Abstract

Blasting is very important for the operation of mines. Factors that influence the condition after blasting include the blasting design and the rock mass condition such as the strength of the rock and the condition of fractures/discontinuities in the rock mass. In particular, the evaluation of fractures in the rock mass will make the evaluation of the rock mass and planned mining more efficient because understanding it will contribute the blasting performance and the prediction of the size of fragmented rocks. Currently, the primary method for evaluating fractures in rock mass is to measure the fracture density using captured images of the bench face. These manual and conventional measuring of the geometry of rock mass fractures takes time and is a tedious procedure. Therefore, a more efficient evaluation method which can rate the fractures in rock mass is needed to increase the efficiency of mining operation. Therefore, this paper discusses the application of fractal dimension as a simple evaluation method for evaluation of fracture conditions in rock mass based on the image analysis of the bench face. By calculating the fractal dimension of a bench face image and comparing with fracture density, it was revealed that they have a correlation when the image meets a requirement. Furthermore, it was revealed that the rate of Bieniawski can be estimated from fractal dimension when the rock mass meets some requirements about its condition, so you can expect a lot from the potential of fractal dimension for on-site evaluation is significant. From the above, fractal dimension can become a new method and indicator of evaluating fractures in rock mass.

Introduction

Blasting has long been used as an important technology for a wide range of materials, including natural materials such as rocks and coal, concrete, and construction materials for buildings in the fields of mining and civil engineering. Even though mechanical excavation by using heavy equipment has improved in mine development in particular, there are many advantages such as reduced excavation costs and shorter construction periods (Japan Explosives Safety Association, 1997).

This content is only available via PDF.
You can access this article if you purchase or spend a download.