A method of reducing pressures on tunnelling shields and tunnel linings in weak rock

摘要

A method of reducing the pressures from weak rock on shields 11 used for tunnel driving, as well as reducing pressures on tunnel linings, by filling the void between the shield 11 and the surrounding rock 3 with an expandable, hardenable and deformable material, said void being filled by injection with the material. The deformation and strength properties of the material will allow controlled deformation of the rock towards the shield 11 and the tunnel support 2 such that the applied rock pressures are reduced. The invention reduces the danger of immobilisation of the shield because of being squeezed by the deforming rock and will allow tunnel supports to be designed for substantially reduced rock pressures. IMAGE