W912P5-16-B-0005_AppA-01.pdf

IFB No. W912P5-16-B-0005 Amendment No. 0002

US Army Corps Of Engineers Nashville District

LOCK EXCAVATION

Chickamauga Lock Replacement Tennessee River Hamilton County, Tennessee

APPENDIX A - GEOTECHNICAL DATA

July 2016

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Appendix A

GEOTECHNICAL DATA

Table of Contents

01 GEOLOGIC INSPECTION OF LOCK FOUNDATION

02 CHICK LOCK INSTRUMENTATION O&M MANUALS

03 UNWATERING PLAN - COFFERDAM STABILIZATION

04 MODIFICATIONS TO EXISTING FLOOD FACILITY BRIDGE

COFFERDAM STABILIZATION

05 ROCK TESTING

06 DEWATERING LOG - WITH REFILL PLOT 6-20-16 WITH FST DATA

07 BORING LOGS

08 UNWATERING PHOTOS

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Geologic Inspection of Lock Foundation in Dewatered Cofferdam

Chickamauga Lock Replacement Project, Chattanooga, Tennessee

June 2012 i

Geologic Inspection of Lock Foundation in Dewatered Cofferdam

Chickamauga Lock Replacement Project

Prepared for:

U.S. Army Corps of Engineers Nashville District

Prepared by:

ARCADIS

1210 Premier Drive Suite 200 Chattanooga Tennessee 37421 Tel 423 756 7193 Fax 423 756 7197

Our Ref.:

Ct053475.0000

Date:

June 2012

This document is intended only for the use of the individual or entity for which it was prepared and may contain information that is privileged, confidential and exempt from disclosure under applicable law. Any dissemination, distribution or copying of this document is strictly prohibited.

Introduction 1

Scope of Work 1

Dewatering Cofferdam 1

Site Conditions 2

Seepage Reconnaissance 2

Apron Inspection 4

Geologic Mapping 4

Splash Pad Evaluation 5

Geology 6

Hermitage Formation 6

Tyrone Formation 7

Carters Formation 8

Joints 8

Overburden Estimation 9

Summary 9

Tables

Table 1. Excerpts of the Modified Seepage Data Collection 3

Appendices

A Project Scope of Work

B Project Photographs

C Seepage Reconnaissance Data

D Seepage and Dye Testing Videos (DVD)

E Figures

F Panorama Section Photographs and Geological Photographs

G Geologic Data and Map

Geologic Inspection of Lock Foundation in Dewatered Cofferdam

Introduction

At the request of the U.S. Army Corps of Engineers (USACE), Nashville District, and as outlined in Task Order No. 0026, Contract No. W912P5-08-D-0001, seepage reconnaissance has been performed and geologic mapping has been developed for the unwatered cofferdam at the Chickamauga Lock and Dam in Chattanooga, Tennessee. A copy of the Scope of Work is provided as Appendix A, Project Scope of Work.

Construction of the existing Chickamauga Lock and Dam began in 1936 and was completed in 1940 by the Tennessee Valley Authority (TVA). The project is located at River Mile 471.0 on the Tennessee River in Hamilton County, Tennessee, 58.9 river miles upstream of Nickajack Dam and 6.8 river miles northeast of the Walnut Street Bridge in Chattanooga, Tennessee. A cofferdam consisting of sheet pile coffercells and a concrete portion of the landside lock wall is intended to facilitate the construction of the 600-foot-long by 110-foot-wide replacement lock.

Scope of Work

The Scope of Work includes a seepage reconnaissance of the cofferdam, geologic mapping of the cofferdam floor, and report development of the findings. The seepage reconnaissance consisted of locating, describing and quantifying inflow into the cofferdam. The inflow locations were digitally recorded. An evaluation of the area at the toe of the flooding structure was completed for the possible installation of a splash pad.

Geologic mapping consisted of surveying formation contacts, measuring geologic structures, and gathering joint data. The work activities are described in this report and all data are provided in the subsequent appendices. The revised 2010 work plan for the scope of work reflects adjustments due to schedule limitations, site conditions, cofferdam contractor issues, and personnel availability.

Dewatering Cofferdam

Reconnaissance and mapping of the cofferdam could not be conducted until successful dewatering was achieved. During dewatering of the cofferdam in September and October 2010 and in June 2011, the inflow exceeded the pumping capacity. Grouting the cofferdam between the dewatering events of 2010 and 2011 did not contain the inflow. During dewatering in June 2011, issues in quantifying pump discharge rates to determine inflow quantities lead the USACE to terminate dewatering and pursue a new approach. In June 2011 the new approach included coordination

Geologic Inspection of with TVA to open Spillway Gate 4 to fill the cofferdam. Using existing instrumentation, the outflow from the interior of the cofferdam was measured to quantify inflow during dewatering. Concurrent with filling the cofferdam, a dive inspection of the exterior of the cofferdam evaluated conditions and located sources of outflow. In December 2011 dewatering was discontinued due to a significant spilling event at the dam. In January 2012 with the cofferdam successfully dewatered using the pump configuration shown in photographs 1 and 2 in Appendix B, Project Photographs, the seepage reconnaissance and geologic mapping was initiated.

Site Conditions

The cofferdam consists of sheet-pile coffer cells and concrete monoliths. The coffer cells are filled with aggregate or cementitious low strength materials which make up the riverside and downstream end of the cofferdam. The landside wall of the cofferdam consists of concrete monoliths which will be integrated in the new landside or north lock wall and the downstream quarter is composed of soft silt and sand on the surface.

The floor of the protected area is approximately 75 percent exposed rock as shown in Photograph 3. The remaining areas are partially covered with alluvium consisting of silt, sand, gravel and boulders. Other than low spots in the cofferdam floor, water pools at the farthest downstream end of the cofferdam as seen in Photograph 4. During the investigation, alluvium was moved by the cofferdam contractor into the footprint of the new lock chamber to expose the monolith foundations as shown in Photograph 5.

During the inspection, the alluvium was moved and adjusted to manage inflow to make other portions of the foundation available for inspection.

Seepage Reconnaissance

A foundation seepage reconnaissance was performed during dewatering by walking the perimeter of the cofferdam and, subsequently, walking the inside of the cofferdam after the dewatering. Evaluations from the top of the cofferdam were made in the form of walk-downs to determine inflow sources. Inflow indicators such as sediment plumes and boils were not observed during those walk-downs. When the cofferdam was successfully dewatered in January 2012, another seepage reconnaissance began on January 23, 2012, at the cofferdam/spillway tie-in by walking the inside perimeter of the cofferdam. The inventory of seepage locations, flow estimates, details and a plan view of the seepage locations are included in Appendix C, Seepage Reconnaissance Data.

Geologic Inspection of

Seepage data is recorded on the modified data sheet shown in Table 1.

Table 1. Excerpts of the Modified Seepage Data Collection

Seepage

ID

Seepage Location

Distance from Face of

Structure (feet)

Estimated Flow (gpm) Notes

11 A-32/C-41 intersection NA 50 boil at arc/cell intersection See video "Seepage A-32_C- 41 Intersection.AVI" See video "Seepage Dye Test C-41 c.AVI"

20 C-38 NA 50

sheet piles 6 and 7 refused on boulder, seepage from beneath boulder

30 C-33 NA 1300

leakage from 13 weep holes in sheet piles 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, and 25 See video "Seepage C-33.AVI"

63 L-09/L-08 NA 15

monolith joint leak See Video "Seepage L09-L08 monolith joint"

Note: Seepage videos are available on a DVD in Appendix D, Seepage and Dye Testing Videos.

Site conditions made quantifying seepage flow difficult as standing water or vigorous flow hindered estimations. Rudimentary dye testing illustrates the relative flow rates at selected locations. Videos of flows and dye testing are shown on the DVD provided in Appendix D. Several coffercells and connector cells are noted to have sheet piles founded on loose material or exhibit sheet pile deflection as seen in Photographs 6 through 18, Appendix B. The loose material adds to the seepage quantities. Some repairs to defects by the cofferdam contractor were made during this investigation causing a reduction to inflow at the repair locations. Repairs were made at the A-35 / apron tie-in by the addition of plating over the inflow source and the removal of the log from the base of C-30. A patch was placed over the opening left by the log removal.

Seepage into the cofferdam shown in Photographs 18 through 25, Appendix B, is from the following sources:

Sheet piles seated on loose material including boulders and a log

Interface at apron

Geologic Inspection of

Weep holes in sheet piles

Boils at base of sheet piles

Defects in sheet piles

Monolith joints

Sheet pile interlocks

No apparent foundation flow was observed. Extensive areas were cleared of alluvium by heavy equipment and then pressure washed. These areas were adjacent to the cellular portion of the cofferdam, riverside lock monolith footprints and landside lock monolith footprints. The areas cleared are the most likely to exhibit foundation flow. No apparent flow was noted from the foundation or from the concrete/rock interface of the landside monoliths. The total estimated inflow from the data sheets is 7,400 gpm.

Apron Inspection

The spillway apron was dewatered February 14, 2012. The bucket of the apron contained silt, sand, boulders, trash, and apparent drill cuttings from the cofferdam-drilled-shaft installation. The water remaining in the apron bucket was clear and visibility of the sediment surface beneath the water level was satisfactory. An attempt to enter the apron bucket was abandoned due to safety considerations. Independent inspections of the apron were conducted by ARCADIS and TVA staff. Seepage was noted at the apron tie-in as shown in Photographs 19 and 20. Minor inflow was noted from the spillway gates and the existing lock shown in Photograph 26. No seepage was noted from relief drains in the apron or piers. Boring C-171 located in the area of the apron at Spillway Gate 1 exhibited artesian flow during pressure testing in August of 2006. Though Boring C-171 could not be located during this inspection, no flow was noted in this area. Photographs 26 through 37 document the apron inspection.

Geologic Mapping

The geologic investigation gained a better understanding of the geologic conditions of the site for the new lock construction. The footprint of the lock monoliths were surveyed and selected points were located with rebar and capped with the point ID. The survey points located were typical monolith corners. Many of the photographs include the rebar location. Three priority areas of concern were delineated by the Nashville District as shown in Figure 1 in Appendix E, Figures. The concern in Priority Area 1 is determining if there was seepage from under the apron. Priority Area 2 has complex geologic conditions, two significant bentonite layers and the splash pad area. Priority

Geologic Inspection of

Area 3 also includes a bentonite layer. Preference was given to gathering information in these areas. A Brunton compass was used to gather structural information. The compass was corrected for the declination of the area such that all bearings given demonstrate True North. All structural information was reported in azimuth rather than quadrant. Data was either recorded on data sheets or in a field note book then later transferred to data sheets.

Areas of the cofferdam were dewatered, cleared of alluvium with heavy equipment and pressure washed. Depressions were excavated and pumped out to the limit which the site conditions will allow. Data was gathered and photographs were taken of the monolith foot prints and other areas were inspected.

Splash Pad Evaluation

The splash pad evaluation area is in a 40-foot-radius off the tangent of Connector Cell A-25 which was cleared of alluvium for inspection as shown on the geologic map in Appendix G, Geologic Data and Map. The competency of the rock determined the need for the installation of a concrete splash pad. Characteristics of the rock considered include the formation and rock type including erosion conditions, jointing and susceptibility to scour.

The area lies within the upper portion of the Tyrone Formation which is medium- bedded limestone interbedded with shale striking at 015 degrees with a shallow dip of 7 degrees to the southeast. Joint spacing ranges from 3.5- to 4.5 feet with the exception of the areas close to the ledge in the southwest portion of the splash pad perimeter. The inspected area is relatively flat except for a depression created by the erosion of a shale bed. A technique shaft installed during cofferdam construction was placed in the 2-foot-depression formed below the ledge. Two technique shafts were installed to demonstrate the cofferdam contractor’s means and methods to drill and construct the drilled shafts for the cofferdam to specifications. Concrete over-pour from the shaft installation covered a portion of the floor of the depression. Photographs of the inspected area are included in Photographs 38 through 47 in Appendix B.

