Wave propagation simulation in underground mines by SPECFEM2D

Abstract

In burst-prone underground mines, seismic waves generated from a fault slip seismic event may play a critical role in causing relatively large, localised rockburst damage. This study hypothesises that altered wave pattern due to geological structures and mine excavations is one of the important causes of localised rockburst damage resulted from a relatively large fault slip seismic event. The study aims to better understand wave propagation patterns around mine tunnels and to capture peak particle velocity (ppv) accurately for rockburst damage forensic analysis and dynamic support design. For these purposes and as the first step, advanced seismic wave propagation modelling tool SPECFEM2D is used to study complex wave propagation patterns in underground mines. In the present study, particular attention is directed to the influence of different mine excavations and geological structures on wavefield patterns. The simulation results show that the ppv distribution around a tunnel can be altered largely, leading to high and low ppv zones around the tunnel. Moreover, the response of ground motion and wavefields become more complicated as more mine excavations and geological structures are involved; modulation of travel time and long S-coda waves can be observed in the complex waveforms. Using the modelling approach, areas in a mine that may experience high potential of rockburst damage could be identified and correlated to field observation, and mine safety could be improved by implementing dynamic rock ground support in these areas.

Seismic anisotropy in deforming halite: evidence from the Mahogany salt body

“…Specfem2D uses the spectral-element method (e.g. Wang & Cai 2014). It has been used to simulate wave propagation in various complex media.…”

Numerical analysis of ground motion in a South African mine using SPECFEM3D

“…Model set-up SPECFEM2D and SPECFEM3D are powerful software for seismic wave propagation modelling at local, regional, and global scales, and it is particularly well-suited for handing complex geometries and interfaces (Komatitsch & Tromp 1999;Komatitsch et al 2000; Computational Infrastructure for Geodynamics 2012, 2014). Studies on using SPECFEM2D for wave propagation simulation in underground mines have been presented by Wang and Cai (2014, 2016, Cai and Wang (2015). However, for many mining applications, modelling using SPECFEM3D is needed.…”