机械法联络通道T接部位受力特性及弱化分析

Stress characteristics and weakening analysis of T-joint of connection passage by mechanical excavation method

机械法联络通道T接部位受力复杂,安全问题突出。提出了一种联络通道管片及洞门结构,采用ANSYS有限元软件建立了机械法联络通道T接部位数值计算模型,分析了在15 m埋深条件下,切削洞口为不同强度的正线隧道的变形及受力情况。研究结果表明:随着切削洞口强度降低,正线隧道位移最大值和洞口管片位移增大,隧道应力最大值有所增大,但影响不大。管片开洞后,洞口中心上下的管片位移最为危险,需做加固处理。连接处的受力主要由螺栓承担,需要特别关注洞口管片之间螺栓连接的安全性。研究结论可为机械法联络通道设计及安全施工提供参考。

The forces on the T-joint parts of connection passage by the mechanical excavation method is complex,and their safety problems are severe.A kind of connection massage segment and a portal structure are proposed.The numerical model for the T-joint of connection passage by the mechanical excavation method is established using the ANSYS finite element software.The deformation and stress of the tunnel with portal structures with different strengths at the buried depth of 15 m are analyzed.The results show that with the decrease of the strength of the portal structures,the maximum displacement of the tunnel and the displacement of the segment increase,and the maximum stress of the tunnel increases,but the increase amplitunde is slight.After the opening of the segment,the displacements of the segment above and below the centre of the opening are the most dangerous and need to be reinforced.The bolts mainly bear the stress at the joint,and special attention should be paid to the safety of the bolt connection between the hole segments.The research conclusions may provide a reference for designing and safely constructing the connection passage by the mechanical excavation mehtod.