Numerical simulation and stability analysis of dynamic stress in the descending section of tuff mine chute blasting based on FLAC^3D software

Ore drawing by chute has gradually become an important ore drawing means in sandstone aggregate mines.Therefore, the analysis and discussion on the stability of chute is conducive to the sustainable development of mine production.Facing the problems of complex internal structure and difficult detection of the chute, in order to better simulate and study the blasting method of the descending section of the chute, based on a tuff sandstone aggregate mine, the finite difference grid model of the chute is established by using FLAC^3D software, which is based on the dynamic stress change and damage displacement during the descending section of the chute.The descending blasting of a tuff mine chute is studied, and the variation law of surrounding rock under the disturbance of dynamic stress in the descending section of continuous blasting in the low mining face of the chute is obtained.The results show that there is obvious stress concentration in most areas at the bottom of the chute shaft in tuff mine.The long-term blasting descending section of low mining face causes damage to the surrounding rock in the chute, reduces the overall stability of the chute and significantly increases the collapse risk.The vibration of stope structures or rock mass is obviously weakened 50-60 m away from the explosion avoidance point.With the continuous decline of mining level, the main cause of impact failure or fatigue damage of chute is the tensile stress caused by dynamic load.When the descending section reaches 180 m surrounding rock, the maximum displacement can reach about 17.83 mm.The results show that the chute model of tuff open-pit mine established in this paper can well reflect the simulation effect of chute blasting.