Viscoelastic finite element analysis in design of potash mines

Abstract

Computer simulation is playing an increasingly important role in evaluating the short and long term structural stability of underground mine openings, and in ground control studies related to mine design and layout. Such simulations are increasingly being used in the design of underground salt and potash mines. Because of the viscoelastic nature of salt rock, simulation models used in these deposits must take into consideration their time dependent properties if they are to correctly predict opening closures, ground stresses, and ground stability based on prescribed failure criteria. A number of computer codes have been developed in Canada in recent years meeting these requirements. This paper describes the use of one of these codes to predict the ground behaviour of a typical room and pillar mining section of a Western Canadian potash mine. Predicted ground behaviour, based on use of the code, was compared with actual behaviour through field measurements. The study provided good correlation between predicted and measured ground behaviour, and is an encouragement to greater use of numerical modelling in mine stability studies related to mine design.