基于振动台实验的典型滑坡单元体震动滑移特征发现

New results of the slid characteristics of a typical earthquake landslide model based on shake table tests

针对典型滑坡滑动单元在地震过程中的滑移特征,制作了典型振动台物理模型,通过输入不同频率、峰值和持时的正弦地震波,开展了一系列的实验研究工作,得了一些比较有意义的新成果:(1)在输入地震波强度足够大时会出现瞬时沿滑带向上的滑移行为,存在向上和向下两个滑移屈服加速度;(2)在研究分析中,不可以坡底输入的地震加速度值而应以滑带处局部加速度值作为判别滑移与否和滑移量大小的计算数据;(3)滑体沿滑带产生的永久滑移总量随地震波持时增加呈阶梯波状增长;(4)不同时刻任一周期的振动滑移特征相对独立,且每一地震波周期时间内具有几乎相同的周期性滑移特征,总体滑移量是无数周期内滑移量的累加;(5)在每一地震波周期时间内,滑体向上和向下的滑移特征受控于相应向上和向下屈服加速度,其向上和向下滑移矢量和构成每一周期时间内的永久位移。

In order to examine the slid characteristics of the typical landslide model triggered by strong earthquakes,physical models for shake tables are created and a series of tests are conducted by inputting sine seismic waves with different frequencies,duration and peaks. The following five interesting findings are obtained from the tests.（1） The slid-body may slide not only downward but also upward along the slid-belt when undergoes a strong shake wave and two yield accelerations（the downward and upward yielding acceleration） exist.（2） The data for slid analysis should be the local acceleration close to the slid-belt other than the acceleration at the bottom of the landslides model.（3） With time growing,the overall displacement of the slid-body along the slid-belt accumulates with the characteristics of the stepped wave in shake-table testes.（4） The slid characteristics of different wave periods are independent of each other and are nearly the same.（5） The slid characteristics of the slid-body are controlled by the downward and upward yielding accelerations and the vector sum of the downward and upward slide displacement along the slid-belt make up the overall permanent displacement in every wave period.