LOCK FOUNDATION AND SITE PREPARATION FOR LOCK and DAM 25 NAVIGATION ECOSYSTEM SUSTAINABILITY PROGRAM (NESP)

The U. S. Army Corps of Engineers, St. Louis District, is seeking a firm to furnishing all equipment, labor, operators, supervision/site superintendent, quality control, supplies, materials, and incidentals necessary to satisfactorily perform and provide construction activities of lock foundation and site preparation work. The lock foundation work establishes the lock wall and floor foundation. It consists of excavation and disposal of existing scour protection riprap that was part of previous scour hole emergency repair, dredging of sand fill, placement of sand fill in the proposed lock foundation, and placement of riprap berm. Work also includes the construction of a separator wall that will separate the river side riprap berm from the dredged sand that will be placed as foundation material for the future river wall monoliths and lock floor. The separate wall will be a sheet pile wall braced with piles. This effort also includes a deflector on the downstream side of the dam to route water flowing through the tainter gated dam adjacent to the river walls around the sheet pile separator wall. For the site preparation work, additional dredge borrow will be placed upland for a future staging and laydown area and a sanitary outfall pipe will be installed.