偏压连拱隧道施工方法研究

文章采川三维有限元数值模拟研究了偏压连拱隧道不同施工顺序下拱顶下沉、中墙稳定性及初期支护受力特征.研究结果表明,先开挖浅埋侧时,拱顶沉降较小,中墙在施工中的稳定安全系数较大、弯矩较小,初期支护受力较大；对于浅埋偏压连拱隧道,围岩变形及中墙在施工中的稳定性控制更为重要.所以,从有利于围岩变形、中墙稳定性控制以及中墙受力的角度出发,宜采用先开挖浅埋侧的施工方法.

A Study of the Construction Method for a Multi-Arch Tunnel with Unsymmetrical Pressure

Using 3D finite element analysis,this study simulated and examined the crown subsidence,the stability of the middle-wall and the internal force of the primary support for a multi-arch tunnel with unsymmetrical pressure under different construction methods.The results showed that when the shallow side is excavated first,the crown subsidence and bending moment are less,and the stability of the middle-wall and the internal force of the primary support are high.For the shallow buried multi-arch tunnel with unsymmetrical pressure,the control of the surrounding rock deformation and the stability of the middle-wall are more important.It is recommended,therefore,that the shallow side be excavated in advance with the aim of controlling the deformation of surrounding rock,the stability of the middle-wall and the force applied on the middle-wall.