A new prediction model for disc cutter wear based on Cerchar Abrasivity Index

The wear evolution indicated that abrasive wear is the dominant wear mechanism for disc cutter wear. Considering the uneven rolling force distribution on the cutterhead, the relative installation radius is introduced to reflect the influence of installation radius on the rolling force, and the CSM rolling force model is corrected based on linear assumption. To accurately predict disc cutter wear, the relative sliding distance between disc cutters and rock is derived based on corrected rolling force and contact theory. The effect of installation radius, cutters radius and penetration on the relative sliding distance is investigated, the results illustrated that the relative sliding distance increase with the installation radius and penetration, conversely, the relative sliding distance increase with the disc cutter radius decrease. In addition, the relationship between wear coefficient and Cerchar Abrasivity Index (CAI) is analyzed by a series CAI test. According to CAI change trend as stylus sliding distance, the effect of stylus shear failure on the abrasivity property within initial test stage was excluded. Furthermore, A new model is proposed to predict disc cutter wear based on the relative sliding distance and wear coefficient. And the effect of installation radius, cutters radius, Uniaxial Compressive Strength (UCS), CAI et al. on the disc cutter wear is investigated, the results illustrate that the disc cutter wear increase with installation radius, penetration, UCS, CAI and spacing between adjacent cutter, conversely, the disc cutter wear increase with the cutter radius and thickness decrease. Finally, the accuracy of proposed model is verified by Yintao water conveyance tunnel project. The research of parameters provides a theoretical basis for optimizing excavation parameters and reducing cutters wear.