Experimental and numerical investigations on rotary rock-breaking force and efficiency of disc cutter

Improving tunnelling efficiency and reducing cutter wear are challenging objectives when tunnelling in hard rocks, determining optimal cutting parameters is crucial for practical projects. Laboratory tests are essential for understanding the load performance of disc cutters. In this study, a novel full-scale rotational cutting platform is employed to investigate cutting force characteristics and determine optimal cutting parameters. Additionally, the finite element method is applied to enhance experimental analysis and provide new insights. Based on experimental results, the variations in cutting forces and rock-breaking efficiency with cutting depth and installation radius are identified. Subsequently, an optimal cutting depth of 6 mm is determined at a cutter spacing of 100 mm. The distribution of rock chips is analyzed using an indicator of cumulative percentage below a given grain size, which decreases and then increases with increasing cutting depth for any cutting radius. The numerical model is validated as reliable based on crack development caused by disc cutter intrusion. The numerical results for disc cutter rock-breaking performance are consistent with experimental findings. The findings provide valuable data for optimizing cutterhead layout and reducing cutter wear.