The majority of the evaluated area consists of firm rock with one area of possible concern. The area is located at the cofferdam interior toe of the A-25/C-34 intersection. The ledge noted earlier measures from 9- to 11 feet from the toe of the connector/cell intersection as in Photograph 38. Joint spacing in this area is 1.5 feet to 2 feet. The orthogonal joint sets trend to and under the cofferdam at this location. Joint orientation which includes the spacing and the erosion susceptibility of the shale bed

Geologic Inspection of beneath creates the potential for rock blocks to be scoured during a spill event. This susceptibility to scour can undermine a portion of C-34 causing potential coffercell instability.

Geology

The area landward of the centerline showed more deformation and increased weathering which is potentially exacerbated by the deformation. Formations in the landward area include the Hermitage Formation which is a shallow dipping massive limestone, the Tyrone Formation which is medium-bedded, shaley limestone and bentonite beds and the Carters Formation which is medium to thick-bedded limestone with shaley partings. Appendix F, Panorama Section Photographs and Geological Photographs, contains all photographs of the site geology.

Hermitage Formation

The Hermitage limestone consists of a light- to dark-gray, mottled, thick- to massive-bedded, medium-crystalline, fossiliferous limestone with argillaceous partings and several thin beds of bentonite. Numerous skeletal fossils appear on the surface.

Bedding orientation, where not locally folded, averages 040 degrees dipping to the southeast at 8 degrees.

Three solution features extend approximately along strike from the riverside to the landside monolith footprints and are shown on the Geologic Map in Appendix G.

These solution features appear to be associated with tan clay seams, which in Solution Feature 3 is bentonite. Features 1 and 2 are shown in Photograph 48.

Erosion and water prevents the acquisition of reliable structural data in Features 1 and 2. However, data on either side of the features in the landside monolith foot prints indicate they are also associated with a network of northeast plunging folds as seen in Photographs 49 and 50. Solution Feature 3 contains a 0.7-foot-thick bentonite bed, gray in color weathering to tan, and is bounded on top by dark gray shale as shown in Photographs 51 through 53. Photographs 52 and 53 illustrate small amplitude folding and calcite/dolomite veins which are indicative of faulting within the bentonite bed.

The Hermitage – Tyrone contact is a 1-foot ledge extending from Coffer Cell C-35 to L-11 as seen in Photographs 54-55. The contact is a 0.8- to 1-foot-thick gray bentonite clay bed as shown in Photograph 56. The contact strikes at 036 degrees and dips at 15 degrees to the southeast.

Geologic Inspection of

Tyrone Formation

The Tyrone limestone is a light greenish-gray, thin- to medium-bedded limestone interbedded with green and red calcareous shale, with two distinct layers of bentonite interstratified. The upper portion of the Tyrone is a gray and greenish-gray limestone with green shaley interbeds. Past drilling core samples indicate the Tyrone limestone contains areas of steeply dipping to vertical bedding planes and healed brecciated zones both above and below a small-scale thrust fault surface. These brecciated zones include angular to subangular fragments of limestone and shale that have been healed or cemented with fluid-precipitated calcite and/or dolomite mineralization. During the inspection significant structural readjustment was noted in the upper Tyrone. Four northwest verging fault surfaces were located in the area of Monolith R-13 though R-15 as shown in Photograph 57. Extremely tight folding exists in the northwest corner of Monolith R-13 and along the Monolith Joint L-11/L-12 as seen in Photographs 58 through 60. As compared to the Hermitage limestone and lower Tyrone limestone, the frequency of closely spaced joints increases significantly in the upper Tyrone as seen in the geologic data in Appendix F.

The T-4 bentonite creates a 3-foot-ledge that traces from C-33 to the monolith joint at L-14/L-15 as shown in Photographs 61 and 62. The T-4 is considered a fault (Teddy’s Fault) which has seen significant movement as evidenced by folding within the bed and by the large quantity of calcite/dolomite veins as shown in Photograph

63. In the base of the T-4 the frequency of closely spaced joints diminishes markedly from that stratigraphically above the bentonite bed. The base of the T-4 is a less than 0.1-foot-thick rippled chert layer. The base of the T-4 strikes at between 001 degree and 028 degrees dipping 8 degrees to the southeast.

The lower portion of the Tyrone limestone is dominated by red and green shale with interbedded gray limestone and lies between the T-4 and T-3 bentonites. This portion of the Tyrone only evidences a small degree of deformation. Gently southeast dipping beds of shale exhibit only minor erosional ledges and small depressions as shown in Photograph 64. In core samples and in the field the shale does not appear to desiccate readily. The frequency of closely spaced joints does increase slightly just above the T-3 Contact. The lower Tyrone strikes between 028 degrees and 032 degrees dipping 8 degrees to the southeast. As with all formations along the land wall, bedding strikes vary due to increased deformation in this area.

The T-3 bentonite creates an approximately 2-foot-high ledge into a shallow, wide depression as shown in Photograph 65. At the base of the T-3 is a 0.2-foot-thick

Geologic Inspection of rippled chert layer. The T-3 strikes between 012 degrees and 032 degrees dipping an average of 7 degrees to the southeast.

Carters Formation

The Carters limestone is a light- to medium-gray and dark gray, medium- to thick-bedded, fossiliferous limestone with dark gray, undulating, calcareous shaley partings. The Carters is exposed along the western end of the cofferdam. The limits of the Carters limestone are shown on the geologic map in Appendix D. At the time of the inspection, the Carters limestone was either covered with alluvium or the quality of exposed rock was too low to gather reliable data. Photographs 66 and 67 exhibit the conditions at the western end of the cofferdam. Using data gathered from the base of the T-3 and the results from past drilling, the strike of the Carters limestone ranges from 012 degrees to 032 degrees with an average dip of 7 degrees to the southeast.

Joints

Joints were inventoried monolith by monolith. The joints within the foot print of a monolith were pressure washed, measured and described. Data gathered to describe a joint include orientation, spacing, formation in which the joint occurs, aperture and other notes. Over 700 joint measurements are noted in the data sheets included in Appendix G.

