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REPORT COVER PAGE

Geotechnical Engineering Report Cross Charlotte Trail 7th-10th Street Segment

Charlotte, North Carolina August 24, 2018

Terracon Project No. 71175040

Prepared for: Alta Planning + Design, Inc.

Durham, North Carolina

Prepared by: Terracon Consultants, Inc.

Charlotte, North Carolina

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REPORT TOPICS REPORT TOPICS

EXECUTIVE SUMMARY ................................................................................................. iINTRODUCTION ............................................................................................................. 1SITE CONDITIONS ......................................................................................................... 1PROJECT DESCRIPTION .............................................................................................. 2GEOTECHNICAL CHARACTERIZATION ...................................................................... 2GEOTECHNICAL OVERVIEW ....................................................................................... 4EARTHWORK................................................................................................................. 6SHALLOW FOUNDATIONS ......................................................................................... 13SEISMIC CONSIDERATIONS ...................................................................................... 15CONCRETE PAVED PATHS ........................................................................................ 15LATERAL EARTH PRESSURES ................................................................................. 16SLOPE STABILITY....................................................................................................... 18GENERAL COMMENTS ............................................................................................... 20 ATTACHMENTS SITE LOCATION AND EXPLORATION PLANS EXPLORATION PROCEDURES AND RESULTS (Laboratory Data and Boring Logs) SUPPORTING INFORMATION (Slope Stability Cross Sections, General Notes and Unified Soil Classification System)

Geotechnical Engineering Report Cross Charlotte Trail 7th-10th Street Segment ■ Charlotte, North Carolina August 24, 2018 ■ Terracon Project No. 71175040

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EXECUTIVE SUMMARY

A geotechnical investigation has been performed for the proposed Cross Charlotte Trail – 7th to 10th Street Segment in Charlotte, North Carolina. A total of 17 soil test borings, designated B-01 through B-17, were performed to depths of approximately 8.9 to 40 feet below the existing surface elevations. Based on the information obtained from our subsurface exploration, the site can be developed for the proposed project. The following geotechnical considerations were identified: The main geotechnical concern for this site is the excavation under the 7th Street bridge. The

excavations for the proposed retaining walls under the 7th Street bridge are in close proximity to the existing bridge foundations. Care should be taken as to not undermine these existing footings. Further details in the Earthwork section.

Based on the provided Underpass Details, the proposed gravity wall will be bearing above/on the existing bridge footings. The project structural engineer should verify that the surcharge caused by the new retaining wall and additional fill does not negatively affect the existing bridge footings.

Near-surface moderate to high elasticity soils (MH materials) were identified at the site. These

soils can be moisture sensitive and difficult to work. We recommend that the contractor be requested to submit a unit rate cost for removal (undercutting) and replacement as part of the bidding process. Additional details are provided herein.

Another geotechnical concern for this site is the existing fill encountered in some of the borings

at the site. Support of retaining walls and concrete paved trails on or above existing fill soils is discussed in this report.

Based on the results of our subsurface investigation, and upon completion of any necessary

remedial grading, it is our opinion that the proposed retaining walls may be supported on a shallow strip foundation system with an allowable bearing capacity of 2,000 psf. A higher allowable bearing capacity may be considered where footings bear directly on PWR. Further details and recommendations are provided herein.

The residual and fill soils encountered at the boring locations may be excavated with

conventional construction equipment, such as bulldozers, backhoes, and trackhoes; however, very dense/hard residual soils, PWR, and auger refusal were encountered at depths shallower than 15 feet below existing grades in several borings. We recommend that the contractor be requested to submit unit rate costs for difficult excavation as part of the bidding process. Additional details are provided herein.


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Based on the 2012 North Carolina State Building Code, the Seismic Site Classification for this site is C.

This summary should be used in conjunction with the entire report for design purposes. It should be recognized that details were not included or fully developed in this section, and the report must be read in its entirety for a comprehensive understanding of the items contained herein. The section titled GENERAL COMMENTS should be read for an understanding of the report limitations.

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INTRODUCTION

Geotechnical Engineering Report Cross Charlotte Trail 7th-10th Street Segment

Charlotte, North Carolina Terracon Project No. 71175040

August 24, 2018 INTRODUCTION This report presents the results of our subsurface exploration and geotechnical engineering services performed for the proposed Cross Charlotte Trail to be generally located between 7th and 10th Streets in Charlotte, North Carolina. The purpose of these services is to provide information and geotechnical engineering recommendations relative to:

■ Subsurface soil conditions ■ Foundation recommendations ■ Groundwater conditions ■ Paved path recommendations ■ Site preparation and earthwork ■ Seismic site classification ■ Excavation considerations ■ Lateral earth pressures ■ Slope Stability

The geotechnical engineering scope of services for this project included the advancement of 17 test borings to depths ranging from approximately 8.9 to 40 feet below existing site grades. Maps showing the site and boring locations are shown in the Site Location and Exploration Plan sections, respectively. The results of the laboratory testing performed on soil samples obtained from the site during the field exploration are included on the boring logs and as separate graphs in the Exploration Results section of this report. SITE CONDITIONS

The following description of site conditions is derived from our site visit in association with the field exploration and our review of publicly available geologic and topographic maps.

Item Description Parcel Information See Site Location. Existing Improvements Paved roadways.

Current Ground Cover Asphalt, concrete, and grass.

Existing Topography

Elevations on the -L1- alignment (7th Street area) range from 650 to 680 feet. Elevations on the -L3- alignment (10th Street area) range from 660 to 695 feet.

Geology Piedmont Physiographic Province. See Geology.



PROJECT DESCRIPTION

Our initial understanding of the project was provided in our proposal and was discussed in the project planning stage. A period of collaboration has transpired since the project was initiated, and our final understanding of the project conditions is as follows:

Item Description

Information Provided Construction Plans of Proposed Cross Charlotte Trail 7th Street to 10th

Street Connector dated March 16, 2018 and the 50% submittal plans entitled 188858_STR50%Submittal, dated April 2018

Project Description Approximately 0.75 miles of new pedestrian trails. Proposed Structures Associated retaining walls along alignment -L1-.

Grading/Slopes Maximum approximate cuts and fills up to 6 and 15 feet, respectively. Maximum final slope angles of as steep as 2H:1V (Horizontal: Vertical).

Free-Standing Retaining Walls

One approximately 600 linear foot long fill wall with a maximum height of 13 feet. One approximately 230 linear foot long cut wall with a maximum height of 6 feet.

GEOTECHNICAL CHARACTERIZATION

Geology

The project site is located in the Piedmont Physiographic Province, an area underlain by ancient igneous and metamorphic rocks. The residual soils in this area are the product of in-place chemical weathering of rock. The typical residual soil profile consists of clayey soils near the surface where soil weathering is more advanced, underlain by sandy silts and silty sands that generally become harder with depth to the top of parent bedrock. Alluvial soils are typically present within floodplain areas along creeks and rivers in the Piedmont. According to the 1985 Geologic Map of North Carolina, the site is within the Charlotte Belt. The bedrock underlying the site generally consists of granitic and metamorphosed quartz diorite rock. The boundary between soil and rock in the Piedmont is not sharply defined. A transitional zone termed “partially weathered rock” is normally found overlying the parent bedrock. Partially weathered rock (PWR) is defined for engineering purposes as residual material with a standard penetration test resistance exceeding 100 blows per foot. The transition between hard/dense residual soils and partially weathered rock occurs at irregular depths due to variations in degree of weathering.



Groundwater is typically present in fractures within the partially weathered rock or underlying bedrock in upland areas of the Piedmont. Fluctuations in groundwater levels on the order of 2 to 4 feet are typical in residual soils and partially weathered rock in the Piedmont, depending on variations in precipitation, evaporation, and surface water runoff. Seasonal high groundwater levels are expected to occur during or just after the typically cooler months of the year (November through April). Subsurface Profile

We have developed a general characterization of the subsurface soil and groundwater conditions based upon our review of the data and our understanding of the geologic setting and planned construction. The following table provides our geotechnical characterization. The geotechnical characterization forms the basis of our geotechnical calculations and evaluation of site preparation, foundation options and pavement options. As noted in General Comments, the characterization is based upon widely spaced exploration points across the site, and variations are likely.

Stratum Approximate

Depth to Bottom of Stratum 1

Material Description Consistency/Density

Surface 1 2 0 to 7 inches Topsoil N/A

Surface 2 3 10.5 to 16 inches Asphalt / Concrete Pavement and Aggregate Base Course N/A

Surface 3 4 2 inches Gravel N/A

1 5 1.9 to 6.7 feet Undocumented fill consisting of

inelastic/elastic silts with varying amounts of sand and silty and clayey sand

Medium Stiff to Hard / Loose to Medium Dense

2 3 to >40 feet Residual soils consisting of

inelastic/elastic silts and lean clays with varying amounts of sand, and silty sand

Medium Stiff to Hard / Loose to Very Dense

3 6 8.9 to >40 feet Partially Weathered Rock N/A 4 7 >8.9 to >37.6 feet Auger Refusal N/A 1. Below existing grades. 2. Encountered in Borings B-01, B-07 through B-13, and B-15 through B-17. 3. Encountered in Borings B-02 through B-06. 4. Encountered in Boring B-14. 5. Encountered in Borings B-01, B-02, B-05, B-06, B-08 and B-13 through B-16. 6. Encountered in Borings B-02 through B-05, B-09, B-12, B-15 and B-17. 7. Encountered in Borings B-02 through B-05, B-09, B-15 and B-17.



Conditions encountered at each boring location are indicated on the individual boring logs shown in the Exploration Results section and are attached to this report. Stratification boundaries on the boring logs represent the approximate location of changes in native soil types; in situ, the transition between materials may be gradual. Groundwater Condit ions

The boreholes were observed while drilling and after completion for the presence and level of groundwater. The water levels observed in the boreholes can be found on the boring logs in Exploration Results, and are summarized below.

