Analysis of the Tunnel Boring Machines (TBM) Performance Parameters Using Boreability Index in Turkey
Performance prediction and the determination of some design parameters of TBMs are becoming very crucial for tunneling industry since they are critical elements in the pre-planning of a mechanical excavation project. In this paper three case studies are analyzed with a detailed field and laboratory studies concerning in Istanbul. The performance parameters of the TBMs (Cutter forces, i.e., thrust force, rolling force, and specific energy values) are also collected during the excavation of the tunnels. Tunnel boring machine's performance results of the tunnels are summarized. Field data are collected carefully in order to compare TBM operational parameters such as field thrust, torque, net cutting rate, specific energy and boreability index. It is shown that specific rock mass boreability index (SRMBI) defined by Gong (2007) is a good indicator of the rock mass properties. Four different Istanbul metro tunnels (supported by The Scientific and Technological Research Council of Turkey (TUBITAK-112M859) are summarized and discussed based on boreability index.