Mutual prediction mechanism between disc cutter cutting forces and rock strength parameters: Experimental study and field application

Proposing an accurate, reliable, convenient and low-cost method to accurately predict the disc cutter cutting forces for different cutting conditions and real-timely obtain the rock strength parameters ahead of the tunnel face is of great importance for the successful use of tunnel boring machine (TBM). To fulfil these two purposes, this study have mainly done two works by analysing the laboratory full-scale linear cutting test results and the field TBM excavation performance data. First, by comparing the experimental and field results to the prediction results, the original semi-theoretical CSM (Colorado School of Mines) prediction model is modified by reconsidering the influence of rock compressive and tensile strengths. The new models can accurately predict the laboratory and field disc cutter cutting forces from rock strength parameters in a convenient and low-cost way. Second, by rearranging these new models, some binary equation groups concerning rock uniaxial compressive strength and Brazilian tensile strength are proposed. By solving these binary equation groups, for each combination of disc cutter normal and rolling forces, rock strength parameters can be reversely predicted. The results of this study have preliminarily revealed the mutual prediction mechanism between disc cutter cutting forces and rock strength parameters. In the future, if one of them is known, then the other can be determined accurately and conveniently, which will surely promote the safe and efficient TBM tunnelling. • Mutual interaction mechanism between disc cutter cutting forces and rock strength parameters is revealed. • Disc cutter normal and rolling forces are predicted more accurately. • Rock strength parameters are predicted from disc cutter cutting forces.