Boring Number Approximate Depth to

Groundwater after Drilling (feet) 1

Estimated Elevation (feet)

B-02 20.5 627.5 B-03 9 639 B-06 39 637 B-10 12 645

1. Below ground surface Groundwater was not observed in the remaining borings while drilling, or for the short duration the borings could remain open. However, this does not necessarily mean the borings terminated above groundwater, or the water levels summarized above are stable groundwater levels. Due to the low permeability of the soils encountered in the borings, a relatively long period may be necessary for a groundwater level to develop and stabilize in a borehole. Long term observations in piezometers or observation wells sealed from the influence of surface water are often required to define groundwater levels in materials of this type. Groundwater level fluctuations occur due to seasonal variations in the amount of rainfall, runoff and other factors not evident at the time the borings were performed. Therefore, groundwater levels during construction or at other times in the life of the structure may be higher or lower than the levels indicated on the boring logs. The possibility of groundwater level fluctuations should be considered when developing the design and construction plans for the project. GEOTECHNICAL OVERVIEW

The main geotechnical concern for this site are the excavation under the 7th Street bridge. The excavations for the proposed retaining walls under the 7 th Street bridge are in close proximity to the existing bridge foundations. Based on the provided Underpass Details, dated April 2018, the bridge bents adjacent to the proposed retaining walls are supported on shallow foundations. Care should be taken as to not undermine these existing footings. We recommend that excavations do



not extend beneath the 1H:1V plane that extends down from the top of the existing footings. This recommendation is based on the understanding that the existing footings are founded on competent rock or PWR. Further details in the Earthwork section. Based on the provided Underpass Details, the proposed gravity wall will be bearing above/on the existing bridge footings. The project structural engineer should verify that the surcharge caused by the new retaining wall and additional fill does not negatively affect the existing bridge footings. Near-surface moderate to high plasticity/elasticity soils (MH materials) were identified at the site. Elastic silts were observed to extend to depths ranging from approximately 8 to 13.5 feet below the existing surface in Borings B-01, B-07, B-14, B-16, and B-17. These soils can be moisture sensitive and difficult to work. If high plasticity/elasticity soils (LL ≥ 60 or PI ≥ 30) are present at proposed subgrade elevations outside of the retaining wall footprints and appear stable when prepared in accordance with the recommendations herein, they may be acceptable to be left in place. If they do not appear stable, or are encountered beneath paved trails or within retaining wall footprints at proposed subgrade elevations, we recommend they are undercut at least 3 feet below the proposed bottom of retaining wall. High plasticity/elasticity soils should not be used as structural fill beneath retaining walls, or within three feet of proposed grades beneath paved trails. They may be used as fill beneath non-structural areas, such as planters and green spaces. Moderate plasticity/elasticity soils (50 < LL < 60 and 20 < PI < 30) may be considered beneath retaining walls and paved trails if they appear stable when prepared in accordance with the recommendations herein; however, the construction difficulties mentioned above should be considered, and close observation of these soils should be performed during construction. We recommend that the contractor be requested to submit a unit rate cost for removal (undercutting) and replacement as part of the bidding process. Additional details are provided herein. With the exception of any high plasticity soils (soils with LL ≥ 60 or PI ≥ 30) the residual and existing fill soils encountered in our borings appear to be suitable for re-use as engineered fill.

Another geotechnical concern for this site is the existing fill encountered in some of the borings at the site. Support of retaining walls and paved trails on or above existing fill soils is discussed in this report. However, even with the recommended construction testing services, there is an inherent risk for the owner that compressible fill or unsuitable material within or buried by the fill will not be discovered. This risk of unforeseen conditions cannot be eliminated without completely removing the existing fill, but can be reduced by performing additional testing and evaluation during construction.



Based on the results of our subsurface investigation, and upon completion of any necessary remedial grading, it is our opinion that the proposed retaining walls may be supported on a shallow strip foundation system with an allowable bearing capacity of 2,000 psf. A higher allowable bearing capacity may be considered where footings bear directly on PWR. Further details and recommendations are provided herein. The residual and fill soils encountered at the boring locations may be excavated with conventional construction equipment, such as bulldozers, backhoes, and trackhoes; however, very dense/hard residual soils, PWR, and auger refusal were encountered at depths shallower than 15 feet below existing grades in 9 out of 17 borings. This material may be encountered in other areas across the site. Relatively deeper excavations may encounter hard excavation and potential bedrock which may require blasting or hammering to remove efficiently. Smaller equipment may have difficulty excavating PWR. A larger trackhoe or bulldozer equipped with a single-tooth ripper may be required to excavate these materials. Some PWR, especially in confined excavations, and rock will require blasting or impact hammering to efficiently excavate. EARTHWORK

Earthwork will include clearing and grubbing, excavations and fill placement. The following sections provide recommendations for use in the preparation of specifications for the work. Recommendations include critical quality criteria as necessary to render the site in the state considered in our geotechnical engineering evaluation for retaining wall foundations and paved trails. Site Preparation

Prior to placing fill, complete stripping of the topsoil and rootmat should be performed in the proposed fill areas. Existing utilities that are to be abandoned should be removed or filled with grout. The excavations resulting from utility removal should be properly backfilled with compacted engineered fill as described in the following subsections. Utilities that are to remain in service should be accurately located horizontally and vertically to minimize conflict with new construction. The subgrade should be proof-rolled with an adequately loaded vehicle such as a fully loaded tandem axle dump truck. The proof-rolling should be performed under the direction of the Geotechnical Engineer. Areas excessively deflecting under the proof-roll should be delineated and subsequently addressed by the Geotechnical Engineer. Such areas should either be removed or modified stabilizing under the direction of the Geotechnical Engineer. Excessively wet or dry material should either be removed or moisture conditioned and recompacted.



Based on the results of our laboratory tests and visual classifications, moderate to high plasticity/elasticity soils were encountered in several of our borings. Moderate to high plasticity/elasticity soils can be moisture sensitive and difficult to work. These difficulties can include softening of exposed subgrade soils, excessive rutting or deflection under construction traffic, and the inability to adequately dry and compact wet soil. If high plasticity/elasticity soils (LL ≥ 60 or PI ≥ 30) are present at proposed subgrade elevations outside of the retaining wall footprints and appear stable when prepared in accordance with the recommendations herein, they may be acceptable to be left in place. If they do not appear stable, or are encountered beneath paved trails or within retaining wall footprints at proposed subgrade elevations, we recommend they are undercut at least 3 feet below the proposed bottom of retaining wall. High plasticity/elasticity soils should not be used as structural fill beneath retaining walls, or within three feet of proposed grades beneath paved trails. They may be used as fill beneath non-structural areas, such as planters and green spaces. Moderate plasticity/elasticity soils (50 < LL < 60 and 20 < PI < 30) may be considered beneath retaining walls and paved trails if they appear stable when prepared in accordance with the recommendations herein; however, the construction difficulties mentioned above should be considered, and close observation of these soils should be performed during construction. We recommend that the contractor be requested to submit a unit rate cost for removal (undercutting) and replacement as part of the bidding process. If subgrade soils are unsuitable, they will require removal and replacement; however, if they are unstable due to excessive moisture, the most economical solution for remediation may be to scarify, dry and recompact the material. This remediation is most effective during the typically hotter months of the year (May to October). If construction is performed during the cooler period of the year, the timeline for scarifying, drying, and recompacting typically increases considerably and may lead to alternative remediation solutions. These solutions can include overexcavation of some or all of the unstable material to be backfilled with either approved engineered fill or geotextile and ABC Stone. Potential undercutting can be reduced if the site preparation work is performed during a period of dry weather and if construction traffic is kept to a minimum on prepared subgrades. We recommend that the contractor submit a unit rate cost for undercutting as part of the bidding process. Exis ting Fil l

As noted in Geotechnical Characterization, Borings B-01, B-02, B-05, B-06, B-08 and B-13 through B-16 encountered existing fill to depths ranging from about 1.9 to 6.7 feet. The fill appears to have been placed in a controlled manner, but we have no records to indicate the degree of control. We anticipate most of this fill will be removed based on proposed grading. Support of footings and paved trails on or above existing fill soils is discussed in this report. However, if left in place even with the recommended construction procedures there is an inherent risk for the owner that compressible fill or unsuitable material within or buried by the fill will not be discovered.



This risk of unforeseen conditions cannot be eliminated without completely removing the existing fill, but can be reduced by following the recommendations contained in this report. If the owner elects to construct the retaining walls on the existing fill, the following protocol should be followed. Once the planned grading has been completed, the area should be undercut 3 feet within the retaining wall area as well as 10 feet beyond the lateral limits of the retaining wall area. Once materials have been removed, the entire area should be proof-rolled with heavy, rubber tire construction equipment, to aid in delineating areas of soft, or otherwise unsuitable soil. Once unsuitable materials have been remediated, and the subgrade has passed the proof-roll test, the existing, and undocumented fill that was removed can be evaluated for reuse as structural fill. If the owner elects to construct concrete paved trails on the existing fill, the following protocol should be followed. Once the planned subgrade elevation has been reached the entire path area should be proof-rolled. Areas of soft, or otherwise unsuitable material should be undercut and replaced with either new structural fill or suitable, existing on site materials. Fil l Material Types

Fill required to achieve design grade should be classified as structural fill and general fill. Structural fill is material used below, or horizontally within 10 feet of structures, paved trails, constructed slopes or as retaining wall backfill. General fill is material used to achieve grade outside of these areas. Earthen materials used for structural and general fill should meet the following material property requirements:

Soil Type 1 USCS Classification Acceptable Parameters (for Structural Fill)

Imported Low Plasticity Cohesive

ML, CL, SC, SM (LL < 50 & PI < 20)

All locations and elevations.

On-Site Low to Moderate Plasticity

Soils

ML, MH, CL, CH, SM, SC

(LL < 60 & PI < 30) All locations and elevations.

On-Site High Plasticity Soils

MH (LL ≥ 60 or PI ≥ 30)

Non-structural areas and greater than 3 feet below paved trails.

1. Structural and general fill should consist of approved materials free of organic matter and debris. Frozen material should not be used, and fill should not be placed on a frozen subgrade. A sample of each material type should be submitted to the Geotechnical Engineer for evaluation prior to use on this site.



Fil l Compaction Requirements

Structural and general fill should meet the following compaction requirements.

Item Structural Fill General Fill

Maximum Lift Thickness

8 inches or less in loose thickness when heavy, self-propelled compaction equipment is used. 4 to 6 inches in loose thickness when hand-guided equipment (i.e. jumping jack or plate compactor) is used.

Same as Structural fill

Minimum Compaction Requirements 1, 2, 3

98% of max. below foundations and within 1 foot of finished paved trails subgrade. 95% of max. above foundations and more than 1 foot below finished paved trail subgrade.

95% of max.

Water Content

Range 1 -3% to +3% of optimum As required to achieve min.

compaction requirements

1. Maximum density and optimum water content as determined by the standard Proctor test (ASTM D 698). 2. High plasticity cohesive fill should not be compacted to more than 100 percent of standard Proctor

maximum dry density. 3. If the granular material is a coarse sand or gravel, or of a uniform size, or has a low fines content,

compaction comparison to relative density may be more appropriate. In this case, granular materials should be compacted to at least 70% relative density (ASTM D 4253 and D 4254).

Grading and Drainage

All grades must provide effective drainage away from retaining walls during and after construction and should be maintained throughout the life of the structure. Water retained next to the retaining walls can result in soil movements greater than those discussed in this report. Greater movements can result in unacceptable differential foundation movements, cracked slabs and walls. After retaining wall construction and landscaping, final grades should be verified to document effective drainage has been achieved. Grades around the retaining walls should also be periodically inspected and adjusted as necessary as part of the structure’s maintenance program. Where flatwork abuts the retaining walls, a maintenance program should be established to effectively seal and maintain joints and prevent surface water infiltration. Earthwork Construction Considerations

The residual and fill soils encountered at the boring locations may be excavated with conventional construction equipment, such as bulldozers, backhoes, and trackhoes; however, PWR was encountered at relatively shallow depths in several of the borings at the site. Shallow PWR and/or bedrock material may also be encountered between boring locations. Smaller equipment may



have difficulty excavating PWR. A larger trackhoe or bulldozer equipped with a single-tooth ripper may be required to excavate these materials. Some PWR, especially in confined excavations, and rock (if encountered) will require blasting or impact hammering to efficiently excavate. We recommend that unit rates for mass rock and trench rock be included in the bid package to limit disputes, in the case that rock-like materials are encountered. PWR may be encountered in deeper cut areas based on proposed grades. The depth and thickness of PWR, boulders, and rock lenses or seams can vary dramatically in short distances and between the testing locations. It is our opinion that a clear and appropriate definition of rock be included in the project specifications to reduce the potential for misunderstandings. A sample definition of rock for excavation specifications is provided below:

Mass Rock is defined as any material that cannot be dislodged by a Caterpillar D-8

Bulldozer, or equivalent, equipped with a single tooth ripper, without the use of impact

hammers or drilling and blasting.

