【摘要】 详细介绍了求解复杂地形在地震波作用下无量纲频率动力响应的有限元方法,并通过与解析解的比较,验证了本文方法的可行性。同时采用本文的方法,计算了圆弧形沉积谷地在平面SV波入射下的地震响应,分析了沉积谷地厚度、地震波入射角度和频率等因素的影响,结果表明:(1)沉积谷地上方的放大系数明显比两侧的大,两侧的放大系数受沉积谷地的影响较小。(2)相对于半圆形沉积河谷,浅圆弧形沉积谷地在无量纲频率η较小时的放大系数较小,高频差别不大。(3)入射角度对放大系数β有影响,特别是当无量纲频率η较小时,随着频率的增大,β有增大,且峰值向入射波的异侧有少许偏移。(4)层状半空间沉积谷地的β比均匀半空间沉积谷地的大。更多还原

【Abstract】 In this paper,the finite element method is introduced in detail to solve the dimensionless frequency dy-namic response of complex topographyby the incident seismic wave,and the feasibility of this method is verified by comparing with the analytical solution. At the same time,the seismic response of circular-arc alluvial valley under the incident plane SV wave is calculated by using the method in this paper. The effect of the thickness of the alluvi-al valley,the incident angle and frequency of the seismic wave is analyzed. The results show that(1)the amplifica-tion factor above the alluvial valley is obviously larger than that of both sides,and the amplification factor of both sides is less affected by the alluvial valley;(2)compared with the semicircular alluvial valley,the amplification co-efficient of shallow circular alluvial valley is smaller when the dimensionless frequency η is small,but the differ-ence is small in the high frequency stage;(3)the incidence angle has an impact on the amplification coefficient β,especially in the low frequency,β increases with the increase of frequency,and the peak value has a little shift to the opposite side of the incident wave;(4)the amplification coefficient β of alluvial valley embedded in a layered half space is larger than that of alluvial valley embedded in a uniform half-space.更多还原