As part of a spillway remediation project in the Southeastern U.S., Barnard is enlarging an existing auxiliary spillway and constructing an innovative, non-mechanical means of controlling the spillway: a Fusegate® system composed of individual concrete gates designed to tip over at certain hydrological thresholds to further increase spillway capacity.
The spillway remediation project involves the modification of a high-hazard dam structure that, in its present configuration, is overtopped at approximately 40 percent of the Probable Maximum Flood (PMF). The remediation will enhance the safe discharge of inflows associated with the PMF. Barnard is expanding the auxiliary spillway through drilling, blasting, and rock excavation. The excavated material is either hauled away or loaded onto barges and deposited within the lake. As the drill and blast activities progress, Barnard is installing rock bolts, wire mesh, and rock anchors and overseeing foundation grouting. Once drill and blast activities are completed, the Fusegate® structure and concrete training walls will be constructed at the mouth of the auxiliary spillway. The final scope of work on the project will involve demolishing approximately 10 feet of the existing dam, which will be built back up with a concrete PMF wall.
Location: Southeastern United States
Owner and Engineer: Confidential
Contract Type: Fixed Lump Sum
Status: Currently under construction
240,000 CY of rock excavation
3,100 barge loads of rock
86,000 LF of precision presplit