The production rate of mechanical excavators such as tunnel boring machine (TBM) and roadheader depend on the geotechnical properties of rock, machine specifications and operational parameters. TBMs are being utilized for the construction of various tunnels for the purpose of access, conveyance of ore and waste, drainage, exploration, water supply and diversion in mining and civil projects. To obtain the maximum production with optimum power from any mining or civil operation, the excavator should be chosen carefully depending on the ground condition and mass rock characterization. Examining those rock characteristics, evaluating the geological structures in the field, and choosing the right TBM for excavation are the main geotechnical and technological investigation steps to conduct the project. In this paper, intact rock properties e.g., strength, density, brittleness and mineralogical features of rock, rock mass characteristics such as frequency and orientation of discontinuities are examined and their influence of TBM advancement are highlighted.
Currently, mechanized excavation is one of the most popular and fastest way of rock and soil excavation around the world due to its high mechanization level, great operational efficiency and low environmental impact. However, the application of the method requires an accurate estimation of possible costs in the primary and secondary stages of projects. Due to that, the assessment of TBM performance via an either rate of penetration (ROP) or field penetration index (FPI) and rate of advance (AR) as well as utilization (U %) is one of the most effective factors, both in estimating the cost and the operation time of any project. Accordingly, the incorrect estimation of these parameters can lead to irrecoverable economic and time losses in proposed project. The ROP is one of the most commonly used parameters of TBM boring process; however, utilization and advance rate are also connected with ROP due to that these three indicators are the main targets to obtain for project scheduling. In present, different models and relations have been introduced to predict the penetration rate as a function of intact and mass rock and also machine specifications. Numerous simple and comprehensive methods have been proposed for predicting the TBM performance by researchers (Graham, 1976; Farmer and Glossop, 1980; Hughes, 1986; Rostami and Ozdemir, 1993; Palmstrom, 1995; Bruland, 1999; Barton, 2000; Yagiz, 2002; Bieniawski et al., 2008; Gong and Zhao, 2009; Hassanpour et al., 2009; Delisio and Zhao, 2014; Yagiz, 2017; Goodarzi et al 2021; Yagiz et al., 2024), and machine manufacturing companies (such as, Robins and Herrenknecht) throughout the world. These methods are generally based on field, machine and laboratory dataset obtain from laboratory tests. In general, these parameters can be classified into three main categories:
