ABSTRACT
Increasing water demand is a significant problem in big cities. High-speed tunneling may only be realized with highly mechanized tunneling operations. This paper summarizes tunneling operations with two EPB-TBMs in highly complex geology in Istanbul. Along the tunnel route, there are fault zones, transition zones, and critical areas passing under a river. The performance of two EPB-TBMs will be summarized, emphasizing the effect of geotechnical parameters. The tunnel diameter is 4 m, while 3 m steel pipes will convey the water. The steel pipes are delivered into the tunnel with specially designed equipment, and special concrete is used to fix the pipes within the tunnel. The main objective of this paper is to discuss the EPB TBM performance in complex geology and share our experience in using highly mechanized systems to transport steel pipes within the tunnel and using special concrete to backfill the pipes
