场地效应对穿越河谷隧道纵向地震反应影响研究  

Study on the Influence of Site Effect on the Longitudinal Seismic Response of Tunnels Crossing River Valleys

作　　者：张启军[1] ZHANG Qijun(China Railway 19th Bureau Group Co.Ltd.,Beijing 100176,China)

机构地区：[1]中铁十九局集团有限公司,北京100176

出　　处：《铁道建筑技术》2025年第2期157-161,共5页Railway Construction Technology

基　　金：中铁十九局集团有限公司科技研究开发计划项目(2024-B02)。

摘　　要：河谷对地震波的散射会导致地震动边缘放大及中心聚焦效应,将影响穿越河谷隧道结构动力响应。采用有限元法研究穿越沉积河谷隧道纵向地震响应特征,探讨剪切波速和河谷坡脚坡度对穿越河谷隧道位移和应力的影响。结果表明,河谷场地效应导致隧道纵向地震响应出现显著空间变化特征,河谷-半空间交界面部位隧道出现位移峰值,易发生应力集中或应力突变;随河谷剪切波速增加,其地震响应呈现显著下降趋势,当河谷剪切波速从100 m/s增至200 m/s时,拱肩最大主应力显著减小,降幅可达50%;随河谷坡脚坡度增大,隧道拱顶和拱底最大主应力峰值呈明显上升趋势,当坡脚坡度从30°增至45°时,最大主应力峰值增加23%。The scattering of seismic waves by river valleys leads to the edge amplification and center focusing effects of ground motions,which affect the structural dynamic response of tunnels through river valleys.This study uses the finite element method to explore the longitudinal seismic response characteristics of the tunnels crossing sedimentary river valleys.The effects of shear wave velocity and the slope gradients of the river valleys on the tunnel displacement and stress are investigated.The results indicate that the valley site effect leads to significant spatial changes in the longitudinal seismic response of the tunnel,and the peak displacement occurs at the valley-half-space interface of the tunnel,which is prone to stress concentration or stress mutation.With the increase in the shear wave velocity of the valley,the seismic response of the tunnel has a significant decrease.When the shear wave velocity is increased from 100 m/s to 200 m/s,the maximum principal stress of the arch shoulder decreases significantly,and the reduction can be up to 50%.When the slope gradient of the valley increases,the peak values of the maximum principal stress at the top and bottom of the tunnel arch show a significant upward trend.If the slope gradient of the river valley increases from 30°to 45°,the maximum principal stress peak value increases by 23%.

关 键 词：场地效应 河谷 隧道 地震响应 

分 类 号：P315.9[天文地球—地震学]