Hydraulic Model Studies of Tiber Dam Auxiliary Outlet Works Missouri River Basin Project Montana.

摘要

The existing canal outlet works tunnel at Tiber Dam, Mont, is used as an intake and as the upstream portion of an auxiliary outlet works designed to provide additional reservoir release capacity. The existing 17-ft-dia horseshoe free flow tunnel is converted to a 15-ft 6-in.-dia pressure tunnel and is connected to a new 10-ft 9-in.-dia tunnel by a drop inlet and vertical bend. The smaller tunnel is equipped with a 7.25- by 9.25-ft slide gate and terminates in a stilling basin in the river channel. A 1:17.53 scale model was used to develop the hydraulic design of the auxiliary outlet works including: the drop inlet and vertical bend from the existing canal outlet works tunnel, and the transition in the tunnel downstream from the gate chamber. Details of the model testing and recommended modifications to the preliminary design prompted by the testing are presented. (Author)