基于FLAC3D的大断面软弱围岩隧道注浆加固数值分析

Numerical Analysis on Grouting Reinforcement for Tunnel of Large Section Weak Surrounding Rock Based on FLAC3D

大断面软弱围岩隧道,因其开挖面积大、岩石强度低、围岩赋存环境差、岩体破碎等特点,使其力学性能与一般围岩存在较大差异.为避免隧道开挖时可能产生的大变形甚至坍塌破坏,对大断面软弱围岩隧道进行注浆加固处理尤为重要.本文应用有限差分软件FLAC3D对不注浆、拱部注浆、全环注浆三种方案进行数值分析,研究隧道注浆加固后围岩的应力分布和位移的大小以及围岩稳定性.结果表明,注浆加固能够有效改善注浆区围岩的力学性能,提高注浆区围岩的强度,减小围岩的位移,增强隧道的自稳能力.

Tunnel of large section weak surrounding rock,because of its large excavation area,low rock strength,poor surrounding rock environment and rock broken zone has a great difference in the mechanical properties with general surrounding rock. In order to avoid the large deformation even the collapse which caused by the tunnel excavation,we also find it is very important to carry out grouting reinforcement for the tunnel. The finite difference software of FLAC3D was used to analyze the three schemes of no grouting,arch grouting and the whole ring grouting. We studied the stress distribution and displacement as well as the stability of surrounding rock. The results show that grouting reinforcement can effectively improve the mechanical properties of surrounding rock in grouting area,improve the strength of surrounding rock in grouting area,reduce the displacement of surrounding rock and enhance the self-stability of tunnel.