软岩隧道湿喷纤维砼支护施工过程非线性分析

在赣州-龙岩铁路DKl33 095～DKl38 237段软弱围岩单线隧道施工过程中,采用湿喷纤维混凝土作为支护结构.介绍了隧道围岩的地质情况和隧道湿喷纤维混凝土支护结构施工工艺,采用非线性有限元法对软弱围岩条件下的铁路隧道施工过程进行了数值模拟.分析模型考虑了台阶步施工过程中围岩应力的释放效应,分析了围岩和支护结构体的非线性力学行为的应力场分布、位移场,围岩塑性区分布特征,并指出台阶步开挖时拱顶下沉、底板上鼓、墙腰收缩的主要控制因素.

Nonlinear Analysis of Tunnel Lining Construction Process Using Wet-sprayed Fiber Reinforced Concrete within Soft Rock Mass

In the Ganzhou-Longyan railway tunnel construction process between DK133 095 and DK138 237,the wet-sprayed fiber reinforced concrete lining structure is used as the first stage lining structure.The geolog- ical condition of IV category railway tunnel rock mass is introduced and the wet-sprayed fiber reinforced concrete construction technique is proposed.The nonlinear finite element analysis is performed for the railway tunnel first stage lining construction process with the wet-sprayed fiber reinforced concrete lining structure.The rock mass release co- efficient is adopted to reflect the three dimensional deformation behavior of the tunnel.The stress field distribution, displacement distribution of the rock mass and the lining structure are analyzed.The rock mass plastic zone distribu- tion during step construction is also investigated.The main factor influencing the tunnel deformation and plastic zone distribution is also pointed out.