Effects of in-situ stresses on the fracturing of rock by blasting

Yi, Changping; Johansson, Daniel; Greberg, Jenny

doi:10.1016/j.compgeo.2017.12.004

Cited by 159 publications

(63 citation statements)

References 28 publications

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“…e rock fragmentation by blasting is the first stage of the comminution process in mine, and it affects every downstream operation, such as digging, hauling, crushing, and grinding; therefore, it is vital for the efficiency of deep mining operation [3,4]. When the rock mass is subjected to high in situ stress, the rock fragmentation by blasting is impeded by high in situ stress [4][5][6], and several issues, such as underbreak and oversize fragmentation, can be aroused. To response this situation, it is essential to study the rock fracturing by blasting with the aim of expected rock fragmentation when the rock mass is subjected to high in situ stress.…”

Section: Introductionmentioning

confidence: 99%

“…More excellent works on the numerical modelling of rock blasting can be found in reviews of Latham and Lisjak [35,36]. At present, many numerical studies [4][5][6][37][38][39][40][41] in investigating the fracturing mechanism of rock under blast loading and in situ stress have been performed. In 1997, Donze et al [41] developed a numerical model based on the discrete element method to investigate the effect of stress waves on the initiation and propagation of radial cracks in an uniaxial static stress field during the dynamic loading phase of an explosion.…”

Section: Introductionmentioning

confidence: 99%

“…In the further study of Xie et al [6], the numerical analysis revealed that the coalescence of blast-induced cracks between adjacent boreholes becomes difficult when the in situ stress is higher than 30 MPa. Inspired by the above numerical studies, Yi et al [4] investigated the rock fracture patterns of full charged borehole under various in situ stress conditions, and the results showed that the crack propagation in the 2…”

Section: Introductionmentioning

confidence: 99%

“…ese numerical investigations mentioned above provide good insights about the effect of in situ stress on the rock crack evolution due to blast loading. However, in these studies, the blast loading was usually represented by a pressure-time history curve [37][38][39][40][41], which cannot accurately characterize the detonation of explosive [4]. Furthermore, the boreholes were fully charged [4][5][6], and this is not always in line with the practices of deep rock blasting.…”

Section: Introductionmentioning

confidence: 99%

“…However, in these studies, the blast loading was usually represented by a pressure-time history curve [37][38][39][40][41], which cannot accurately characterize the detonation of explosive [4]. Furthermore, the boreholes were fully charged [4][5][6], and this is not always in line with the practices of deep rock blasting. In fact, in deep mining, the charging in a number of boreholes is decoupled, especially in presplit blasting, smooth blasting, buffer blasting, and some production blasting [42][43][44], but few papers can be found to study the rock fracturing in blasting with a decoupled charge under high in situ stress.…”

Section: Introductionmentioning

confidence: 99%

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Study of the Rock Crack Propagation Induced by Blasting with a Decoupled Charge under High In Situ Stress

Liu

Yang

2020

Advances in Civil Engineering

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The high in situ stress can significantly affect the blast-induced rock fragmentation and cause difficulties in deep mining and civil engineering where the drilling and blasting technique is applied. In this study, the rock crack propagation induced by blasting under in situ stress is first analyzed theoretically, and then a numerical model with a decoupled charge in LS-DYNA is developed to reveal how the initiation and propagation of rock cracks are under high in situ stress. Through simulation, the mechanisms of blast-induced crack evolution under various hydrostatic pressures and nonhydrostatic pressures are investigated, and the differences in crack evolution with specific decoupling coefficients are compared. According to the simulation, three damage zones, i.e., the crushed zone, the nonlinear fracture zone, and the radial crack propagation zone, are formed, and the radial crack evolution is greatly suppressed by the high in situ stress which has no much influence on the crack propagation in the crushed and the nonlinear fracture zones. The velocity of crack propagation is slightly reduced, and the process of crack propagation is stopped early when the rock is subjected to high in situ stress. Furthermore, the numerical analysis indicates that the crack grows preferentially in the direction of maximum principal stress, and the radial crack propagation is predominantly controlled by the preloaded pressure, which is vertical to the crack propagation direction. Based on the numerical results, it is suggested that the optimal decoupling coefficients for rock cracking are 2.65, 1.87, 1.37, and 1.22 for 0, 10, 20, and 30 MPa, respectively. This study provides not only an analysis of the rock crack evolution under high in situ stress but also a reference for resolving excavation difficulties in deep mining.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Study of the Rock Crack Propagation Induced by Blasting with a Decoupled Charge under High In Situ Stress

Liu

Yang

2020

Advances in Civil Engineering

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Investigation of the process of perforating hard roof in an innovative technology of directional roof‐cutting by composite blasting

Tai

et al. 2023

Energy Science & Engineering

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The hard roof in coal mines will induce strong pressure problems for the working face and the lanes, which will seriously affect the safe and efficient production of the mine. For these issues, our team developed a new technology of cutting hard roof by composite blasting. With the new technology, a penetrating process is key to the directionally cut roof. Thus, an arbitrary Lagrange–Euler method is proposed to calculate the penetrating process. In this method, it was taken that the Jones–Wilkins–Lee constitutive model, Johnson–Cook constitutive model, and Holmquist–Johnson–Cook constitutive model to build a numerical model, by LS‐DYNA software, of the process of the penetrating the hard roof. Finally, the following conclusions were obtained: (1) The velocity variation law of metal liner from head to tail is revealed. The speeds of the metal liner's head and tail are 3500 and 450 m/s, respectively. (2) The shape of the channel formed by shaped charge jets is like a funnel, whose mouth's depth and diameter are 33 and 49 mm, respectively. The funnel's narrow diameter is 7.5 mm. (3) With the increase of the channel depth, the rock damage area changes in three different states: slow increase, rapid increase, and linear increase. Then, a shovel‐shaped geometric model of rock damage zone is established, whose key size parameters in the model are given.

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Damage analysis of cement sheath and rock subjected to electrohydraulic shock waves under the perforation completion

Zhang,

Yu,

et al. 2024

Energy Science & Engineering

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The high‐voltage pulse discharge technology, which is based on the electrohydraulic effect, can generate powerful, controllable, and repetitive electrohydraulic shock waves (EHSWs) in underground confined space, so it has been applied in the petroleum industry to improve the permeable of the reservoir. In this paper, a numerical model based on LS‐DYNA is built to study the damage analysis of the cement sheath and rock subjected to EHSWs during perforation completion. The results show that the stress state of the cement sheath and rock surrounding the perforation hole is determined by the shock pressure from both the perforation hole and the wellbore; the damage of the cement sheath and rock is mainly caused by tensile stress; the damage zone of the cement sheath is mainly distributed on the inner surface and near the perforation hole, while the damage zone of rock is distributed near the perforation hole; after multiple discharges, the damage of cement sheath and rock gradually accumulates, and the damage zone eventually forms a vertical plane along perforation holes. Overall, these results provide guidance for the safe application of the high‐voltage pulse discharge technology in the oil field.

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Effects of in-situ stresses on the fracturing of rock by blasting

Cited by 159 publications

References 28 publications

Study of the Rock Crack Propagation Induced by Blasting with a Decoupled Charge under High In Situ Stress

Study of the Rock Crack Propagation Induced by Blasting with a Decoupled Charge under High In Situ Stress

Investigation of the process of perforating hard roof in an innovative technology of directional roof‐cutting by composite blasting

Damage analysis of cement sheath and rock subjected to electrohydraulic shock waves under the perforation completion

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