMENT AND COMPACTION SURFACE WATER/GROUNDWATER CONTROL TEMPORARY EXCAVATION RECOMMENDATIONS CONTINUATION OF SERVICES LIMITATIONS PAGE Kimley-Horn and Associates, Inc. Barracks Road Sidewalks Albemarle County, Virginia F&R File No. 71S0272 April 27, 2015 Page - i -

5 APPENDIX I Site Vicinity Map (Drawing No. 1) Boring Location Plan (Drawing No. 2, 3, 4) APPENDIX II Key to Soil Classification Unified Soil Classification System Key to Boring Log Rock Classification Boring Logs Subsurface Profile Laboratory Test Results APPENDICES APPENDIX III ASFE Document Important Information about Your Geotechnical Engineering Report Kimley-Horn and Associates, Inc. Barracks Road Sidewalks Albemarle County, Virginia F&R File No. 71S0272 April 27, 2015 Page - ii -

6 1.0 PURPOSE & SCOPE OF SERVICES The purpose of the subsurface exploration and geotechnical engineering evaluation was to explore the subsurface conditions on the project site and provide geotechnical engineering evaluation and construction recommendations that can be used during planning process of the proposed structures and site work. F&R s scope of services included the following: Visited the site to observe existing surface conditions; Coordinated utility clearance with Miss Utility; Reviewed readily available geologic and subsurface information relative to the project site; Completion of six soil test borings to depths of 7.9 feet to 15 feet below the existing ground surface and perform 5 feet of rock coring; Performed laboratory testing on selected soil samples, consisting of water content, wash sieve analysis, Atterberg Limits, standard Proctor, and CBR; Preparation of typed Boring Logs and development of a Subsurface Profile; Performing a geotechnical engineering evaluation of the subsurface conditions with regard to their suitability for the proposed construction; Provided general comments regarding the proposed retaining wall, as well as the requested LRFD parameters for retaining wall. Provided recommendations regarding the design and construction of the stormwater management facilities. Provided recommendations regarding the anticipated suitability of the soil subgrades for sidewalk or curb and gutter support, including recommendations for undercutting (if judged necessary). Provided recommendations regarding the placement and compaction of fill materials required to achieve site subgrades. Recommendations regarding rock excavation are also provided. Preparation of this geotechnical report by professional engineers. Our scope of services did not include a survey of the boring locations, quantity estimates, preparation of plans or specifications, or the identification and evaluation of wetland or other environmental aspects of the project site. Kimley-Horn and Associates, Inc. Barracks Road Sidewalks Albemarle County, Virginia F&R File No. 71S0272 April 27, 2015 Page - 1 -

7 2.0 PROJECT INFORMATION 2.1 Site Description The project site currently consists of an approximately 3,500 foot length of Barracks Road, starting at its intersection with the Route Bypass and extending northwest to the intersection of Barracks Road and Salem Loop, in Albemarle County, Virginia (See Site Location Plan, Drawing No. 1, Appendix I). The existing roadway consists of four lanes and a narrow median (i.e. one lane in each direction) near the bypass and narrows to two lanes at the intersection with Huntwood Lane. The surrounding area is mostly residential. Existing grades along Barracks Road slope from El 610 at the northwest end of the improvements to El 500 at the southeast end of the improvements. 2.2 Proposed Construction Project information was provided in telephone and correspondence with you, which included a site plan package by Kimley-Horn dated 12/23/14 ( Public Hearing Plans ), which included plan, profile, and section sheets. F&R was also provided updated plan and profile sheets for Sta to dated 4/1/15. It is understood that a sidewalk is planned along the south side of Barracks Road starting at its intersection with the Route Bypass, running approximately 500 feet west (Sta to Sta ). A short retaining wall, up to 4 feet tall, may be required to facilitate the required grading for a portion of this length of sidewalk. The wall will likely consist of some type of gravity wall system using large concrete blocks, and we understand that the Stone Strong 6 SF system is being considered for this application. Another sidewalk is planned along the north side of Barracks Road, starting near Huntwood Lane and extending to Old Salem Drive, an approximate 1300 ft length (Sta to Sta ). Curb and gutter is also planned for this area. In addition, a SWM pond is planned for the empty lot near Sta 109 (shown as Parcel 005 on the drawings). The drawings indicate a 48 diameter pipe that will serve as underground detention, however, we understand that a conventional basin is also possible. Kimley-Horn and Associates, Inc. Barracks Road Sidewalks Albemarle County, Virginia F&R File No. 71S0272 April 27, 2015 Page - 2 -

8 3.0 EXPLORATION PROCEDURES 3.1 Soil Borings The exploration program was performed on March 23, 2015, and consisted of six soil test borings designated B-1 through B-6. The borings were drilled to depths of 7.9 feet to 15 feet below existing grades The locations of the borings are shown on the attached Boring Location Plans (Drawing Nos. 2, 3, and 4). The planned boring locations were determined and staked in the field by F&R by measuring from existing site features such as building corners, edges of pavement, etc. Surface elevations at the boring locations were estimated from the topography indicated on the provided site plans. In consideration of the methods used in their determination, the test boring locations shown on the attached boring location plan should be considered approximate. The soil test borings were performed in accordance with generally accepted practice using a track-mounted CME-55 rotary drill rig equipped with an automatic safety hammer. Hollowstem augers were advanced to pre-selected depths, the center plug was removed, and representative soil samples were recovered with a standard split-spoon sampler (1 3/8 in. ID, 2 in. OD) in general accordance with ASTM D 1586, the Standard Penetration Test. For these tests, a weight of 140 pounds was freely dropped from a height of 30 inches to drive the splitspoon sampler into the soil. The number of blows required to drive the split-spoon sampler three consecutive 6-inch increments was recorded, and the blows of the last two increments were summed to obtain the Standard Penetration Resistance (N-value). The N-value provides a general indication of in-situ soil conditions and has been correlated with certain engineering properties of soils. Research has shown that the Standard Penetration Resistance (N-value) determined by automatic hammer is different than the N-value determined by the safety hammer method. Most corrections that are published in the technical literature are based on the N-value determined by the safety hammer method. This is commonly termed N 60 as the rope and cathead with a safety hammer delivers about 60 percent of the theoretical energy delivered by a 140-pound hammer falling 30 inches. Several researchers have proposed correction factors for the use of hammers other than the safety hammer. The correction is made by the following equation: N 60 = N field x C E where N field is the value recorded in the field, and C E is the drill rod energy ratio for the hammer used. A correction factor (C E ) of 1.3 was utilized for the automatic hammer used during the drilling of borings for this site, based on previous energy measurements made for the automatic hammer system. Plotted N-values reported on Boring Logs are the actual, field-derived blow Kimley-Horn and Associates, Inc. Barracks Road Sidewalks Albemarle County, Virginia F&R File No. 71S0272 April 27, 2015 Page - 3 -

