王之洋^1,3,,
李幼铭^2,3,,,
白文磊^1,3
1. 北京化工大学, 北京 100029
2. 中国科学院地质与地球物理研究所, 中国科学院油气资源研究院重点实验室, 北京 100029
3. 高铁地震学联合研究组, 北京 100029

基金项目: 国家自然科学基金重点项目（41630319），国家科技重大专项课题（2016ZX05024-001-001）共同资助


详细信息

作者简介: 王之洋, 男, 1987年生, 2015年博士毕业于中国科学院地质与地球物理研究所, 主要从事地震波数值模拟和逆时偏移成像方法研究.E-mail:wangzy@mail.buct.edu.cn

通讯作者: 李幼铭, 男, 1939年生, 研究员.1988年起组织"八五"、"九五"国家基金重大项目, 1998年, 主持中科院知识创新工程第一期的重大项目.E-mail:ymli@mail.iggcas.ac.cn

中图分类号: P631

收稿日期:2020-04-30
修回日期:2020-10-29
上线日期:2020-12-05

Numerical modelling of exciting seismic waves for a simplified bridge pier model under high-speed train passage over the viaduct

WANG ZhiYang^1,3,,
LI YouMing^2,3,,,
BAI WenLei^1,3
1. Beijing University of Chemical Technology, Beijing 100029, China
2. Key Laboratory of Petroleum Resource Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
3. The Joint Research Group of High-Speed Rail Seismology, Beijing 100029, China


More Information

Corresponding author: LI YouMing,E-mail:ymli@mail.iggcas.ac.cn

MSC: P631

--> Received Date: 30 April 2020
Revised Date: 29 October 2020
Available Online: 05 December 2020


摘要
摘要:高铁列车运行过程中绝大部分时间都是行驶在高架桥上的，高铁列车经过桥梁时，通过与大地耦合的桥墩激发地震波发震过程和平地不完全一样.本文探索高铁列车行驶经过高架桥桥墩，通过桥墩对地下介质激发地震波的机理及过程.为了便于理论分析，文中将高铁列车简化为在高架桥上沿一个方向运动的移动线源，通过每节车厢前后组轮对，对每一个桥墩施加力的作用，而桥墩插入地面几十米深至围岩，与表层土壤和深层围岩双重耦合，由此给出高铁列车通过桥墩激发地震波的震源时间函数.同时，基于广义连续介质力学框架下的修正偶应力理论，推导包含介质特征尺度的弹性波动方程，并应用此弹性波动方程以及构建的高铁震源时间函数，采用优化的交错网格有限差分算法，实现数值模拟，将合成的地震记录与实际地震记录对比分析，其结论将为进一步的基于高铁震源的成像和反演研究提供理论依据.
关键词: 桥墩模型/
高铁震源/
数值模拟/
修正偶应力理论

Abstract:Most of the time, high-speed trains run on the viaducts, and when high-speed trains pass over the viaducts, the process of exciting seismic waves is not exactly the same as that of exciting seismic waves on the ground due to exciting seismic waves through bridge piers coupled with the ground. We explore the mechanism and process of excitation of seismic waves through bridge piers when high-speed trains passage over the viaducts. To simplify the analysis, we consider the high-speed train as a moving linear source along one direction, and the high-speed train exerts forces on bridge piers which insert into the ground at a depth of tens of meters, coupled with the topsoil and surrounding rock, through front and rear wheels of each car. After this analysis, the time function of high-speed-train source under high-speed train passage over the viaduct is derived. Meanwhile, we derive the elastic wave equation including the characteristic scale parameter, based on the modified couple stress theory in the frame of the generalized continuum mechanics, and apply this elastic wave equation, the time function of the high-speed-train source and the optimized staggered grid finite difference scheme in performing numerical modelling. By comparing and analyzing the synthetic seismograms with the field seismograms, the conclusions will provide a theoretical basis for further research of imaging and inversion based on train source.
Key words:Bridge piers model/
Train source/
Numerical modelling/
Modified couple stress theory



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