摘要
在弹性力学和波动理论的基础上,运用时域和频域计算方法分析出平面SH波穿越地裂缝介质时的传播规律。通过引入地裂缝界面等效切向刚度等有关参数,对出平面波传播的频域及时域分析方法进行对比验证,分析地裂缝界面的等效切向刚度、入射波频率、入射角和裂缝面剪切强度对穿越地裂缝时出平面SH波的传播规律的影响。多个参数的交叉对比分析结果表明,等效切向刚度或入射角度越小,地裂缝界面的低通滤波效应越明显。裂缝面的剪切滑移导致透射波速在达到临界值时被截止。输入实际地震波时,随着透射系数的减小,透射波幅值减小不明显但波形变化较大;反射波幅值和波形将逐渐趋近入射波,但相位相对于入射波存在一定的滞后。为得到真实有效的波动传播规律,采用线性内插对波动时程数据进行处理,结果表明本文方法不会影响计算的精度。
It is important to study seismic wave propagation through fractures in the field of earth quake engineering. Based on elasticity mechanics and wave motion theories, the propagation law of an anti plane SH wave across a ground fissure interface is analyzed using time domain and fre quency domain calculation methods in this paper. Recursion equations are established and a con trast verification between the two methods is conducted. The influence of certain related parame ters on the propagation law of anti plane SH waves are discussed, including the equivalent shear stiffness of the ground fissure interface, incidence wave frequency, incident angle, and shear strength of the fissure surface. Furthermore, a cross comparison of these parameters is per formed, and recursion equations considering the shear strength of fissure are established. Results indicate that the transmission coefficient increases with an increase in equivalent shear stiffness and the incident angle, but decreases with an increase in incident frequency. In addition, the low pass filtering effect of the ground fissure interface is more evident with a decrease in equivalent shear stiffness and the incident angle. Under the input of a real seismic wave, there is a decrease of transmission coefficient but no obvious decrease in the amplitude of the transmission wave. However, the waveform change is obvious. The amplitude and wave form of the reflection wave gradually approach the incident wave, but the effect of hysteresis occurs in the phase relative to incident wave. To obtain an effective and real propagation law of wave motion, fluctuation time history data were processed using linear interpolation, and results indicate that there are no chan ges to the precision of calculation results using this method.
作者
王雷
王瑞
胡志平
柴少波
王启耀
WANG Lei;WANG Rui;HU Zhiping;CHAI Shaobo;WANG Qiyao(College of Geology Engineering and Geomatics, Chang＇an University, Xi＇an 710054, Shaanzi, China;School of Civil Engineering, Chang＇an University, Xi＇an 710061 , Shaanzi, China;Institute of Underground Structure and Engineering, Chang＇an University, Xi＇an 710061 , Shaanzi, China)
出处
《地震工程学报》
CSCD
北大核心
2018年第2期335-343,共9页
China Earthquake Engineering Journal
基金
国家自然科学基金项目(41072221)
陕西省自然科学基金项目(2016JM4013)
长安大学中央高校基本科研业务费专项资金资助(310828163409)
关键词
SH波
地裂缝
透反射系数
剪切滑移
波动理论
SH wave
ground fissure
transmission and reflection coefficient
shear slip
wave motion theory