9 counts (N field ). Drilling notes on each Boring Log indicates whether penetration resistances presented on the Boring Log were determined using automatic hammer or conventional hammer systems. Corrected N 60 values were used for all analyses. In some soils it is not always practical to drive a split-spoon sampler the full three consecutive 6-inch increments. Whenever more than 50 blows are required to drive the sampler over a 6- inch increment, or the sampler is observed not to penetrate after 10 blows, the condition is called split-spoon refusal. Split-spoon refusal conditions may occur because of obstructions or because the earth materials being tested are very dense or very hard. When split-spoon refusal occurs, often little or no sample is recovered. The SPT N-value for split-spoon refusal conditions is typically estimated as > 100 blows per foot (bpf). Where the sampler is observed not to penetrate after 10 blows, the N-value is reported as 10/0. Otherwise, the depth of penetration after 50 blows is reported in inches, i.e. 50/5, 50/2, etc. The test borings were advanced through the soil overburden by soil drilling procedures until the planned termination depth or auger refusal material was encountered. Subsurface water level readings were taken in each of the borings during the drilling process. Upon completion of drilling, the boreholes were backfilled with auger cuttings (soil). Periodic observation of the boreholes should be performed to monitor subsidence at the ground surface, as the borehole backfill could settle over time. Representative portions of the split-spoon soil samples obtained throughout the exploration program were placed in glass jars and transported to our laboratory. In the laboratory, the soil samples were evaluated by a member of our engineering staff in general accordance with techniques outlined in the visual-manual identification procedure (ASTM D 2488). The soil descriptions and classifications discussed in this report and shown on the attached Boring Logs are based on visual observation and should be considered approximate. A copy of the boring logs are provided and classification procedures are further explained in Appendix II. Split-spoon soil samples recovered on this project will be stored at F&R s office for a period of 60 days. After 60 days, the samples will be discarded unless prior notification is provided to us in writing. 3.2 Laboratory Testing Representative soil samples were subjected to Water Content (ASTM D 2216), #200 Sieve Wash (ASTM D 1140), Atterberg Limits (ASTM D 4318), standard Proctor (ASTM D698) and CBR (ASTM D1883) to substantiate the visual classifications and assist with the estimation of the soils pertinent engineering properties. The results are shown in Section 4.4. Kimley-Horn and Associates, Inc. Barracks Road Sidewalks Albemarle County, Virginia F&R File No. 71S0272 April 27, 2015 Page - 4 -

10 4.0 REGIONAL GEOLOGY & SUBSURFACE CONDITIONS 4.1 Regional Geology The project site is located in an upland area of the Piedmont Plateau, at the western edge of the Piedmont Physiographic Province, an area underlain by ancient metamorphic rocks. Information obtained from publication entitled Geology and Mineral Resources of Charlottesville (Virginia Division of Mineral Resources Bulletin No 77, 1962) indicates that this area is underlain by the Lynchburg Formation of the Precambrian Age. The Lynchburg Formation is described as fine grained sediments, metamorphosed in part, varved-like layers of graphitic and sericitic schist and thick beds of quartz biotite gneiss. 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 clayey soils near the surface where soil weathering is more advanced, underlain by sandy SILTS and silty SANDS. The boundary between soil and rock is often times not sharply defined. The transitional term Hard or Soft Weathered Rock is normally found overlying the parent bedrock. For engineering purposes, SWR is described as broken and partially weathered rock with Standard Penetration Resistance N-values between 50 blows per 6 inches and 50 blows per inch. HWR is described as broken and partially weathered rock with N values in excess of 50 blows per inch. Weathering is facilitated by fractures, joints and the presence of less resistant rock types. Consequently, the profile of the SWR or HWR is often quite irregular, even over very short horizontal distances. Also, it is not unusual to find lenses, layers, or zones of less resistant SWR and more resistant HWR, and boulders of hard rock within the soil mantle well above the general bedrock level. 4.2 Subsurface Conditions 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 boring data using normally accepted geotechnical engineering judgments. The transitions between different soil strata are usually less distinct than those shown on the boring logs. Sometimes the relatively small sample obtained in the field is insufficient to definitively describe the origin of the subsurface material. In these cases, we qualify our origin descriptions with possible before the word describing the material s origin (i.e. possible fill, etc.). 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 attached Boring Logs in Appendix II. Kimley-Horn and Associates, Inc. Barracks Road Sidewalks Albemarle County, Virginia F&R File No. 71S0272 April 27, 2015 Page - 5 -

11 A Subsurface Profile has been prepared from the boring data to graphically illustrate the subsurface conditions encountered at the site. The Subsurface Profile can be found after the boring logs in Appendix II. Strata breaks designated on the Boring Logs and Subsurface Profile represent approximate boundaries between soil types. The transition from one soil type to another may be gradual or occur between soil samples. This section of the report provides a general discussion of subsurface conditions encountered within areas of proposed construction at the project site. Below the existing ground surface, the borings generally encountered pavements (borings B-1, B-2, and B-5), surficial organics (boring B-3, B-4, and B-6), existing fill (boring B-1, B-2, and B-6), residual soils (each boring), soft weathered rock (B-3 through B-6), and auger refusal materials (borings B-3 and B-4). These materials are generally discussed in the following paragraphs Pavement The following pavement sections were encountered in the borings: Boring No. Asphalt Thickness (inches) Stone Base Thickness (inches) B B B B B B Surficial Materials Surficial organic soils were encountered in borings B-3, B-4, and B-6, and extended to depths of 4 inches to 7 inches. Surficial organic 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 organic soil materials. Therefore, the term surficial organic soil is not intended to indicate a suitability for landscaping and/or other purposes. The surficial organic soil depths provided in this report are based on driller observations and should be considered approximate. We note that the transition from surficial organic soil to underlying materials may be gradual, and therefore the observation and measurement of surficial organic soil depths is subjective. Actual surficial organic soil depths should be expected to vary. Kimley-Horn and Associates, Inc. Barracks Road Sidewalks Albemarle County, Virginia F&R File No. 71S0272 April 27, 2015 Page - 6 -

