Probability Baseline Finite Element Model Of Tunnels Based On Dynamic Monitoring Feedback

It is essential to accurately determine the physical parameters of surrounding rock of tunnels in order to ensure the safety of tunnel construction and operation because the load of surrounding rock always acts to the tunnel structures during the process of construction and operation.Addressing this issue,the parameters of surrounding rock of tunnels are deemed as stochastic variables,and then the probability baseline finite element model of tunnels are proposed by using the stochastic finite element model updating.The research status of numerical simulation of tunnel construction are summarized systematically,and the key issues of determining the physical parameters of surrounding rock based on inverse analysis theory are anlyzied emphatically.Based on these jobs,this study proposes to establish the probability distribution of surrounding rock with the measured monitoring feedfack during the process of tunnel construction.The method of simulating the process of tunnel construction considering the action of sorrouding rock load is investigated deeply.The related theory of tunnel simulation is introduced,and then the procedure of finite element analysis uing ANSYS software is described in detail.An actual tunnel engineering is taken as an example,three finite element models considering different construction method are established,and these finite element models are applied to simulate the construction process of this tunnel.The meta-model is investigated in detail in order to obtain a surrogate model of finite element model of tunnels.Some key methods are discussed such as the selection of feature samples,the mathematical express of Kriging model,the asseeement of accuracy of Krtiging predictor etc,.After this,the Kriging model of this actual tunnel is established for usage of finite element model updating subsequently.Finally,this study focuses on the method of eatablishing the probability finite element model of tunnels based on the Kriging preditor.The probability distribution of the measured deformation of tunnel structure are analyized statistically at first.Then,the optimization issue,the selection of updating parameters and the sensitivity analysis are described and discussed deeply.With these results,the probability baseline finite element of this actual tunnel is established in this study.