Trench Rock is defined as any material that cannot be dislodged by a Caterpillar 312

hydraulic backhoe, or equivalent, without the use of impact hammers or drilling and

blasting.

Boulders or masses of rock exceeding ½ or ¼ cubic yard in volume shall also be

considered mass or trench rock, respectively, during excavation. These

classifications do not include materials such as loose rock, concrete, or other

materials that can be removed by means other than impact hammering, but which for

any reason, such as economic reasons, the Contractor chooses to remove by impact

hammering.

We anticipate that a horizontal to vertical slope of 3H:1V for permanent slopes greater than 5 feet tall should provide stable excavations. Permanent slopes between 3H:1V to 2H:1V should not be greater than 5 feet tall. The design for permanent tie-in slopes for the proposed improvements have not been evaluated as part of our scope of services. Temporary (construction) slopes inclined 1-1.5H:1V are expected to be stable against deep-seated failures, provided they are at least 2 feet above the water table. If excavations extend below the water table, the excavation sidewalls may slough or flow into the excavation. As such, the excavations may need temporary shoring if sidewalls cannot be sloped back sufficiently enough to provide a stable excavation.



The excavations for the proposed retaining walls under the 7th Street bridge are in close proximity to the existing bridge foundations. Based on the provided Underpass Details, dated April 2018, the bridge bents adjacent to the proposed retaining walls are supported on shallow foundations. Care should be taken as to not undermine these existing footings. We recommend that excavations do not extend beneath the 1H:1V plane that extends down from the top of the existing footings. This recommendation is based on the understanding that the existing footings are founded in competent rock. See the following sketch for details.

Based on the provided Underpass Details, the proposed gravity wall will be bearing above/on the existing bridge footings. The project structural engineer should verify that the surcharge caused by the new retaining wall and additional fill does not negatively affect the existing bridge footings.

As a minimum, excavations should be performed in accordance with OSHA 29 CFR, Part 1926, Subpart P, “Excavations” and its appendices, and in accordance with any applicable local, and/or state regulations.



Construction site safety is the sole responsibility of the contractor who controls the means, methods, and sequencing of construction operations. Under no circumstances shall the information provided herein be interpreted to mean Terracon is assuming responsibility for construction site safety, or the contractor's activities; such responsibility shall neither be implied nor inferred. Shallow excavations, for the proposed construction, are anticipated to be accomplished with conventional construction equipment. Upon completion of filling and grading, care should be taken to maintain the subgrade water content prior to construction of paved trails. Construction traffic over the completed subgrades should be avoided. The site should also be graded to prevent ponding of surface water on the prepared subgrades or in excavations. Water collecting over, or adjacent to, construction areas should be removed. If the subgrade freezes, desiccates, saturates, or is disturbed, the affected material should be removed, or the materials should be scarified, moisture conditioned, and recompacted, prior to paved trail construction. Construction Observation and Testing

The earthwork efforts should be monitored under the direction of the Geotechnical Engineer. Monitoring should include documentation of adequate removal of vegetation and top soil, proof-rolling and mitigation of areas delineated by the proof-roll. Each lift of compacted fill should be tested, evaluated, and reworked as necessary until approved by the Geotechnical Engineer prior to placement of additional lifts. Each lift of fill should be tested for density and water content at a frequency of at least one test for every 2,500 square feet of compacted fill in the structural fill areas. One density and water content test for every 50 linear feet of compacted utility trench backfill. In areas of foundation excavations, the bearing subgrade should be evaluated under the direction of the Geotechnical Engineer. In the event that unanticipated conditions are encountered, the Geotechnical Engineer should prescribe mitigation options. In addition to the documentation of the essential parameters necessary for construction, the continuation of the Geotechnical Engineer into the construction phase of the project provides the continuity to maintain the Geotechnical Engineer’s evaluation of subsurface conditions, including assessing variations and associated design changes.



SHALLOW FOUNDATIONS

If the site has been prepared in accordance with the requirements noted in Earthwork, the following design parameters are applicable for shallow foundations supporting retaining walls.

Based on the provided Underpass Details, the proposed gravity wall will be bearing above/on the existing bridge footings. The project structural engineer should verify that the surcharge caused by the new retaining wall and additional fill does not negatively affect the existing bridge footings. Design Parameters – Compressive Loads

Item Description Maximum Net Allowable Bearing Pressure 1, 2

▪ 2,000 psf (foundations bearing within structural fill or suitable residual soils)

▪ 5,000 psf (foundations bearing on/within PWR)

Required Bearing Stratum 3 Structural fill, in-situ suitable residual soil, or PWR

Minimum Foundation Dimensions Continuous: 18 inches

Minimum Embedment Below Finished Grade 4

18 inches

Estimated Total Settlement from Structural Loads 2

Less than about 1 inch

Estimated Differential Settlement 2, 5 About 2/3 of total settlement

1. The maximum net allowable bearing pressure is the pressure in excess of the minimum surrounding overburden pressure at the footing base elevation. An appropriate factor of safety has been applied. These bearing pressures can be increased by 1/3 for transient loads unless those loads have been factored to account for transient conditions. Values assume that exterior grades are no steeper than 20% within 10 feet of structure.

2. Values provided are for maximum loads noted in Project Description. 3. Unsuitable or soft soils should be over-excavated and replaced per the recommendations presented in the

Earthwork. 4. Embedment necessary to minimize the effects of frost and/or seasonal water content variations. For sloping

ground, maintain depth below the lowest adjacent exterior grade within 5 horizontal feet of the structure. 5. Differential settlements are as measured over a span of 50 feet.

Foundation Construction Considerations As noted in Earthwork, the footing excavations should be evaluated under the direction of the Geotechnical Engineer. The base of all foundation excavations should be free of water and loose soil, prior to placing concrete. Concrete should be placed soon after excavating to reduce bearing soil disturbance. Care should be taken to prevent wetting or drying of the bearing materials during construction. Excessively wet or dry material or any loose/disturbed material in the bottom of the footing excavations should be removed/reconditioned before foundation concrete is placed.



If unsuitable bearing soils are encountered at the base of the planned footing excavation, the excavation should be extended deeper to suitable soils, and the footings could bear directly on these soils at the lower level or on lean concrete backfill placed in the excavations. This is illustrated on the following sketch.

Over-excavation for structural fill placement below footings should be conducted as shown below. The over-excavation should be backfilled up to the footing base elevation, with structural fill placed, as recommended in the Earthwork section.



SEISMIC CONSIDERATIONS

The seismic design requirements for buildings and other structures are based on Seismic Design Category. Site Classification is required to determine the Seismic Design Category for a structure. The Site Classification is based on the upper 100 feet of the site profile defined by a weighted average value of either shear wave velocity, standard penetration resistance, or undrained shear strength in accordance with Section 20.4 of ASCE 7-10.

Description Value

2012 North Carolina State Building Code (NCSBC) 1 C 2

1. Seismic site classification in general accordance with the 2012 NCSBC, which refers to ASCE 7-10. 2. The 2012 NCSBC uses a site profile extending to a depth of 100 feet for seismic site classification. Borings

at this site were extended to a maximum depth of 40 feet. The site properties below the boring depth to 100 feet were estimated based on our experience and knowledge of geologic conditions of the general area.

PAVED PATHS

Design parameters for paved trails assume the requirements for Earthwork have been followed. Specific attention should be given to positive drainage away from aggregate base beneath paved trails. Paved Path Design Parameters

Item Description

Concrete Slab Support 1 Natural residual soils or new engineered fill compacted in accordance with Earthwork section of this report.

Estimated Modulus of Subgrade Reaction 2

150 pounds per square inch per inch (psi/in) for point loads

Aggregate base course/capillary break

Minimum 4 inches of free-draining granular material (less than 5% passing the U.S. No. 200 sieve)

1. Paved trails should be structurally independent of structures or walls to reduce the possibility of concrete cracking caused by differential movements between paved trails and foundations.

2. Modulus of subgrade reaction is an estimated value based upon our experience with the subgrade condition, the requirements noted in Earthwork, and the paved trail support as noted in this table. It is provided for point loads. For large area loads the modulus of subgrade reaction would be lower.

Saw-cut control joints should be placed in the paved trails to help control the location and extent of cracking. For additional recommendations refer to the ACI Design Manual. Joints or cracks should be sealed with a water-proof, non-extruding compressible compound specifically recommended for heavy duty concrete pavement and wet environments.



Paved Path Construction Considerations

Finished subgrade within and for at least 5 feet beyond any paved trails should be protected from traffic, rutting, or other disturbance and maintained in a relatively moist condition until paved trails are constructed. If the subgrade should become damaged or desiccated prior to construction of paved trails, the affected material should be removed and structural fill should be added to replace the resulting excavation. Final conditioning of the finished subgrade should be performed immediately prior to placement of the concrete slab support course. The Geotechnical Engineer should approve the condition of the paved trail subgrades immediately prior to placement of the slab support course and concrete. Attention should be paid to high traffic areas that were rutted and disturbed earlier, and to areas where backfilled trenches are located. LATERAL EARTH PRESSURES

Design Parameters

Structures with unbalanced backfill levels on opposite sides should be designed for earth pressures at least equal to values indicated in the following table. Earth pressures will be 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. Two wall restraint conditions are shown. Active earth pressure is commonly used for design of free-standing cantilever retaining walls and assumes wall movement. The "at-rest" condition assumes no wall movement and is commonly used for basement walls, loading dock walls, or other walls restrained at the top. The recommended design lateral earth pressures do not include a factor of safety and do not provide for possible hydrostatic pressure on the walls (unless stated).



Lateral Earth Pressure Design Parameters

Earth Pressure

Condition 1 Coefficient for Backfill Type2, 3

Surcharge Pressure 4, 5, 6

p1 (psf)

Effective Fluid Pressures p2 (psf) 2, 5, 6

Unsaturated 7 Submerged 7

Active (Ka) On-site low plasticity soils – 0.42 Off-site granular material – 0.33

(0.42)S (0.33)S

(50)H (40)H

(87)H (80)H

At-Rest (Ko) On-site low plasticity soils – 0.59 Off-site granular material – 0.5

(0.59)S (0.5)S

(71)H (60)H

(97)H (91)H

Passive (Kp) On-site low plasticity soils – 2.37 Off-site granular material – 3.00

--- (284)H (360)H

(198)H (235)H

1. For active earth pressure, wall must rotate about base, with top lateral movements 0.002 H to 0.004 H, where H is wall height. For passive earth pressure, wall must move horizontally to mobilize resistance.

2. Uniform, horizontal backfill, compacted to at least 95 percent of the ASTM D 698 maximum dry density, rendering a maximum unit weight of 120 pcf.

