METHOD AND APPARATUS FOR FEEDING A TUNNEL ROOF SUPPORT SYSTEM FROM THE ROOF SHIELD OF A TBM

摘要

A primary support for a tunnel roof comprising elongated lagging members which are "extruded" from tubes forming a shield for a tunnel boring machine. The lagging is inserted into the tubes at different times so as to avoid having the ends of adjacent lagging members coincide. As the tunneling machine progresses in the direction of boring, the lagging members emerge from the shield tubes to form a primary tunnel roof lining. Ring beams or arc beams may be installed as required by means of rock bolts or other fastening means.