Experimental and theoretical investigation of roadway fracture induced by static-blast loading using acoustic emission

Abstract

Underground metal mine is characterized by a large mining range involving complex spatial roadways layout and high mining intensity along with strong blast disturbances. Roadway destruction is easily triggered by blast-induced disturbances from different directions. In this study, the relationships between the fracture pattern of the roadway and static-blast loading were investigated by the means of theoretical analysis and experiment. The results showed that the macroscopic cracks around the roadway could be attributed to the combined action of the static loading and blast-induced disturbances. Under static loading, the stresses of the spandrel and wall corners were concentrated, as well as the AE events were clustered significantly. Blast-induced disturbances aggravated the damage to both the blast-facing side and high-stress areas, resulting in generations of large-scale AE events and deformation inside the rock. The differences in the spatial distribution of AE parameters indicated that the damage caused by static stress loading was stronger than that caused by blast-induced disturbances. To control the progressive fracture of rock surrounding the roadway caused by dynamic disturbances, it is essential to strengthen the support for the high-stress area and the blast-facing side respectively.