偏压情况下连拱隧道施工顺序的数值分析

Numerical Simulation Study on Construction Process of Partial Pressure in Joint Arch Tunnel

采用有限元法数值模拟云南思小高速公路的双连拱隧道中导洞施工法分步开挖过程,研究双连拱隧道在偏压作用下施工过程的力学行为.通过动态数值模拟,得到隧洞在不同开挖顺序下围岩的应力变化和塑性区的发展范围以及中隔墙、衬砌的应力情况;对比分析不同施工方案各关键工序的模拟结果,并从应力转移的角度分析洞室开挖的影响,得到偏压作用下连拱隧道施工顺序的优选方案.

Advancing middle drift construction process of Si-xiao joint arch tunnel in Yunnan is simulated with FEM, and then the structural mechanics behavior in joint arch tunnel construction under partial pressure is studied. The results under different excavation sequences which are the surrounding rock stress variation, plastic area development, stress of tunnel＇s mid-partition and lining are got through dynamic numerical simulation. By means of comparatively analyzing simulation results on key steps of various construction schemes and stress transfer effect on tunnel excavation, optimized construction scheme of partial pressure joint arch tunnel finally is obtained.