12 4.2.4 Existing Fill Materials Fill consists of any materials deposited by man. Existing fill materials were encountered in borings B-1, B-2, and B-6 and extended to depths of 3.5 feet below existing grades. Sampled fill materials consisted of SILT (ML) and silty SAND (SM) with varying amounts of gravel. The fill materials were brown, reddish brown, and grayish brown in color, with moisture contents visually characterized as moist. The Standard Penetration Test values (N-Values) in the fill ranged from 8 bpf to 14 bpf Residual Soils Residual soils, formed by the in-place weathering of the parent rock, were encountered at each boring location and extended to the boring termination depths or soft weathered rock depths. Sampled residual soil consisted of lean CLAY (CL), silt (ML), elastic SILT (MH), and silty SAND (SM). These soils were brown, light brown, reddish brown, and light gray in color, with moisture contents visually characterized as moist. The Standard Penetration Test values (N- Values) in the residuum ranged from 6 bpf to 39 bpf Soft Weathered Rock Soft weathered rock (SWR) is a transitional material between soil and rock which contains the relic structure of the rock with very hard consistencies or very dense densities. SWR materials were encountered in test borings B-3 through B-6 at depths ranging from 3.5 ft to 8.5 ft, and extended to boring termination depths or until encountering auger refusal materials. The SWR materials became SILT (ML) and silty SAND (SM) when sampled. These materials were gray, light gray, and reddish brown in color, with moisture contents visually characterized as moist. SPT values in the SWR ranged between 75/6 to 50/ Auger Refusal Materials Auger refusal occurs when materials are encountered that cannot be penetrated by the soil auger and is normally indicative of a very hard or very dense material, such as boulders, rock lenses, rock pinnacles, or the upper surface of rock. Auger refusal was encountered in boring B- 3 at a depth of 15 feet and boring B-4 at a depth of 7.9 feet below existing grades. Auger refusal conditions with a CME 55 do not necessarily indicate conditions impenetrable to other equipment. Auger refusal conditions will likely vary in unexplored areas of the site. 4.3 Subsurface Water The test borings were monitored during and after drilling operations to obtain short-term subsurface water information. Subsurface water was not encountered in the borings during drilling or upon removal of the augers. Borings B-3 and B-4 were also dry at the time of readings taken 24 hours after the completion of drilling. It should be noted that the location of the subsurface water table could vary by several feet because of seasonal fluctuations in Kimley-Horn and Associates, Inc. Barracks Road Sidewalks Albemarle County, Virginia F&R File No. 71S0272 April 27, 2015 Page - 7 -

13 precipitation, evaporation, surface water runoff, local topography, and other factors not immediately apparent at the time of this exploration. Normally, the highest subsurface water levels occur in the late winter and spring and lowest levels occur in the late summer and fall. 4.4 Laboratory Test Results As discussed in Section 3.2, laboratory testing was performed on representative soil samples collected during our subsurface exploration and the results are indicated in the tables below. Boring No. Sample Depth (Feet) Natural Water Content (%) Liquid Limit/ Plasticity Index % Passing No. 200 Sieve USCS Class. B / ML B B / MH B B / ML B / MH B B B B Boring No. Sample Depth (Feet) Maximum Dry Density (pcf) Optimum Moisture (%) B B Soaked CBR (%) Kimley-Horn and Associates, Inc. Barracks Road Sidewalks Albemarle County, Virginia F&R File No. 71S0272 April 27, 2015 Page - 8 -

14 5.0 GEOTECHNICAL DESIGN RECOMMENDATIONS 5.1 General The following evaluations and recommendations are based on our observations at the site, interpretation of the field data obtained during this exploration, and our experience with similar subsurface conditions and projects. Soil penetration data has been used to estimate an allowable bearing pressure and associated settlement using established correlations. Subsurface conditions in unexplored locations may vary from those encountered. If the structure locations, loadings, or elevations are changed, we should be notified and requested to confirm and, if necessary, re evaluate our recommendations. Determination of an appropriate foundation system for a given structure is dependent on the proposed structural loads, soil conditions, and construction constraints such as proximity to other structures, etc. The subsurface exploration aids the geotechnical engineer in determining the soil stratum appropriate for structural support. This determination includes considerations with regard to both allowable bearing capacity and compressibility of the soil strata. In addition, since the method of construction greatly affects the soils intended for structural support, consideration must be given to the implementation of suitable methods of site preparation, fill compaction, and other aspects of construction, where applicable. 5.2 Retaining Wall We understand that the retaining wall is likely to consist of some type of gravity wall system using large concrete blocks. According to the information provided, this type of wall system is accepted by VDOT as an alternative to the typical RW 3 concrete gravity wall. Further, this project is being designed using the LRFD method, and specific soil/rock parameters have been requested to aid in the design. Therefore, some of the parameters given herein are not applicable for ASD methods. We recommend that shallow foundations bearing on firm residual soils be designed using a factored bearing resistance of 3.75 ksf. Existing fill materials, if encountered at planned bearing levels, should be removed to reach firm residual soils. To reduce the possibility of localized shear failures, footings should be a minimum of 2 feet wide. We recommend that all exterior footings be placed a minimum of 2 feet below finished exterior grades, which should be adequate to protect exterior footings against the effects of frost. Earth pressures on walls below grade are influenced by structural design of the walls, conditions of wall restraint, methods of construction and/or compaction, and the strength of the materials being restrained. The most common conditions assumed for earth retaining wall design are the active and at rest conditions. Active conditions apply to relatively flexible earth retention structures, such as freestanding walls, where some movement and rotation may Kimley Horn and Associates, Inc. Barracks Road Sidewalks Albemarle County, Virginia F&R File No. 71S0272 April 27, 2015 Page 9

15 occur to mobilize soil shear strength. Walls that are rigidly restrained, such as basement, pit, pool and tunnel walls, should be designed for the structure requiring the use of at-rest earth pressures. A third condition, the passive state, represents the maximum possible pressure when a structure is pushed against the soil, and is used in wall foundation design to help resist active or at-rest pressures. Soils used as backfill behind the proposed retaining walls should consist of Select Material Type I, as defined in Section 207 of the VDOT 2007 Road and Bridge Specifications. This backfill material should extend a horizontal distance equal to the wall height behind the wall. VDOT Select Material Type I Backfill Design Parameter Unit Weight of In-place Select Type I (pcf) 145 Soil Friction Angle (φ) 38 Friction Angle for Dissimilar Material/Wall Friction 25 Earth Pressure Conditions: Active (K a ) 0.24 Passive (K p ) 4.2 Sliding Resistance Factor ɸ τ 0.85 Passive Earth Pressure Resistance Factor ɸ ep 0.5 Based on VDOT Volume V Part 2 Design Aids and Typical Detail, Chapter 17 Our recommendations were given assuming that the ground surface above the wall is level. The recommended equivalent fluid pressures were provided assuming that a constantly functioning drainage system is in place to prevent the accidental buildup of hydrostatic pressures and lateral stresses in excess of those stated. The wall drainage requirements should be determined by the wall designer. If a functioning drainage system is not installed, then lateral earth pressures should be determined using the buoyant weight of the soil. Hydrostatic pressures calculated with the unit weight of water (62.4 pcf) should be added to these earth pressures to obtain the total stresses for design. Heavy equipment should not operate within 5 feet of below grade walls to prevent lateral pressures in excess of those cited. Adjacent footings or other surcharge loads located a short distance outside below grade walls will also exert appreciable additional lateral pressures. Surcharge loads should be evaluated using the appropriate active or at-rest pressure coefficients provided above. The effect of surcharge loads should be added to the recommended earth pressures to determine total lateral stresses. Kimley-Horn and Associates, Inc. Barracks Road Sidewalks Albemarle County, Virginia F&R File No. 71S0272 April 27, 2015 Page

