Identification of grouting discontinuity of rock bolts as an efficient way to control safety conditions in mine roadways

摘要

The function of the rock bolt support system is to anchor and reinforce the rock zone in the near field of an underground opening to deeper rock strata, Li [1]. Predominantly for that purpose steel rock bolts are used, Ulusay [2]. The rock bolt consists of a steel bar grouted in an oversize hole. A portable installation machine is used to spin the bolt into the hole filled with fast setting epoxy resin cartridges. After hardening of resin layer a plate and nut is driven up the bolt. Although robust resin cartridges are available on the market, in mining practice the rock bolt is quite frequently not fully encapsulated as a consequence of rock divergence, cement sedimentation, escape of grout into crevices, rock strata movement or improper grouting.