An Elastic-Plastic Solution for a Circular Pressure Tunnel with Liner Based on a New Model

The elastic-plastic problem for a circular pressured tunnel with liner is furthermore investigated. A new mechanical model to model the construction sequence of the tunnel structure is applied. Based on the linear Mohr-Coulomb yield criterion, for the case that the yield range is in the surrounding rock is dealt with. With consideration of boundary conditions along the internal and external boundaries of the liner and the interface between the elastic and yield regions, the stress solutions for the total field, and the relations to determinate the support pressure and the yield radius are given. Also, the confinement of the liner to the surrounding rock and the effect of the internal pressure on the surrounding rock pressure and the yield range are considered in the above-mentioned analyses. Numerical results indicate that the internal pressure has the same action as the support. And that with the increase of the relative liner rigidity the support pressure is increased. However, the radial displacement along the tunnel wall and the yield radius may decrease with increasing the relative liner rigidity. Moreover, when the surrounding rock is in elastic-plastic state, the variation ranges of the internal pressure, the support pressure, the radial along the tunnel wall and the yield radius decrease with increasing the relative liner rigidity. The presented solutions contain previously known result as the special cases, for example, classical Fenner's solution.