Stochastic Analysis of Subway Tunnel Deformation Using the Finite Element Method Considering Soil Inherent Variability

Urbanization has driven the necessity for subway networks as a reliable and efficient public transportation system. Therefore, controlling the deformation of subway tunnels and adjacent structures is of great importance. Additionally, soil heterogeneity and uncertainty significantly affect tunnel deformation by altering stress distribution and structural response, leading to inaccurate deformation predictions. In this study, the deformation of a subway tunnel in a heterogeneous soil environment is investigated using a developed program in the present study based on the finite element method combined with a random variable approach. The proposed model is analyzed using six-node triangular elements with the Mohr-Coulomb Elasto-Plastic failure criterion. To incorporate the uncertainty of soil parameters such as internal friction angle, cohesion, and unit weight, a random variable approach is employed, considering their cross-correlation. The probability density function of displacement parameters at critical tunnel points is predicted. The results indicate that neglecting the inherent uncertainties of soil parameters can lead to inaccurate estimation of deformations and also the probability of failure.

Keywords:

Tunnel , Random variable approach , Uncertainty , Finite element , Deformation