Calculation of the surrounding rock pressure on a shallow buried tunnel using linear and nonlinear failure criteria

A method to calculate the surrounding rock pressure on a shallow buried tunnel was established using linear and nonlinear failure criteria based on Terzaghi failure mode. The modified Terzaghi theory, which was expanded to include complex strata and the corresponding recurrence formulas used to calculate vertical earth pressure, was obtained through theoretical derivation. The surrounding rock in the fractured zone of the tunnel side wall was analyzed as an isolated body using the limit equilibrium method to obtain the explicit calculation expressions of the horizontal earth pressure of a shallow buried tunnel. Case analysis indicates that this method is feasible. The effects of the lateral pressure coefficient of overlying strata and the nonlinear coefficient on the surrounding rock pressure with linear and nonlinear failure criteria are further studied, and results show that the surrounding rock pressure notably decreases with an increase in the lateral pressure coefficient of the overlying strata. Surrounding rock pressure slowly decreases with an increase in the nonlinear coefficient, and the effect of the nonlinear coefficient on horizontal earth pressure is significant.