石棉MS4.5级地震斜坡动力响应规律

2022年9月雅安市石棉县发生M_s4.5级地震，布置在泸定冷竹关沟的强震监测仪记录到了地震数据，利用MATLAB进行小波变换后，得到时频图谱。分析结果表明：S波在穿越岩层到达地表后会分化成高频和低频两部分，但在时域上间隔很小；山体的山脊部位地震动响应强烈，S波低频携带能量更高，在发震时高频与低频能量会相互叠加，而低频叠加能量会更大；地震动响应规律存在方向性，东西向和南北向比垂直向的响应更加强烈；单薄山脊场地放大效应强于浑厚山体，原因为浑厚山体对地震波存在过滤作用。

ANALYSIS OF THE SLOPE DYNAMIC RESPONSE LAW OF THE SHIMIAN Ms 4.5 EARTHQUAKE

The western part of the country has developed natural disasters and is prone to earthquakes. In September 2022, a Ms4.5 magnitude earthquake occurred in Shimian, and the strong seismic monitor arranged in Lengzhuguan ditch in Luding recorded this precious data, and the wavelet transform was used to obtain the time-frequency mapping by MATLAB. The analysis results show that: (1) the S-wave will be divided into high-frequency and low-frequency parts after crossing the rock layer and reaching the surface, but the interval is small in the time domain; (2) the ground shaking response is strong at the ridge part of the mountain, and the S-wave carries higher energy at low frequency, and the high-frequency and low-frequency energy will be superimposed on each other during the seismic event, and the low-frequency superimposed energy will be larger; (3) there is directionality in the ground shaking response pattern, and the response is stronger in the east-west and north-south directions than in the vertical direction; (4) the amplification effect is stronger at the single thin ridge site than at the thick mountain, and the thick mountain has a filtering effect on the seismic waves.