Physical Model Tests for Closing Forces on Emergency Gate of Xiaqu Project

Enough closing force is a basic guarantee of the safe operation of the emergency gate. In order to analyze the closing force of the emergency gate of Xiaqu Project, a physical model with the geometrical scale of 1:25 was designed and the tested results showed that small opening degrees corresponded to large horizontal thrusts on the gate, and the gate underwent large frictions. Thus, small closing forces always appeared when the emergency gate was about to be fully closed and the opening degree was small. When the water level in the surge shaft in Xiaqu Project covered a range of 2411.55 m to 2522.81 m, the minimum closing forces were calculated as -374.5 kN and the corresponding opening degree was 0.02, which meant an additional weight of at least 38.5 t was needed to ensure the closing of the emergency gate. The relevant research results in this paper could also provide technical references for other similar projects.