【摘要】 基于气幕隔震控制的气-液-固三相耦合数值模型,在该模型中考虑了坝体混凝土的开裂行为,采用黏弹性人工边界模拟坝基截断边界的辐射阻尼效应,首次完成了混凝土重力坝气幕隔震效果的三维非线性数值模拟。结果表明:气幕可以有效降低坝体上游面的动水压力及坝体加速度反应,从而减小坝体的开裂范围。随着气幕厚度的增大,动水压力和加速度削减越多,削减幅度的提高率递减。采用变厚度气幕能提高利用率,更有效地发挥气幕的隔震效果,该工况,变厚度气幕对混凝土重力坝动水压力极值的削减幅度约为50%,坝顶加速度峰值的消减幅度超过30%。更多还原

【Abstract】 The gas-liquid-solid tri-phase coupling numerical model for a concrete gravity dam based on air-cushion isolation control was presented here. In this model,the cracking behavior of dam concrete was considered. The radiation damping effect of the truncated boundary of the dam foundation was simulated with a visco-elastic artificial boundary condition. The 3D nonlinear simulation of air-cushion isolation effects on the concrete gravity dam was conducted for the first time. It was shown that the air-cushion reduces the hydrodynamic pressure and the acceleration response of the dam body effectively,so the cracking range of the dam body decreases; with increase in the thickness of the air-cushion,the reduction of hydrodynamic pressure and the acceleration response is more significant; the rate of reduction level decreases progressively; compared with the uniform-thickness air-cushion, the variable-thickness air-cushion can improve the utilization ratio and develop the air-cushion isolation effects more effectively. In the various cases here,the maximum hydrodynamic pressure is reduced by 50% approximately,the maximum dam peak acceleration is reduced by more than30% with the variable-thickness air-cushion.更多还原