Calculation method for surrounding rock pressure of a loess highway tunnel with an extra-large section

Using the construction of the Tangjiayuan tunnel in loess with an extra-large section as an example, the surrounding rock pressure is calculated by five common methods, of which the results from the Terzaghi theory-based method were very consistent with the measured data. A correction method is put forward regarding the lateral pressure coefficient, and is recommended for application to the Tangjiayuan tunnel. Furthermore, in light of the definition criterion between the shallow-and deep-buried tunnels, a simulation method is also proposed for determining the boundary of the shallow and deep depths based on the variation rule of the lateral pressure coefficient of the soil body on the centerline, the Tangjiayuan tunnel is considered to be shallow-buried, with a boundary of 90 m. ©, 2015, Editorial Office of Modern Tunnelling Technology". All right reserved."