Prediction of air over pressure due to blasting in tropically weathered granite quarries in Malaysia with multi-variable regression analysis

Abstract

World class infrastructure is developed ai Johor Bahru city of Malaysia. Granite is the most commonly available rock for production of aggregates. Blasting is essential for breaking of rocks. Environmental effects due to blasting are associated with flyrock, ground vibration, air over pressure and dust. Some of the aggregate quarries are proximate to human habitation. Many complaints are received by quarry management from different quarries by nearby habitants for (noise) air over pressure due to the blasting. This study was undertaken to investigate different parameters which contribute to air over pressure. At the end of study, multi variable regression analysis used for correlating with air over pressure (AOp) developed. Tropically weathered granite can be classified as fresh, slightly weathered, moderately weathered, highly weathered and completely weathered. Data were collected for 110 blasts from three quarries consisting of hole diameter (mm), burden(m), stemming length(m), charge per meter(kg/m), powder factor(kg/m3), joint aperture (mm), maximum charger per delay (kg), distance of blast from monitoring point (m) and measured AOp. Sensitivity analysis varies from 0.82 to 0.98. The data is analysed with multi variable regression analysis (MVRA) and equation was developed for predicting AOp with 8 input parameters. R2 with predictor equation and measured value shows 0.66.