Hancock Brook Lake Dam, Plymouth CT, Thomaston Dam & Black Rock Lake Dam, Thomaston, CT
Contract # W912WJ-06-C-0006
The replacement and repair of various concrete structural and surface defects at three different U.S. Army Corps of Engineers flood control dam sites in Connecticut were the main requirements of this project. Each dam site required unique approaches.
At the Hancock Brook Lake Dam, two structural steel debris collection units were removed and replaced. An outlet manhole structure and a five-foot diameter reinforced concrete pipe were repaired. A four-foot diameter cast iron flap gate was removed, repaired, and reset.
The Thomaston Dam site required concrete repairs to the structural concrete dam wing walls and drainage improvements to the access road. An historic bridge upstream of the dam was re-pointed and coated with a protective cement membrane. Bridge walls were also repaired and made structurally sound.
The Black Rock Lake Dam required the repair of the concrete surface at the bottom of the thirty-foot deep inlet structure. In addition, a twelve-foot long by five-foot thick portion of the dam’s concrete wing wall retaining structure had to be removed and replaced. After replacement, five-foot deep weep holes were cored into the structure below to relieve water pressure and the new concrete was waterproofed.
At all three sites, removal and replacement of various sections of the existing water level gauge system were required, some at elevations thirty feet above grade. Work accessibility and the provision of safe working platforms were a major component of these projects. Various combinations of swing staging, boom lift work platforms, and staging were utilized individually or in combination to effect safe and secure personnel access and ensure optimal performance and results.