摘要
利用数值方法建立了隧道计算模型,采用Hoek-Brown准则描述隧道围岩破坏情况,通过厚度折减法,分析了Hoek-Brown准则情况下,隧道开挖的顶板稳定性,得出结论:①随着隧道跨度的增大,安全顶板厚度也逐渐增大,二者关系符合线性特征;②隧道围岩开挖后,大部分处于受压状态,仅在隧道正上方局部位置存在拉应力区域;随着隧道跨度的增大,顶部围岩所承受的拉应力逐渐增大;③跨度较小时,隧道顶板和边墙主要发生剪切破坏,破坏范围呈现以隧道为中心向外扩散的翼型形状;随着跨度的增大,此范围出现部分拉剪破坏区域。
A numerical calculation model for excavation of tunnel is built by numerical method, the Hock-Brown criterion is applied to describe the condition of failure in the surrounding rock mass; then, with the thickness reduction method, the safe thickness of the roof after excavation in tunnel is obtained with the Hock-Brown criterion. The results show that, （1） with the increase of the span of tunnel, the safe roof thickness increases gradually, in a linear manner; （2） when tunnel is excavated, the stress in the surrounding rock mass is compressive, while the stress in some areas in the top of tunnel is tensile; with the increase of the tunnel span, the tensile stress in the roof increases as well; （3） when the span is small, the roof and the side wall of the tunnel mainly fail in shear, and the plastic areas are in the form of a wing which expands from the middle of the roof to the outer side; with the increase of the span, some areas may fail in tension and shear.
出处
《科技导报》
CAS
CSCD
北大核心
2009年第7期52-55,共4页
Science & Technology Review
基金
国家自然科学基金项目(50878212)
关键词
隧道
非线性破坏准则
顶板
稳定性
tunnel
nonlinear failure criterion
roof
stability
