隧道结构系统可靠度研究

在结构系统可靠度研究的基础上，根据隧道结构的特点，应用概率理论及工程结构系统可靠度分析方法，对整个隧道结构系统可靠度进行了探讨。隧道结构系统可靠度研究包括衬砌断面可靠度、在各种不同围岩压力作用下衬砌断面可靠度、同种围岩地段衬砌可靠度以及整座隧道可靠度的研究。整座隧道可看作由两端洞门和洞内不同围岩地段隧道衬砌所组成的串联系统，任一围岩地段衬砌和任一洞门结构的破损，都认为该隧道破损，则运用“概率网络估算技术”（又称PNET法）可求得整座隧道系统的失效概率与可靠指标。通过实例计算得到，整座隧道系统的总体可靠指标比所有单段结构的可靠指标都要低。

Research on reliability of tunnel structural system

Some problems of tunneling system reliability are solved by using probability theory and system reliability analysis of engineering structures in light of characteristics of tunnel structure. The reliability of tunnel structural system contains reliability of lining sections, reliability of lining sections in various surrounding rock pressure. reliability of lining in the same surrounding rock sections and reliability of the whole tunnel. The whole tunnel can be regarded as a series system of the portals at two ends and lining sections rock condition in the tunnel. Damage to any section of lining or any one portal is regarded as damage to the whole system. Thereby, using the PNET method, the failure probability and reliability index can be obtained for the whole tunnel. Case calculation shows that the general reliability index of whole tunnel is lower than all single sections of structure.