特长隧道竖井交叉段爆破施工安全开挖进尺研究

Study on blasting security excavation depth at extra-long tunnel shaft intersections

特长隧道主洞爆破开挖过程中,先行开挖的联络通道和竖井会受到扰动,研究爆破荷载作用下隧道与竖井交叉段围岩稳定性对特长隧道安全施工具有一定指导意义。分别考虑开挖进尺为0.5 m,1 m,1.5 m,2 m四种工况,对主隧道与联络通道交叉段围岩的振速、位移及应力进行分析,揭示该复杂段落围岩力学性态,探究开挖进尺、爆源距离对围岩稳定性影响规律。

During the blasting excavation of main cavern of extra-long tunnel,the pre-excavated liaison channel and tunnel shaft will be disturbed.Therefore,it is of great guiding meaning to study the tunnel and shaft intersection surrounding rock stability in extra-long tunnel construction under the blasting load.The paper respectively analyzes the vibration speed,displacement and stress of the surrounding rock at the liaison channel and tunnel shaft intersections with the excavation depth of 0.5 m,1 m,1.5 m and 2 m,and then demonstrates the mechanical properties of surrounding rock.In the end,it explores the influence pattern of excavation depth and the explosion source distance upon surrounding rock stability.