Advancements and future prospects in the fundamental theories of rock blasting research Ⅱ—Dynamic–static relationship

Abstract

Blasting is a process in which the chemical energy of explosives is rapidly released, causing strong impact on the rock mass and achieving efficient rock fragmentation. The blasting stress wave and blasting gas generated by explosive detonation are the main driving forces for rock fragmentation. The high peak value and short duration of blasting stress wave are generally referred to as “dynamic action”, the low peak value and long duration of blasting gas are generally referred to as “quasi-static action”. The coupling mechanism between the work done by explosive detonation and the energy consumption of rock fragmentation, as well as the fine control principle of explosive energy release and blast crack propagation, are two key scientific problems that need to be solved in the fundamental theories of rock blasting. The study of “dynamic−static relationship” is one of the important ways to solve key scientific problems. Because of the complexity of the blasting process, traditional blasting design often relies on empirical formulas and field tests, posing problems such as low efficiency, high cost, and uncontrollable safety risk. Traditional designs often only focus on the final crushing effect but ignore the fine control of the blasting process. However, the study of dynamic–static relations has introduced a new approach to solution. This article uses a literature review analysis method to conduct a topic search and analysis of journal papers published in CNKI (China national knowledge infrastructure) and WOS (Science citation index-expanded database) in 2000–2023. The study of the dynamic–static relationship in rock blasting is divided into three different stages: Stages I (before 2006), Ⅱ (2007–2015), and Ⅲ (2016–present). Stage I focuses on the dynamic action of blasting stress waves, revealing the propagation mechanism of blasting stress waves and providing a scientific basis for related engineering applications. Stage Ⅱ studies the crack propagation behavior under the action of blasting stress waves; many studies researched the interaction mechanism between blasting stress waves and cracks and the change in the dynamic stress field at the crack tip, helping relevant researchers to understand the crack propagation and rock fracture process under the action of blasting stress waves. Under a national strategy, Stage Ⅲ has a clear application scenario, and the effect of blasting gas has become the focus of this stage. Through the combination of experiments and numerical simulations, the mechanism of the effect of blasting gas on rock fragmentation, energy transfer, and crack propagation during blasting is deeply discussed. These studies reveal the behavioral characteristics of blasting gas under different conditions and provide theoretical support for practical engineering applications. In addition, authors and research institutions with important contributions to the study of dynamic–static relationships are identified. Keywords and their cooccurrence relationships are revealed, highlighting the focus and trends of the research. Through a systematic review of existing research, combined with the research work and achievements of the author team, the research direction of the dynamic–static relationship in the new era has been clarified, including the distribution and efficient utilization of dynamic–static energy between the blasting stress wave and blasting gas, numerical simulation algorithms considering the real physical processes of rock blasting fracture, and quantitative control of the dynamic–static rock breaking effect of blasting stress waves and blasting gas. The in-depth study of the dynamic–static relationship will promote blasting engineering, from experience-led to theoretical guidance and from extensive to fine.

Keywords

• dynamic–static relationship
• rock blasting
• blasting stress wave
• blasting gas
• fracture process