Orthogonal joint sets trending northeast and northwest are the primary joint sets with other minor joint sets along varying orientations. The spacings were measured and the apertures noted. Joint spacing ranges from as great as 32 feet in the area of U-3 to less than 1 foot. The average joint spacing ranges from 2- to 5 feet. The frequency of joints increase and the spacing decreases as their proximity to areas of structural readjustment occurs.

As shown in the photographs, the majority of the joints are only visible from the surface therefore only their trend can be measured. Joints with face exposure at formation contacts were measured; dip is vertical to near-vertical with only a few exceptions.

Joint aperture ranges from tight at the surface to 1.5 feet with alluvial fill. The average range of joint aperture is from tight at the surface to 0.4 foot. The aperture of most joints only extends a shallow distance below the surface as the result of solutioning of the limestone.

Geologic Inspection of

Inspection of the landside monolith footprints does not yield the relative quantity of joint data as did the riverside monoliths. The available rock in the landside monolith footprints is limited due to several factors. Water filled excavations from construction of the cofferdam and erosion of the rock facilitated by the structural readjustments limit the amount and quality of exposure for measurement. Caution should be used when using this data in developing excavation assumptions.

A rose diagram was generated for each monolith and the results place on the geologic map. The rose diagrams demonstrate the quantity and orientation ranges of the joints in a given monolith footprint. Individual rose diagrams for each monolith are included in Appendix G.

Overburden Estimation

The overburden within the cofferdam consists of alluvium, cell fill aggregate and excavated materials from the cofferdam construction. The alluvium is silt, sand, cobbles and boulders. The overburden also contains residuum. The boulders range in size from approximately 5-foot-wide, 6-foot-long, 2-foot-thick slabs to approximately 5-foot-wide, 5-foot-long and 5-foot thick blocks. During the inspections most of the overburden was moved into the footprint of the new lock chamber. The remainder was used to redirect flowing water or moved into discrete piles in other areas.

A quantification of the amount of overburden is needed. As the pile of overburden was not surveyed, the estimation is a Rough Order of Magnitude (ROM) type of estimation.

The assumptions are based on dimensions scaled from photographs in Appendix F.

The calculations are based on the assumption that all the material visible in the photographs was relocated into one pile 8 feet high, 20 feet at the base and 750 feet long. The estimated overburden, with a 15 percent contingency, is 3600 cubic yards.

Detailed calculations are provided in Appendix F.

Summary

In summary, all inspection goals were met. The seepage reconnaissance estimated a total inflow of 7400 gpm from several sources including sheet pile-rock interface, weep holes, defects, and the tie-in at the apron. The splash pad evaluation noted one area of potential concern at the toe of the A-25/C-34 intersection where closely spaced joints in shaley lime stone may impact coffercell stability. Geologic mapping concludes that the geology is complex with significant deformation along the landwall portion of the cofferdam. This deformation includes folding and faulting of the rocks. Jointing is

Geologic Inspection of closely spaced in areas of faulting and stratigraphically just above bentonite beds and weaker shale. Estimation of the quantity of overburden results in a ROM estimation of 3600 cubic yards of alluvium and residuum.

Appendix A

Project Scope of Work

Section C - Descriptions and Specifications

STATEMENT OF WORK

Geologic Inspection of Lock Foundation

In Dewatered Cofferdam

Chickamauga Lock Replacement Project Chattanooga, Tennessee

I. General. The objective of the work under this Task Order is to perform geologic mapping inside the cofferdam at the Chickamauga Lock Project. The project is located at mile 471 on the Tennessee River, in Chattanooga, TN.

II. Safety. Applicable provisions of the U.S. Army Corps of Engineers Safety and Health

Requirements Manual, EM 385-1-1, shall govern all work performed under this task order.

The safety manual may be found at http://140.194.76.129/publications/eng-manuals/em385- 1-1/2008_English/toc.html. The contractor shall submit a draft of the Health and Safety Plan (HSP) and a job Activity Hazard Analysis (AHA), for approval, at least two weeks prior to commencement of field work.

A. Background Check. All Contractor employees (U.S. citizens and Non-U.S. citizens) working under this contract or applicable task orders who require unescorted access in or around hydropower plants, navigation locks, or other facilities deemed necessary by the Nashville District Security Officer, must have or obtain a favorable background investigation. The investigation must be completed by a Department of Defense (DOD) approved investigation agency, such as Office of Personnel Management or the Defense Security Service. The investigative requirements are a favorable National Agency Check with Inquiries (NACI) utilizing a Standard Form 85-P (SF85-P) Questionnaire for Public Trust Positions. Each applicable contractor/subcontractor shall complete an investigation package which must be submitted to the Nashville District Security Office within three

(3) working days after award of any contract or task order or prior to the individual being permitted unescorted access in or around all district facilities considered restricted by the Nashville District Security Office. Contractors which have a Facility Security Clearance through the Defense Security Service shall process the NACIs and forward results to the Nashville District Security Officer. For those contractors which do not have a Facility Security Clearance, the Nashville District Security Management Office (Connie Hardeman, Security Manager, (615) 736-5567) can process the investigation in coordination with the Contractor and contract employees.

(1) SF-85P, Questionnaire for Public Trust Positions

(2) OF-306, Declaration for Federal Employment (Questions 1, 2, 8-13, 16 and 17a)

(3) I-9, Employment Eligibility Verification (completed by contract employee and employer)

(4) FD-258, Contractor Fingerprint Card (1 card for digital prints, 2 for ink prints) (Note: ORI block on FD-258 must be USOPM000Z)

The SF-85P and OF-306 can be printed from the following website:

http://www.opm.gov/forms/

The I-9 can be printed from the following website:

http://www.uscis.gov/files/form/i-9.pdf

The Contractor Fingerprint Cards (FD-258) can be obtained by contacting the Nashville District Security Manager.

Foreign Nationals: In accordance with Engineering Regulation, ER 380-1-18, Section 4, all foreign nationals who work on Corps of Engineers’ contracts or task orders shall be approved by the HQUSACE Foreign Disclosure Officer or higher before beginning work on the contract/task order. This regulation includes subcontractor employees. The contractor shall submit to the Nashville District Security Manager, the names of all foreign nationals proposed for performance under this contract/task order, along with documentation to verify that he/she was legally admitted into the United States and has authority to work and/or go to school in the U.S. Such documentation may include a U.S. passport, Certificate of U.S.

