Publication Abstract

not signed in
Log In
Title Seismic wave propagation to diagnose the state of fracturing

Authors H.W. Hildyard, R.P. Young, D.S. Collins and W. Pettitt

Publication Reference 2005, The Journal of The South African Institute of Mining and Metallurgy, 105, 437-446

Abstract This paper presents a variety of experimental and numerical results where seismic waves show clear differences in wave-speed and amplitudes due to different degrees of fracturing. It presents results from the ‘Omnibus’ project commissioned to develop new ultrasonic technologies for diagnosing fracturing for nuclear waste repositories. This included using models to investigate assemblies of cracks where the effects of crack density and crack size on waveforms are shown to be coupled. Results indicate that these effects can be decoupled in the frequency domain, where the Fourier amplitude aids in estimating crack size, while the low frequency phase-difference has a direct relationship to crack density. Models are also shown to aid interpretation of waveforms by isolating geometric effects from the effects due to cracks. Two rock engineering problems experienced in the South African mining industry are investigated through numerical examples. These demonstrate that determining whether ‘crush’ pillars have failed and determining the degree of fracturing in the hangingwall of stopes, may be possible through the use of active seismic surveys.

Key Figure

Link http://www.saimm.co.za/pages/papers/papers-v105-n06.htm



Return to publications list

< Return to the home page   ::  Contact Us
Applied Seismology Consultants