This paper explains the characteristics and the design features of a new full scale laboratory Rotary Cutting Machine (RCM) developed by Hyundai E&C for the simulation of hard rock TBM tunneling, which includes the analysis of the process of TBM cutter head RPM, relative position of the disc cutter on the cutter head, constant normal force mode, and constant penetration rate mode. The major goal of RCM is to investigate the characteristics of cutting performance of the hard rock TBM tunneling with a more realistic method in contrast to commonly used method of Linear Cutting Machine (LCM). The results of a set of tests performed on a Korean Granite for various spacing and penetrations are discussed with a focus on optimal spacing and actual specific energy.
Subsequently, RCM is applied to Jinhae Geoje gas pipeline tunnel project, which is the longest (7.8 km) and the deepest (90 m) subsea tunnel in South Korea. This tunnel will accommodate pipelines to carry natural gas from the mainland to Geoje Island southeast of the country to alleviate the increased demands for natural gas. Tunneling is currently underway using two slurry shield TBMs of 3.5 m diameter. To describe the major design elements of the TBM and their performance evaluation, a thorough analysis of geotechnical information using well known models as well as RCM model was performed. As a result, the RCM model was applied to Jinhae Geoje gas pipeline tunnel project and yielded estimation which is very close to the actual value.
Throughout the history of TBM, major enhancements have been achieved especially for cutting efficiency in both cutting geometry and characteristics of cutting tools. The process of cutting with tools such as disc cutter has been studies in detail by many researchers e.g. Rostami (1993, 1997, and 2008), Sato et al. (1991) and Sanio (1985). Most of these research studies are conducted with laboratory machine, LCM (linear cutting machine), which has been used to simulate the cutting process and to study both the TBM design and cutting characteristics.