ARMA 12-233 An experimental investigation of the properties of weak rocks surrounding mine workings

摘要

This paper describes the program of laboratory testing of soft rock samples that has been carried out at the University of Nottingham to characterize weak materials. This work, which is part of the EU RFCS project "Geosoft", has been conducted to examine alternative methods of obtaining physical properties of soft rock when conventional rock mechanics testing methods are not appropriate. This is because the weakness of these strata types often results in samples breaking up into pieces when being collected at the working face, during transport to the laboratory or during sample preparation. In this study, tests were conducted on intact, reconstructed and broken samples to obtain the strength and stiffness parameters that could be fed into numerical modeling of underground situations. The Unconfined Compressive Strength (UCS) of intact and reconstituted rock samples was determined in the stiff press. The friction angle and cohesion of reconstituted and broken soil-like samples were determined using conventional soil element testing techniques such as the shear box and triaxial cell. The experimental data obtained from all the tests are compared and analyzed in this paper.