Applicability of energy-absorbing support system for rockburst prevention in underground roadways

摘要

Rockburst is one of the leading disasters in mining and rock engineering causing serious casualties and property losses. A major engineering challenge for underground roadways in mines experiencing significant seismicity is the performance of the support system. Applicability of energy-absorbing support system was studied basing on a novel facility, and the support performance was compared with that of the ordinary rock bolt support under the same simulated geology conditions. The results demonstrate that the modelled roadway still kept in good condition after several successive impacts with increasing energy level, suggesting that the roadway retained its resistance to dynamic loads at that time. The bursting failure occurred suddenly when the dynamic loading energy reached a certain critical level. Significant differences of acceleration signals from two roadway sections with different support types appeared, indicating that the energy-absorbing support could greatly change the shock behaviour of the roadway under dynamic loading. A very significant decrease in acceleration amplitudes was produced by the good shock resistance of the roadway section supported with additional energy-absorbing elements to perfect absorbing shock energy of the roadway structure. During the bursting failure, roadway section with traditional rock bolt support was severely damaged and almost closed, while the front roadway section supported by additional energy-absorbing elements remained in relative good condition. The combination of energy-absorbing elements and rock bolt support provides a very efficient and ductile support type in extreme burst-prone conditions.