Abstract
With the increase in mining depth, the deep hard rock mass is under threat of rockburst under high geostress, high temperature, high osmotic pressure, and strong disturbance. To reduce the probability and strength of rockburst, a new energy‐absorbing bolt for guaranteeing the stability of deep hard rock mass was developed utilizing the energy absorption characteristic of high‐damping rubber. To analyze the practicability and obtain the quantified behaviors of this new energy‐absorbing bolt, a series of impact tests on specimens of high‐damping rubber, granite, and granite–rubber composite specimens was carried out by a split Hopkinson pressure bar (SHPB) method. Further, considering the different working depths with different rock temperatures, the dynamic energy‐absorbing characteristics of high‐damping rubber under different temperatures were tested. The testing results show that the new energy‐absorbing bolt can consume the storage energy in host rock effectively, and the environmental temperature will produce certain effects on the energy‐consuming rate. In addition, the optimal energy‐absorbing thickness–diameter ratio of high‐damping rubber was confirmed by SHPB tests.
Highlights
As shallow resources decrease constantly, people must pursue much deeper resources
Jiang et al (2010) studied rockburst characteristics based on the new energy index in a 2500-m depth tunnel [6]; Kornowski and Kurzeja (2012) predicted rockburst probability by employing the given seismic energy [7]
Weng et al (2017) adopted the strain energy density index to analyze the rockburst characteristics of roadways in the Linglong gold mine, China [9]
Summary
As shallow resources decrease constantly, people must pursue much deeper resources. the excavation depths of mines are becoming deeper, and kilometer-level and even deeper mining are becoming normal. Rockburst is a serious disaster affecting an excavation or pillars. It occurs in a sudden or violent manner and is associated with a seismic event, especially during deep mining. It can cause serious casualties, mechanical damage, project delays, and economic loss. For increasingly serious rockburst disasters, people have tried some active defense methods to release the storage energy in the host rock, such as the deep-hole directional fracturing method [10], blasting fracturing method [11], hydraulic fracturing method [12], and optimization of mining parameters [13, 14]
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