铁路隧道洞门体系极限状态及可靠度研究

摘要

Research purposes:Railway tunnel portal is a complicated spatial structural system.Based on the structure reliability,a set of research methods of reliability for tunnel portal structure are established.Research results can provide references for the design and code revising of railway tunnel portal. Research conclusions:(1 )According to the failure models of railway tunnel portal structure,it is considered to be in series system.Reliability index and failure probability of structural systems are employed in quantitatively evaluating reliability of railway tunnel portal structure.An approximate method is a kind of simple and accurate computing way to calculate the reliability of railway tunnel portal structure.(2)An approach for reliability calculation method of railway tunnel portal structure is given,and demonstrated by examples.A calculation example shows the safe probability of end wall portal structure system of single track railway tunnel that allows the speed of 140 km/h can be more than 99.22%, and the main failure mode of structure system is overturning.(3 )In this paper,the tunnel portal limit state design method can be directly used to guide the design of railway tunnel portal structure.%研究目的：铁路隧道洞门结构体系受力极为复杂，本文从结构可靠度理论出发，建立一套系统完善的铁路隧道洞门极限状态研究方法，为铁路隧道洞门的设计和规范转轨提供参考。研究结论：（1）铁路隧道洞门结构体系可靠度是串联系统，可通过失效概率或可靠指标进行度量，采用近似方法计算铁路隧道洞门结构的可靠度是一种有效而实用的途径；（2）提出铁路隧道洞门体系可靠度分析和计算方法，实现了铁路隧道洞门的可靠度分析计算，并通过实例进行了验证，通过对时速为140 km单线铁路隧道端墙式洞门的安全概率进行计算，其安全概率在99．22％以上，倾覆极限状态是隧道洞门结构失效主要控制模式；（3）本文提出的铁路隧道洞门极限状态设计方法，可直接指导铁路隧道洞门设计。