通过动力时程方法求出地震作用系数,分析拟静力方法计算偏于保守的原因。并依据动力时程方法的计算结果给出拟静力方法的适用范围并修正拟静力方法的地震作用力和地震作用系数公式。数值模拟结果表明,坡高与波长的比是影响边坡稳定性的重要因素,而坡角对其影响则较小;其次,拟静力方法的适用范围是非常有限的,在坡高很小时,拟静力方法的计算结果偏于危险,当坡高较大时,拟静力方法计算结果偏于保守;在远场和近场地震作用下,地震动加速度峰值系数不同,远场地震主要是水平地震作用力,近场地震主要是竖向地震作用力。
The coefficient of seismic peak ground acceleration is obtained by the method of dynamical time-history, and then, the reason of the conservation of the pseudo-static method is analyzed. The application range of pseudo-static method, the seismic force and the formula of safety factor are given by the method of dynamical time-history. It is proved that the key factor is the ratio of the height of slope to its wave length, but the slope angle. Then, the scope of the method of pseudo-static is finite, and the calculated result is conser- vative for higher slope. At last, the coefficients of seismic peak ground acceleration are different in consideration of earthquakes of far- field and near-field. The far-field earthquake is mainly in horizontal seismic action, and the near-field earthquake is mainly in vertical seismic action.