基于响应面法的隧道可靠度分析及其指标确定

Reliability Analysis of the Tunnel and Determination of Its Index Based on Response Surface Method

在隧道初次衬砌的设计中还依赖经验法和现场的监测数据,规范也没有明确地给出隧道初次衬砌的目标可靠指标值。以大瑶山隧道基础数据为计算依据,以隧道初次衬砌作为研究对象,采用"地层-结构模型"分析了衬砌在极限承载能力作用下的可靠度。主要内容包括:分析、计算了各个变量的统计特征,结合这些变量应用同济曙光软件计算了初次衬砌在Ⅲ级围岩下的受力情况;利用响应面法计算了隧道初次衬砌的功能函数;根据所计算的内力值分析了作用效应的统计特征和抗力的统计特征;通过一次二阶矩法计算初次衬砌的可靠指标,并用MATLAB软件得以实现;最后,利用校准法给出了Ⅲ级围岩初次衬砌的目标可靠指标值。

With the fast growth of the national economy,the technology on the tunnel in China is mature more and more.But at present the design of the first lining of the tunnel mainly depends on experience and the field monitoring data,and the target reliability index is not given definitely in the criterion.So aiming at this,this paper analyses the structure reliability of the first lining of the Dayao mountain tunnel by the structure model of soil layer.Firstly,it analyses and accounts the statistical characteristics of the variables. Then, it calculates the stress of the first lining of tunnel by the software of the ＂Tongji Shuguang＂ in the rock class Ⅲ, combining Response Surface method to deduce the performance function. And the statistical characteristics of the action effect and the resistance are given. The reliability index is calculated by the first order second moment and MATLAB software. The target reliability index in the rock Ⅲ is given by the calibration method.