铁路隧道复合式衬砌初期支护可靠性分析  

Reliability Analysis of Primary Lining for Composite Lining of Railway Tunnel

作　　者：龚彦峰[1] 员健祥 焦齐柱[1] 宋玉香 郑强 Gong Yanfeng;Yuan Jianxiang;Jiao Qizhu;Song Yuxiang;Zheng Qiang(China Railway Siyuan Survey and Design Group Co.Ltd.,Wuhan 430063,China;School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China)

机构地区：[1]中铁第四勘察设计院集团有限公司,湖北武汉430063 [2]石家庄铁道大学土木工程学院,河北石家庄050043

出　　处：《石家庄铁道大学学报（自然科学版）》2023年第1期84-91,126,共9页Journal of Shijiazhuang Tiedao University(Natural Science Edition)

基　　金：中铁第四勘察设计院集团有限公司科研项目(2020K152-1)。

摘　　要：《铁路隧道设计规范(极限状态法)》(Q/CR 9129—2018)使得概率极限状态法在铁路隧道结构设计中得到迅速发展,但其规定的设计方法以及目标可靠指标都是针对二次衬砌结构的,尚不适用于初期支护的设计。为将规范的适用范围扩大到初期支护,以8套铁路隧道衬砌通用参考图的复合式衬砌结构为研究对象,建立初期支护与二次衬砌共同作用的荷载-结构模型,用梁单元模拟初期支护与二次衬砌,采用杆单元模拟初期支护与二次衬砌之间的弹性链杆、围岩与支护间的弹性约束。对正态分布的随机变量,取截断正态分布。用蒙特卡罗法对初期支护荷载效应进行统计分析,以JC法对初期支护进行可靠度分析,通过校准法确定初期支护的目标可靠指标。通过与国内外相关规范的比较以及对材料性能的分析,推荐二级安全等级的隧道初期支护的目标可靠指标分别为2.7、3.2。The issue of Code for Design of Railway Tunnel(Limit State Method)(Q/CR 9129—2018)makes the probabilistic limit state method develop rapidly in the design of railway tunnel structure.However,the prescribed design method and the target reliability index are all for the secondary lining structure,which is not suitable for the design of primary lining.To expand the application scope of the specification to the primary lining,the composite lining structure of eight sets of general reference maps of railway tunnel lining was taken as the research object,and the load-structure model of the interaction between the primary lining and the secondary lining was established.The beam unit was used to simulate the initial primary and secondary lining,and the rod unit was used to simulate the elastic chain link between the initial primary and secondary lining,and the elastic constraint between the surrounding rock and the support.For normally distributed random variables,truncated normal distribution was taken.The Monte Carlo method was used to analyze the load effect of the primary lining,and the JC method was used to analyze the reliability of the primary lining.The target reliability index of the primary lining was determined by the calibration method.Through the comparison with the relevant norms at home and abroad and the analysis of the material performance,the target reliability indexes of the secondary safety grade tunnel primary lining are 2.7 and 3.2 respectively.

关 键 词：复合式衬砌 可靠性 目标可靠指标 校准法 初期支护 

分 类 号：U25[交通运输工程—道路与铁道工程]