Study on Rock Fracture with TBM Cutter Under Different Confining Stresses

Based on fracture mechanics and previous study, theoretical, laboratory and numerical studies are conducted to investigate the influence of confining stress on rock fracture characteristics and cutting efficiency of TBM cutters. Both theoretical and numerical studies show directly that the increasing confining stress will restrain the initiation and propagation of median cracks, while the fracture angle of lateral cracks will be increased. The fracture characteristics of the specimens in laboratory tests affirm the conclusions made by theoretical and numerical studies in further. Based on relevant assumptions, both favorable and adverse effects on cutting efficiency are observed as the confining stress increases. Combined with theoretical results, the conclusions proposed about the cutting efficiency are affirmed. © 2015, Indian Geotechnical Society.