Strategy Towards Accurate Location of Seismic Events Sources in Mining Environments: Effect of Voids and Backfill

Abstract

ABSTRACT: Seismic events may occur naturally or unnaturally as a result of human activity. The focus of this research is on seismicity caused by human activities in underground mines. Despite significant technological advances in the mining industry, the phenomenon of rockburst and its mitigation measures are still controversial technique. Predicting the time of occurrence of rockbursts remains a challenge. At best we can estimate the potential location of seismic events from numerical modelling. Seismic monitoring systems play a major role in the mitigation of rockbursts by identifying their potential source locations. The accuracy of seismic event source locations depends on the reliability of the velocity model. Because the mining environment is constantly changing, a constant input velocity may result in spurious seismic event locations. In this paper physical laboratory models mimicking the continuously changing mining environment are used to investigate the impact of the changing mining environment on seismic wave velocity to provide means for predicting the seismic wave velocity in real-time to improve the accuracy of seismic source locations. 1. INTRODUCTION Seismicity can occur naturally or be caused by human activity. This study focuses on underground mine seismicity induced by mining operations. A seismic event that occurs suddenly resulting in a damage to an excavation, equipment and or injury to personnel is known as a rockburst (Zhou, Li & Mitri, 2018). Rockbursts are a common problem in deep underground mines and affect mine operations in terms of safety, productivity and efficiency. Predicting the time of rockburst occurrence is difficult due to its complex nature. The only way to deal with the problem is to identify possible locations of rockburst occurrence through site experience or numerical modelling (Trifu & Suorineni, 2009). Microseismic monitoring systems are common tools used for monitoring seismicity for the estimation of different hazard sources. These equipment are widely used in deep underground mines and are vital to control and mitigate the risks caused by seismicity. The microseismic monitoring system helps to detect, locate and identify seismic events in underground mines, and therefore they are essential part of the rockburst understanding mechanism.