Controlled-compressible thrust bearing for tubbing rings in tunnels

摘要

In order to permit elastic absorption of the rock pressure occurring after the excavation of the tunnel in the case of tubbing rings which are composed of individual tubbing segments (1, 1'), compressible thrust bearings (2) are inserted between these segments. Each thrust bearing (2) is a box of elastically deformable material which has several hollow spaces in its interior. The boxes are compressed by the rock pressure until the hollow spaces are filled by the box material. The diameter of the tubbing ring is accordingly reduced. The deformation of each thrust bearing can be accurately controlled by appropriate dimensioning of the hollow spaces and also by filling the same with material when required and by controlled discharge of this material.