葡萄山公路隧道通风机房洞室群施工力学分析

Analysis on construction mechanics of ventilation cabinet caverns of Putao Mountain extra-long tunnel

在长大隧道施工过程中,通风机房洞室群的施工是整个隧道施工过程的关键。本文借助ANSYS通用软件,结合葡萄山特长公路隧道通风机房洞室群开挖施工过程,建立了基于D-P准则的非线性三维有限元分析模型,对通风机房洞室群在施工过程中围岩的稳定性进行了研究。以应力和位移变化最为明显的送风通道轴线剖切模型所得到的断面为例,分析了施工步的变化及各支洞的开挖对主隧道位移、应力和塑形区的影响,并与隧道监控量测资料进行了对比分析,得到了计算位移与监测资料比较一致的结论,为隧道通风机房洞室群优化设计和安全施工提供了依据。

In long tunnel construction process, ventilation cabinet caverns construction is the key. Combined with the construction of ventilation cabinet caverns of Putao Mountain extra-long tunnel caverns, a three- dimensional nonlinear finite element model that based on DP yielding principle was established and stability of ventilation cabinet caverns surrounding rock in the construction was analyzed by ANSYS. For the example of the section where variations of stress, displacement were most significant, effects of each construction step and adit excavation on main tunnel stress, displacement and plastic zone were analyzed. Then compared with monitoring measurement information, the conclusion that calculating displacement was in accordance with monitoring measurement information was obtained. So a science basis for design and construction of tunnel ventilation cabinet caverns was offered.