Linear Cutting Machine (LCM) test, which is expensive and difficult to perform for measurement of rock cutting forces, is one of the most powerful tests to estimate cuttability of rocks in laboratory. It is performed to measure the cutting force using rock mass blocks instead of intact rocks, which is not represent the mass features. In this study, the LCM tests were conducted on 8 different rock types consist of various granitic gneiss, meta-andesite, dolerite, meta-dolerite, Paragneiss and calc-silicate. Further, intact rock tests including uniaxial compressive strength, tensile strength, density, brittleness and Cerchar abrasivity index were carried out on a rock specimen. Then relations between measured intact rock properties and measured cutting force via LCM tests were examined. It is found that the intact rock properties could be employed to estimate cutting force (Fn) for similar rocks as the LCM test is not accessible.
It is known that rock properties and their influence on rock cutting and boring is crucial for any type of mechanized excavators. Due to that Linear Cutting Machine Test (LCM) is developed to estimate the rock cutting forces as a function of rock properties and cutter specifications in the laboratory. One of the famous institute having LCM equipment is Earth Mechanics Institute (EMI) of Colorado School of Mines (CSM). Besides the EMI, several institutes such as Istanbul Technical University, Turkey and Central South University, China also have LCM in their laboratories to use for measuring rock cutting force. As using TBMs (tunnel boring machines) to excavate underground tunnels, it is very important to identify the optimum rock cutting condition and determine the corresponding rock cutting results (Pan et al., 2019). Using LCM, Rostami and Ozdemir, (1993) developed cutting force equation, a basis of tunnel boring machine (TBM) performance prediction model developed at CSM. Yagiz (2006) stated that cutting force can be estimated using rock properties such as strength and brittleness of rocks. Pan et al., (2019) used LCM tests results to propose some empirical formulas for TBM disc performance prediction. Balci, (2009) studied correlation of rock cutting tests with field performance of a TBM in a highly fractured rock formation in Turkey. He stated that LCM test, where the cutter forces are measured by full-size cutters in large rock samples, combined with rock physical property tests are probably the most reliable production estimation technique in present. Xai et al., (2017) compared experimental and semi-theoretical cutting forces of Constant Cross-Section (CCS) disc cutters. Abu Bakar et al., (2014) evaluate the impact of moisture content on rock behavior and rock excavation by disc cutters. Entacher and Lassnig, (2012) performed LCM tests, very powerful tests to estimate the rock cutting force, on Alpine lithology's; however, analysis of cutting tests shows that cutting forces are not necessarily proportional to results of rock strength like uniaxial compressive strength and tensile strength tests. In this paper, the LCM tests and physical properties tests were performed on different rock blocks and the intact samples to estimate rock cutting force that relevant with rock excavators.
