Effect of structural planes on rockburst distribution: Case study of a deep tunnel in Southwest China

Abstract

Abstract Rockburst is a type of dynamic failure and often causes considerable damage during the construction of underground engineering. Geological structures have been regarded as a crucial factor influencing rockburst distribution, and more related research is urgently needed. This paper presents microseismic monitoring information, characteristics of 151 rockbursts, and various structural planes collected in detail from a deep tunnel located in Southwest China. The results show that microseismic activity tends to increase when joints with large scale begin to appear and vanish. Rockburst risk always increases between the spandrels and around the intersection of two joint sets. The joint dip angle changes the rockburst risk. In the presence of one or two joint sets with a 70–\u202f80° dip angle, rockbursts are more prone to occur. The conclusions can be interpreted with the discrete element method. When more joints are encountered, the total number of rockbursts may decrease, but the rockbursts are more likely to be strong or induce collapse, causing more damage. This research can improve the understanding of rockburst mechanisms and guide the choice of construction and support methods.