SV波斜入射下局部地形对隧道地震响应的影响  

Influence of local topographic on seismic response of tunnels subjected to obliquely incident SV waves

作　　者：傅方[1] 赵成刚[1] 李伟华[1] 张卫华[1] 

机构地区：[1]北京交通大学土木建筑工程学院,北京100044

出　　处：《北京交通大学学报》2012年第6期79-84,共6页JOURNAL OF BEIJING JIAOTONG UNIVERSITY

基　　金：国家自然科学基金重大研究计划资助项目(90715035);北京市教委重点项目资助(KZ200910016008);中央高校基本科研业务费专项资金资助(2009JBM064)

摘　　要：不规则地形及地震波斜入射引起的局部场地地震动空间变化,会对隧道的整体动力响应产生影响.本文基于波动理论建立了可同时考虑局部不规则地形影响和地震波斜入射引起的,非一致地震动输入的隧道整体动力响应分析模型,进而研究了单一坡地地形及相邻地形下,SV波以不同方向、不同角度入射时的隧道地震动力响应.结果表明:局部不规则地形下SV波斜入射时产生的波形转换会造成隧道周边的应力分布及最大动力响应位置发生明显改变,隧道的潜在不稳定性增加,而SV波的入射方向则决定了隧道各关键节点位移动力响应的变化趋势.因此在进行地震敏感区隧道地震动力危险性分析时,应同时考虑地震波入射角度、入射方向及地形条件等因素的影响.The spatial variation of local ground motion caused by irregular topography and obliquely incident seismic waves will have influence on the global dynamic response analysis of tunnels.Based on wave theory,a whole numerical dynamic analysis model of tunnels was established,which simultaneously considered the effect of local irregular sites and the inconsistency of seismic waves caused by special obliquely incident direction.The model was used to evaluate the seismic response of tunnels subjected to obliquely incident SV seismic waves under slope and neighboring topography.Among the main conclusions of the study are that wave-type conversion caused by obliquely incident SV seismic waves and local topographic effects can make a change on the stress state of tunnel periphery,as well as the location of maximum dynamic response of tunnels.As a result,the potential instability of tunnels will increase.Moreover,the incident direction of SV waves has significant effect on the changing trend of dynamic-displacement responses of key points in tunnel.In view of this,the incident angle and the incident direction of SV waves as well as the topographic condition should be taken into account simultaneously in the seismic safety risk assessment of tunnels,especially in areas susceptible to seismic phenomena.

关 键 词：隧道 局部地形 地震响应 斜入射 黏弹性人工边界 

分 类 号：U452.28[建筑科学—桥梁与隧道工程]