(AE-DBB_23824429) (SIOP) Seismic Repair DD4, B704, PSNS (DBB-AE)

DBB with Construction Contract award in FY27 or FY28 (FY25 AE Design) This project completes full wall tieback repairs and performs work on the floor of Dry Dock 4, as needed to support a ship stability system. The dry dock is currently limited to one asset at a time without full wall tieback. This project will also include the installation of foundations on the dry dock floor, as needed to support ship stability systems. Existing ground water relief wells will be overhauled, and additional groundwater relief wells will be installed in the dry dock floor to ensure drain system integrity. Drainage wells and pumps will be installed to alleviate ground water infiltration issues in Pumpwell 4 during extended dock floodings. Evidence from the previous wall tie back project indicates that injected grout has migrated into the drainage curtain, and potentially reducing its drainage capacity. Overhaul of the existing ground water relief wells and installing new wells is needed to ensure restoration of the groundwater drainage system to its design capacity. Drainage pumps will be installed to alleviate flooding issues in Pumpwell 4.