| The life-cycle of tunnel structure is composed of construction stage, serving stage and aging stage. Balance of initial stress in the surrounding rock mass is destroyed, and the strength of jet concrete and rock bolting is increasing in the construction stage. So, all kinds of dangerous situations are faced any time. In the aging stage, for entironment and corrosive media acting on the structure long time, load carrying capacity decreases gradually. Simultaneity for the creeping of surrounding rock mass, internal force of liner increases gradually. As a result, the structure shows the higher risk in the stage. In serving stage, the risk is lower. However, the risk is elevated to a higher level under the disastrous earthquake action. The study is not fully. Based on the published research result, the research on character of three stages in the tunnel structure life-cycle is new development for tunnel structural reliability. The research is of significance for tunnel structural safety, applicability, durability and economy. So research work is conducted along tunnel structure life-cycle as follows:1. Study on stability reliability of excavation face of shield tunneling and reliability of initial support in the construction stageThe limit support pressure at excavation face of shield tunneling is studied with numerical simulation method. BP neural net work is trained, which parameters of surrounding rock mass and ratio of limit support pressure of tunnel face as for samples. After training, the net work can predict ratio of limit support pressure when lots of parameters are imported. The statistics character of ratio of limit support pressure is gained. Principle of designed earth pressure of shield tunneling is discussed based on theory and engineering practice. Limit state function of tunnel face stability is established, and reliability is solved with the genetic algorithms. In the thesis, not only stability of tunnel face is appraised rationally, but also it is reference to select support pressure rightly.Up to date there is no broad applicability method for reliability of the initial support calculation in the construction stage. The model of plane is used to simulate the space effect near tunnel face by free coefficient of stress of surrounding rock. Initial support of tunnel is looked as time-dependent structure, and geometric optimization model of initial support is founded. To large search space and small feasible space of the optimization model, the method for reliability calculation based on improved Genetic Algorithms is putted in the thesis. The precision of the result solved by the method in the thesis is compared with the one solved by crude importance sampling method. Reliability of initial support at every time is solved by the method in the thesis under different speed of dig. Furthermore, the sensitivity analysis of the reliability to changes in distribution parameters is also made. The result is of significance for ascertaining the key quality controlled item during construction stage.2. Study on reliability of spatial tunnel structural system and the reliability under earthquake action in the serving stageResearch work of tunnel spatial structural system reliability is conducted as follows. Firstly, equivalent deviation increasing function is putted in this thesis based on geostatistics theory. So the variability of spatial interaction among the surrounding rock mass and second liner is simplified to plane problem. Secondly, spatial resistance of second liner is solved by the Weibull-???????? statistical theory for brittleness material. The problem of tunnel spatial structural system reliability is simplified plane problem. At last, main failure model of tunnel structure and the method for reliability calculation are discussed. Jinzhou tunnel as for example in this thesis, its' spatial structural system reliability is estimated. The research creates a new way for estimation of tunnel spatial structural system reliability.The statistical characteristics of internal forces most disadvantageous position of tunnel structure under earthquake action is solved using stratum response displacement reaction method based on the response spectrum of tunnel structure. Limit state function of carrying capacity of tunnel structure is founded, and the method for reliability calculation based on Matlab's optimization tool box is researched. Shallow part of Jinzhou tunnel as for example, reliability of most disadvantageous position of tunnel structure under minor earthquake, moderate earthquake, major earthquake action respectively. The reliability decreases clearly with the increasing of seismic levels.3. Study on reliability of tunnel structure in the aging stageDegradation of small eccentric compression member and character of destroying for the corrosion of steel bar are analyzed. Time-dependent carrying capacity of small eccentric compression tunnel structure limit state function is deduced based on the existing theory. The viscous deformation of surrounding rock mass as initial elastic deform, visco-elastic stochastic finite element incremental formulations were derived based on elastic finite element theory. Program of visco-elastic stochastic finite element is compiled. Average and deviation of internal force of Jinzhou tunnel structure at different time is solved. Reliability of three key section of tunnel structure at different time is solved. The result show that reliability decreases linearly with the extension of time. The reason of reliability decreasing is analyzed. The research is very significance in academic and practical for tunnel's management, maintenance, reinforcement.
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