Abstract
Mechanical methods of tunnel excavation are widely used because of their high excavation output, and the selection of appropriate technology depends on ground composition and project-related features. Compared with tunnel boring machines (TBMs) and roadheaders, mechanical pre-cutting machines are used in tunnel widening and have proven to be reliable in tunnel capacity expansion. Compared to other machines, the excavation characteristics of pre-cutting machines are not systematically analyzed because of their rare use. In this study, the excavation characteristics of a pre-cutting machine are analyzed in a laboratory based on linear cutting tests performed on four rock specimens with different uniaxial compressive strengths. During testing, changes in tool forces, cutting volume, and specific energy are determined while maintaining different penetration depths, spacings, and rock strengths. The variations in these variables are selected accordingly. The results showed high similarity with the case of TBMs and roadheaders. However, in the excavation by the pre-cutting machine, the ratios of the peak-to-mean cutting forces and cutting-to-normal forces reached a maximum value at a specific s/p (spacing and penetration ratio), which is related to the optimal cutting conditions. This study can provide useful information for the operation and design of pre-cutting machines.
Funder
National Research Foundation of Korea
Subject
Fluid Flow and Transfer Processes,Computer Science Applications,Process Chemistry and Technology,General Engineering,Instrumentation,General Materials Science
Reference41 articles.
1. Numerical evaluation of new Austrian tunneling method excavation sequences: A case study;Rehman;Int. J. Min. Sci. Technol.,2020
2. Rehman, H., Naji, A.M., Nam, K., Ahmad, S., Muhammad, K., and Yoo, H.-K. (2021). Impact of Construction Method and Ground Composition on Headrace Tunnel Stability in the Neelum–Jhelum Hydroelectric Project: A Case Study Review from Pakistan. Appl. Sci., 11.
3. Richart, F.E., Hall, J.R., and Woods, R.D. (1970). Vibrations of Soils and Foundations, Prentice-Hall.
4. Santamarina, J.C., Klein, K.A., and Fam, M.A. (2001). Soils and Waves, John Wiley & Sons.
5. The mechanical pre-cutting method;Bougard;Tunn. Undergr. Space Technol.,1988
Cited by
3 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献