Prediction of Backbreak in Surface Production Blasting Using 3-Dimensional Finite Element Modeling and 3-Dimensional Nearfield Vibration Modeling

Abstract

In the context of modern industrialization and global development, blasting operations have become essential for meeting the growing demand for raw materials through large-scale opencast mining. However, if not meticulously planned and executed, blasting can lead to adverse outcomes, including backbreak, flyrock, and structural damage caused by vibrations. These issues can significantly undermine operational safety, reduce efficiency, and negatively impact environmental sustainability. Addressing these challenges requires innovative control techniques, including empirical approaches like vibration analysis, machine learning methods, and numerical simulations, to mitigate the negative impacts effectively. This paper focuses on a numerical approach to controlling backbreak, presenting a comprehensive 3-dimensional finite element (3D FE) model developed to simulate rockmass deformation under blast-load conditions. The model is implemented using Ansys Explicit Dynamics, incorporating the Drucker-Prager strength model and the Jones-Wilkins-Lee equation of state for explosives to accurately predict the extent of rock breakage zones. To evaluate its predictive accuracy, this 3D FE model is compared with 3-dimensional nearfield vibration models. Our findings reveal that the FE model closely aligns with both the vibration model outcomes and field observations, establishing its reliability in predicting backbreak without the need for historical blasting data. This aspect is particularly valuable for preliminary checks in new blasting sites, where historical data may not be available. By offering a dependable alternative for predicting the rock breakage zone extent, the FE model significantly contributes to the refinement of blasting designs, enhancing the safety, productivity, and environmental stewardship of surface mining operations.