Reliability Analysis And Application Of Tunnel

Tunnel is an important part of geotechnical engineering. It is difficult to consider uncertainty of tunnel using the traditional stability analysis methods. The reliability analysis method provides an effective way to study the stability of the tunnel.The response surface method is combined with numerical simulation to consider the uncertainties such as elastic modulus, internal friction angle and cohesion etc in this thesis. Response surface method is adopted to build the limit state function and optimization is used to calculate the reliability index and failure probability of tunnel. The proposed method provides a rational way to tunnel design, stability analysis and construction safety. The main contents are as follows:Firstly, the reliability analysis methods were reviewed in detail..It has to choose a resonable method to analyze the reliability of tunnel, because the uncertainties can effect seriously on the stability of tunnel.Secondly, it is difficult to represent the mechanics behavior of tunnel in closed solution, so the limit state function is usually represented in implicit form such as numerical mthod. The response surface method was adopted to build limited state function by combing with numerical method which calculates the displacement of tunnel in different geomechanical parameters in this thesis. The optimization method was used to search the reliability index based on first order reliability method(FORM). In order to verify the proposed method, a circular tunnel was analyzed subjected to hydrostatic far field stress and uniform support pressure. The results show the relative error is within a reasonable range for the reliability analysis.Finally, the proposed method is applied in the Dong Chuan tunnel to complete the corresponding reliability analysis.