Numerical modelling calculation of probabilistic seismic hazard in cave mining

Abstract

Numerical modelling has been used for more than 30 years to assess the seismic potential in underground excavations. However, the outcome from modelling tools rarely considers the probabilistic nature of seismic hazards. This paper presents a method to generate a distribution of synthetic seismic data based on numerical modelling results. The distribution of this data follows an exponential model and can be utilized to perform statistical analysis of the largest magnitudes expected from the rockmass deformation due to underground excavations. This method is illustrated with a case study in a caving mine where the seismic potential is evaluated using a numerical model back-analysis exercise, resulting in the calculation of the exceedance probability of any seismic-event magnitude through the modelled period. The proposed method has an advantage over other methods that estimate seismic hazard because it implicitly calculates the statistical distribution of seismic events to obtain the exceedance probability of the largest event.