3. On-site low plasticity soil parameters are based on the results of our laboratory limits. 4. Uniform surcharge, where S is surcharge pressure. 5. Loading from heavy compaction equipment is not included. 6. No safety factor is included in these values. 7. In order to achieve “Unsaturated” conditions, follow guidelines in Subsurface Drainage for Retaining

Walls below. “Submerged” conditions are recommended when drainage behind walls is not incorporated into the design.

Backfill placed against structures should consist of granular soils or low plasticity cohesive soils. For the granular values to be valid, the granular backfill must extend out and up from the base of the wall at an angle of at least 45 and 60 degrees from vertical for the active and passive cases, respectively. Subsurface Drainage for Retain ing Walls

A perforated rigid plastic drain line installed behind the base of walls and extends below adjacent grade is recommended to prevent hydrostatic loading on the walls. The invert of a drain line around a retaining wall should be placed near foundation bearing level. The drain line should be sloped to provide positive gravity drainage to daylight or to a sump pit and pump. The drain line should be surrounded by clean, free-draining granular material having less than 5 percent passing the No. 200 sieve, such as No. 57 aggregate. The free-draining aggregate should be encapsulated in a filter fabric. The granular fill should extend to within 2 feet of final grade, where it should be capped with compacted cohesive fill to reduce infiltration of surface water into the drain system.



As an alternative to free-draining granular fill, a pre-fabricated drainage structure may be used. A pre-fabricated drainage structure is a plastic drainage core or mesh which is covered with filter fabric to prevent soil intrusion, and is fastened to the wall prior to placing backfill. SLOPE STABILITY

As part of our geotechnical investigation, we have performed global slope stability analyses for proposed retaining wall sections along the alignment. The following sections include details of our analyses. Mechanics of Stabil ity

Slope stability analyses take into consideration material strength, presence and orientation of weak layers, water (piezometric) pressures, surcharge loads, and the slope geometry. Mathematical computations are performed using computer-assisted simulations to calculate a Factor of Safety (FS). Minor changes to slope geometry, surface water flow and/or groundwater levels could result in slope instability. Reasonable FS values are dependent upon the confidence in the parameters utilized in the analyses performed, among other factors related to the project itself. Geometric Analysis Results

Slope stability analyses were performed for the cross-section geometries and elevations obtained from Construction Plans of Proposed Cross Charlotte Trail 7th Street to 10th Street Connector

dated 3/22/2018 and Retaining Wall Envelopes, sheet S4, dated April 2018. Parameters for the analyses were derived from our exploratory borings, experience, and laboratory tests. Stability analyses were conducted using the computer program Slope/W Version 8.16 developed by Geo-Slope International.

Slope to drain away from retaining wall

Retaining wall

Layer of cohesive fill or other

impermeable layer



Unstable or Potentially Unstable Slopes

Based on the results of our field investigation, laboratory testing program and geotechnical analyses, development of the site is considered feasible from a geotechnical viewpoint provided the conclusions and considerations provided herein are incorporated into the design and construction of the project. The stability of the slopes at the cross-section locations shown on the Exploration Plans were analyzed based on the provided topography, proposed grading, soil properties derived from our geotechnical exploration, laboratory test results and our experience with similar soil conditions. Soil and bedrock properties used in the analyses are shown below:

Material Moist Unit Weight (pcf)

Drained Cohesion (psf)

Drained Friction Angle (degrees)

Structural Fill 120 200 24 Residual Soil 120 200 24

Partially Weathered Rock 130 500 35 Bedrock 150 Impenetrable

Based on the analyses, the calculated FS for the critical surface identified in each section is shown below. The typically accepted minimum FS for long-term slope stability supporting improvements is 1.5. The slope stability results are included in the Appendix of this report.

Cross-Section Approximate Station of

Cross-Section1

Minimum Calculated Factor-of-Safety for Slopes

Circular Failure Surface A-A’ (Upper Wall)

-L1- 12+50 2.6

A-A’ (Lower Wall) 1.7 A-A’ (Combined Walls) 2.2

B-B’ (Upper Wall) -L1- 14+00

2.0 B-B’ (Lower Wall) 1.8

B-B’ (Combined Walls) 2.3 C-C’ -L1- 15+50 2.1

1. Cross-section geometry taken from Cross Sections, sheets XS1-XS5, dated March 22, 2018 and Retaining Wall Envelopes, sheet S4, dated April 2018.

The minimum factor-of-safety for global stability at the cross sections analyzed is greater than 1.5. Refer to the Supporting Information section in the attachments for graphical results of our analysis.



Surfic ial Slope Stabili ty

Surficial slope instability typically impacts the upper 3 to 5 feet of the subsurface profile, predominantly during extended wet periods. Regular maintenance should be anticipated to identify and address changes in natural drainage creating potential for soil creep or erosion near improvements. This includes replacing or replanting trees and grasses as necessary and grading the slope to reduce soil creep and erosion. In the event that future surficial slope erosion occurs near the crest of slopes, we recommend the slope face be restored as soon as practical. We recommend irrigated landscaping be setback a minimum of 30 feet from the crest of the slopes. Fill slopes should be re-vegetated as soon as possible after grading and protected from erosion until vegetation is established. Slope planting should consist of ground cover, shrubs, and trees, which possess deep, dense root structures that require minimum irrigation. It is the responsibility of the owner to maintain such planting. GENERAL COMMENTS

Our analysis and opinions are based upon our understanding of the project, the geotechnical conditions in the area, and the data obtained from our site exploration. Natural variations will occur between exploration point locations or due to the modifying effects of construction or weather. The nature and extent of such variations may not become evident until during or after construction. Terracon should be retained as the Geotechnical Engineer, where noted in the final report, to provide observation and testing services during pertinent construction phases. If variations appear, we can provide further evaluation and supplemental recommendations. If variations are noted in the absence of our observation and testing services on-site, we should be immediately notified so that we can provide evaluation and supplemental recommendations. Our scope of services does not include either specifically or by implication any environmental or biological (e.g., mold, fungi, bacteria) assessment of the site or identification or prevention of pollutants, hazardous materials or conditions. If the owner is concerned about the potential for such contamination or pollution, other studies should be undertaken. Our services and any correspondence or collaboration through this system are intended for the sole benefit and exclusive use of our client for specific application to the project discussed and are accomplished in accordance with generally accepted geotechnical engineering practices with no third-party beneficiaries intended. Any third-party access to services or correspondence is solely for information purposes to support the services provided by Terracon to our client. Reliance upon the services and any work product is limited to our client, and is not intended for third parties. Any use or reliance of the provided information by third parties is done solely at their own risk. No warranties, either express or implied, are intended or made.



Site characteristics as provided are for design purposes and not to estimate excavation cost. Any use of our report in that regard is done at the sole risk of the excavating cost estimator as there may be variations on the site that are not apparent in the data that could significantly impact excavation cost. Any parties charged with estimating excavation costs should seek their own site characterization for specific purposes to obtain the specific level of detail necessary for costing. Site safety, and cost estimating including, excavation support, and dewatering requirements/design are the responsibility of others. If changes in the nature, design, or location of the project are planned, our conclusions and recommendations shall not be considered valid unless we review the changes and either verify or modify our conclusions in writing.

ATTACHM ENTS

ATTACHMENTS



EXPLORATION AND TESTING PROCEDURES

Field Explo ration

Number of Borings Boring Depth (feet) Planned Location

12 8.9 to 40 -L1- Alignment (7th St. to Central Ave.)

5 13.5 to 20 -L3- Alignment (Jackson Ave to 10th St.) Boring Layout and Elevations: Unless otherwise noted, Terracon personnel provided the boring layout. Coordinates were obtained with a handheld GPS unit (estimated horizontal accuracy of about ±10 feet) and approximate elevations were obtained by interpolation from the Cross Charlotte Trail Plan and Profile Sheets dated 6/29/2018. If elevations and a more precise boring layout are desired, we recommend borings be surveyed following completion of fieldwork. Subsurface Exploration Procedures: We advanced the borings with a track-mounted rotary drill rig using continuous flight augers. Four samples were obtained in the upper 10 feet of each boring and at intervals of 5 feet thereafter. In the split-barrel sampling procedure, a standard 2-inch outer diameter split-barrel sampling spoon was driven into the ground by a 140-pound automatic hammer falling a distance of 30 inches. The number of blows required to advance the sampling spoon the last 12 inches of a normal 18-inch penetration was recorded as the Standard Penetration Test (SPT) resistance value. The SPT resistance values, also referred to as N-values, are indicated on the boring logs at the test depths. We observed and recorded groundwater levels during drilling and sampling. For safety purposes, all borings are backfilled with auger cuttings after their completion. Pavements are patched with hot-mix asphalt or non-shrink grout, as appropriate. The sampling depths, penetration distances, and other sampling information were recorded on the field boring logs. The samples were placed in appropriate containers and taken to our soil laboratory for testing and classification by a geotechnical engineer. Our exploration team prepared field boring logs as part of the drilling operations. These field logs include visual classifications of the materials encountered during drilling and our interpretation of the subsurface conditions between samples. Final boring logs were prepared from the field logs. The final boring logs represent the geotechnical engineer's interpretation of the field logs and include modifications based on observations and tests of the samples in our laboratory. Laboratory Testing

The project engineer reviews the field data and assigns various laboratory tests to better understand the engineering properties of the various soil strata as necessary for this project. Procedural standards noted below are for reference to methodology in general. In some cases, variations to methods are applied because of local practice or professional judgment. Standards



noted below include reference to other, related standards. Such references are not necessarily applicable to describe the specific test performed.

■ ASTM D2216 Standard Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass

■ ASTM D4318 Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils

■ ASTM D1140 Standard Test Methods for Determining the Amount of Material Finer than 75-μm (No. 200) Sieve in Soils by Washing

■ ASTM D4767 Standard Test Method for Consolidated Undrained Triaxial Compression Test for Cohesive Soils

■ ASTM D698 Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort

The laboratory testing program often includes examination of soil samples by an engineer. Based on the material’s texture and plasticity, we describe and classify the soil samples in accordance with the Unified Soil Classification System. The results of our laboratory testing program can be found in the Exploration Results and on the respective boring logs.

SITE LOC ATION AND EXPLOR ATION PL AN S

SITE LOCATION AND EXPLORATION PLANS

SITE LOCATIONCross Charlotte Trail - 7th Street to 10th Street ■ Charlotte, North CarolinaAugust 24, 2018 ■ Terracon Project No. 71175040

DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES AERIAL PHOTOGRAPHY PROVIDED

BY MICROSOFT BING MAPS

SITES

EXPLORATION PLANCross Charlotte Trail - 7th Street to 10th Street ■ Charlotte, North CarolinaAugust 24, 2018 ■ Terracon Project No. 71175040

C

C’

B’

B A

A’

LEGEND: = Approximate Soil Boring Location

= Slope Stability Cross Section

EXPLORATION PLANCross Charlotte Trail - 7th Street to 10th Street ■ Charlotte, North CarolinaAugust 24, 2018 ■ Terracon Project No. 71175040

DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES AERIAL PHOTOGRAPHY PROVIDED

BY GOOGLE EARTH PRO


EXPLORATION PLANCross Charlotte Trail 7th-10th Street Segment ■ Charlotte, North CarolinaAugust 24, 2018 ■ Terracon Project No. 71175040 SITE LOC ATION PL AN



A

A’

B-01

B-02

B-03

B-04

B-05

B-06

PLANS TAKEN FROM PROVIDED PLAN AND PROFILE SHEETS (SHEETS 5-10) DATED

6/29/2018.

DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION

PURPOSES.

EXPLORATION PLANCross Charlotte Trail 7th-10th Street Segment ■ Charlotte, North CarolinaAugust 24, 2018 ■ Terracon Project No. 71175040

B-07 B-08

B-09

B-10

B-11 B-12



B’

B

C’

C


6/29/2018.


PURPOSES.




6/29/2018.


PURPOSES.

B-13




6/29/2018.


PURPOSES.

B-14

B-15




6/29/2018.


PURPOSES.

B-16

B-17

EXPLOR ATION RESULTS

EXPLORATION RESULTS

0

10

20

30

40

50

60

0 20 40 60 80 100

CH or

OH

CL or

OL

ML or OL

MH or OH

"U" L

ine

"A" Line

ATTERBERG LIMITS RESULTSASTM D4318

PLASTICITY

INDEX

LIQUID LIMIT

PROJECT NUMBER: 71175040

SITE: 7th Street to 10th Street Charlotte, NC

PROJECT: Cross Charlotte Trail - 7th Street to10th Street

CLIENT: Alta Planning + Design Durham, NC

2701 Westport RdCharlotte, NC

LABO

RAT

OR

Y TE

STS

ARE

NO

T VA

LID

IF S

EPAR

ATED

FR

OM

OR

IGIN

AL R

EPO

RT.

A

TTER

BER

G L

IMIT

S 7

1175

040

CR

OSS

CH

ARLO

TTE

T.G

PJ T

ERR

ACO

N_D

ATAT

EMPL

ATE.

GD

T 7

/31/

18

6 - 7.5

3.5 - 5

6 - 7.5

3.5 - 5

1 - 2.5

3.5 - 5

3.5 - 5

1 - 2.5

29

37

46

61

36

34

53

38

27

23

38

47

33

32

48

33

2

14

8

14

3

2

5

5

79

49

62

90

46

43

81

79

ML

SC

ML

MH

SM

SM

MH

ML

SILT with SAND

CLAYEY SAND

SANDY SILT

ELASTIC SILT

SILTY SAND

SILTY SAND

ELASTIC SILT with SAND

SILT with SAND

DescriptionUSCSFinesPIPLLLBoring ID DepthB-02

B-05

B-06

B-07

B-10

B-11

B-16

B-17

CL-ML

75

80

85

90

95

100

105

110

115

120

125

130

135

0 5 10 15 20 25 30 35 40 45

Test Method

Remarks:

TEST RESULTS

PIPLLL

ATTERBERG LIMITS

36 33 3

PCF%

Maximum Dry Density Optimum Water Content

110.4

% Percent Fines

ASTM D698 Method A

15.845.9

DR

Y D

ENSI

TY, p

cf

WATER CONTENT, %

ZAV for Gs = 2.8

ZAV for Gs = 2.7

ZAV for Gs = 2.6

Source of MaterialDescription of Material

MOISTURE-DENSITY RELATIONSHIPASTM D698/D1557

B-10 @ 0 - 5 feetSILTY SAND(SM)

PROJECT NUMBER: 71175040

SITE: 7th Street to 10th Street Charlotte, NC

PROJECT: Cross Charlotte Trail - 7th Street to10th Street

CLIENT: Alta Planning + Design Durham, NC


LABO

RAT

OR

Y TE

STS

ARE

NO

T VA

LID

IF S

EPAR

ATED

FR

OM

OR

IGIN

AL R

EPO

RT.

C

OM

PAC

TIO

N -

V2 7

1175

040

CR

OSS

CH

ARLO

TTE

T.G

PJ T

ERR

ACO

N_D

ATAT

EMPL

ATE.

GD

T 7

/30/

18

TRIAXIAL SHEAR TEST REPORTTested by: Terracon Consultants, Inc.

Chattanooga, TN

Client: Alta Planning + Design

Project: Cross Charlotte Trail

Source of Sample: B-10 Depth: 0.0-5.0

Proj. No.: 71175040 Date Sampled: 6/28/18

Type of Test:CU with Pore Pressures

Sample Type: RemoldedDescription: Silty Sand

LL= 36 PI= 3 Assumed Specific Gravity= 2.7Remarks: Remolded at 95% MDD and +2 OMC

Sample No.Water Content, %Dry Density, pcfSaturation, %Void RatioDiameter, in.Height, in.Water Content, %Dry Density, pcfSaturation, %Void RatioDiameter, in.Height, in.

Excess Pore Pr., psi

Excess Pore Pr., psi

Strain rate, in./min.Back Pressure, psiCell Pressure, psiFail. Stress, psi

Ult. Stress, psi

s1 Failure, psis3 Failure, psi

Initi

alAt

Test

117.8

104.979.3

0.60642.8005.600

22.5104.9100.0

0.60722.8085.5690.001

50.055.010.3

1.0

4.014.4

217.8

104.979.3

0.60642.8005.600

25.1100.4100.0

0.67842.8725.5630.001

50.060.016.9

1.7

8.325.3

317.8

104.979.3

0.60642.8005.600

22.8104.3100.0

0.61632.8285.5230.001

50.070.022.6

6.7

13.335.9

Dev

iato

rStre

ss,p

si

0

5

10

15

20

25

30

Axial Strain, %

0 5 10 15 20

1

23

Shea

rStre

ss,p

si

0

8

16

24

Total Normal Stress, psiEffective Normal Stress, psi

0 8 16 24 32 40 48

C, psif, deg Tan(f)

Total Effective2.30

170.31

1.6124

0.44

Client: Alta Planning + DesignProject: Cross Charlotte TrailSource of Sample: B-10 Depth: 0.0-5.0Project No.: 71175040 Terracon Consultants, Inc.

q,ps

i

0

6

12

18

p, psiStress Paths: Total Effective

0 6 12 18 24 30 36

Peak StrengthTotal Effective

a=a=

tan a=

2.63 psi16 deg0.28

1.58 psi22 deg0.40

Exce

ssPo

rePr

essu

reD

evia

torS

tress

psi

-10

0

10

20

30

40

0% 8% 16%

1

Exce

ssPo

rePr

essu

reD

evia

torS

tress

psi

-10

0

10

20

30

40

0% 8% 16%

3

Exce

ssPo

rePr

essu

reD

evia

torS

tress

psi

-10

0

10

20

30

40

0% 8% 16%

2

Exce

ssPo

rePr

essu

reD

evia

torS

tress

psi

-10

0

10

20

30

40

0% 8% 16%

4

12

655.5+/-

650+/-

648.5+/-

646+/-

4-5-4N=9

4-4-8N=12

1-1-2N=3

2-3-4N=7

0.3

6.0

7.5

10.0

TOPSOIL, 3-inchesFILL - SANDY SILT (ML), trace organics, brownish red, stiff, trace gravelfrom 3.5'-5'

NO RECOVERY

ELASTIC SILT WITH SAND (MH), red to tan, medium stiff, residuum

Boring Terminated at 10 Feet

Elevations estimated from provided plans dated 6/29/18.

GR

APH

IC L

OG

Hammer Type: AutomaticStratification lines are approximate. In-situ, the transition may be gradual.

THIS

BO

RIN

G L

OG

IS N

OT

VALI

D IF

SEP

ARAT

ED F

RO

M O

RIG

INAL

REP

OR

T. G

EO S

MAR

T LO

G-N

O W

ELL

711

7504

0 C

RO

SS C

HAR

LOTT

E T.

GPJ

TER

RAC

ON

_DAT

ATEM

PLAT

E.G

DT

8/1

/18

PER

CEN

T FI

NES

WAT

ERC

ON

TEN

T (%

)

LL-PL-PI

ATTERBERGLIMITS

ELEVATION (Ft.)

Approximate Surface Elev: 656 (Ft.) +/-

WAT

ER L

EVEL

OBS

ERVA

TIO

NS

DEP

TH (F

t.)

5

10

SAM

PLE

TYPE

FIEL

D T

EST

RES

ULT

S

DEPTH

LOCATION See Exploration Plan

Page 1 of 1

Advancement Method:Hollow Stem Auger

Abandonment Method:Boring backfilled with auger cuttings upon completion.


Notes:

Project No.: 71175040

Drill Rig: Geoprobe

BORING LOG NO. B-01Alta Planning + DesignCLIENT:Durham, NC

Driller: B. Burnett

Boring Completed: 07-17-2018

PROJECT: Cross Charlotte Trail - 7th Street to 10thStreet

See Exploration and Testing Procedures for adescription of field and laboratory proceduresused and additional data (If any).

See Supporting Information for explanation ofsymbols and abbreviations.

7th Street to 10th Street Charlotte, NCSITE:

Boring Started: 07-17-2018WATER LEVEL OBSERVATIONSNo free water observed

7922 29-27-2

647+/-

642.5+/-

640+/-

636+/-

629.5+/-

622.5+/-

1-2-4N=6

6-8-13N=21

4-8-11N=19

15-15-8N=23

27-29-40N=69

50/4"

50/4"

50/1"

0.9

5.5

8.0

12.0

18.5

25.5

CONCRETE, 10.5-inchesFILL - SILT WITH SAND (ML), red with tan, medium stiff to very stiff

SILT WITH SAND (ML), trace gravel, red with tan, very stiff, residuum

SILTY SAND (SM), fine to coarse grained, orangish tan, medium dense,residuum

SILTY SAND (SM), fine to medium grained, brown, with black and pink,very dense, residuum

PARTIALLY WEATHERED ROCK (PWR), sampled as brown, silty SAND

Auger Refusal at 25.5 Feet


GR

APH

IC L

OG


THIS

BO

RIN

G L

OG

IS N

OT

VALI

D IF

SEP

ARAT

ED F

RO

M O

RIG

INAL

REP

OR

T. G

EO S

MAR

T LO

G-N

O W

ELL

711

7504

0 C

RO

SS C

HAR

LOTT

E T.

GPJ

TER

RAC

ON

_DAT

ATEM

PLAT

E.G

DT

7/3

1/18

PER

CEN

T FI

NES

WAT

ERC

ON

TEN

T (%

)

LL-PL-PI

ATTERBERGLIMITS

ELEVATION (Ft.)


WAT

ER L

EVEL

OBS

ERVA

TIO

NS

DEP

TH (F

t.)

