强地震荷载作用下临水挡土墙的拟动力法稳定性分析

STABILITY ANALYSIS OF WATER FRONT RETAINING WALL SUBJECTED TO SEISMIC LOADS USING PSEUDO-DYNAMIC METHOD

假设墙后填土破坏面为曲面,用正弦波模拟地震加速度时程曲线,采用拟动力法对临水挡土墙进行稳定性分析,确定了挡土墙和墙后填土所受的阻尼力和惯性力,获得地震荷载作用下挡土墙的被动土压力、抗滑和抗倾覆稳定性系数的封闭形式解析解。定量分析地震加速度、放大系数、墙后填土的物理力学参数和动水压力对挡土墙的滑动位移、挡土墙的抗滑和抗倾覆稳定性系数的影响,得出当地震加速度、放大系数越大,水位越高,内摩擦角越小,临水挡土墙的稳定性越差。

It is assumed that failure surface of backfill soil is composite curved one. Pseudo-dynamic method, in which time-history curves of acceleration was simulated by sinusoidal motions, was adopted to research the stability of the water front retaining wall subjected to seismic loads. The damping force and the inertial force acting on retaining wall and backfill soil were investigated. The closed-form solutions of passive earth pressure and dynamic factor of safety against sliding and rotation of the retaining wall during earthquake were obtained. Finally, effects of seismic acceleration, amplification factor, wall height, physico-mechanical parameters of backfill soil and hydrodynamic pressure acting on water front retaining wall on sliding displacement, dynamic factor of safety against sliding and rotation of the retaining wall were quantitatively analyzed. It is concluded that the stability of the water front retaining wall is getting worse when the earthquake speeds up, the water level gets higher and the internal friction angle gets smaller.