DESIGNING AND OVERSEEING THE SAFE EXECUTION OF CONTROLLED BLASTING WORK TO EXCAVATE HARD ROCK AND MASS CONCRETE IN AND NEAR DAMS

摘要

Modifications to existing dams often require the excavation of rock located in abutment and downstream/upstream areas. Modifications might also require the demolition and removal of mass concrete or concrete structures located in critical areas of dams and/or near operating power plants. In some cases, modifications have required excavation of tunnels that penetrate mass concrete in dams. Engineers charged with designing dam modification work and Dam Safety Officials who must approve methods and limitations face challenging decisions. In some cases, due to the volume of hard rock or mass-concrete that must be removed and/or access and safety considerations, the use of mechanical excavation methods is impractical or very limited. Water storage and delivery interruption constraints often limit excavation method options due to the limited time the work can occur. When the use of drill-blasting methods is desired, determining what methods can be used and controlled to assure critical rock and structural elements of dams are protected is an extremely important element of the design work. Preventing disruptions to ongoing power generation and water delivery systems is also critical.