5

10

15

20

25SA

MPL

E TY

PE

FIEL

D T

EST

RES

ULT

S

DEPTH


Page 1 of 1


Abandonment Method:Boring backfilled with auger cuttingsSurface capped with non-shrink grout


Notes:


Drill Rig: D-50


Driller: E. Rummage






Boring Started: 06-28-2018

Dry Cave-In

After drilling

Dry Cave-In

WATER LEVEL OBSERVATIONSAfter drilling

647+/-

645+/-

640+/-

629.5+/-

6-8-21N=29

23-33-41N=74

18-24-25N=49

28-42-50/5"

44-50/3"

50/2"

0.9

3.0

8.0

18.7

CONCRETE, 11-inchesSANDY SILT (ML), with rock fragments, light brown and white, very stiff,residuumSILTY SAND (SM), fine grained, light brown with black, very dense,residuum

PARTIALLY WEATHERED ROCK (PWR), sampled as light brown, withblack and white, silty SAND with red fat clay seams and rock fragments



GR

APH

IC L

OG


THIS

BO

RIN

G L

OG

IS N

OT

VALI

D IF

SEP

ARAT

ED F

RO

M O

RIG

INAL

REP

OR

T. G

EO S

MAR

T LO

G-N

O W

ELL

711

7504

0 C

RO

SS C

HAR

LOTT

E T.

GPJ

TER

RAC

ON

_DAT

ATEM

PLAT

E.G

DT

7/3

1/18

PER

CEN

T FI

NES

WAT

ERC

ON

TEN

T (%

)

LL-PL-PI

ATTERBERGLIMITS

ELEVATION (Ft.)


WAT

ER L

EVEL

OBS

ERVA

TIO

NS

DEP

TH (F

t.)

5

10

15

SAM

PLE

TYPE

FIEL

D T

EST

RES

ULT

S

DEPTH


Page 1 of 1




Notes:


Drill Rig: D-50


Driller: E. Rummage







Dry Cave-In

After drilling

Dry Cave-In


647+/-

644.5+/-

639+/-

9-13-13N=26

50/2"

50/1"

50/0"50/0"

0.9

3.5

8.9

CONCRETE, 10.5-inchesSILTY SAND (SM), fine to medium grained, reddish brown with white,medium dense, residuum

PARTIALLY WEATHERED ROCK (PWR), sampled as gray and white,silty SAND with rock fragmentsReddish brown

Gray and tanAuger Refusal at 8.9 Feet


GR

APH

IC L

OG


THIS

BO

RIN

G L

OG

IS N

OT

VALI

D IF

SEP

ARAT

ED F

RO

M O

RIG

INAL

REP

OR

T. G

EO S

MAR

T LO

G-N

O W

ELL

711

7504

0 C

RO

SS C

HAR

LOTT

E T.

GPJ

TER

RAC

ON

_DAT

ATEM

PLAT

E.G

DT

7/3

1/18

PER

CEN

T FI

NES

WAT

ERC

ON

TEN

T (%

)

LL-PL-PI

ATTERBERGLIMITS

ELEVATION (Ft.)


WAT

ER L

EVEL

OBS

ERVA

TIO

NS

DEP

TH (F

t.)

5

SAM

PLE

TYPE

FIEL

D T

EST

RES

ULT

S

DEPTH


Page 1 of 1




Notes:


Drill Rig: D-50


Driller: E. Rummage







Dry Cave-InDry Cave-In

WATER LEVEL OBSERVATIONSNo free water observed

4919

28

37-23-14

672+/-671.5+/-

666.5+/-

661+/-

654.5+/-

635.5+/-

3-3-3N=6

4-4-4N=8

11-14-10N=24

4-7-17N=24

40-26-50N=76

17-50/3"

50/3"

50/3"

50/2"

50/1"

1.21.4

6.7

12.0

18.5

37.6

ASPHALT, 14-inchesAGGREGATE BASE COURSE, 2-inchesFILL - CLAYEY SAND (SC), reddish brown with white, loose

SANDY SILT (ML), reddish tan, very stiff, residuum

SILTY SAND (SM), fine to medium grained, brownish gray, very dense,residuum

With red fat clay seams

PARTIALLY WEATHERED ROCK (PWR), sampled as brownish tan, siltySAND



GR

APH

IC L

OG


THIS

BO

RIN

G L

OG

IS N

OT

VALI

D IF

SEP

ARAT

ED F

RO

M O

RIG

INAL

REP

OR

T. G

EO S

MAR

T LO

G-N

O W

ELL

711

7504

0 C

RO

SS C

HAR

LOTT

E T.

GPJ

TER

RAC

ON

_DAT

ATEM

PLAT

E.G

DT

7/3

1/18

PER

CEN

T FI

NES

WAT

ERC

ON

TEN

T (%

)

LL-PL-PI

ATTERBERGLIMITS

ELEVATION (Ft.)


WAT

ER L

EVEL

OBS

ERVA

TIO

NS

DEP

TH (F

t.)

5

10

15

20

25

30

35

SAM

PLE

TYPE

FIEL

D T

EST

RES

ULT

S

DEPTH


Page 1 of 1


Abandonment Method:Boring backfilled with auger cuttingsSurface capped with hot mix asphalt


Notes:


Drill Rig: D-50


Driller: E. Rummage









62

22

21

23 46-38-8

675.5+/-674.5+/-

669.5+/-

636+/-

10-5-4N=9

2-4-5N=9

4-4-7N=11

3-5-5N=10

6-8-6N=14

7-9-13N=22

14-14-17N=31

12-12-17N=29

11-15-22N=37

20-22-34N=56

0.71.4

6.7

40.0

ASPHALT, 8-inchesAGGREGATE BASE COURSE, 8-inchesFILL - SILT WITH SAND (ML), reddish brown, stiff

SANDY SILT (ML), brown and white, stiff to hard, residuum

Dark gray and white

Dark gray and white with black



GR

APH

IC L

OG


THIS

BO

RIN

G L

OG

IS N

OT

VALI

D IF

SEP

ARAT

ED F

RO

M O

RIG

INAL

REP

OR

T. G

EO S

MAR

T LO

G-N

O W

ELL

711

7504

0 C

RO

SS C

HAR

LOTT

E T.

GPJ

TER

RAC

ON

_DAT

ATEM

PLAT

E.G

DT

7/3

1/18

PER

CEN

T FI

NES

WAT

ERC

ON

TEN

T (%

)

LL-PL-PI

ATTERBERGLIMITS

ELEVATION (Ft.)


WAT

ER L

EVEL

OBS

ERVA

TIO

NS

DEP

TH (F

t.)

5

10

15

20

25

30

35

40

SAM

PLE

TYPE

FIEL

D T

EST

RES

ULT

S

DEPTH


Page 1 of 1


Abandonment Method:Boring backfilled with auger cuttingsSurface capped with hot mix asphalt


Notes:


Drill Rig: D-50


Driller: E. Rummage







Dry Cave-In

After drilling

Dry Cave-In


9051 61-47-14

667.5+/-667+/-

656+/-

633+/-

4-2-2N=4

1-2-3N=5

3-4-5N=9

2-3-4N=7

3-3-4N=7

2-3-5N=8

1-2-4N=6

2-4-7N=11

2-5-12N=17

0.50.8

12.0

35.0

TOPSOIL, 6-inchesFILL - ELASTIC SILT WITH SAND (MH), tan with black and brownELASTIC SILT (MH), tan with black and brown, medium stiff to stiff,residuum

SANDY LEAN CLAY (CL), tan, with black and brown, medium stiff to verystiff, trace gravel from 33.5'-35', residuum



GR

APH

IC L

OG


THIS

BO

RIN

G L

OG

IS N

OT

VALI

D IF

SEP

ARAT

ED F

RO

M O

RIG

INAL

REP

OR

T. G

EO S

MAR

T LO

G-N

O W

ELL

711

7504

0 C

RO

SS C

HAR

LOTT

E T.

GPJ

TER

RAC

ON

_DAT

ATEM

PLAT

E.G

DT

7/3

1/18

PER

CEN

T FI

NES

WAT

ERC

ON

TEN

T (%

)

LL-PL-PI

ATTERBERGLIMITS

ELEVATION (Ft.)


WAT

ER L

EVEL

OBS

ERVA

TIO

NS

DEP

TH (F

t.)

5

10

15

20

25

30

35

SAM

PLE

TYPE

FIEL

D T

EST

RES

ULT

S

DEPTH


Page 1 of 1




Notes:


Drill Rig: Geoprobe


Driller: B. Burnett









655.5+/-

654+/-

650.5+/-

641+/-

4-10-10N=20

12-14-15N=29

18-30-32N=62

16-20-18N=38

16-28-36N=64

0.3

1.9

5.5

15.0

TOPSOIL, 4-inchesFILL - SILTY SAND (SM), brown, medium denseSILTY SAND (SM), tan and brown, medium dense, residuum

SILTY SAND (SM), trace gravel, tan and brown, dense to very dense,residuum



GR

APH

IC L

OG


THIS

BO

RIN

G L

OG

IS N

OT

VALI

D IF

SEP

ARAT

ED F

RO

M O

RIG

INAL

REP

OR

T. G

EO S

MAR

T LO

G-N

O W

ELL

711

7504

0 C

RO

SS C

HAR

LOTT

E T.

GPJ

TER

RAC

ON

_DAT

ATEM

PLAT

E.G

DT

7/3

1/18

PER

CEN

T FI

NES

WAT

ERC

ON

TEN

T (%

)

LL-PL-PI

ATTERBERGLIMITS

ELEVATION (Ft.)


WAT

ER L

EVEL

OBS

ERVA

TIO

NS

DEP

TH (F

t.)

5

10

15

SAM

PLE

TYPE

FIEL

D T

EST

RES

ULT

S

DEPTH


Page 1 of 1




Notes:


Drill Rig: Geoprobe


Driller: B. Burnett









655.5+/-

644+/-

639+/-

632.5+/-

628.5+/-

50/4"

48-50/4"

50/6"

36-30-50/4"

31-28-45N=73

9-10-14N=24

34-50/5"

50/0"

0.3

12.0

17.0

23.5

27.7

TOPSOIL, 3-inchesPARTIALLY WEATHERED ROCK (PWR), sampled as tan and white, siltySAND, with rock fragmentsWith light brown

SILTY SAND (SM), fine to medium grained, orangish brown, white, andtan, very dense, residuum

SILT WITH SAND (ML), gray and orange with tan, very stiff, residuum

PARTIALLY WEATHERED ROCK (PWR), sampled as gray, orange, andtan, silty SAND, with rock fragments, and trace red fat clay seams



GR

APH

IC L

OG


THIS

BO

RIN

G L

OG

IS N

OT

VALI

D IF

SEP

ARAT

ED F

RO

M O

RIG

INAL

REP

OR

T. G

EO S

MAR

T LO

G-N

O W

ELL

711

7504

0 C

RO

SS C

HAR

LOTT

E T.

GPJ

TER

RAC

ON

_DAT

ATEM

PLAT

E.G

DT

7/3

1/18

PER

CEN

T FI

NES

WAT

ERC

ON

TEN

T (%

)

LL-PL-PI

ATTERBERGLIMITS

ELEVATION (Ft.)


WAT

ER L

EVEL

OBS

ERVA

TIO

NS

DEP

TH (F

t.)

