PREDICTION OF BOULDER COUNT IN LIMESTONE QUARRY BLASTING: STATISTICAL MODELING APPROACH

This paper describes the development of statistical models for assessing the boulder count resulting from the limestone quarry blasting. A database of three hundred blasts was created for the development of the model. The database consists of number of holes per row, number of rows, average spacing, average burden, average depth, average stemming, explosive type, total charge fired in one round and the boulder count. All the variables in the database are ratio type except the type of the explosive, which is a nominal variable. Hence two distinct statistical models have been developed for the ANFO and the SME blasts. The models have been developed in SPSS 20.0. The Student'st-Tests and Fisher's Exact Tests have been carried out on the models to identify the significant variables. It is further found that the prediction capability of the statistical models is strong, and it provides an easy option to the field engineers to assess the blast design for the boulder-count. The developed statistical models are suitable for practical use at the limestone quarries having similar geotechnical setup.