Theoretical calculation model of the soil arching effect considering tunnel influence

Accurately determining the distribution of soil pressure influenced by tunnels is essential for ensuring the safe development of deep underground spaces. This study presents a theoretical calculation model based on limit equilibrium theory to calculate the soil arching effect considering tunnel influence, which comprises an end-bearing arch, a frictional arch, and a stable zone. Depending on the spacing between the tunnel and the trapdoor, the model is further classified into two types: independent arch and interaction arch. A comparative analysis with previous numerical simulations and theoretical models confirmed the accuracy of the proposed model, as it reliably predicts the central stress on the trapdoor and effectively captures the overall stress distribution. The vertical stress on the tunnel is significantly influenced by the internal friction angle, burial depth, and trapdoor width, while the differential soil arching ratio across the width of the trapdoor decreases as the distance from its centerline increases.