5

10

15

20

25SA

MPL

E TY

PE

FIEL

D T

EST

RES

ULT

S

DEPTH


Page 1 of 1




Notes:


Drill Rig: D-50


Driller: E. Rummage









4619

21

36-33-3

656.5+/-

630+/-

627+/-

3-5-5N=10

3-5-6N=11

4-8-12N=20

7-6-7N=13

7-12-16N=28

7-8-13N=21

15-19-27N=46

8-16-28N=44

0.3

27.0

30.0

TOPSOIL, 4-inchesSILTY SAND (SM), white, tan, and gray, medium dense to dense,residuumWith orange

With black

SILT WITH SAND (ML), light brown and orange, with black, hard,residuum


Elevations estimated from provided plans dated 6/29/18.Bulk sample collected from auger cuttings from 0 to 5 feet.

GR

APH

IC L

OG


THIS

BO

RIN

G L

OG

IS N

OT

VALI

D IF

SEP

ARAT

ED F

RO

M O

RIG

INAL

REP

OR

T. G

EO S

MAR

T LO

G-N

O W

ELL

711

7504

0 C

RO

SS C

HAR

LOTT

E T.

GPJ

TER

RAC

ON

_DAT

ATEM

PLAT

E.G

DT

7/3

1/18

PER

CEN

T FI

NES

WAT

ERC

ON

TEN

T (%

)

LL-PL-PI

ATTERBERGLIMITS

ELEVATION (Ft.)


WAT

ER L

EVEL

OBS

ERVA

TIO

NS

DEP

TH (F

t.)

5

10

15

20

25

30

SAM

PLE

TYPE

FIEL

D T

EST

RES

ULT

S

DEPTH


Page 1 of 1




Notes:


Drill Rig: D-50


Driller: E. Rummage







After drilling

Wet Cave-In

While drilling

After drilling

Wet Cave-In

WATER LEVEL OBSERVATIONSWhile drilling

43

12

14 34-32-2

661.5+/-

652+/-

4-3-3N=6

5-7-6N=13

7-8-9N=17

8-10-12N=22

0.3

10.0

TOPSOIL, 3-inchesSILTY SAND (SM), fine grained, white, orange, and tan, loose to mediumdense, residuum



GR

APH

IC L

OG


THIS

BO

RIN

G L

OG

IS N

OT

VALI

D IF

SEP

ARAT

ED F

RO

M O

RIG

INAL

REP

OR

T. G

EO S

MAR

T LO

G-N

O W

ELL

711

7504

0 C

RO

SS C

HAR

LOTT

E T.

GPJ

TER

RAC

ON

_DAT

ATEM

PLAT

E.G

DT

7/3

1/18

PER

CEN

T FI

NES

WAT

ERC

ON

TEN

T (%

)

LL-PL-PI

ATTERBERGLIMITS

ELEVATION (Ft.)


WAT

ER L

EVEL

OBS

ERVA

TIO

NS

DEP

TH (F

t.)

5

10

SAM

PLE

TYPE

FIEL

D T

EST

RES

ULT

S

DEPTH


Page 1 of 1




Notes:


Drill Rig: D-50


Driller: E. Rummage









6

664+/-

661+/-

652+/-

647+/-

642+/-

627+/-

624+/-

25-46-50N=96

30-50/5"

50/5"

50/5"

5-26-42N=68

29-50/6"

23-38-40N=78

21-38-26N=64

26-34-37N=71

15-32-50/5"

0.2

3.0

12.0

17.0

22.0

37.0

40.0

TOPSOIL, 2-inchesSILTY SAND (SM), fine to medium grained, white and tan, very dense,residuumPARTIALLY WEATHERED ROCK (PWR), sampled as white, tan, andorange, silty SAND

With red

SILTY SAND (SM), fine to medium grained, tan, white, and orange, verydense, residuum

PARTIALLY WEATHERED ROCK (PWR), sampled as reddish tan, siltySAND

SILTY SAND (SM), tan and brown with black, residuum

PARTIALLY WEATHERED ROCK (PWR), sampled as tan and brown,with black, silty SAND



GR

APH

IC L

OG


THIS

BO

RIN

G L

OG

IS N

OT

VALI

D IF

SEP

ARAT

ED F

RO

M O

RIG

INAL

REP

OR

T. G

EO S

MAR

T LO

G-N

O W

ELL

711

7504

0 C

RO

SS C

HAR

LOTT

E T.

GPJ

TER

RAC

ON

_DAT

ATEM

PLAT

E.G

DT

7/3

1/18

PER

CEN

T FI

NES

WAT

ERC

ON

TEN

T (%

)

LL-PL-PI

ATTERBERGLIMITS

ELEVATION (Ft.)


WAT

ER L

EVEL

OBS

ERVA

TIO

NS

DEP

TH (F

t.)

5

10

15

20

25

30

35

40

SAM

PLE

TYPE

FIEL

D T

EST

RES

ULT

S

DEPTH


Page 1 of 1




Notes:


Drill Rig: D-50


Driller: E. Rummage









15

693.5+/-

691+/-

684.5+/-

682+/-

674+/-

14-17-17N=34

10-14-9N=23

8-8-10N=18

38-32-15N=47

10-9-9N=18

23-21-18N=39

0.3

3.0

9.5

12.0

20.0

TOPSOIL, 4-inchesFILL - SANDY SILT (ML), red, black, and tan, hard, trace gravel

SILTY SAND (SM), fine to medium grained, tan, white, and gray, mediumdense, residuum

SANDY LEAN CLAY (CL), red with black, residuum

SILTY SAND (SM), fine to medium grained, tan, orange, ands gray,medium dense to dense, quartz deposits 18.5'-20', residuum



GR

APH

IC L

OG


THIS

BO

RIN

G L

OG

IS N

OT

VALI

D IF

SEP

ARAT

ED F

RO

M O

RIG

INAL

REP

OR

T. G

EO S

MAR

T LO

G-N

O W

ELL

711

7504

0 C

RO

SS C

HAR

LOTT

E T.

GPJ

TER

RAC

ON

_DAT

ATEM

PLAT

E.G

DT

7/3

1/18

PER

CEN

T FI

NES

WAT

ERC

ON

TEN

T (%

)

LL-PL-PI

ATTERBERGLIMITS

ELEVATION (Ft.)


WAT

ER L

EVEL

OBS

ERVA

TIO

NS

DEP

TH (F

t.)

5

10

15

20

SAM

PLE

TYPE

FIEL

D T

EST

RES

ULT

S

DEPTH


Page 1 of 1




Notes:


Drill Rig: Geoprobe


Driller: B. Burnett







17

681+/-

678+/-

675.5+/-

673+/-

669+/-

661+/-

4-5-8N=13

8-11-14N=25

6-6-8N=14

6-6-6N=12

7-9-10N=19

18-34-26N=60

0.2

3.0

5.5

8.0

12.0

20.0

POORLY GRADED GRAVEL (GP), gray, 2-inchesFILL - SILTY SAND (SM), fine to coarse grained, brownish red, mediumdense, trace gravelFILL - SANDY SILT (ML), red with yellowish tan, very stiff, trace gravel

SILTY SAND (SM), fine to medium grained, yellowish tan and red,medium dense, trace gravel, residuum

ELASTIC SILT (MH), tan with black, stiff, slightly micaceous, residuum

SILTY SAND (SM), fine to coarse grained, tan and black to tan, black, andwhite, medium dense to very dense, residuum



GR

APH

IC L

OG


THIS

BO

RIN

G L

OG

IS N

OT

VALI

D IF

SEP

ARAT

ED F

RO

M O

RIG

INAL

REP

OR

T. G

EO S

MAR

T LO

G-N

O W

ELL

711

7504

0 C

RO

SS C

HAR

LOTT

E T.

GPJ

TER

RAC

ON

_DAT

ATEM

PLAT

E.G

DT

7/3

1/18

PER

CEN

T FI

NES

WAT

ERC

ON

TEN

T (%

)

LL-PL-PI

ATTERBERGLIMITS

ELEVATION (Ft.)


WAT

ER L

EVEL

OBS

ERVA

TIO

NS

DEP

TH (F

t.)

5

10

15

20

SAM

PLE

TYPE

FIEL

D T

EST

RES

ULT

S

DEPTH


Page 1 of 1




Notes:


Drill Rig: Geoprobe


Driller: B. Burnett







666.5+/-

664+/-

661.5+/-

659+/-

655+/-

653.5+/-

8-9-11N=20

7-8-10N=18

8-8-13N=21

11-12-12N=24

50/0"

0.5

3.0

5.5

8.0

12.0

13.5

TOPSOIL, 6-inchesFILL - SANDY SILT (ML), brownish red, very stiff

SANDY SILT (ML), orangish red, very stiff, residuum

SILTY SAND (SM), fine to medium grained, orangish tan, medium dense,residuum

SILTY SAND (SM), fine to coarse grained, orange, tan, and black,medium dense, trace gravel, residuum

PARTIALLY WEATHERED ROCK (PWR), No recovery



GR

APH

IC L

OG


THIS

BO

RIN

G L

OG

IS N

OT

VALI

D IF

SEP

ARAT

ED F

RO

M O

RIG

INAL

REP

OR

T. G

EO S

MAR

T LO

G-N

O W

ELL

711

7504

0 C

RO

SS C

HAR

LOTT

E T.

GPJ

TER

RAC

ON

_DAT

ATEM

PLAT

E.G

DT

7/3

1/18

PER

CEN

T FI

NES

WAT

ERC

ON

TEN

T (%

)

LL-PL-PI

ATTERBERGLIMITS

ELEVATION (Ft.)


WAT

ER L

EVEL

OBS

ERVA

TIO

NS

DEP

TH (F

t.)

5

10

SAM

PLE

TYPE

FIEL

D T

EST

RES

ULT

S

DEPTH


Page 1 of 1




Notes:


Drill Rig: Geoprobe


Driller: B. Burnett







8130 53-48-5

654.5+/-

652+/-

647+/-

643+/-

638+/-

635+/-

4-4-3N=7

3-3-2N=5

2-2-4N=6

2-5-8N=13

11-21-32N=53

13-20-44N=64

0.5

3.0

8.0

12.0

17.0

20.0

TOPSOIL, 6-inchesFILL - SILT WITH SAND (ML), red with black, medium stiff

ELASTIC SILT WITH SAND (MH), orangish tan, medium stiff, residuum

SILTY SAND (SM), fine to coarse grained, yellowish tan, medium dense,residuum

SILT WITH SAND (ML), tannish brown, hard, residuum

SILTY SAND (SM), fine to coarse grained, tan and gray, with black, verydense, residuum



GR

APH

IC L

OG


THIS

BO

RIN

G L

OG

IS N

OT

VALI

D IF

SEP

ARAT

ED F

RO

M O

RIG

INAL

REP

OR

T. G

EO S

MAR

T LO

G-N

O W

ELL

711

7504

0 C

RO

SS C

HAR

LOTT

E T.

GPJ

TER

RAC

ON

_DAT

ATEM

PLAT

E.G

DT

7/3

1/18

PER

CEN

T FI

NES

WAT

ERC

ON

TEN

T (%

)

LL-PL-PI

ATTERBERGLIMITS

ELEVATION (Ft.)


WAT

ER L

EVEL

OBS

ERVA

TIO

NS

DEP

TH (F

t.)