16 5.3 Stormwater Management We understand that a stormwater management facility is planned for the empty lot near Sta 109 (shown as Parcel 005 on the drawings). The drawings indicate a 48 diameter pipe that will serve as underground detention, however, we understand that a conventional basin is also possible. The provided profile drawings indicate an invert level for Structure 4-2 at El Boring B-3, which is located just east of this structure indicates that Soft Weathered Rock was encountered at El 578. As a result, some difficult excavation should be expected to reach the planned subgrade levels. We recommend that typical VDOT bedding requirements be followed for this pipe. Any overexcavations needed to reach firm soils considered suitable for pipe support should be backfilled with No. 57 Stone. If a basin is constructed, we recommend that it be designed in accordance with the Virginia Stormwater Management Handbook. At this time details regarding the possible basin were not provided to F&R, and therefore, F&R s recommendations are general in nature. If the basin will be used to retain water on a permanent basis, a clay liner will be needed (properties of the clay liner are specified in Table of the Virginia Stormwater Management Handbook). Embankments will require a cutoff trench and impervious core, as outlined in Standard 3.01 of the Virginia Stormwater Management Handbook. In addition, seepage control along any conduits penetrating embankments should be accomplished using a filter diaphragm, as outlined in Standard 3.02 of the Virginia Stormwater Management Handbook. 5.4 Sidewalk/Curb Subgrades F&R has been requested to comment on the anticipated suitability of the subgrade soils for sidewalk and curb and gutter support. The borings indicate firm existing fill or residual soils at the planned subgrade levels. The sampled fill materials did not include excessive amounts of organics or debris and are generally considered suitable as subgrade materials, provided that they are also inspected and approved by the geotechnical engineer at the time of construction (refer to Section 6.1 of this report). 6.0 GEOTECHNICAL CONSTRUCTION RECOMMENDATIONS 6.1 Subgrade Preparation Before proceeding with construction, surficial organics, concrete and crushed stone, and other deleterious non-soil materials (if any) should be stripped or removed from the proposed construction area. Attention should be given to these areas to ensure all unsuitable material is removed prior to continuing with construction. During the site preparation operations, positive surface drainage should be maintained to prevent the accumulation of water. Kimley-Horn and Associates, Inc. Barracks Road Sidewalks Albemarle County, Virginia F&R File No. 71S0272 April 27, 2015 Page

17 After stripping, areas intended to support new fill or subbase materials should be carefully evaluated by a geotechnical engineer. At that time the engineer may require proofrolling of the subgrades with a 20 to 30-ton loaded truck or other pneumatic-tired vehicle of similar size and weight. Proofrolling should be performed during a time of good weather and not while the site is wet, frozen, or severely desiccated. The purpose of the proofrolling is to locate soft, weak, or excessively wet soils present at the time of construction. The proofrolling observation is an opportunity for the geotechnical engineer to locate inconsistencies intermediate of our boring locations in the existing subgrade. Any unsuitable materials observed during the evaluation and proofrolling operations should be undercut and replaced with compacted fill or stabilized in-place. Fill materials which are encountered in planned paved areas may generally be left in place provided that they do not contain excessive amounts of organics or debris, and are stable during proofrolling. The possible need for, and extent of, undercutting and/or in-place stabilization required can best be determined by the geotechnical engineer at the time of construction. Once the site has been properly prepared, at-grade construction may proceed. 6.2 Excavation Conditions Auger refusal was encountered in borings B-3 and B-4 at depths of 15 feet and 7.9 feet respectively, and Soft Weathered Rock was encountered in borings B-3 through B-6 at depths of 3.5 feet to 8.5 feet. It must also be understood that it is not unusual for the profile of the bedrock surface to be irregular, and bedrock and/or float boulders could be encountered at higher elevations between test boring locations. Therefore, based on the boring data, difficult excavation conditions could be encountered on the site, especially in excavations for the underground detention piping and for the retaining wall. In mass excavations for general sitework, hard or dense soils (soils with standard penetration resistances of 30 or more blows per foot) can usually be removed by ripping with a single-tooth ripper attached to a large crawler tractor or by breaking it out with a tracked excavator or large front-end loader. However, we note that while ripping and/or breaking out with large tracked equipment might be possible, it may be time prohibitive for deep mass excavations. Blasting is not expected to be necessary for this project. In confined excavations such as foundations, utility trenches, etc., removal of partially weathered rock typically requires use of large backhoes, hoe ramming, or pneumatic spades. The definition of rock can be a source of conflict during construction. The following definitions have been incorporated into specifications on other projects and are provided for your general guidance: Kimley-Horn and Associates, Inc. Barracks Road Sidewalks Albemarle County, Virginia F&R File No. 71S0272 April 27, 2015 Page

18 GENERAL EXCAVATION: Rip Rock - Blast Rock - Any material that cannot be removed by scrapers, loaders, pans, dozers, or graders; and requires the use of a single-tooth ripper mounted on a crawler tractor having a minimum draw bar pull rated at not less than 56,000 pounds. Any material which cannot be excavated with a single-tooth ripper mounted on a crawler tractor having a minimum draw bar pull rated at not less than 56,000 pounds (Caterpillar D-8K or equivalent) or by a Caterpillar 977 front-end loader or equivalent; and occupying an original volume of at least one (1) cubic yard. TRENCH EXCAVATION: Blast Rock - Any material which cannot be excavated with a backhoe having a bucket curling force rated at not less than 25,700 pounds (Caterpillar Model 225 or equivalent), and occupying an original volume of at least one-half (1/2) cubic yard. The gradation of rip rock and blast rock materials is typically very erratic, making them unsuitable for re-use as structural fill, unless they are crushed, screened, and blended as necessary to create a well graded material. 6.3 Structural Fill Placement and Compaction Fill materials may consist of the non-organic on-site soils, or an off-site borrow having a classification of CL or more granular, as defined by the Unified Soil Classification System. Controlled structural fill should have a maximum particle size of 4 inches and should be free of organics or other deleterious materials. Fill materials should also have a Standard proctor (ASTM D698) maximum dry density of at least 100 pounds per cubic foot. Based on our visual classifications and the laboratory testing, we anticipate that the on-site soils should serve satisfactorily as fill provided that the moisture contents can be maintained within acceptable limits. The on-site soils are considered moisture sensitive and may be difficult to work with when they are wet of the optimum moisture content. The natural moisture contents of some of the tested samples were above the optimum moisture content. In particular, the two bulk samples tested were 9 to 10 percentage points above their optimum moisture content. As a result, some drying efforts should be expected to achieve the required degree of compaction. Kimley-Horn and Associates, Inc. Barracks Road Sidewalks Albemarle County, Virginia F&R File No. 71S0272 April 27, 2015 Page

