地震波的入射方向对河谷岸坡放大系数的影响

用有限元和无穷元耦合模型计算了半圆形河谷在单位脉冲入射下的河谷地面反应，从而分析了地震波的入射方向对河谷岸坡放大系数的影响．岸坡放大系数定义为：河谷沿岸不同高程处的地震动峰值加速度与河谷底处地震动峰值加速度之比．因此，岸坡放大系数的变化将改变拱坝的应力和应力分布．研究表明：地震波人射角的轻微变化将对河谷岸坡放大系数产生极大影响，这说明高拱坝的抗震分析宜考虑输入地震波的不同入射方向的作用．

Effects of Earthquake Wave Input Direction on Canyon Surface Amplifier Factor

A finite element and infinite element coupling model is used to calculate the seismic motion ofcanyon surface subjected to the unit plus in different directions. The canyon surface amplifier factor is comput-ed. The canyon surface amplifier factor is defined as: the seismic motion peak accelerations at canyon surfaceare divided by the peak acceleration at canyon bottom. Therefore, the factor's change will affect the arch damstress and stress distribution. The study demonstrates: a small change of input angle will have a large effect onthe canyon surface amplifier factor. It seems to be suitable that the input direction of input seismic motion isconsidered in the dynamic analysis on high arch dam.