Study of Air-cushion Isolation Effects in Concrete Gravity Dam
Chen Jiang1,2, Xiong Feng1,2
1. College of Architecture and Environment, Sichuan University, Chengdu 610065, China; 2. Key Laboratory of Energy Engineering Safety and Disaster Mechanics, Ministry of Education, Sichuan University, Chengdu, 610065, China
Abstract：The gas-liquid-solid tri-phase coupling numerical model of the air-cushion isolation control was presented in this paper, in which the cracking behavior of concrete was considered. The radiation damping effect on truncated boundary of dam foundation was considered by using viscous-spring artificial boundary condition. The 3D nonlinearity simulation of air-cushion isolation effects in concrete gravity dam was carried out for the first time. It shows that air-cushion reduces the hydrodynamic pressure and acceleration effectively, so the cracking range of dam body are decreased. As the thickness of air-cushion increases, the reduction of hydrodynamic pressure and acceleration increases, the increment rate of reduction degree decreases progressively. Compared with uniform-thickness air-cushion, variable-thickness air-cushion can improve the utilization ratio and develop the air-cushion isolation effects more effectively. In the various cases of this paper, the maximum of hydrodynamic pressure is reduced by 50% approximately, the maximum of dam crest acceleration is reduced by more than 30% with variable-thickness air-cushion.
2014, Vol. 33 
