The Effect of Blast Loading on the Behavior of Shallow Tunnels

The present study investigates blast-induced deformations in the ground surface and lining of shallow tunnels. Using a 2D finite element method (FEM), numerical simulation of the interaction effect of factors such as depth, shape (circular and square), tunnel diameter, the modulus of elasticity of the soil, the size of the blast loading, and the distance from the explosion site to the center of the tunnel on maximum ground surface settlement, maximum deformation in tunnel crown, and maximum bending moment in tunnel lining are discussed. The results show that circular tunnels perform better than square tunnels under blast loadings. The tunnel's behavior is more suitable in soils with high elasticity. The improvement in the system's performance would be more significant for tunnels with smaller sections and deeper locations due to a larger distance from the center of the blast.