Comparison of an empirical S-wave velocity model and a calculated stress-strain model for a rock mass disturbed by mining

Krzysztof Krawiec,Rafał Czarny,Z Pilecki,H Marcak

doi:10.1051/e3sconf/20172403001

Krzysztof Krawiec, Rafał Czarny + Show 2 more

Open Access

https://doi.org/10.1051/e3sconf/20172403001

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Abstract

In the article a comparison analysis is presented between a numerical model of the stress and deformation state in a rock mass and an S-wave velocity model obtained as a result of in situ measurement. The research was conducted using data from the Jastrzebie and Moszczenica coal mines. The part of the rock mass examined was strongly disturbed by multi-seam exploitation of coal. To obtain the S-wave velocity model 6 hours of ambient seismic noise data were recorded using 11 seismometers. The propagation of the Rayleigh surface wave between the seismometers was reconstructed utilising the seismic interferometry and the cross correlation technique. Estimation of a two dimensional model of the Swave velocity field was performed on the basis of dispersion curves of the Rayleigh wave phase velocity. The stress and deformation field were calculated assuming a plane state of stress with the use of the elastic-plastic Coulomb-Mohr strength criterion. Images of the vertical stress, horizontal stress, vertical strain and horizontal strain as well as the subsidence profile on the model surface were obtained as a result of the calculation. Analysis of the results shows correlation between the field of S-wave velocity and the modelled field of stress and strain.

Highlights

Information about the stress and deformation processes developing in a rock mass disturbed by underground mining is essential in terms of the terrain surface subsidence and its effect on structures and the environment [1,2,3]
Seismic interferometry has been used for imaging [12, 13] and monitoring of the rock mass influenced by mining [14, 15]
An S-wave velocity model was calculated on the basis of seismic interferometry with the use of ambient seismic noise

Summary

Introduction

Information about the stress and deformation processes developing in a rock mass disturbed by underground mining is essential in terms of the terrain surface subsidence and its effect on structures and the environment [1,2,3]. One of the parameters that describe the stress and deformation changes in the rock mass is the velocity of seismic waves [6] In mines this parameter has mainly been determined by seismic profiling [7, 8] or active and passive seismic tomography [9,10,11]. Seismic interferometry has been used for imaging [12, 13] and monitoring of the rock mass influenced by mining [14, 15] This cost-effective tool can turn seismic noise into a useful signal produced by a so-called “virtual seismic source” [16]

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