大跨度小间距隧道开挖围岩稳定性分析

Stability Analysis on Surrounding Rock of Large Span Small Spacing Tunnel Excavation

大跨度小净距隧道开挖对岩土体扰动较大,其开挖过程的稳定性问题一直是人们关注的焦点之一。以大帽山隧道为研究对象,选择V级围岩采取CRD法开挖为研究目标,运用FLAC软件对隧道开挖全过程进行数值分析,结果表明新建隧道采取CRD法开挖围岩竖向应变大于水平方向,有利于减小围岩扰动程度并充分发挥自身稳定性,拱腰和拱底围岩应力释放较大,开挖过程中应加强支护刚度,研究成果可为施工过程中有效控制围岩应力、应变提供借鉴。

For the effects of excavation processing technology on the disturbance of surrounding rocks of large-span tunnel and closely-spaced tunnel, the excavation stability of tunneling is as one of focal points. In this paper, the numerical analysis method was adopted to analyze the Da Maoshan Tunnel by FLAC with selecting V grade rock combines with CRD method to construct. Consequently, new tunnel adopts CRD method and its vertical strain was more than horizontal direction, which contributed to reduce the disturbance of surrounding rock and make it stable. The stress of the surrounding rock of arch and arch was larger. The stiffness of support should be strengthened during excavation. The research results could provide reference for the effective control of stress and strain in the process of construction