Technical Blasting and Ripping of Overburden to Reduce the Effect of Ground Vibration on Slope Stability and Residence around Coal Mine

Abstract

The coal mining method at the West Banko Pit 1 North is carried out in an open pit using a shovel-dump truck system. The overburden consists of topsoil and claystone with a strength of 0.2 – 3 MPa. The digging force of the Komatsu PC 2000 excavator is 0.697 MPa, so to optimize the productivity of the excavator, it must be carried out using a Komatsu D375A ripper and blasting. Considering that the pit limit in the west is close to residential buildings, it is necessary to design the mining area to be ripping and the area to be blasted as well as blasting technical design to reduce the impact of ground vibration on slope stability and damage to buildings in residential areas around the mine. Based on the results of the analysis of overburden blasting at the West Banko Pit 1 North on the stability of static and pseudo-static slopes with the simulation of the optimal Berm, the maximum Berm is 12 m with a safety factor (SF) of 1.5, while the overburden blasting was based on research at West Banko pit 2 because the material conditions were relatively the same. The number of safe explosives for predicting the Peak Vector Sump (PVS) value 3.5 mm/second is 50 Kg/ Delay with a minimum distance of 500 m from residential areas. The analysis results of the area to be blasted are 112.59 Ha, and the area that remains ripped is 134.04 Ha.