AmerenUE, owner of Bagnell Dam and the Osage Hydroelectric Project, desired to mitigate leakage through concrete monolith joints in Bagnell Dam. With the assistance of Golder Associates Inc., AmerenUE screened available technologies to reduce the volume of leakage, which was believed to result from deterioration of the copper strip waterstops originally installed during construction of the dam in the 1930s. AmerenUE ultimately elected to install an inflatable waterstop seal system, which was installed in four of the joints with the highest observed water leakage rates into the drainage gallery. Nominal 8-inch diameter inflatable rubber waterstop seals were installed vertically along the entire length of each joint in boreholes carefully drilled from the dam crest. Seepage water flows, as measured and observed in the gallery drains of the East and West Retaining Sections were recorded before and after installation of new waterstop seals to document the effectiveness of the seals to reduce leakage through the joints. Results indicate a significant decrease in water flow in the repaired east and west retaining section joints/drains compared to the previous year's condition. Seepage flow rates into the West Retaining Section gallery were reduced up to 95% along one of the joints, with an average reduction of approximately 60% across three joints. This seepage reduction met or exceeded the project goals and indicated a successful use of the inflatable waterstop technology for the project.
展开▼
