摘要
小净距隧道的中间夹岩处于复杂的三维受力状态。基于单轴抗拉或抗压强度为基础的围岩力学评价指标已显不足,Von-mise等效应力虽同时考虑了三个主应力的影响,但局限于剪切屈服。为此,引入基于Mohr-Coulomb剪切屈服准则与拉伸屈服准则的屈服接近度函数用以描述夹岩应力危险程度。文章主要对上下重叠模式和水平平行模式的两类小净距隧道中间夹岩力学特征进行了研究。研究结果表明,无论是重叠还是平行隧道,其夹岩的中间部分比两侧部分相对稳定;对于城市浅埋隧道,在同等静力学条件下,上下重叠隧道夹岩的受力优于水平平行隧道。计算结果为今后类似工程的设计、超前注浆孔的合理布置提供了指导。
Sandwiched rock between twin closely spaced tunnels is in complicated and three-dimensional stress state. So the criterion for rock stability based on uniaxial stress is not valid. Although Von-Mises equivalent stress criterion takes all the three principal stresses into account, it can not reflect tensile yield. Therefore, this paper introduces yield approach index （YAI） function based on Mohr-Coulomb shear yield criterion and tensile yield criterion to identify the stressed extent of materials. The mechanical performance of sandwiched rock between two types of twin tunnels, including overlap tunnels and parallel tunnels, has been analyzed. Results indicated that the middle part of sandwiched rock is relatively stable compared with side parts. For shallow twin tunnels, the sandwiched rock between overlap tunnels is in better stress state than that between parallel tunnels under the same static conditions.
出处
《现代隧道技术》
EI
北大核心
2009年第3期22-26,32,共6页
Modern Tunnelling Technology
关键词
重叠隧道
平行隧道
中间夹岩
屈服接近度
主应力
Overlap tunnels
Parallel tunnels
Sandwiched rock
Yield approach index
Principal stress
作者简介
章慧健（1982-），男，博士研究生，主要从事隧道及地下工程支护力学机理的研究．E-mail：huijianz@163．com．
