Full-Scale Linear Cutting Tests to Propose Some Empirical Formulas for TBM Disc Cutter Performance Prediction

Determination of the TBM disc cutter performance at the optimum rock cutting condition is very important, but the existing theoretical, laboratory, numerical or empirical methods still have some shortcomings. Full-scale rock cutting test is regarded as the most accurate and reliable method in the laboratory, but it still requires large rock blocks and specific testing equipment, which make the use of this method very limited and costly. Thus, by collecting, analyzing and formulizing the results of many full-scale linear cutting tests, this study partly overcomes the shortcoming of the full-scale rock cutting test and proposes some new empirical formulas to predict TBM disc cutter performance in a much easier and less costly way. First, this study reveals the general rules to characterize the change of rock cutting results with the increase of rock uniaxial compressive strength and cutter penetration depth by conducting full-scale linear cutting tests on five different rock types. Then, by analyzing a large amount of full-scale linear cutting test results, this study correlates the TBM disc cutter performance at the optimum rock cutting condition with rock uniaxial compressive strength and a widely used semi-theoretical prediction model. The new proposed empirical formulas in this study only use rock properties, cutter geometries and cutting geometries to design the machine specifications and select the TBM operation parameters, which is a much easier and less costly method.