金华山软岩铁路隧道湿喷纤维混凝土支护结构可靠度分析

Analysis on Reliability of Wet-sprayed Fiber Reinforced Concrete Lining Structure for Jinhuashan Railway Tunnel in Soft Rock Mass

以赣州—龙岩铁路金华山软岩隧道湿喷纤维混凝土支护结构为研究对象[1,2],由于湿喷纤维混凝土支护结构物理、力学参数和喷层厚度的离散性及混凝土强度破坏准则难以用支护材料参数显式表达,对该类隧道支护结构进行可靠度分析十分困难。采用响应面法计算湿喷纤维混凝土支护结构的可靠度方法,并给出了计算流程;其中围岩-支护结构的确定性分析采用非线性有限元法,可靠度分析采用二次响应面法。分析结果表明:金华山隧道湿喷纤维混凝土支护结构可靠度指标高,处于安全状态。

The wet-sprayed fiber reinforced concrete lining structure for Jinhuashan Tunnel in soft rock mass on Ganzhou-Longyan Railway is the object of study. Due to the physical and mechanical parameters, the discreteness of spray layer, and the strength failure criterion of concrete are difficult to be expressed by the parameters of the lining material explicitly, the reliability analysis of such structure is difficult as well. In this paper, response surface method is proposed to calculate the reliability of wet-sprayed concrete lining structure and the calculation process is given too, wherein the certainty analysis of the rock mass-lining structure is carried out by nonlinear finite element method and the reliability analysis is carried out by square response surface method. The analysis result shows that the reliability index for the wet-sprayed concrete tunnel lining structure for Jinhuashan Tunnel is higher and stays in a safe state.