O. Moustachi et Jf. Thimus, P-WAVE ATTENUATION IN CREEPING ROCK AND SYSTEM-IDENTIFICATION, Rock mechanics and rock engineering, 30(4), 1997, pp. 169-180
The aim of this paper is to contribute to the evaluation of rock crack
ing using ultrasonic wave propagation. The rock specimens (siltstone s
ampled from a coal mine at a depth of 820 meters in Belgium) are subje
cted to incremental creep. The study of the rock transfer function sho
ws P-wave attenuation in the direction of loading as a function of str
ess and time during the test: this attenuation becomes more significan
t at the stage at which the rock dilates. It is obvious from the speci
men dimensions that the signal is affected by reflection phenomena. So
, we have modelled the output signals with a model containing reflecti
ons. The simulations obtained from the model and input signal are very
conclusive and the model validation is satisfying.