Achieving Fast EPB Advance in Mixed Ground: A Study of Contributing Factors
Earth Pressure Balance (EPB) tunneling in mixed ground conditions is a challenging prospect, as it often includes excavation in boulder fields, sections of rock, and/or sticky clay, under high water pressure or changing water pressure. Maintaining a rapid advance rate in such conditions is a function of many factors—from adequate cutting tools to cutterhead design, pre-planning and execution of an appropriate ground conditioning regime as well as proper maintenance and operation of the TBM. This paper will analyze recent record-breaking and high-performing projects seeking to identify factors that contribute to fast machine advance. These factors will then be discussed and an effort made to form simple, high level guidelines for optimal TBM excavation in mixed ground conditions.
- Rock Tunnels at High Water Pressure: Non-Continuous Pressurized TBMs vs. Slurry
- Hybrid TBM Excavation in Challenging Mixed Ground Conditions at the Mumbai Metro
- TBM Excavation in Himalayan Geology: Over 1,200 Meters per Month at the Bheri Babai Diversion Multipurpose Project
- Tunneling through 48 Fault Zones and High Water Pressures on Turkey’s Gerede Water Transmission Tunnel
- Overcoming Multiple Caverns: Successful TBM Tunneling in Karst Geology at Galerie des Janots