Achieving Fast EPB Advance in Mixed Ground:A Study of Contributing Factors

摘要

Earth Pressure Balance (EPB) tunneling in mixed ground conditions is a challenging prospect,rnas it often includes excavation in boulder fields, sections of rock, and/or sticky clay, under high waterrnpressure or changing water pressure. Maintaining a rapid advance rate in such conditions is a function ofrnmany factors—from adequate cutting tools to cutterhead design, pre-planning and execution of an appropriaternground conditioning regime as well as proper maintenance and operation of the TBM. This paper will analyzernrecent record-breaking and high-performing projects seeking to identify factors that contribute to fast machinernadvance. These factors will then be discussed and an effort made to form simple, high level guidelines forrnoptimal TBM excavation in mixed ground conditions.