Full-Scale Rotary Cutting Test to Study the Influence of Disc Cutter Installment Radius on Rock Cutting Forces

Disc cutters mounted on the cutterhead of tunnel boring machine (TBM) can be divided into center cutter, face cutter and gauge cutter according to their installment radius. Due to the differences in rock cutting condition, disc cutter turning radius and cutterhead stiffness distribution, they show very different characteristics in the magnitude of disc cutter normal and rolling forces. For the realistic modeling of whole cutterhead, full-scale rotary cutting test using disc cutter with different installment radius is a useful and inspiring way to study the influence of disc cutter installment radius on rock cutting forces. By conducting full-scale rotary cutting test, two main conclusions are obtained. First, disc cutter normal and rolling forces both decrease rapidly and then remain nearly stable when disc cutter installment radius increases. Second, the normal and rolling forces of the innermost disc cutters are two to four times higher than those of the outermost disc cutters. This study verifies the very uneven distribution of the disc cutter cutting forces on the cutterhead, and it can contribute to better arrangement of the disc cutters to ensure that they subject to similar loading and wear conditions and also can offer suggestions for field TBM operation to avoid severe overloading of the inner disc cutters.