Citizenship (INS Form N-560 or N-561), Certificate of Naturalization (INS Form N- 550 or N-570), Alien Registration Card with photograph (INS Form I-151 or I-551), Employment Authorization Card (INS Form I-688A), etc. All foreign nationals shall be escorted at all times by a cleared federal employee unless approved by the Nashville District Security Manager on a case-by-case basis.

B. Processing of background checks should be coordinated with the Nashville District Security Manager.

III. Coordination. The assigned Contracting Officer’s Representative (COR) for this Task Order is Mr. Doug Mullendore/CELRN-EC-R, (615) 736-7556. For purposes of this project, the Corps’ point of contact for contractual matters is Bill Vecchione/CELRN-EC-E, (615) 736- 5110. The point of contact for technical matters is Mark Elson/CELRN-EC-CD, (615) 736- 7897. On site activities shall be coordinated with the Construction field office Resident Engineer, Bill DeBruyn, (423) 875-5027, or designated representative. No Government personnel, other than the Contracting Officer, will have the authority to do other than clarify technical points or supply relevant information. Specifically, no requirement in this Statement of Work may be altered as a sole result of such verbal clarification.

The A/E shall establish and maintain a liaison and coordinate with the U.S. Army Corps of Engineers representatives. The A/E shall establish a single point of contact for the project.

IV. Major/Project Requirements: The Government and the Contractor understand and agree that the services to be provided and delivered under this Task Order by the Contractor are non-personal services and the parties recognize and agree that no employer-employee relationship exists or will exist under this Task Order between the Government and the Contractor employees.

In order for the Contractor to accomplish the work under this Task Order, it shall be necessary for the Contractor to complete the following tasks:

A. The AE shall record seepage through and under the cofferdam. This shall include, but is not limited to, location, photographs, digital video, and flow estimates of all significant seepage within the cofferdam. Photos and video shall contain an object to serve as a scale reference. The AE shall also document seepage through the relief drains in the concrete pad at the toe of the dam. During the environmental inspection, performed by others, the AE shall perform a preliminary inspection from the top of the cells. The intent is to look for signs of large inflows before the cofferdam is completely dewatered.

B. The AE shall perform geologic mapping within the dewatered area of the cofferdam.

Emphasis shall be placed on the areas outlined in red, in Enclosure 1. The AE shall have an approximate period of two weeks to perform field activities. Geologic mapping shall include, but is not limited to, the following activities:

1. Evaluation for a splash pad at the base of the flooding facility.

2. Formation descriptions and contact locations.

3. Bedding strike and dip data.

4. Fracture descriptions and orientations.

5. Overburden thickness.

6. Other geologic and topographic features, i.e. Ledges and overhangs, bentonite layers, weathered zones.

C. Survey shall be provided by the construction contractor. Coordination with the surveyor shall be handled through the Government construction representative onsite. The construction contractor shall also provide a crew for the purpose of cleaning debris and overburden, as directed, from the bedrock.

D. The AE shall submit a report based on the lock foundation inspection. The report shall include, at a minimum:

1. Description of the activities performed

2. Description of the surface geology

3. Description of dominant joint sets

4. Documentation of seepage

5. Estimate of total inflow and pump recommendations

6. Photo and video documentation

7. Plan view drawings of the geology and seepage

8. Tables of measurements taken

V. Quality Control.

A. Quality Control Plan - The A/E shall submit a Quality Control Plan (QCP) at the start of the project. The QCP shall follow the format of the Quality Control Plan Guide for A/E Contracts (see Enclosure 2). The QCP should generally address scope of work, review process, coordination, customer involvement, crucial design features, site visits, quality indicators, research and development plan (if appropriate) and independent technical review.

B. Quality Control Review - The A/E shall carefully coordinate and review all work in accordance with their quality control plan prior to submission to the Government.

Submittals should require only policy and scoping assurance with minimal technical review by the Government. It should be understood that the Government may not be able to technically review the A/E’s submittals. The A/E is responsible for coordination and technical accuracy of all submitted work. The A/E shall submit certification(s) of an internal review by their office the at 100% completion stage. Payment may be withheld from the A/E if this documentation is not included with the product submittals. The certification(s) for each completion stage shall be submitted in the format of the CERTIFICATION OF INDEPENDENT TECHNICAL REVIEW (see Enclosure 3).

The certification(s) shall include documentation annotating independent technical reviewers’ comments and how the design team resolved them. The certification(s) are to be signed by a Principal with the A/E firm. The A/E shall additionally furnish the signed form, COMPLETION OF INDEPENDENT TECHNICAL REVIEW (see Enclosure 4), with the final product submittal.

VI. Submittals and Schedules. The AE shall submit the following for USACE Technical Personnel review and comment, if any:

A. Quality Control Plan. The QCP shall be submitted within two weeks of the Notice to Proceed.

B. Work Plan. The Work Plan shall be submitted for approval a minimum of two weeks before commencement of field activities. It shall include, but is not limited to, survey coordination, work schedule, data gathering procedures, and personnel.

C. Safety Plan. The Health and Safety Plan (HSP) shall be submitted for approval a minimum of two weeks before commencement of field activities. The HSP shall include a job Activity Hazard Analysis, and shall conform to EM 385-1-1.

D. Geologic Inspection of Lock Foundation Report. The draft report and mapping shall be submitted for review 30 days after the conclusion of field activities, with the final report due 21 days after submission of the draft report. The report shall be added to the Lock Geotechnical Baseline Report, as an appendix. The drawings shall be submitted in DGN format. Photographs shall be taken with a digital camera with a minimum resolution of 5 megapixels and submitted in JPG format. Digital video shall be submitted in MPG or AVI format.

VII. Meetings and Reviews: It is anticipated that the Contractor shall participate in periodic teleconferences as necessary to complete the referenced tasks.

