地震动输入界面处剪切波速对加速度峰值的影响

The Effect of Shear Wave Velocity of Seismic Wave Inputting Interface on the Peak Accelerations

利用目前工程上广泛应用的一维土层地震反应计算程序对成都平原某典型卵石场地剖面进行了计算,得到了不同输入地震强度下的加速度峰值随输入界面处剪切波速增大的变化规律。结果表明,无论是地表加速度峰值,还是地下5m处的加速度峰值,在相同的地震动输入强度下,均随着输入界面处剪切波速值的增大呈对数形式增大。且在小震输入下的增加速率最快,中震输入下的增加速率次之,大震输入下增加的速率最慢。当地震动输入界面处剪切波速值从500m/s增加至800m/s时,加速度峰值均增大20%以上,最大达到32%。统计得到的二者间的经验关系式,可作为本地区具有相似场地条件工程换算加速度峰值的经验公式,为工程抗震设计人员提供参考。

Based on one actual engineering site profile of Chengdu area, studied the effect of shear wave velocity of seismic wave inputting interface on the peak acceleration. The results show that both the peak ground acceleration and the peak acceleration underground 5 meters increased logarithmically with shear wave velocity＇s increasing. The increase rate was the fastest under small earthquake input, the increase rate of moderate earthquake input was second, major earthquake input increase was slowest. When the wave velocity value increased from 500 m/s to 800 m/s, the peak acceleration increased more than 20%, the biggest reached 32 %. The experience formula can be used as a conversion formula of the peak accelera- tion in this region and provide reference for seismic design of engineering personnel.