Abstract
As a non-explosive low-disturbance rock breaking technology, carbon dioxide phase transition blasting (CDPTB) is widely used in rock breaking projects such as pressure relief and permeability enhancement in coal mines, open-pit mining, road subgrade excavation, foundation pit excavation, etc. In this paper, the principle and equipment of CDPTB are systematically analyzed, and the characteristics of a reusable fracturing tube and disposable fracturing tube are determined. Different energy calculation methods are analyzed to determine the magnitude or equivalent explosive equivalent of CDPTB. According to the characteristics of impact stress wave and high-pressure gas, the cracking mechanism of CDPTB is proposed. Under the action of medium-impact stress, rock mass will produce multi-point cracking, and high-pressure gas will produce a gas wedge effect in the initial fracture, which determines the comprehensive action path of the stress wave and high-pressure gas. In terms of fracture characteristics, the fractal method is used to evaluate the macroscopic crack and fragment, microscopic fracture and pore characteristics. In terms of vibration characteristics, the attenuation law of CDPTB vibration with distance is statistically analyzed, and the Hilbert−Huang transform method is used to analyze the time−frequency characteristics of CDPTB. This rock breaking technology can be widely used in different projects, and the existing problems and future challenges are put forward.