Lock Excavation, Chickamauga Lock - Request for Information

There are two Request for Information (RFI) associated with the Lock Excavation at Chickamauga Lock Project, Chattanooga, TN. First, is a general RFI to determine a competitive basis. Second, is a Project Labor Agreement (PLA) RFI to determine if use of a PLA is appropriate for this project. We request that you respond to both. The Nashville District U.S. Army Corps of Engineers (USACE) anticipates a requirement for a firm fixed-price construction contract to accomplish the following work* at Chickamauga Lock project: Major components of the Lock Excavation contract include: 1. Access by water. Most work components will be on or inside the existing cofferdam located immediately downstream of the dam. The only access to provide equipment and materials to this worksite will be by water or across the channel for the lock's lower approach. A ramp dedicated to the contractor to provide land access to floating plant for this delivery is located within one eighth of a mile to the cofferdam and additional land area adjacent to the ramp will be available to the contractor. 2. Dewatering. The contractor will be required to install a dewatering system to dewater the cofferdam and keep it dewatered during all construction activities within the cofferdam. 3. Secant Pile Wall. After dewatering, a 51 foot long secant pile wall will be constructed in the cofferdam interior. The concrete secant piles will be 2 feet in diameter with the secondary piles having the addition of reinforcing steel. The piles will range in length from 22 to 44 feet and will require drilling through the limestone bedrock. 4. Inclined Rock Anchors. Also within the cofferdam interior, the contractor will install 44 inclined rock anchors. These are 60 to 68 strand anchors with design capacities of 1900 to 2100 kips. They range in length from 66 to 102 feet, have bond lengths of 39 to 43 feet, and are inclined 40 degrees off of horizontal. 5. Exploratory Drilling. Within the cofferdam, 71 exploratory drill holes will be required, up to approximately 70 feet deep. 6. Instrumentation. Contractor will be required to operate and maintain an existing automated and manual government furnished instrumentation system. Existing instruments include inclinometers, piezometers, alignment pins, pressure cells and survey markers. 7. Rock Excavation. Excavation and disposal of approximately 100,000 CY of predominantly limestone within the cofferdam. It is expected the contractor employ strict controlled blasting in the excavation of the rock in lifts ranging from 5 to 20 feet. Portions of the excavation will require approximately 5,000 CY of mechanical excavation. The maximum depth of rock excavation is approximately 32 feet. The excavation will be carried down utilizing excavation support measures such as rock bolts and shotcrete. Excavated rock will be disposed of in an upland disposal site located on Government property at Chickamauga Dam. The contractor will be required to prepare and maintain this disposal area during the duration of the contract. The contractor will be required to provide all plant, labor and materials to construct these features. *Please note that this description is subject to change.