Application of mechanical excavators for rock excavation in both civil construction and mining engineering fields has increased significantly in recent years. Prediction of the excavation performance of any mechanical excavators – tunnel boring machines, roadheaders, impact hammers, continuous miners and shearers for any geological formation is one of the main concerns in determining the economics of a mechanized mining and/or tunneling operation. This paper presents and discusses detailed field and laboratory studies concerning boreability prediction of rapid excavation systems (roadheaders, continuous miners, shearers, tunnel boring machines etc.) based on linear full-scale and small-scale laboratory rock cutting tests. The results of the tests are used to calculate rapid excavation system's design and performance parameters such as torque and thrust requirements and cutting rates. In this paper most common performance prediction models for mechanical excavators in the world and Turkey have been explained. Within the scope of this study, some tunnel excavation machines and performance prediction results from Istanbul metro tunnels,Kozyatagi-Kartal (design and selection determination of preliminary results of a project supported by The Scientific andTechnological Research Council of Turkey (TÜB˙ITAK-106M298) are mentioned in this study) tunnels are summarized and discussed based on full-scale rock cutting tests.
Istanbul is a very fast developing city with more than 14 millions of population. Tunnelling activities like metro, sewerage and water tunnels are increasing tremendously and at the end of 2009 it is planned that around 23 TBMs with different diameters will be working in the city. The total cost of the current tunnelling projects is calculated to be around 20 Billion US Dollars. A great effort is spent by the authors of this paper to collect data concerning the performance of mechanized excavation systems related to geology and rock mass properties in order to have guidelines for the future tunnel projects.