19 Predicated on the boring and laboratory results, and the recommendations provided above, the best time for construction of the structural fills and compacted subgrades would be during the warmer, drier months of the year, such as from late April through early October. During this time frame, on-site soils that are wet of optimum can usually be dried to near optimum levels with relatively little effort. If grading is performed during the colder, wetter months of the year, such as late October through early April, and suitable dry materials are not available on site, then off-site drier borrow sources will likely be necessary. Fill materials should be placed in horizontal lifts with a maximum loose lift thickness of 8 inches. New fill should be adequately keyed into stripped and scarified subgrade soils. The fill should be compacted to at least 95 percent of the material s maximum dry density as determined by the standard Proctor method (ASTM D 698). In confined areas, portable compaction equipment and thin lifts of 3 to 4 inches may be required to achieve specified degrees of compaction. Each lift of the fill should be tested in order to confirm that the recommended degree of compaction is attained. Excessively wet or dry soils should not be used as fill materials without proper drying or wetting. We recommend a moisture content range of plus or minus 3 percentage points of the material s optimum moisture content. We recommend that the contractor have equipment on site during earthwork for both drying and wetting of fill soils. Where construction traffic or weather has disturbed the subgrade, the upper 8 inches of soils intended for structural support should be scarified and re-compacted. Field density tests to determine the degree of compaction should be performed on each lift of fill. 6.4 Surface Water/Groundwater Control Subsurface water for the purposes of this report is defined as water encountered below the existing ground surface. Based on the subsurface water data obtained during our exploration program, we do not anticipate that subsurface water will be encountered during anticipated earthwork and shallow foundation excavations for the footing construction. However, the contractor should be prepared to dewater should water levels vary from those encountered during the drilling program. Fluctuations in subsurface water levels and soil moisture can be anticipated with changes in precipitation, runoff, and season. An important aspect to consider during development of this site is surface water control. During the construction, we recommend that steps be taken to enhance surface flow away from any excavations and promote rapid clearing of rainfall and runoff water following rain events. It should be incumbent on the contractor to maintain favorable site drainage during construction to reduce deterioration of otherwise stable subgrades. Kimley-Horn and Associates, Inc. Barracks Road Sidewalks Albemarle County, Virginia F&R File No. 71S0272 April 27, 2015 Page

20 6.5 Temporary Excavation Recommendations 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. All 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. 6.0 CONTINUATION OF SERVICES We recommend that we be given the opportunity to review the foundation plan, grading plan, and project specifications when construction documents approach completion. This review evaluates whether the recommendations and comments provided herein have been understood and properly implemented. We also recommend that Froehling & Robertson, Inc. 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. The Geotechnical Engineer of Record should be retained to monitor and test earthwork activities, and subgrade preparations for foundations, excavations and floor slabs. It should be noted that the actual soil conditions at the various subgrade levels and footing bearing grades will vary across this site and thus the presence of the Geotechnical Engineer and/or his representative during construction will serve to validate the subsurface conditions and recommendations presented in this report. We recommend that F&R be employed to monitor the earthwork and foundation construction, and to report that the recommendations contained in this report are completed in a satisfactory manner. Our involvement on the project will aid in the proper implementation of the recommendations discussed herein. The following is a recommended scope of services: Kimley-Horn and Associates, Inc. Barracks Road Sidewalks Albemarle County, Virginia F&R File No. 71S0272 April 27, 2015 Page

21 Review of project plans and construction specifications to verify that the recommendations presented in this report have been properly interpreted and implemented; Observe all foundation excavations and footing bearing grades for compliance with the geotechnical recommendations. These services are not included in our current scope of services and can be rendered for an additional cost. 7.0 LIMITATIONS This report has been prepared for the exclusive use of the Kimley-Horn and Associates, Inc., or their agent, for specific application to the Barracks Road Sidewalks project, in accordance with generally accepted soil and foundation engineering practices. No other warranty, express or implied, is made. Our evaluations and recommendations are based on design information furnished to us; the data obtained from the previously described subsurface exploration program, and generally accepted geotechnical engineering practice. The evaluations and recommendations do not reflect variations in subsurface conditions which could exist intermediate of the boring locations or in unexplored areas of the site. Should such variations become apparent during construction, it will be necessary to re-evaluate our recommendations based upon on-site observations of the conditions. There are important limitations to this and all geotechnical studies. Some of these limitations are discussed in the information prepared by ASFE, which is included in Appendix III. We ask that you please review this ASFE information. Regardless of the thoroughness of a subsurface exploration, there is the possibility that conditions between borings 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, pavement, 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. In the event that changes are made in the design or location of the proposed structure, the recommendations presented in the 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. Kimley-Horn and Associates, Inc. Barracks Road Sidewalks Albemarle County, Virginia F&R File No. 71S0272 April 27, 2015 Page

22 APPENDIX I

23 SITE FROEHLING & ROBERTSON, INC. Engineering Stability Since Rockfish Gap Turnpike Crozet, Virginia T I F Site Location Plan Client: Kimley-Horn and Associates, Inc. Project: Barracks Road Sidewalk F&R Project No. 71S0272 Date: April, 2015 Scale: 1 =2000 Drawing No.: 1

24 Boring Location Plan Client: Kimley-Horn and Associates, Inc. Project: Barracks Road Sidewalk F&R Project No.: 71S0272 FROEHLING & ROBERTSON, INC Engineering Stability Since Rockfish Gap Turnpike, Crozet, VA T F B-1 B-2 Date: April, 2015 Scale: 1 = 50 Drawing No. 2

25 Boring Location Plan Client: Kimley-Horn and Associates, Inc. Project: Barracks Road Sidewalk F&R Project No.: 71S0272 FROEHLING & ROBERTSON, INC Engineering Stability Since Rockfish Gap Turnpike, Crozet, VA T F B-4 B-3 B-5 Date: April, 2015 Scale: 1 = 50 Drawing No. 3

26 Boring Location Plan Client: Kimley-Horn and Associates, Inc. Project: Barracks Road Sidewalk F&R Project No.: 71S0272 FROEHLING & ROBERTSON, INC Engineering Stability Since Rockfish Gap Turnpike, Crozet, VA T F B-6 Date: April, 2015 Scale: 1 = 50 Drawing No. 4

27 APPENDIX II

28 Particle Size and Proportion KEY TO BORING LOG SOIL CLASSIFICATION 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 ¾ - 3 inch -Fine #4 ¾ 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 Loose Medium-Dense Dense Very Dense > 50 Very Soft Soft Medium Stiff Stiff Very Stiff 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 splitspoon 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.