VIII. Period of Performance: All work performed under this Task Order shall be completed by 31 December 2010.

Enclosure 1

Appendix B

Project Photographs

Chickamauga Lock Cofferdam Chattanooga, TN

Project Photos

Photograph 1. Pump array used to dewater cofferdam.

Photograph 2. Close-up of pump array.

5” wide x 3.5” high

Project Photos

Photograph 3. Dewatered cofferdam prior to work commencing.

Photograph 4. Water pooling at end of cofferdam.

5” wide x 3.5” high

Project Photos

Photograph 5. Alluvium relocation to aid in site investigation.

Caption

5” wide x 3.5” high

Photograph 6. A-33. Sheet piles founded on loose tabular limestone boulder.

Project Photos

Photograph 7. C-42. . Sheet piles founded on loose tabular limestone boulder.

5” wide x 3.5” high

Photograph 8. C-42. Sheet piles

Project Photos

Photograph 9. C-42/A-32 Intersection. Sheet piles founded on loose tabular limestone boulder.

Note sheet pile deflection.

5” wide x 3.5” high

Photograph 10. A-31. Sheet piles

Project Photos

Photograph 11. A-31. Close-up of Photograph 10.

5” wide x 3.5” high

Photograph 12. C-38. Sheet piles

Project Photos

Photograph 13. C-38. Sheet pile deflection..

5” wide x 3.5” high

Photograph 14. C-35. sheet pile deflection.

Project Photos

Photograph 15. C-35. Sheet piles founded on loose tabular limestone boulder. Note seepage.

5” wide x 3.5” high

Photograph 16. C-32. Sheet pile deflection and seepage.

| 9

Project Photos

Photograph 17. C-30. End of log protruding out of coffercell.

5” wide x 3.5” high

Photograph 18. C-30. Log protruding out of coffercell. Note seepage..

Project Photos

5” wide x 3.5” high

Photograph 19. Leakage at apron Interface.

Photograph 20. Seepage into apron during apron inspection

Project Photos

Photograph 21. Seepage into apron during apron inspection.

Photograph 22. Seepage from weep hole in sheet piles.

Project Photos

Photograph 23. Seepage from boils at base of sheet piles.

5” wide x 3.5” high

Photograph 24. Seepage from defects in sheet piles

5” wide x 3.5” high

Weep hole

Sheet pile defect

Project Photos

Photograph 25. Seepage from monolith joints.

Photograph 26. Seepage from existing lock and Spillway Gate 1 into dewatered apron.

Project Photos

Photograph 27. Apron Inspection at Spillway Gate 1.

Photograph 28. Apron Inspection at Spillway Gate 2.

Project Photos

Photograph 29. Apron Inspection at spillway gates 2, 3, and 4.

Photograph 30. Apron Inspection at spillway gates 3, 4, and 5 (tie-in).

Project Photos

Photograph 31. Apron Inspection at spillway gates 2, and 3.

Photograph 32. Apron Inspection at spillway gates 2, and 3.

Project Photos

Photograph 33. Apron Inspection at spillway gates 3, and 4.

Photograph 34. Apron Inspection at Spillway Gate 4, and apron tie-in.

Project Photos

Photograph 35. Apron Inspection at Spillway Gate 4, and apron tie-in.

Photograph 36. Apron Inspection at apron tie-in.

Project Photos

Photograph 37. Apron Inspection at apron tie-in.

Photograph 38 Splash pad area evaluation.

Project Photos

Photograph 39 Splash pad area evaluation.

Photograph 40

Project Photos

Photograph 41 Splash pad area evaluation.

Photograph 42

Project Photos

Photograph 43 Splash pad area evaluation.

Photograph 44

Project Photos

Photograph 45 Splash pad area evaluation.

Photograph 46

Project Photos

Photograph 47 Splash pad area evaluation.

Caption

Photograph 48 Solution features 1 and 2 in riverside monolith foot prints.

Project Photos

Photograph 49 Fold at L-4/L-5 monolith joint.

Photograph 50 Fold at L-6/L-7 monolith joint.

Project Photos

Photograph 51 Bentonite bed in Solution Feature 3 in monolith foot print R-12.

Photograph 52 Small amplitude folding in bentonite monolith foot print L-10.

Project Photos

Photograph 53 Calcite/dolomite veins in bentonite bed in monolith foot print L-10.

Photograph 54 Hermitage – Tyrone contact.

Project Photos

Photograph 55 Hermitage – Tyrone contact.

Photograph 56 Bentonite at Hermitage – Tyrone contact.

Project Photos

Photograph 57 Folding and faulting through R13 and R14.

Photograph 58 Close-up of folding in R-13.

Project Photos

Photograph 59 Northeast plunging fold , monolith joint L-11/L-12 just left of center .

Photograph 60 Steeply dipping fold limb, dipping to southeast, monolith L-11 in the background.

Project Photos

Photograph 61 T-4 Bentonite looking southwest.

Photograph 62 T-4 Bentonite. looking northeast

Project Photos

Photograph 63 Folding and calcite/dolomite veins in the T-4 bentonite

Photograph 64 Typical lower Tyrone limestone.

Project Photos

Photograph 65 T-3 bentonite.

Photograph 66 Conditions at western end of cofferdam, in area of Carters limestone.

T-3

Project Photos

Photograph 67 Conditions at western end of cofferdam, in area of Carters limestone.

Appendix C

Seepage Reconnaissance Data

Chickamauga Seepage Reconnaissance Project No.CT0533475

1. Initials 2. Date Page 1

3.

Seepage

ID

7. Notes along DS horz. jt C-47 btwn. C-45 and C- 46 vert./horz.

base of C-45 and apron baffle base of A-35 at spillway tie-in

A-35

C-43

C-43/A-33 intersection

A-33/C-42 intersection

C-42

C-42/A-32 intersection

A-32/C-41 intersection

C-41

LMC / DAP 1/23/2012

NA 70

NA

NA

4.

Seepage Location

5. Distance from face of

Structure (feet)

6.

