摘要
龙溪隧道出口段主要有表层覆盖层和下伏基岩组成。文章根据边坡地形地貌以及地质结构分析了隧道在地震作用下的变形破裂特征。在此基础上,运用ansys有限元软件对龙溪隧道在Ⅺ度地震烈度荷载作用下的动力响应进行分析,并结合5·12地震后的现场调查,将数值模拟结果与现场的破坏现象进行了对比,得出地震作用下隧道洞口横向边坡的动力反应从坡内向坡外、坡底向坡顶整体上呈逐步放大的趋势;从洞口至基岩与崩坡积分界面处,变形主要在隧道管段之间的接缝处发生相对错动,并且有逐渐减弱的趋势;在隧道基岩与覆盖层分界面上,隧道衬砌变形量发生突变,衬砌开裂方向与基覆界面产状基本一致,从分界面向内,衬砌变形变得不明显。研究这一变形破坏现象,对认识隧道洞口段在地震作用下的变形破坏规律及极震区隧道洞口段的抗震结构设计具有重要意义。
The paper analyzes deformation-fracture characteristics of Longxi tunnel under 5.12 Great Earthquake. By using ANSYS finite element software authors analyzed the earthquarke dynamic response properties of Longxi tunnel under seismic load incorporating the spot investigation after the earthquake, comparing the destruction at the site with numerical simulation results. It concluded that the earthquarke dynamic responses on the side slopes of tunnel entrance were large, and more larger from inside to outside, from base to top of the slop. There were severe damages at the interface between the covering layer and underlying bedrock. Valeting degree dislocations also occurred at the construction joints of tunnel lining. Displacement difference of the rock lithology was one of the main reasons that the tunnel lining was destroyed along the interface. Research results could contribute much to tunnel anti-seismeic design and tunnel route selection in earthquake areas in the future.
出处
《现代隧道技术》
EI
北大核心
2009年第5期40-45,共6页
Modern Tunnelling Technology
