Page - 844 - in Book of Full Papers - Symposium Hydro Engineering

61.454 m connected with Tunnel along 546,221m and Outlet tunnel ends at Plunge pool. There are two types of plugging done that is Primary plugging along the 17,74 m the starting position of the conduit and Main plugging along the 41 m at the core of the dam. Immediately after closing of closure gate on August 31, 2015, Engineer will confirm the area where is in the right bank of Plunge Pool up to front of Tunnel Outlet is satisfied to use for access and material loading area from above. After closure gate, lining concrete of tunnel at position grout stopper shall be cut by using electric grinder to make groove for fixing of the Steel Galvanized Plate. After the completion of the installation of Steel Galvanized Plate, so Grout Pipes, including Riser Pipes, Backfill pipes, and T-type Socket are installation and fixed firmly by U-bolts at 10 cm center to center at the correct position from Grout Pipe. Drainage pipe is installed at the bottom of tunnel before 1st stage of concrete placing then Shut-off gate, tied with a wire rope of 12 mm diameter, is installed at the upstream end drainage pipe. Forms are installed and firmly fixed together by using wooden timbers, anchor bars tension bars to avoid displacement or deformation. All supports wooden timbers and anchor bars at upstream of forms for all lift (up to 5th layer of A1 Block) shall be installed and firmly fixed prior to the placing concrete. Cooling pipe was constructed for each Block. All cooling pipes are tested for the leakage under the pressure of 3.5 kg/cm2. The cooling water will be continuously provided by pump through the cooling pipes from the time of placing concrete until the concrete temperature comes down to 26oC. The discharge of water shall be controlled not to exceed 50oC of the concrete temperature. If necessary the water temperature shall be controlled by ice. KEYWORDS Large Diversion tunnel, Primary plug, Main plug, control the concrete temperature 844