Inverse Reliability Method And Its Application In Design Of Tunnel Lining Structure

With the development of the structural reliability theory, which is based on Probability statistics, need to search for the unknown design Parameter based on the Prescribed reliability index, which meet corresponding pre-set target reliability levels. The tradition forward structural reliability theory to deal with this problem only by means of "trial and error," this approach sometimes is invalid, and at the same time the cost of calculation is commonly large, then the inverse reliability method is elicited here. This thesis deals with the following aspects concerning the inverse reliability method and its applications in design of tunnel lining structure.(1) This article firstly introduces the basic theoretics of the forward reliability, accordingly the inverse reliability theory is also put forward, the another summarize the detailed calculation steps by the numbers, showing the efficiency and applicability of the procedures by several examples.(2) The traditional "load-structure" model which especially applies to unitary lining is still the main basis of design and construction of tunnel and underground structure. Moreover, the continuous medium model which can be numerical simulated through element method to further study the design of tunnel. This text is according to the all kinds of domestic and oversea information to calculate the statistical characteristic of inner force by Monte-Carlor method related to "load-structure" model for shallow tunnel. When the reliability index is given, inverse reliability method is used to calculate the tunnel lining thickness of each section by iterations according to its state either tension or compression, and the profile of tunnel lining is protracted in the thesis.(3) Based on continuous medium model, after sensitivity analysis of factors ofrandom variable such as c,φ,E and D influencing load effects is discussed for the difference of surrounding grade and depth of burial, the limit state function of load effects about random variables is established. The inverse reliability analysis of lining structure is studied for the difference depth of burial ofⅡ,Ⅲ,Ⅳsurrounding grade with the method in this text to obtain the tunnel lining thickness. The detailed calculational steps are given later. It will supply the guidelines for tunnel design and construction.