Numerical investigation on rock fracture induced by a new directional rock-breaking technology

• Published in: Engineering fracture mechanics 2022-06, Vol.268, p.108473, Article 108473
• Main Authors: Guo, Shan, Zhang, Quan, He, Manchao, Wang, Jiong, Liu, Jianning, Ming, Can, Guo, Longji, Fan, Lanxiang
• Format: Article
• Language: English
• Subjects: Alternative explosives; Breaking; Coal mines; Crack growth; Crack initiation; Crack propagation; Cutting; Directional rock breaking; Finite element analysis; Finite element method; Fracture mechanics; Heterogeneity; Mathematical analysis; Principles; Rock fracture; Roofs; Slitting; Technology assessment; Tensile stress
• ISSN: 0013-7944; 1873-7315
• DOI: 10.1016/j.engfracmech.2022.108473

•IESF is a new type of nonexplosive directional rock-breaking technology.•IESF is much safer and produces lower vibration than directional fracture blasting.•IESF produces concentrated tensile stress in presplit direction to break rock.•IESF can create superimposed stress between two holes.•IESF has a good ability of directional rock breaking by a roof cutting test. Instantaneous expansion with a single fracture (IESF) is a new type of nonexplosive directional rock-breaking technology, which uses expansion gas induced by special slitting agents to produce a single fracture of the rock instantly in the selected direction. The technical principle of IESF and principle of roof cutting using IESF technology are analysed theoretically. To figure out the process of fracture initiation and propagation, a damage variable is introduced to describe rock fracturing, and a micromechanical model considering the heterogeneity of the rock is established using the finite element method. The numerical results show that the IESF technology can produce concentrated tensile stress and generate a single fracture in the selected direction, and there is stress superposition between the two holes. On this basis, a field roof cutting test was carried out in an actual coal mine, which indicated that the IESF technology has the advantages of a high crack rate, low degree of induced vibration, high-level safety, and a rapid rock-breaking response. The development and application of this technology provides a new method for directional rock-breaking.