Effect of blast induced vibration on coal mine overburden dump slope through discrete element method

Abstract

Blast induced ground vibration (BIGV) is a serious threat for the coal mine overburden (OB) dump slopes. The problem becomes intricate considering heterogeneity of the OB dump materials. The performance of an OB dump slope under BIGV is investigated considering Voronoi tessellation scheme of universal distinct element code (UDEC) for the heterogeneity of the OB materials. Variations of BIGV, expressed in terms of peak particle acceleration, velocity and displacement, with the density of explosive and the distance of OB dump slope from the blasting source are comprehensively reported considering single-benched as well as double-benched OB dump slopes. Nonlinear dynamic analyses are carried out considering the expected BIGV at the base of the OB dump slope and effects of blasting parameters on the performance of the dumps were investigated considering different monitoring points along the surface of the slope. The effects of heterogeneity on the dynamic response of OB dump slopes are also presented in comparison with the homogeneous condition. A comparative study based on the performance of single-benched and double-benched slopes under BIGV is also presented. Finally, the failure state of the OB dumps were inferred from the permanent ground displacement experienced by the slopes considering BIGV. The methodology and the presented results are supposed to be beneficial for the mining authority in framing the safety guidelines for OB dump slopes in coal mines.