NEW DEVELOPMENTS IN GROUND SUPPORT TECHNOLOGY FOR OPEN-TYPE TUNNEL BORING MACHINES

摘要

Open-type, or Main Beam, TBMs can achieve impressive rates of production. Thisrntype of tunnel boring machine typically outperforms other types of TBM currently inrnuse around the world today. In good ground conditions, Main Beam machines havernachieved production rates of over 1 kilometer per month.rnHowever, installing effective ground support in poorer rock conditions on MainrnBeam machines can be a major cause of concern. The design of Main Beam machinesrnis such that installation of ground support equipment, particularly at the front of thernmachine in what is commonly known at the L1 support zone, has traditionally been limitedrnto rock drills & basic working platforms. Personnel working in the L1 zone have untilrnrecently been protected by roof supports and extended fingers, often with restrictedrnaccess to working areas.rnThis paper will discuss the advances and developments of ground support systemsrncurrently in use today in the L1 support zone on Main Beam machines. A casernstudy of the benefits and challenges of providing such equipment on a 10 m Main Beamrnmachine, currently in use on a project in China, will be presented.