Study of Flyrock to Reduce Safe Radius from 500 m to 300 m on Blasting Quarry at PT Vale Indonesia, Sorowako, Luwu Timur, South Sulawesi

Abstract

Flyrock exceeding the safe radius can cause harm to equipment and humans. In recent years there has been frequent flyrock exceeding 500 m which has caused a significant impact on the environment in addition to several quarries adjacent to the population at a distance of 500 meters. Data collection at PT. Vale Indonesia uses Leica GS and GoPro with an analysis method using Tracker 5.1.5 to observe blasting activities. The estimated maximum flyrock trajectory distance is determined using empirical and dimensional analysis methods. It is done to obtain accurate and precise results on the conditions of the blasting sites. The empirical method is based on the theories of Lundborg (1981) and Richard and Moore (2005), while the dimensional analysis method is based on the theory of Ebrahim Ghasemi (2012). A comparison of the actual flyrock trajectory deviation between the dimensional analysis method of Ebrahim Ghasemi and the empirical method of Richard and Moore shows that Ebrahim Ghasemi’s method is closer to the deviation percentage, which is 7.76%. From the estimated distance, the flyrock closest to the actual flyrock dimension analysis method has a deviation of 4.89m with a factor of safety value against flyrock hazards of 1.5. A trial was conducted based on the dimensional analysis method to determine the appropriate safe radius.