Directed fracture of rocks by blasting

Isakov, A. L.

doi:10.1007/bf02497175

Cited by 6 publications

(2 citation statements)

References 4 publications

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“…Cho et al [3] performed model tests and numerical simulations, observed signifcantly directed blast-hole grooves that were conducive to the formation of a fat crack surface. Isakov [4] proposed a loading method in which an axially grooved solid shell was positioned along the blast-hole wall; experiments revealed that the crack distribution caused by an explosion may be infuenced by shell strength, shell thickness, and the initial burst pressure of the cavity. Te caustic specks at the crack tip can be observed in the dynamic caustic experiment system, and the crack propagation velocity and stress intensity factor can be calculated [5,6].…”

Section: Introductionmentioning

confidence: 99%

Propagation Characteristics of Explosion Wave and Explosion Gas in Blast-Hole

Zuo

Xie

2023

Shock and Vibration

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In order to explore the propagation characteristics of explosion wave and gas in blast-hole, design a model to simulate blast-hole charge in the laboratory, adopted a high-speed schlieren experiment system used to study the evolution characteristics of explosion wave field under two kinds of charge structures. The results showed similar explosion wave velocities for the two cartridges, the explosion wave was reflected when it reaches the hole wall, and the reflected wave velocity was lower than an incident wave. The explosion gas tends to cluster and spread in a cutting direction, resulting in intensified destruction in that direction. The explosion wave first emerges in the direction of the slits, and then moves towards the blast-hole walls, which indicates that the explosion energy can be accumulated in the slit direction and cause directional destruction of the medium. To study this process in detail, establish numerical model for the propagation of explosive in the hole. The results indicated that the detonation products first come out in the direction of the slits and then go around towards other areas in a distribution that is consistent with the observations by high-speed schlieren photography.

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Section: Introductionmentioning

confidence: 99%

Propagation Characteristics of Explosion Wave and Explosion Gas in Blast-Hole

Zuo

Xie

2023

Shock and Vibration

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“…Ordinary peripheral blasting can form cracks between the blastholes, but a large number of random cracks will also be generated in other directions around the holes, leading to the decrease of the stability and integrity of surrounding rock [1]. In order to meet the excavation requirements of blasting and to protect the stability of surrounding rock, directional fracture controlled blasting technology has been proposed [2]. Among them, empty-hole directional blasting can make rock blasting within a certain distance form stress concentration around the empty hole [3], guide the priority propagation of initiation crack toward the direction of the empty hole, improve the blasting performance of roadway excavation, and realize the purpose of directional blasting.…”

Section: Introductionmentioning

confidence: 99%

Influence of Charge Hole Spacing on the Crack Propagation Behavior under the Effect of Empty-Hole Directional Blasting

Tian

Dai

et al. 2020

Advances in Civil Engineering

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In order to explore the reasonable spacing of charge holes in empty-hole directional blasting, based on the action mechanism of empty-hole directional blasting, the influence of charge hole spacing on crack propagation is studied, the calculation formula of charge hole spacing is deduced, and the blasting excavation process in Shijiazhuang South Ring Expressway Tunnel is simulated by finite element software. The results show that by setting empty holes on both sides of the charge holes in the peripheral blasting, the guiding cracks can be formed in the connecting direction between the empty hole and the charge hole, the propagation of cracks in other directions can be suppressed, and the spacing of charge holes can be enlarged. Reasonable charge hole spacing is very important to realize the effect of empty-hole directional blasting; the spacing is small, the rock will be overbroken, and the utilization ratio of explosives is reduced; large spacing, the guiding effect of empty holes is weak, and the effective directional cracks cannot be formed. The spacing between charge holes is closely related to the mechanical properties of rock, detonation parameters of explosive, and aperture of the charge hole and empty hole. According to the simulation results of crack propagation in different spacing, the blasting performance is the best when the charge hole spacing is 800–1000 mm, which is completely consistent with the theoretical calculation result of charge hole spacing 948 mm.

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A mechanism for directional breaking of rocks by blasting

Isakov¹,

Basheev²

1985

Soviet Mining Science

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Directed fracture of rocks by blasting

Cited by 6 publications

References 4 publications

Propagation Characteristics of Explosion Wave and Explosion Gas in Blast-Hole

Propagation Characteristics of Explosion Wave and Explosion Gas in Blast-Hole

Influence of Charge Hole Spacing on the Crack Propagation Behavior under the Effect of Empty-Hole Directional Blasting

A mechanism for directional breaking of rocks by blasting

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