Tunnel support structure using built-up pipe support set, and unit pipe support member therefor

摘要

Structure for supporting the excavated wall of a tunnel comprises a plurality of unit pipe support members connected in end-to-end relation by pipe couplings with lap joints, or by flanges on the ends of the support members, to form a plurality of sub-assemblies which are then connected by a closure member to form a pipe support having a periphery substantially conforming to the periphery of the tunnel wall, and having ports through which the pipe support can be filled with mortar or concrete. The unit pipe support members are substantially the same size and shape for mass production from ductile cast iron or cast steel and are provided with integral reinforcing ribs.