ABSTRACT
Two EPB-TBMs are working on this project in complex geology. A certain amount of this tunnel in length is subjected to a detailed study of TBM performance. A water ingress of 60 m3/h was experienced in a transition zone from clay to an interbedded siltstone-claystone formation, and 115 m3 of double component polyurethane was applied to create a curtain to stop the water ingress into the tunnel. It is emphasized that EPB face pressure is a mitigation factor in overcoming face collapses and TBM jamming in transition zones. A face pressure of 2.1 bar was a key factor in passing a major transition zone. Normalized thrust force, normalized torque, penetration and specific energy values were compared with those of other 8 projects in Turkey in different formations in order to understand better the effect of the operational parameters and geotechnical properties on TBM performance of EPB-TBM.