5

10

15

20

SAM

PLE

TYPE

FIEL

D T

EST

RES

ULT

S

DEPTH


Page 1 of 1




Notes:


Drill Rig: Geoprobe


Driller: B. Burnett







7922 38-33-5

652.5+/-

650+/-

646.5+/-

639.5+/-

638+/-

5-5-5N=10

8-8-17N=25

27-25-25N=50

9-25-18N=43

50/4"

50/0"

0.6

3.0

6.5

13.5

15.0

TOPSOIL, 7-inchesSILT WITH SAND (ML), red and tan, stiff, residuum

SILTY SAND (SM), fine to coarse grained, reddish orange, mediumdense, trace gravel, residuum

ELASTIC SILT WITH SAND (MH), tannish brown, hard, residuum

PARTIALLY WEATHERED ROCK (PWR), sampled as reddish orangeand tan, silty SAND, with trace gravelAuger Refusal at 15 Feet


GR

APH

IC L

OG


THIS

BO

RIN

G L

OG

IS N

OT

VALI

D IF

SEP

ARAT

ED F

RO

M O

RIG

INAL

REP

OR

T. G

EO S

MAR

T LO

G-N

O W

ELL

711

7504

0 C

RO

SS C

HAR

LOTT

E T.

GPJ

TER

RAC

ON

_DAT

ATEM

PLAT

E.G

DT

7/3

1/18

PER

CEN

T FI

NES

WAT

ERC

ON

TEN

T (%

)

LL-PL-PI

ATTERBERGLIMITS

ELEVATION (Ft.)


WAT

ER L

EVEL

OBS

ERVA

TIO

NS

DEP

TH (F

t.)

5

10

15

SAM

PLE

TYPE

FIEL

D T

EST

RES

ULT

S

DEPTH


Page 1 of 1




Notes:


Drill Rig: Geoprobe


Driller: B. Burnett







SUPPORTING INFORM ATION

SUPPORTING INFORMATION

SLOPE STABILITY – CROSS SECTION A-A’ – COMBINED WALLSCross Charlotte Trail 7th-10th Street Segment ■ Charlotte, North CarolinaAugust 24, 2018 ■ Terracon Project No. 71175040

SITE LOC ATION PL AN

LEGEND: = Structural Fill (γ=120 pcf, Φ=24°, c=200 psf)

= Residual Soil (γ=120 pcf, Φ=24°, c=200 psf)

= PWR (γ=130 pcf, Φ=35°, c=500 psf)

= Bedrock (γ=130 pcf, impenetrable)

A A’

75 psf

250 psf

SLOPE STABILITY – CROSS SECTION A-A’ – LOWER WALLCross Charlotte Trail 7th-10th Street Segment ■ Charlotte, North CarolinaAugust 24, 2018 ■ Terracon Project No. 71175040

SITE LOC ATION PL AN



= PWR (γ=130 pcf, Φ=35°, c=500 psf)


A A’

75 psf

250 psf

SLOPE STABILITY – CROSS SECTION A-A’ – UPPER WALLCross Charlotte Trail 7th-10th Street Segment ■ Charlotte, North CarolinaAugust 24, 2018 ■ Terracon Project No. 71175040



= PWR (γ=130 pcf, Φ=35°, c=500 psf)


A A’

75 psf

250 psf

SLOPE STABILITY – CROSS SECTION B-B’ – COMBINED WALLSCross Charlotte Trail 7th-10th Street Segment ■ Charlotte, North CarolinaAugust 24, 2018 ■ Terracon Project No. 71175040



B B’

75 psf

250 psf

SLOPE STABILITY – CROSS SECTION B-B’ – LOWER WALLCross Charlotte Trail 7th-10th Street Segment ■ Charlotte, North CarolinaAugust 24, 2018 ■ Terracon Project No. 71175040



B B’

75 psf

250 psf

SLOPE STABILITY – CROSS SECTION B-B’ – UPPER WALLCross Charlotte Trail 7th-10th Street Segment ■ Charlotte, North CarolinaAugust 24, 2018 ■ Terracon Project No. 71175040



B B’

75 psf

250 psf

SLOPE STABILITY – CROSS SECTION C-C’Cross Charlotte Trail 7th-10th Street Segment ■ Charlotte, North CarolinaAugust 24, 2018 ■ Terracon Project No. 71175040



C C’

75 psf

UNIFIED SOIL CLASSIFICATION SYSTEMCross Charlotte Trail 7th-10th Street Segment ■ Charlotte, North CarolinaAugust 24, 2018 ■ Terracon Project No. 71175040

UNIFIED SOIL C L ASSIFIC AT ION SYSTEM

Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests A Soil Classification

Group Symbol Group Name B

Coarse-Grained Soils: More than 50% retained on No. 200 sieve

Gravels: More than 50% of coarse fraction retained on No. 4 sieve

Clean Gravels: Less than 5% fines C

Cu 4 and 1 Cc 3 E GW Well-graded gravel F Cu 4 and/or [Cc<1 or Cc>3.0] E GP Poorly graded gravel F

Gravels with Fines: More than 12% fines C

Fines classify as ML or MH GM Silty gravel F, G, H Fines classify as CL or CH GC Clayey gravel F, G, H

Sands: 50% or more of coarse fraction passes No. 4 sieve

Clean Sands: Less than 5% fines D

Cu 6 and 1 Cc 3 E SW Well-graded sand I Cu 6 and/or [Cc<1 or Cc>3.0] E SP Poorly graded sand I

Sands with Fines: More than 12% fines D

Fines classify as ML or MH SM Silty sand G, H, I Fines classify as CL or CH SC Clayey sand G, H, I

Fine-Grained Soils: 50% or more passes the No. 200 sieve

Silts and Clays: Liquid limit less than 50

Inorganic: PI 7 and plots on or above “A” line J

CL Lean clay K, L, M PI 4 or plots below “A” line J ML Silt K, L, M

Organic: Liquid limit - oven dried

0.75 OL Organic clay K, L, M, N Liquid limit - not dried Organic silt K, L, M, O

Silts and Clays: Liquid limit 50 or more

Inorganic: PI plots on or above “A” line CH Fat clay K, L, M PI plots below “A” line MH Elastic Silt K, L, M

Organic: Liquid limit - oven dried

0.75 OH Organic clay K, L, M, P Liquid limit - not dried Organic silt K, L, M, Q

Highly organic soils: Primarily organic matter, dark in color, and organic odor PT Peat A Based on the material passing the 3-inch (75-mm) sieve B If field sample contained cobbles or boulders, or both, add “with cobbles

or boulders, or both” to group name. C Gravels with 5 to 12% fines require dual symbols: GW-GM well-graded

gravel with silt, GW-GC well-graded gravel with clay, GP-GM poorly graded gravel with silt, GP-GC poorly graded gravel with clay.

D Sands with 5 to 12% fines require dual symbols: SW-SM well-graded sand with silt, SW-SC well-graded sand with clay, SP-SM poorly graded sand with silt, SP-SC poorly graded sand with clay

E Cu = D60/D10 Cc = 6010

230

DxD

)(D

F If soil contains 15% sand, add “with sand” to group name. G If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM.

H If fines are organic, add “with organic fines” to group name. I If soil contains 15% gravel, add “with gravel” to group name. J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay. K If soil contains 15 to 29% plus No. 200, add “with sand” or “with

gravel,” whichever is predominant. L If soil contains 30% plus No. 200 predominantly sand, add

“sandy” to group name. M If soil contains 30% plus No. 200, predominantly gravel, add

“gravelly” to group name. N PI 4 and plots on or above “A” line. O PI 4 or plots below “A” line. P PI plots on or above “A” line. Q PI plots below “A” line.

Cross Charlotte Trail - 7th Street to 10th Street Charlotte, NC8/24/2018 Terracon Project No. 71175040

0.25 to 0.50

> 4.00

2.00 to 4.00

1.00 to 2.00

0.50 to 1.00

less than 0.25

Unconfined Compressive StrengthQu, (tsf)

Split Spoon

Trace

PLASTICITY DESCRIPTION

Water levels indicated on the soil boring logs arethe levels measured in the borehole at the timesindicated. Groundwater level variations will occurover time. In low permeability soils, accuratedetermination of groundwater levels is notpossible with short term water levelobservations.

DESCRIPTION OF SYMBOLS AND ABBREVIATIONSGENERAL NOTES

> 3011 - 301 - 10Low

Non-plasticPlasticity Index

#4 to #200 sieve (4.75mm to 0.075mm

Boulders12 in. to 3 in. (300mm to 75mm)Cobbles

3 in. to #4 sieve (75mm to 4.75 mm)GravelSand

Passing #200 sieve (0.075mm)Silt or Clay

Particle Size

Water Level Aftera Specified Period of Time

Water Level After aSpecified Period of Time

Water InitiallyEncountered

Soil classification is based on the Unified Soil Classification System. Coarse Grained Soils have more than 50% of theirdry weight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand. Fine Grained Soilshave less than 50% of their dry weight retained on a #200 sieve; they are principally described as clays if they are plastic,and silts if they are slightly plastic or non-plastic. Major constituents may be added as modifiers and minor constituentsmay be added according to the relative proportions based on grain size. In addition to gradation, coarse-grained soils aredefined on the basis of their in-place relative density and fine-grained soils on the basis of their consistency.

GRAIN SIZE TERMINOLOGY

RELATIVE PROPORTIONS OF FINESRELATIVE PROPORTIONS OF SAND AND GRAVEL

DESCRIPTIVE SOIL CLASSIFICATION

LOCATION AND ELEVATION NOTES

SAMPLING WATER LEVEL FIELD TESTSN

(HP)

(T)

(DCP)

UC

(PID)

(OVA)

Standard Penetration TestResistance (Blows/Ft.)

Hand Penetrometer

Torvane

Dynamic Cone Penetrometer

Unconfined CompressiveStrength

Photo-Ionization Detector

Organic Vapor Analyzer

Medium

0Over 12 in. (300 mm)

>12

5-12

<5

Percent ofDry Weight

TermMajor Component of Sample

Modifier

With

Trace

Descriptive Term(s) ofother constituents

>30Modifier

<15

Percent ofDry Weight

Descriptive Term(s) ofother constituents

With 15-29

High

Unless otherwise noted, Latitude and Longitude are approximately determined using a hand-held GPS device. Theaccuracy of such devices is variable. Surface elevation data annotated with +/- indicates that no actual topographicalsurvey was conducted to confirm the surface elevation. Instead, the surface elevation was approximately determined fromtopographic maps of the area.

Standard Penetration orN-Value

Blows/Ft.

Descriptive Term(Density)

CONSISTENCY OF FINE-GRAINED SOILS

Hard

15 - 30Very Stiff> 50Very Dense

8 - 15Stiff30 - 50Dense

4 - 8Medium Stiff10 - 29Medium Dense

2 - 4Soft4 - 9Loose0 - 1Very Soft0 - 3Very Loose

(50% or more passing the No. 200 sieve.)Consistency determined by laboratory shear strength testing, field visual-manual

procedures or standard penetration resistance

STRENGTH TERMS

> 30

Descriptive Term(Consistency)

Standard Penetration orN-Value

Blows/Ft.

RELATIVE DENSITY OF COARSE-GRAINED SOILS

(More than 50% retained on No. 200 sieve.)Density determined by Standard Penetration Resistance

geotechnical engineering report · construction plans of proposed cross charlotte trail 7th street...

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