无中导洞施工双连拱隧道的数值模拟分析

Numerical simulation of multi-arch highway tunnel constructed without advancing middle drift

针对双连拱隧道采用三导洞或中导洞超前施工方法施工工序多、临时支护量大的不足,以黄延高速公路羊泉沟隧道为例,提出在Ⅲ类围岩中采用无中导洞超前施工方法。基于弹塑性有限元方法对其施工过程进行分析,获得了施工各阶段围岩的应力、应变状态,以及初期支护和二次衬砌的受力状态。结果表明:在Ⅲ类围岩中连拱隧道采用无中导洞施工方法,围岩和支护结构处于安全状态。分析结果为羊泉沟隧道的顺利贯通提供了有效指导。

Aiming at the shortcoming of multi-arch highway tunnel construction with three or middle advancing drift which needs excessive construction process and temporary support, based on the practical engineering of Yangquangou multi-arch highway tunnel, a method constructed without advancing middle drift is firstly put forward. On the basis of elastic-plastic FEM, the construction process is analyzed. The stress and strain field of surrounding rock and the support system is obtained. The analysis results show that surrounding rock and the support system are stability, which provide a scientific basis and technical guidance for the construction optimization of multi-arch highway tunnels.