Safe range analysis of clear distance of twin shallow tunnels based on limit analysis and reliability theory

Abstract

A method of analyzing the stability of twin shallow tunnels was presented using both limit analysis with nonlinear failure criterion and reliability theory. In the condition of nonlinear failure criterion, the critical clear distances of twin shallow tunnels were obtained by analyzing the change of surrounding pressure. A reliability model was established based on limit state equation, and the failure probability was solved by virtue of Monte Carlo method. Safety factor and corresponding clear distance of different safety levels were obtained by introducing a target reliability index. The scope of clear distance for different safety levels is described, which can be used as a supplement and improvement to the design codes of tunnels.

Keywords

twin shallow tunnels / limit analysis / nonlinear failure criterion / reliability theory / clear distance

References

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