Estimated

Flow (GPM)

NA

NA

NA

NA

NA

NA

NA

NA

NA

NA

NA

two boils; sheet pile 11 (50 gpm), sheet pile 12 (50 gpm) See video "Seepage C-41 a.AVI" See video "Seepage Dye Test C-41 b.AVI" boil at arc/cell intersection See video "Seepage A-32_C-41 Intersection.AVI" See video "Seepage Dye Test C-41 c.AVI" tie-in at spillway, tailwater elevation at 642?

See video "Seepage Cofferdam-apron tie-in.AVI" tie-in at spillway See video "Seepage Cofferdam-apron tie-in.AVI" tie-in, grout bags, wooden patch in video See video "Seepage Cofferdam-apron tie-in.AVI" in cellular cofferdam beneath sheet pile at spillway toe-in (1 ft from concrete box) See video "Seepage Cofferdam-apron tie-in.AVI" deflected sheet piles on boulder See video "Seepage C-42_A-32 Intersection.AVI" base of sheet piles 5-8 on floater See video "Seepage A-33_C-42 Intersection.AVI" flow over grout from cell/arc intersection See video "Seepage A-33_C-42 Intersection.AVI" leak at arc/cell intersection, interlock sheet pile refused on small boulder at sheet pile 24/25 DS from cell/arc intersection two holes at approximately 10 gpm each in sheet piles (~9' and 11' DS from concrete box)

1. Initials 2. Date Page 2

3.

Seepage

ID

7. Notes

Chickamauga Seepage Reconnaissance Project No.CT0533475

LMC / DAP 1/24/2012

4.

Seepage Location

5. Distance from face of

Structure

6.

Estimated

Flow (GPM)

13 C-41 NA 100

boil from beneath sheet pile interlock 20-21 See video "Seepage C-41 b.AVI" See video "Seepage Dye Test C-41 a.AVI"

14 C-41 NA 100

boil from beneath sheet pile interlock 24-25 See video "Seepage C-41 b.AVI" See video "Seepage Dye Test C-41 a.AVI"

15 C-40 NA 50

boil from beneath sheet pile 8 See video "Seepage C-40 a.AVI" See video "Seepage Dye Test C-40.AVI"

16 C-40 NA 25

boil from beneath sheet pile interlock 17-18 See video "Seepage C-40 b.AVI"

17 A-30 NA 150

flow from three weep holes, sheet interlocks and a boil from beneath sheet pile 150 gpm total See video "Seepage A-30.AVI" See video "Seepage Dye Test A-30.AVI"

18 A-30/C-39 NA 10

leak at arc/cell intersection See video "Seepage A-30.AVI"

19 C-39 NA 30

leak from beneath sheet piles and beneath sheet pile interlock 25-26 See video "Seepage C-39.AVI"

20 C-38 NA 50

sheet piles 6 and 7 refused on boulder, seepage from beneath boulder

21 A-28 NA 100

five leaks from beneath sheet piles 3 through 8 See video "Seepage A-28.AVI"

22 A-28 NA 30

leak from beneath sheet pile interlock 11-12 See video "Seepage A-28.AVI"

23 A-28 NA 70

leak from beneath sheet pile 15 See video "Seepage A-28.AVI"

24 A-28/C-37 NA 15

leak from beneath cell/arc intersection See video "Seepage A-28_C-37.AVI"

1. Initials 2. Date Page 3 3.

Seepage

ID

7. Notes

LMC / DAP 1/24/2012

4.

Seepage Location

5. Distance from face of

Structure

6.

Estimated

Flow (GPM)

25 C-36 NA 65

25 gpm beneath sheet pile interlock 3-4, 20 gpm beneath sheet pile 9, 20 gpm beneath sheet piles See videos "Seepage C-36 a .AVI" and "Seepage C-36 b .AVI"

26 A-26 NA 20

leakage beneath sheet piles 25,26,and 27

27 C-35 NA 70

sheet piles 23 and 24 refused on boulder, deflected inward See video "Seepage C-35.AVI" See video "Seepage Dye Test C-35.AVI"

28 C-34 NA 35

leakage from weep hole in sheet pile 9 and sheet pile interlock 5-6 See video "Seepage C-34.AVI"

29 A-24 NA 330

leakage from weep holes in sheet piles 12, 14, 16, and 18 (3 at 100 gpm and 1 at 30 gpm, 1 at 30 gpm is one foot higher than rest) See video "Seepage A-24.AVI"

30 C-33 NA 1300

leakage from 13 weep holes in sheet piles 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, and 25 See video "Seepage C-33.AVI"

31 A-23 NA 100

leakage beneath sheet piles 15-17 See video "Seepage A-23.AVI" See video "Seepage Dye Test A-23.AVI"

32 C-32 NA 70

leakage from weep hole in sheet pile 2 See video "Seepage C-32 a.AVI"

33 C-32 NA 100

leakage beneath sheet piles 9 and 10, sheet piles are deflected inward See video "Seepage C-32 a.AVI"

34 C-32 NA 30

leakage from beneath sheet pile 12 See video "Seepage C-32 b.AVI"

35 C-32 NA 140

leakage from beneath sheet pile 15, 50 gpm leakage from defects/holes in sheet pile 17, 20gpm boil beneath sheet pile 17, 70gpm See video "Seepage C-32 b.AVI" See video "Seepage Dye Test C-32 a.AVI"

36 C-32 NA 50

leakage from beneath sheet pile 21 See video "Seepage C-32 b.AVI"

1. Initials 2. Date Page 4

3.

Seepage

ID

7. Notes

LMC / DAP 1/23/2012

4.

Seepage Location

5. Distance from face of

Structure

6.

