Research on the dynamic damage characteristics and numerical simulation of low-temperature frost-expanded rocks under impact loading.

In this paper, the purpose of this paper is to investigate the dynamic properties of the rock under the low-temperature freezing-expansion-impact coupling effect and the optimization of the blasting parameters of the high-altitude open terrace blasting, to investigate the dynamic strength characteristics of the low-temperature freezing-expansion rock at different depths of burial at different low temperatures, and to lay the foundation for the subsequent research. The Hopkinson compression rod simulation experiment and wave velocity test device are used to study the development of internal cracks and dynamic properties of the rock; LS-DYNA numerical simulation software is used to simulate the Hopkinson compression rod test of the rock, to study the crack expansion and stress wave propagation law of the rock under the impact load, and to make a comprehensive comparison of the damage pattern of the rock in the indoor test and numerical simulation; LS-DYNA numerical simulation software is used to set up a two-dimensional blasting software, to establish a two-dimensional blasting strength and optimization of blasting parameters in the high-altitude open terrace blasting. Using LS-DYNA numerical simulation software, a two-dimensional blasting model is established to study the parameters of the hole network applicable to the Jurong Copper Industry in Tibet. A three-dimensional step blasting model was established to investigate the crack expansion pattern of step blasting and the feasibility of the selected hole network parameters. The results show that the dynamic strength of the rock is the highest in - 20 ℃ environment and the lowest in - 10 ℃ environment; the numerical simulation results are similar to the indoor test results, which can better simulate the dynamic damage characteristics of the rock. The results of the study can provide a reference for the subsequent blasting and mining of the mine.