【摘要】 与低坝相比,高土石坝受地基刚性的约束减弱,坝体的自振周期延长。在坝体地震反应中,高阶自振周期容易与地震卓越周期迂合,高阶振型的振动易于被激发放大,从而导致坝体地震加速度沿坝高分布与低坝有所不同。现行《DL5073-1997水工建筑物抗震设计规范》对土石坝动态分布系数的规定适合于150m以下的土石坝,已不能适应高土石坝建设的发展需要。因此,利用反应谱法,研究了高土石坝地震动态分布系数,得到了随着坝高的增加,振型数目、高阶周期与地震卓越周期的迂合几率以及加速度分布的变化规律,最终给出了坝高大于150m的土石坝的切速度分布。更多还原

【Abstract】 Compared with low dams high earth-rock dams get less constraint from stiffness of foundation and its self-vibrating period becomes prolonged. During the seismic response high order self-vibrating period is easily to coincide with the seismic predominant period and the vibrations of high order get more opportunities to be activated and magnified which result in the seismic acceleration distribution is somewhat different from low dams. However the seismic dynamic distribution coefficient suggested in the present Code for Seismic Design of Hydraulic Structure DL5073-1997 is suitable for earth-rock dams lower than 150 meters but not for higher earth-rock dams any longer. Therefore for the improvement of seismic design level of high earth-rock dams it is an urgent task to investigate the seismic dynamic distribution coefficient and determine the seismic design load.更多还原