Estimated

Flow (GPM)

37 C-32 NA 70

boil from beneath sheet pile 24 See video "Seepage C-32 c.AVI" See video "Seepage Dye Test C-32 b.AVI"

38 C-32 NA 30

leakage from weep hole in sheet pile 26 See video "Seepage C-32 c.AVI"

39 C-32 NA 150

high velocity leakage from beneath sheet piles 28, 29 and 30 See video "Seepage C-32 c.AVI"

40 A-22 NA 100

high velocity leakage from beneath sheet pile 8 See video "Seepage A-22 a.AVI"

41 A-22 NA 150

high velocity leakage from beneath sheet pile interlock 10-11 See video "Seepage A-22 a.AVI"

42 A-22 NA 80

leakage from holes in sheet piles 14-15, 20 gpm leakage from beneath sheet pile interlock 18-19, 60gpm See video "Seepage A-22 b.AVI"

43 C-31 NA 60

leakage from beneath sheet pile 5 See video "Seepage C-31.AVI"

44 A-21 NA 300

boils from beneath sheet piles 3-7, deep flow, water ~

2.5 feet deep, video may not represent true conditions See video "Seepage A-21 a.AVI" See video "Seepage Dye Test A-21.AVI"

45 A-21 NA 30

leakage from weep hole in sheet pile 10 See video "Seepage A-21 b.AVI" See video "Seepage Dye Test A-21.AVI"

46 A-21 NA 30

flow from holes in sheet pile 19 See video "Seepage A-21 c.AVI"

47 C-30 NA 50

leakage from beneath sheet pile 8 See video "Seepage C-30 a.AVI" See video "Seepage Dye Test C-30 a.AVI"

48 C-30 NA 250

sheet piles 18 and 19 refused on a log protruding out of the base of the coffercell source of leakage.

See video "Seepage C-30 b.AVI" See video "Seepage Dye Test C-30 b.AVI"

1. Initials 2. Date Page 5

3.

Seepage

ID

7. Notes

LMC / DAP 1/24/2012

4.

Seepage Location

5. Distance from face of

Structure

6.

Estimated

Flow (GPM)

49 A-20 NA 120

leakage from beneath sheet piles 11, 13, 14, 15 and 18, 60gpm; leakage from beneath sheet pile 20, 60gpm See video "Seepage A-20.AVI" See video "Seepage Dye Test A-20.AVI"

50 C-29 NA 50

leakage from beneath sheet piles 15, 17, 18, and 20, 50gpm See video "Seepage C-29.AVI"

51 A-19 NA 180

leakage from weep hole in sheet pile 2 and defect in sheet pile 7 See video "Seepage A-19.AVI"

52 A-19 NA 50

leakage from beneath sheet pile 11 See video "Seepage A-19.AVI"

53 A-19 NA 100

leakage from weep holes in sheet piles 16 and 21 See video "Seepage A-19.AVI"

54 A-18 NA 90

leakage from weep holes in sheet piles 2, 4 and 6, about 30 gpm each See video "Seepage A-18.AVI"

55 A-19/C-28 intersection NA 50 leakage from weep hole in sheet pile 1 of C-28 See video "Seepage A-19 and C-28.AVI"

Water too deep past A-18 to continue walking inspection Inspection continues on 02/15/12 with inspection of landside monoliths

56 L-17/L-16-2 NA 10

monolith joint leak See Video "Seepage L17-L16_2 monolith joint"

57 L-116-1/L-15 NA 5

monolith joint leak See Video "Seepage L16_1-L15 monolith joint"

58 L-14/L-13 NA 5

monolith joint leak See Video "Seepage L14-L13 monolith joint"

59 L-13/L-12 NA 10

monolith joint leak See Video "Seepage L13-L12 monolith joint"

1. Initials 2. Date Page 6

3.

Seepage

ID

7. Notes

LMC / DAP Feb. 2012 4.

Seepage Location

5. Distance from face of

Structure

6.

Estimated

Flow (GPM)

60 L-12/L-11 NA 5

monolith joint leak See Video "Seepage L12-L11 monolith joint"

61 L-11/L-10 NA 10

monolith joint leak See Video "Seepage L11-L10 monolith joint"

62 L-10/L-09 NA 15

monolith joint leak See Video "Seepage L10-L09 monolith joint"

63 L-09/L-08 NA 15

monolith joint leak See Video "Seepage L09-L08 monolith joint"

64 L-08/L-07 NA 10

monolith joint leak See Video "Seepage L08-L07 monolith joint"

65 L-07/L-06 NA 5

monolith joint leak See Video "Seepage L07-L06 monolith joint"

66 L-06/L-05 NA 5

monolith joint leak See Video "Seepage L06-L05 monolith joint"

67 L-05/L-04 NA 3

monolith joint leak See Video "Seepage L05-L04 monolith joint"

68 L-04/L-03 NA 10

monolith joint leak See Video "Seepage L04-L03 monolith joint"

69 L-03/Lock NA 3 monolith joint leak See Video "Seepage L03-Lock monolith joint"

70 A-17 NA 150

boil at toe of connector cell at sheet piles 14-15-16 counting from rive-left to river-right.150+GPM See video"Seepage A-17.MOV"

71 A-17 NA 15

weep hole in sheet pile 4.

See video"Seepage A-17.MOV"

1. Initials 2. Date Page 7

3.

Seepage

ID

7. Notes

74 Apron-cofferdam tie-in NA 1000

Apron dewatered for inspection, additional seepage revealed below water line.

See Video "Seepage Apron Tie-in Dewatered" weep holes in sheet piles 10, 11, 12 counting river-left (riverside) to river-right. 50 GPM combined

73 C-27 NA 20

two holes in sheet piles 4 and 6 counting river-right (landside) to river-left. 20 GPM combined

LMC / DAP Feb. 2012 4.

Seepage Location

5. Distance from face of

Structure

6.

Estimated

Flow (GPM)

72 C-25 NA 50

Appendix D

Seepage and Dye Testing Videos

(DVD)

Appendix E

Figures

Figure Number

Chickamauga

Cofferdam Work Plan Lay-out CT053475

Priority Area 2

Priority Area 1

Priority Area 3

CT053475

Figure Number

CHICKAMAUGA LOCK

COFFERDAM,

PROFILE THROUGH R-13, R-14,

T-4 (Otb)

Tyrone (Ot)

Tyrone (Ot)

Hermitage (Oh) Tyrone (Ot)

T-4 (Otb)

INDICATES THRUST SURFACE AND RELATIVE MOMENT

Note; Dips shown are apparent dips

A A’R-13R-14R-15

Appendix F

Panorama Section Photographs and Geological Photographs

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