Abstract In this paper, the calculation method of surrounding rock pressure of shallow buried tunnels under linear and nonlinear failure criteria is established on the basis of the Terzaghi failure mode. The modified Terzaghi theory is applied to compound stratum, and the recursive formula is derived for calculating the vertical surrounding rock pressure under the compound stratum. The surrounding rock at the fractured zone of the tunnel side wall is analyzed as an isolated body by the limit equilibrium method, and the explicit calculation expression of the horizontal rock pressure of shallow buried tunnels is obtained. A case analysis indicates that this method is feasible. Further the influence of the lateral pressure coefficient of overlying strata and the nonlinear coefficient on the surrounding rock pressure is studied with linear and nonlinear failure criteria. The results prove that for increasing lateral pressure coefficients and nonlinear coefficients, the surrounding rock pressure decreases dramatically and gradually respectively, and the influence of the nonlinear coefficient is slightly higher regarding horizontal surrounding rock pressure.
Abstract:
In this paper, the calculation method of surrounding rock pressure of shallow buried tunnels under linear and nonlinear failure criteria is established on the basis of the Terzaghi failure mode. The modified Terzaghi theory is applied to compound stratum, and the recursive formula is derived for calculating the vertical surrounding rock pressure under the compound stratum. The surrounding rock at the fractured zone of the tunnel side wall is analyzed as an isolated body by the limit equilibrium method, and the explicit calculation expression of the horizontal rock pressure of shallow buried tunnels is obtained. A case analysis indicates that this method is feasible. Further the influence of the lateral pressure coefficient of overlying strata and the nonlinear coefficient on the surrounding rock pressure is studied with linear and nonlinear failure criteria. The results prove that for increasing lateral pressure coefficients and nonlinear coefficients, the surrounding rock pressure decreases dramatically and gradually respectively, and the influence of the nonlinear coefficient is slightly higher regarding horizontal surrounding rock pressure.
.Calculations of Surrounding Rock Pressures of Shallow Buried Tunnels
under Linear and Nonlinear Failure Criteria[J] MODERN TUNNELLING TECHNOLOGY, 2013,V50(5): 68-74