P波入射分界面叠加区质点运动形成机制与峰值规律  

Formation mechanism and peak distribution of seismic motions in superposition areas with an incident P wave at the interface

作　　者：何卫平 李小军[2] 杜修力[2] 姚惠芹 HE Weiping;LI Xiaojun;DU Xiuli;YAO Huiqin(Hubei Key Laboratory of Construction and Management in Hydropower Engineering,China Three Gorges University,Yichang 443002,China;Key Laboratory of Urban Security and Disaster Engineering of the Ministry of Education,Beijing University of Technology,Beijing 100124,China;College of Hydraulic and Environmental Engineering,China Three Gorges University,Yichang 443002,China)

机构地区：[1]三峡大学湖北省水电工程施工与管理重点实验室,湖北宜昌443002 [2]北京工业大学城市与工程安全减灾教育部重点实验室,北京100124 [3]三峡大学水利与环境学院,湖北宜昌443002

出　　处：《振动与冲击》2023年第18期81-87,163,共8页Journal of Vibration and Shock

基　　金：国家自然科学基金(51809152,51809153);北京市博士后基金(Q6004014202002);湖北省重点实验室开放基金(2020KSD16)。

摘　　要：该文章针对平面P波入射分界面条件下质点运动的形成机制和空间变化规律开展研究,以期为地震动的时域解释提供理论基础和规律性认知。依据地震波传播特征给出分界面附近的空间域划分和叠加区边界,然后通过波函数叠加给出分界面两侧空间质点运动的解析表达,进而阐明不同空间域内质点运动的成分序列和峰值分布规律。研究结果显示,分界面近区为叠加区,远区为分离区。质点运动的成分序列随空间域产生变化,在叠加区内包含无波、单波、双波和三波贡献时段,在分离区内包含无波和单波贡献时段。分界面附近质点运动峰值分布包含峰型分布和谷型分布两类,前者由同号地震波分量叠加引起,后者由异号地震波分量叠加引起,在算例中分界面附近质点运动峰值的最大差异为2.589。To provide theoretical support for the time-domain interpretation of seismic motions,the formation mechanism and spatial variation of motions near the interface under an incident plane P wave were investigated.The spatial domains and boundaries between domains were investigated based on the superposition relation of seismic waves.Then,the analytical expression of particle motions in spatial domains at both sides of the interface was derived via the superposition of wave functions and the component waves of particle motion were defined as a component sequence.The component sequence and peak value distribution were illuminated in different spatial domains.The result shows that the near field and the far field are the superposition area and the separation area respectively.The component sequence of motion varies with the spatial domain.In the superposition domain,the particle motion contains the periods of no wave,single wave,double wave,and triple wave.In the separation domain,the particle motion contains the periods of no wave and single wave.The peak distribution near the interface is divided into two types:the mountain type that is formed by the same sign wave components,and the valley type that is formed by different sign wave components.In the studied cases,the maximum peak difference near the interface is 2.589.

关 键 词：地震动形成机制 分界面 平面P波 地震动成分序列 峰型分布 谷型分布 

分 类 号：P315[天文地球—地震学] TV312[天文地球—固体地球物理学]