| As an effective and rapid means, Blasting is widely used in mining engineering, water conservation, and urban construction. But it always leads shocks. The rupture damage caused by blasting during the production of mines is accumulated, which will lead the rock fracture. Nowadays, the research on the cumulative damage effection caused by the frequent blasting of mines on rocks mass is rarely. However, the damage caused by cyclic blasting loading is complex. Using acoustic-waves-monitor and blasting vibration measuring instrument, this paper have a research on the cumulative damage effects of engineering rock mass under the condition of frequency blasting. The main research content and result is as following:(1)Using geological drilling to get acoustic-waves test hole. It ensures the smooth of parallel level of the test hole and hole wall to couple the water and rock face. Also it eliminates the impact damage of the rock mass during drilling, which decrease the test data error significantly. During the test, 11 tests of the recycle production blasting and 5 tests of small charge simulation blasting have been carried out by use of RSM-SY5 acoustic-waves-monitor and Minimate Blaste blasting vibration measuring instrument which have a study on the rock mass at open pit mine acoustic velocity and accumulative damage effected by frequent blasting loading.(2)For the engineering rock mass at moderate and far distance area, there exists small amount of measuring points with cumulated damage at the condition of frequency blasting loading. And the points with damage effects have the damage increasing suddenly. The smaller of the blasting center distance, the more obvious damage effect. There is a positive correlation between the single stage maximum loading and the damage strength. It shows a strong correlation between the vibration frequency of blasting hinrichs wave and propagation direction to the accumulative damage of rock mass.(3)Through the experimental data, it showed that the engineering rock with developed cleavage mainly has the cumulative damage with the form of macro-native cracks open, expand, and other forms under cyclic blasting. Microscopic cracks deterioration opening, closed and the new expansion cracks formation and mechanical properties reduction is not obvious. The blasting stress wave in the role of district engineering rock, rock mechanical properties exhibited are mainly determined by the mechanical properties of the macro-structure of the surface.(4)Using Geo Studio simulation software to analysis the changing of slope safety factor in blasting loading. After the calculating by the software, it reflects that the slope damage under blasting loading is relevant to the vibration intensity and vibration frequency. By analyzing the safety factor changing with the time, it also reflects that rock slope damages under blasting seismic wave.This paper has a research on the damage effects of engineering rock under cyclic blasting loading, which provides a large amount of field data and technical basis for the study of engineering rock mechanical forms and damage theory under frequency blasting loading. |
