断层对小净距隧道稳定性的影响分析

文章针对福州魁岐2号特大断面小净距隧道工程特点,以Ⅴ级围岩为研究对象,利用离散单元法对节理岩体中断层存在时初始围岩应力分布特征以及断层与隧道不同相对位置情况下围岩变形特征进行了定性分析。结果表明,当节理岩体中有断层存在时,初始围岩应力不再呈水平层状分布,而是出现一定程度的应力集中现象;围岩变形在断层附近区域显著增大,而距断层较远处基本不受影响;对于小净距隧道,当中间岩柱中存在断层时更不利于隧道和中间岩柱的整体稳定。

Influence Analysis of Fault on Stability of Small Space Tunnels

The article analyzes the engineering characteristics of Kuiqi No.2 Tunnel,the pro-ject that has constructing small space tunnel with large fracture surface. Taking the V grade rock wall as study object,the article uses discrete element method to analyze the character-istics of rock wall when fractures are embedded and the stress force surrounding the area.The results indicate that,when fracture occurs,the stress force of the target rock wall are no longer horizontally distributed and are somewhat concentrated.Rock wall near fracture also have a higher possibility to experience deformation.It is especially unstable for small space tunnels to be built near rock fracture.