Journal
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
Volume 74, Issue -, Pages 119-130Publisher
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.tust.2018.01.014
Keywords
Underground mine; Short-delay blasting; Free surface; Vibration control; Blasting crater; Experimental test
Funding
- National Key R&D Program of China [2017YFC0602902]
- Fundamental Research Funds for the Central Universities of Central South University [2016zzts094]
- China Scholarship Council (CSC)
Ask authors/readers for more resources
Delay blasting with relatively long-delay intervals is widely used in mining engineering since the former detonated blast-holes can produce new free surfaces for the later detonated blast-holes. With the application of electronic detonators, which have a minimum delay and a delay accuracy of 1 ms, a new blasting pattern using short-delay intervals is proposed in the present study in order to improve rock breaking and control blast-induced vibrations in cutting blasting with single free surface in underground mines. Theoretical analyses are firstly conducted to investigate the mechanisms of blasting crater formation and vibration reduction of short-delay blasting. Then a series of blasting crater tests with different delay intervals are performed to compare the characteristics of blasting craters and blast-induced vibrations produced by short-delay and simultaneous blastings. The results of crater sizes show that it is possible to form a common blasting crater only when the delay intervals are shorter than the formation time of a new free surface. It is also found that the short-delay blasting can effectively reduce PPV compared with the simultaneous blasting, particularly in the near-field. Spectral analysis indicates that there is less energy in the low-frequency content in short-delay blasting than simultaneous blasting. The possibility and feasibility of reducing vibration via short-delay blasting in underground mines are also discussed in this study.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available