Abstract
The principles of fracture development during underwater blasting are examined based on explosion and impact dynamics, fluid dynamics, fracture dynamics, and field testing. The research reveals that the fracturing of the surrounding rock during underwater blasting is due to the combined action of shock and stress waves for the initial rock breakage and subsequent water expansion. The fracture development model for the surrounding rock of a drilling hole during underwater blasting is established. The rock fracturing range under the combined action of shock and stress waves is developed, as well as the fracture propagation rules after the wedging of the water medium into the fractures. Finally, the results of deep-hole underwater blasting tests on large rocks confirm the efficient utilization of explosive in the hole to improve the safety conditions. Accordingly, safe and static rock breaking under the detonation of high-effect explosive can be achieved. In addition, super-dynamic loading from the explosions and static loading from the water medium in the hole can be adequately combined for rock breaking.
Highlights
The principles of fracture development during underwater blasting are examined based on explosion and impact dynamics, fluid dynamics, fracture dynamics, and field testing
The research reveals that the fracturing of the surrounding rock during underwater blasting is due to the combined action of shock and stress waves for the initial rock breakage and subsequent water expansion
Super-dynamic loading from the explosions and static loading from the water medium in the hole can be adequately combined for rock breaking
Summary
Traditional blasting technology consists of drilling and underwater blasting that uses a static water medium to replace the air medium in rock holes to enhance the wave impedance for explosive media. The shock wave decays gradually into a stress wave that acts on the surrounding rock outside the compressive damage region and produces tensile failure This forms radial fractures in the holes. During the rock breaking process, the shock wave produced from the explosive in the hole and the high-temperature high-pressure detonation products expand isotopically in the original charging space This can instantaneously heat the surrounding media of the explosive and cause secondary damage via expansion extrusion. The shock wave decays gradually into a stress wave and imposes tensile failures on the surrounding rock, thereby producing certain radial and circular fractures at some distance from the blasting holes (Li 2011; Yang et al 2018). When the tangential stress in the surrounding rock reaches the ultimate tensile strength, the surrounding
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: International Journal of Coal Science & Technology
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