29 UNIFIED SOIL CLASSIFICATION SYSTEM (ASTM D-2487) Major Divisions Group Symbols Typical Names Laboratory Classification Criteria Coarse-grained soils (More than half of material is larger than No. 200 sieve size) Gravels (More than half of coarse fraction is larger than No. 4 sieve size) Sands (More than half of coarse fraction is smaller than No.4 sieve size) Clean gravels (little or no fines) Gravels with fines (Appreciable amount of fines) Clean sands (little or no fines) Sands with fines (Appreciable amount of fines) GW GP GM GC SW SP SM SC Well-graded gravels, gravel-sand mixtures, little or no fines Poorly graded gravels, gravelsand mixtures, little or no fines Silty gravels, gravel-sand-silt mixtures Clayey gravels, gravel-sand-clay mixtures Well-graded sands, gravelly sands, little or no fines Poorly graded sands, gravelly sands, little or no fines Silty sands, sand-silt mixtures Clayey sands, sand-clay mixtures Determine percentages of sand and gravel from grain-size curve. Depending on percentage of fines (fraction smaller than No. 200 Sieve), coarse-grained soils are GW, GP, SW, SP GM, GC, SM, SC Borderline cases requiring dual symbols classified as follows: Less than 5 per cent More than 12 per cent 5 to 12 per cent C u=d 60/D 10 greater than 4; C c=(d 30) 2 /(D 10x D 60) between 1 and 3 Not meeting all gradation requirements for GW Atterberg limits below A line or PI less than 4 Atterberg limits below A line or PI greater than 7 C u=d 60/D 10 greater than 6; C c=(d 30) 2 /(D 10x D 60) between 1 and 3 Above A line with PI between 4 and 7 are borderline cases requiring use of dual symbols Not meeting all gradation requirements for SW Atterberg limits above A line or PI less than 4 Atterberg limits above A line or PI greater than 7 Above A line with PI between 4 and 7 are borderline cases requiring use of dual symbols Fine-grained soils (More than half material is smaller than No. 200 sieve Silts and clays (Liquid limit less than 50) Silts and clays (Liquid limit greater than 50) Highly organic soils ML CL OL MH CH OH Pt Inorganic silts and very fine sands, rock flour, silty or clayey fine sands, or clayey silts with slight plasticity Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, silty clays, lean clays Organic silts and organic silty clays of low plasticity Inorganic silts, micaceous or diatomaceous fine sandy or silty soils, elastic silts Inorganic clays of high plasticity, fat clays Organic clays of medium to high plasticity Peat and other highly organic soils Plasticity Index, PI CL Plasticity Chart "A" line 10 CL-ML ML & OL Liquid Limit, LL CH MH & OH

30 DEPTH (ft) ELEVATION (ft) S O I L STANDARD PENETRATION TEST N-VALUE FIELD DATA SOIL RECOVERY (%) SAMPLE LEGEND SAMPLE INTERVAL CORE RECOVERY (%) R O C K ROCK QUALITY DESIGNATION STRATA DIP JOINTS STRATA LEGEND PROJECT #: LOCATION: STRUCTURE: R45 Albemarle County, Virginia RT. TURN LANE STATION: NORTHING: ft SURFACE ELEVATION: ft Date(s) Drilled: 3/23/2015-2/23/2015 Drilling Method(s): 2 1/4" HSA SPT Method: Automatic Hammer Other Test(s): Driller: C. Ingo Logger: GROUND WATER NOT ENCOUNTERED DURING DRILLING NO LONG TERM MEASUREMENTS TAKEN FIELD DESCRIPTION OF STRATA 0.0 / INCHES, ASPHALT ASPH 0.75 / INCHES, CRUSHED AGGREGATE CRA 1.42 / FILL Gray and brown, SANDY SILT, firm, moist ML 3.5 / RESIDUUM Red-brown, ELASTIC SILT, little sand, stiff, moist MH 6.0 / RESIDUUM Brown, SANDY SILT, firm, moist ML OFFSET: Easting: ft COORD. DATUM: 8.5 / RESIDUUM Light gray, fine to coarse, SILTY SAND, medium dense, moist SM Test Boring Terminated at 10 ft. 15BH-001 PAGE 1 OF 1 LAB DATA LIQUID LIMIT LL PLASTICITY INDEX PI MOISTURE CONTENT (%) SPT_LOG:71S0272 BORING LOGS.GPJ: :021011:2/17/17 REMARKS: Rig Type: CME-55 Truck. Backfilled with soil cuttings and asphalt patch. Copyright 2017, Commonwealth of Virginia PAGE 1 OF 1 15BH-001

31 DEPTH (ft) ELEVATION (ft) S O I L STANDARD PENETRATION TEST N-VALUE FIELD DATA SOIL RECOVERY (%) SAMPLE LEGEND SAMPLE INTERVAL CORE RECOVERY (%) R O C K ROCK QUALITY DESIGNATION STRATA DIP JOINTS STRATA LEGEND PROJECT #: LOCATION: STRUCTURE: R45 Albemarle County, Virginia RT. SHOULDER STATION: NORTHING: ft SURFACE ELEVATION: ft Date(s) Drilled: 3/23/2015-2/23/2015 Drilling Method(s): 2 1/4" HSA SPT Method: Automatic Hammer Other Test(s): Driller: C. Ingo Logger: GROUND WATER NOT ENCOUNTERED DURING DRILLING NO LONG TERM MEASUREMENTS TAKEN FIELD DESCRIPTION OF STRATA 0.0 / INCHES, ASPHALT ASPH 0.75 / INCHES, CRUSHED AGGREGATE CRA 2.0 / FILL Brown, fine to coarse, SILTY SAND, trace gravel, medium dense, moist SM 3.5 / RESIDUUM Brown, LEAN CLAY, little sand, stiff, moist CL 6.0 / RESIDUUM Light brown, SANDY SILT, very stiff, moist ML 8.5 / RESIDUUM Brown, fine to coarse, SILTY SAND, medium dense, moist SM Test Boring Terminated at 10 ft. OFFSET: Easting: ft COORD. DATUM: 15BH-002 PAGE 1 OF 1 LAB DATA LIQUID LIMIT LL PLASTICITY INDEX PI MOISTURE CONTENT (%) SPT_LOG:71S0272 BORING LOGS.GPJ: :021011:2/17/17 REMARKS: Rig Type: CME-55 Truck. Backfilled with soil cuttings and asphalt patch. Copyright 2017, Commonwealth of Virginia PAGE 1 OF 1 15BH-002

32 DEPTH (ft) 2 ELEVATION (ft) S O I L STANDARD PENETRATION TEST N-VALUE 14 FIELD DATA SOIL RECOVERY (%) SAMPLE LEGEND SAMPLE INTERVAL CORE RECOVERY (%) R O C K ROCK QUALITY DESIGNATION STRATA DIP JOINTS STRATA LEGEND PROJECT #: LOCATION: STRUCTURE: NOT ENCOUNTERED DURING DRILLING DRY AFTER && HRS R45 Albemarle County, Virginia TEMP. CONST. EASE. STATION: NORTHING: ft SURFACE ELEVATION: ft Date(s) Drilled: 3/23/2015-2/23/2015 Drilling Method(s): 2 1/4" HSA SPT Method: Automatic Hammer Other Test(s): Driller: C. Ingo Logger: GROUND WATER FIELD DESCRIPTION OF STRATA 0.0 / INCHES, TOPSOIL TOPS 0.33 / RESIDUUM Red-brown, ELASTIC SILT, little sand, stiff, moist MH OFFSET: Easting: ft COORD. DATUM: 15BH-003 PAGE 1 OF 1 LAB DATA LIQUID LIMIT LL PLASTICITY INDEX PI MOISTURE CONTENT (%) / RESIDUUM Light gray, fine to coarse, SILTY SAND, loose, moist SM /3" / IGM Gray, fine to coarse, SILTY SAND, very dense, moist SM /6" /1" SPT_LOG:71S0272 BORING LOGS.GPJ: :021011:2/17/17 REMARKS: Rig Type: CME-55 Truck. Backfilled with soil cuttings. Copyright 2017, Commonwealth of Virginia Auger Refusal at 15 ft. Test Boring Terminated at 15 ft. PAGE 1 OF 1 15BH-003

