珙县低山区不同震源作用下斜坡地震动响应

在宜宾市珙县五同村布设斜坡地震动监测仪器，采集兴文县3.1级、珙县4.5级及长宁县4.6级地震数据。对监测剖面上1^#、2^#监测点采集到的珙县余震地震动响应数据进行滤波和校正处理，对比分析震级、高程、方位等因素对斜坡造成的地震响应后认为：1）当地震波的半波长与山体某些特定部位之间的距离接近时，斜坡地形与地震波的波峰产生耦合作用，地形放大效应显著，达到参考点的2.765倍，此处山体更容易产生较大幅度的摇晃，造成山体地质灾害；2）分析珙县4.5级与长宁县4.6级地震得出，当地震波沿特殊部位（如山脊等）传播时，地震加速度及阿里亚斯强度更加显著；3）分析地震加速度变化得出，在地震荷载作用下，随着震级的增大，斜坡的加速度响应也会增大；4）随着高程和震级的变化，监测点的地震加速度和阿里亚斯强度随之变化，高程和震级对斜坡的地震动响应具有放大效应；5）在高程和微地貌的耦合作用下，斜坡地震加速度也具有明显的放大效应。

Slope Seismic Response under Different Earthquake Sources in Gongxian Low Mountainous Areas

By arranging slope seismic monitoring instruments in Wutong village, Gongxian county, Yibin, we collect data from the Xingwen county M_S3.1, Gongxian M_S4.5 and Changning county M_S4.6 earthquakes. We filter and correct the seismic response data of Gongxian aftershocks collected at 1^#, 2^# monitoring points on the monitoring profile, and the magnitude, elevation after the seismic response caused by azimuth and other factors to the slope. We infer that: 1) the distance between the half wavelength of the local seismic wave and some specific parts of the mountain is close, the slope terrain and the wave crest of the seismic wave are coupled, and the topographic amplification effect is significant, up to 2.765 times of the reference point. Here, the mountain is more likely to produce large-scale shaking, which is more likely to cause mountain geological disasters. 2) Through the analysis of the Gongxian M_S4.5 and Changning county M_S4.6 earthquakes, we infer that when the seismic wave propagates along special parts(such as ridge, etc), the seismic acceleration and arias intensity are more significant. 3) Through the analysis of the change of seismic acceleration of seismic data, we conclude that under the action of seismic load, the acceleration response of slope increases with increased magnitude. 4) With the change of elevation and magnitude, the seismic acceleration and arias intensity of monitoring points also change, and we conclude that elevation and magnitude have amplification effect on the seismic response of slope. 5) Under the coupling effect of elevation and micro landform, the seismic acceleration also has obvious amplification effect.