Damage prediction and improvement method based on cutting mode of circular empty hole

Huifeng Qin; Yan Zhao; Hailong Wang; Lijie Ge; Xiao Tong

doi:10.1038/s41598-024-61599-x

Damage prediction and improvement method based on cutting mode of circular empty hole

Sci Rep. 2024 May 17;14(1):11322. doi: 10.1038/s41598-024-61599-x.

Authors

Huifeng Qin¹, Yan Zhao^{2

3

4

5}, Hailong Wang^{1

6

7}, Lijie Ge^{1

8}, Xiao Tong⁹

Affiliations

¹ Hebei University of Architecture, Hebei, 075000, China.
² Hebei University of Architecture, Hebei, 075000, China. 304965624@qq.com.
³ School of Mechanics and Civil Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China. 304965624@qq.com.
⁴ Hebei Provincial Key Laboratory of Civil Engineering Diagnosis, Reconstruction and Disaster Resistance, Hebei, 075000, China. 304965624@qq.com.
⁵ Zhangjiakou BIM Engineering Technology Innovation Center, Zhangjiakou, 075000, China. 304965624@qq.com.
⁶ School of Mechanics and Civil Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China.
⁷ Hebei Provincial Key Laboratory of Civil Engineering Diagnosis, Reconstruction and Disaster Resistance, Hebei, 075000, China.
⁸ Zhangjiakou BIM Engineering Technology Innovation Center, Zhangjiakou, 075000, China.
⁹ School of Earth Science and Engineering, Hebei University of Engineering, Handan, 056038, China.

Abstract

Based on the theory of empty hole effect of cutting blasting, the Hopkinson effect and Saint-Venant principle are integrated to establish a two-dimensional calculation model of dynamic stress evolution of the holes wall, and then the dynamic fracture mechanism and damage distribution mode of the rock mass in the cutting area under the action of longitudinal waves are predicted. The results of the calculation and numerical simulation are verified by experiments, and the results show that: The time-varying stress function of the circular cavity wall conforms to the periodic dynamic evolution of the trigonometric function, and the theoretical calculation is consistent with the simulation results. Through the calculation of the round holes cut model and the square empty hole cut model, the change of the shape of the holes in the cut area changes the failure form of the surrounding rock mass. The circular empty hole wall is affected by the stress wave to produce "interval ring" destruction, and the effect of the reflected stretch wave is inhibited. The large range of rock mass in the square empty hole wall produces tensile and shear failure, and the rock mass collapses inward under the influence of the second stage stress. Among them, the empty space utilization rate of the square empty hole model is about 8.5 times that of the circular holes model. Vibration monitoring in the center of the cutting area shows that the vibration effect of the circular empty hole is larger than that of the square empty hole, and the proportion of rock breaking energy is lower.

Keywords: Dynamic evolution of stress; Holes space utilization rate; Mode of injury; Prediction and improvement; The proportion of rock breaking energy.