33 DEPTH (ft) ELEVATION (ft) S O I L STANDARD PENETRATION TEST N-VALUE /4" FIELD DATA SOIL RECOVERY (%) SAMPLE LEGEND SAMPLE INTERVAL CORE RECOVERY (%) R O C K ROCK QUALITY DESIGNATION STRATA DIP JOINTS STRATA LEGEND PROJECT #: LOCATION: STRUCTURE: NOT ENCOUNTERED DURING DRILLING DRY AFTER && HRS R45 Albemarle County, Virginia DRAINAGE EASE. STATION: NORTHING: ft SURFACE ELEVATION: ft Date(s) Drilled: 3/23/2015-2/23/2015 Drilling Method(s): 2 1/4" HSA SPT Method: Automatic Hammer Other Test(s): Driller: C. Ingo Logger: GROUND WATER FIELD DESCRIPTION OF STRATA 0.0 / INCHES, TOPSOIL TOPS 0.5 / RESIDUUM Red-brown, SANDY SILT, stiff, moist ML 3.5 / RESIDUUM Brown and light gray, fine to coarse, SILTY SAND, contains mica, medium dense, moist SM 6.0 / IGM Light gray and red-brown, fine to coarse, SANDY SILT, contains mica, very hard, moist ML Auger Refusal at 7.9 ft. Test Boring Terminated at 7.9 ft. OFFSET: Easting: ft COORD. DATUM: 15BH-004 PAGE 1 OF 1 LAB DATA LIQUID LIMIT LL PLASTICITY INDEX PI MOISTURE CONTENT (%) SPT_LOG:71S0272 BORING LOGS.GPJ: :021011:2/17/17 REMARKS: Rig Type: CME-55 Truck. Backfilled with soil cuttings. Copyright 2017, Commonwealth of Virginia PAGE 1 OF 1 15BH-004

34 DEPTH (ft) ELEVATION (ft) S O I L STANDARD PENETRATION TEST N-VALUE 25 50/6" 50/4" 50/4" FIELD DATA SOIL RECOVERY (%) SAMPLE LEGEND SAMPLE INTERVAL CORE RECOVERY (%) R O C K ROCK QUALITY DESIGNATION STRATA DIP JOINTS STRATA LEGEND PROJECT #: LOCATION: STRUCTURE: NOT ENCOUNTERED DURING DRILLING DRY AFTER && HRS R45 Albemarle County, Virginia RT. SHOULDER STATION: NORTHING: ft SURFACE ELEVATION: ft Date(s) Drilled: 3/23/2015-2/23/2015 Drilling Method(s): 2 1/4" HSA SPT Method: Automatic Hammer Other Test(s): Driller: C. Ingo Logger: GROUND WATER FIELD DESCRIPTION OF STRATA 0.0 / INCHES, ASPHALT ASPH 0.5 / INCHES, CRUSHED AGGREGATE CRA 1.25 / RESIDUUM Red-brown, SANDY SILT, little gravel, very stiff, moist ML 3.5 / IGM Light gray, fine to coarse, SILTY SAND, very dense, moist SM Test Boring Terminated at 10 ft. OFFSET: Easting: ft COORD. DATUM: 15BH-005 PAGE 1 OF 1 LAB DATA LIQUID LIMIT LL PLASTICITY INDEX PI MOISTURE CONTENT (%) SPT_LOG:71S0272 BORING LOGS.GPJ: :021011:2/17/17 REMARKS: Rig Type: CME-55 Truck. Backfilled with soil cuttings and asphalt patch. Copyright 2017, Commonwealth of Virginia PAGE 1 OF 1 15BH-005

35 DEPTH (ft) 2 ELEVATION (ft) S O I L STANDARD PENETRATION TEST N-VALUE 14 FIELD DATA SOIL RECOVERY (%) SAMPLE LEGEND SAMPLE INTERVAL CORE RECOVERY (%) R O C K ROCK QUALITY DESIGNATION STRATA DIP JOINTS STRATA LEGEND PROJECT #: LOCATION: STRUCTURE: NOT ENCOUNTERED DURING DRILLING DRY AFTER && HRS R45 Albemarle County, Virginia RT. SHOULDER STATION: NORTHING: ft SURFACE ELEVATION: ft Date(s) Drilled: 3/23/2015-2/23/2015 Drilling Method(s): 2 1/4" HSA SPT Method: Automatic Hammer Other Test(s): Driller: C. Ingo Logger: GROUND WATER FIELD DESCRIPTION OF STRATA 0.0 / INCHES, TOPSOIL TOPS 0.58 / FILL Red-brown, SANDY SILT, stiff, moist ML OFFSET: Easting: ft COORD. DATUM: 15BH-006 PAGE 1 OF 1 LAB DATA LIQUID LIMIT LL PLASTICITY INDEX PI MOISTURE CONTENT (%) / RESIDUUM Brown, SANDY SILT, contains mica, very stiff, moist ML /2" / RESIDUUM Light brown, fine to coarse, SILTY SAND, contains mica, dense, moist SM 8.5 / IGM Light gray, fine to coarse, SILTY SAND, very dense, moist SM /4" SPT_LOG:71S0272 BORING LOGS.GPJ: :021011:2/17/ Test Boring Terminated at 15 ft. REMARKS: Rig Type: CME-55 Truck. Backfilled with soil cuttings. Copyright 2017, Commonwealth of Virginia PAGE 1 OF 1 15BH-006

36 R Froehling & Robertson, Inc. Project No: 71S0272 Client: Barracks Road Sidewalk Project: Kimley-Horn and Associates, Inc. City/State: Albemarle County, Virginia SUBSURFACE PROFILE Plot Based on Depth Profile Name: 1 0 B-1 B-2 B-3 B-4 B-5 B / /3 50/4 50/ /6 50/4 50/2 10 Depth (ft) /1 50/4 16 DEPTH_LANDSCAPE_8.5X11 71S0272.GPJ F&R.GDT 4/27/

37 GRAIN SIZE DISTRIBUTION REPORT /2 in 1 in 3/4 in 1/2 in 3/8 in #4 #8 #16 #30 #40 #50 #100 # PERCENT FINER GRAIN SIZE (mm) % GRAVEL % SAND % SILT/CLAY SIEVE SIZE 1 1/2 in 1 in 3/4 in 1/2 in 3/8 in #4 #8 #10 #16 PERCENT FINER # # # # # SPEC PERCENT PASS? (X=NO) Soil Description Brown, sandy SILT with little gravel Atterberg Limits LL= 40 PL= 27 PI= 13 Coefficients D 85 = D 60 = D 50 = D 30 = D 15 = D 10 = C u = C c = Classification USCS= ML AASHTO= A-6 Remarks Moisture Content= 24.4 % Specific Gravity= F Lab No.: 2738 Location: B-1 Froehling and Robertson, Inc. Client: Project: Location: Project No.: Date: 4/24/15 Elev/Depth: 0-10' Kimley-Horn & Associates, Inc. Barracks Road Sidewalks Albemarle County, Virginia 71S0272

