深埋隧洞围岩支护设计方法研究

Study on Design Methods of Surrounding Rock Support for Deep-buried Tunnel

对于深埋隧洞,地应力高,围岩蠕变时间长,若把握不好支护措施的设计,容易造成支护结构的浪费或者围岩发生大的变形甚至坍塌。本文通过平面有限元软件,运用应力折减法得到围岩特征曲线,结合改进的围岩纵向变形曲线及支护特性曲线,运用收敛-约束法分析了围岩-支护的相互作用,得出了不同围岩条件下的最佳支护时机,并结合工程实践进行验证分析,为深埋隧洞的围岩稳定分析和支护设计提供有益探索。

For deep-buried tunnels,the ground stress is high and the creep time of surrounding rock is long.If the design of supporting measures is not well grasped,it is easy to cause waste of supporting structure or large deformation even collapse of surrounding rock.In this paper,the characteristic curve of surrounding rock was obtained by plane finite element software using stress reduction method.Combining with the improved longitudinal deformation curve of surrounding rock and supporting characteristic curve,the interaction between surrounding rock and support is analyzed by convergence-restraint method.The optimum supporting time under different surrounding rock conditions are obtained,and the results are verified and analyzed by engineering practice,which provides useful exploration for stability analysis and supporting design of deep-buried tunnel.