地铁隧道群对地震动的放大作用

Amplification of ground motion by metro tunnel group

本文采用有限元方法在时域内研究了基岩上均匀场地中隧道群对地震动的放大作用,分析了隧道间距、入射地震波频谱等因素对隧道群附近地表地震动反应谱的影响。研究表明,隧道群对地震动具有显著的放大作用,放大作用的大小与隧道间距和入射地震波频谱有着密切关系;隧道之间存在相互作用,加速度峰值的最大值多大于单隧道情况,且水平加速度峰值的最大值位于两个隧道之间。

This paper investigates the amplification of ground motion in time domain by metro tunnel group in single layer on bedrock using finite element method,discusses the effects of distance between tunnels and spectra of incident seismic waves,etc.on the response spectra of surface ground motions near the tunnel group.It is shown that the tunnel group has significant amplification effect on the ground motion,and the amplitude of the amplification depends on the distance between tunnels and the spectra of incident seismic waves.There is interaction between two tunnels,and the maximum of the peak ground acceleration of the surface ground motion is located between two tunnels and is usually larger than that in the case of single tunnel.