38

39 Client: Kimley-Horn & Associates, Inc. Record #: Project: Location: Barracks Road Sidewalks F&R Lab No.: 2738 B-1 (0-10') Test Date: 24-Apr-15 Unsoaked CBR X Soaked CBR Compaction method: VTM - 1; Surcharge weight - 10 lbs Sample Depth: 0 to 1.5 feet Compactive effort: FROEHLING & ROBERTSON, INC. Engineering Environmental Geotechnical 6181 Rockfish Gap Turnpike Crozet, Virginia I USA T I F California Bearing Ratio (AASHTO T 193) 5 Layers with 45 blows per layer 71S Stress on Piston (psi) Penetration (inches) 0.1 in. penetration: 15.5 Proctor Max. Dry Density (pcf): Swell (%): N/A Proctor Opt. Moisture Content (%): 15.9 Dry Density Before Soak (pcf): Liquid Limit: 40 Moisture Content Before Soak (%): 15.9 Plasticity Index: 13 % Compaction Before Soak: 101.3% % Retained No. 4 Sieve 5.2 Dry Density After Soak (pcf): N/A % Passing No. 200 Sieve: 51.4 Moisture Content After Soak, Top in. (%): N/A Visual Description: % Compaction After Soak: N/A Brown, sandy SILT with little gravel Resiliency Factor: 2.5 USCS Classification: ML AASHTO Classification: A-6 {4} Tested By: RK Reviewed By: Froehling and Robertson, Inc.

40 Client: Kimley-Horn & Associates, Inc. Record #: Project: Location: Barracks Road Sidewalks F&R Lab No.: 2738 B-1 (0-10') Test Date: 24-Apr-15 Unsoaked CBR Soaked CBR X Compaction method: VTM - 1; Surcharge weight - 10 lbs Sampling Depth: 0 to 1.5 feet Compactive effort: FROEHLING & ROBERTSON, INC. Engineering Environmental Geotechnical 6181 Rockfish Gap Turnpike Crozet, Virginia I USA T I F California Bearing Ratio (AASHTO T 193) 5 Layers with 45 blows per layer 71S Stress on Piston (psi) Penetration (inches) 0.1 in. penetration: 14.5 Proctor Max. Dry Density (pcf): Swell (%): 0.37% Proctor Opt. Moisture Content (%): 15.9 Dry Density Before Soak (pcf): Liquid Limit: 40 Moisture Content Before Soak (%): 15.8% Plasticity Index: 13 % Compaction Before Soak: 101.8% % Retained No. 4 Sieve 5.2 Dry Density After Soak (pcf): % Passing No. 200 Sieve: 51.4 Moisture Content After Soak, Top in. (%): 18.4% Visual Description: % Compaction After Soak: 101.5% Brown, sandy SILT with little gravel Resiliency Factor: 2.5 USCS Classification: ML AASHTO Classification: A-6 {4} Tested By: RK Reviewed By: Froehling and Robertson, Inc.

41 GRAIN SIZE DISTRIBUTION REPORT /2 in 1 in 3/4 in 1/2 in 3/8 in #4 #8 #16 #30 #40 #50 #100 # PERCENT FINER GRAIN SIZE (mm) % GRAVEL % SAND % SILT/CLAY SIEVE PERCENT SIZE FINER 1 1/2 in in /4 in /2 in /8 in 99.9 # # # # # # # # # SPEC PERCENT PASS? (X=NO) Soil Description Brown, sandy SILT with trace gravel Atterberg Limits LL= 32 PL= 24 PI= 8 Coefficients D 85 = D 60 = D 50 = D 30 = D 15 = D 10 = C u = C c = Classification USCS= ML AASHTO= A-4 Remarks Moisture Content= 25.3 % Specific Gravity= F Lab No.: 2739 Location: B-3 Froehling and Robertson, Inc. Client: Project: Location: Project No.: Date: 4/24/15 Elev/Depth: 0-10' Kimley-Horn & Associates, Inc. Barracks Road Sidewalks Albemarle County, Virginia 71S0272

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43 Client: Kimley-Horn & Associates, Inc. Record #: Project: Location: Barracks Road Sidewalks F&R Lab No.: 2739 B-3 (0-10') Test Date: 24-Apr-15 Unsoaked CBR X Soaked CBR Compaction method: VTM - 1; Surcharge weight - 10 lbs Sample Depth: 0 to 1.5 feet Compactive effort: FROEHLING & ROBERTSON, INC. Engineering Environmental Geotechnical 6181 Rockfish Gap Turnpike Crozet, Virginia I USA T I F California Bearing Ratio (AASHTO T 193) 5 Layers with 45 blows per layer 71S Stress on Piston (psi) Penetration (inches) 0.1 in. penetration: 17.5 Proctor Max. Dry Density (pcf): Swell (%): N/A Proctor Opt. Moisture Content (%): 15.5 Dry Density Before Soak (pcf): Liquid Limit: 32 Moisture Content Before Soak (%): 15.5 Plasticity Index: 8 % Compaction Before Soak: 101.8% % Retained No. 4 Sieve 0.3 Dry Density After Soak (pcf): N/A % Passing No. 200 Sieve: 54.7 Moisture Content After Soak, Top in. (%): N/A Visual Description: % Compaction After Soak: N/A Brown, sandy SILT with trace gravel Resiliency Factor: 2.5 USCS Classification: ML AASHTO Classification: A-4 {2} Tested By: RK Reviewed By: Froehling and Robertson, Inc.

44 Client: Kimley-Horn & Associates, Inc. Record #: Project: Location: Barracks Road Sidewalks F&R Lab No.: 2739 B-3 (0-10') Test Date: 24-Apr-15 Unsoaked CBR Soaked CBR X Compaction method: VTM - 1; Surcharge weight - 10 lbs Sampling Depth: 0 to 1.5 feet Compactive effort: FROEHLING & ROBERTSON, INC. Engineering Environmental Geotechnical 6181 Rockfish Gap Turnpike Crozet, Virginia I USA T I F California Bearing Ratio (AASHTO T 193) 5 Layers with 45 blows per layer 71S Stress on Piston (psi) Penetration (inches) 0.1 in. penetration: 13.1 Proctor Max. Dry Density (pcf): Swell (%): 0.33% Proctor Opt. Moisture Content (%): 15.5 Dry Density Before Soak (pcf): Liquid Limit: 32 Moisture Content Before Soak (%): 15.5% Plasticity Index: 8 % Compaction Before Soak: 101.8% % Retained No. 4 Sieve 0.3 Dry Density After Soak (pcf): % Passing No. 200 Sieve: 54.7 Moisture Content After Soak, Top in. (%): 18.8% Visual Description: % Compaction After Soak: 101.4% Brown, sandy SILT with trace gravel Resiliency Factor: 2.5 USCS Classification: ML AASHTO Classification: A-4 {2} Tested By: RK Reviewed By: Froehling and Robertson, Inc.