Evaluation of safety of buildings above tunnels accounting for spatial variability of soil properties

Considering the spatial variability of soil properties, a probabilistic evaluation method is proposed for the safety of buildings above tunnels based on the random field theory and the numerical analysis method. The elasticity modulus of soils is considered as the random fields, and the stress release method is employed to simulate the tunnel excavation. Then based on the assumption that the surface buildings are treated as the flexible beam model, the safety of buildings can be probabilistically assessed through the method of limit tensile strain. It is shown that the proposed method can properly evaluate the safety of buildings in variable soils. In addition, there is a significant influence of coefficients of variation and auto-correlation length of elasticity modulus on the safety of buildings. The higher the variability of elasticity modulus, the more scattering the distribution of the maximum tensile strain in buildings, and the larger the probability of higher category of building damages.