Author(s)

J. Vacek & S. Hrachová

Abstract

Failure of rock mass is not a static process, but has its own history. Its duration varies from several seconds to several hundreds of years. Rock mass movements often reach hundreds of metres and significantly change their original shape. Failure mechanics can be studied experimentally. We can observe the onset of failure on nonhomogeneous models (prior to and during the failure, during the increase of deformations on sliding surfaces), the chronology of various stages of failure (cavings, slides), and the final shape of the rock mass. We can also observe influences, exerted by modelled joints, adits and other features, upon the failure history and shapes of cavings and slides. Research will be concentrated on the stability of internal tailings of Northern Bohemia open coal mines. There is a very smooth plane between the tailings and the bedrock. It was built up during mining, while being exposed to weather attacks, such as rain, frost and sun shine, and it was plastificated by the movement of mining machines. Tailings will be strengthened by piles that join bedrock with tailing over the predestinated slip plane. Methods used for the study of geotechnical problems have to allow for it to be studied on the basis of two presumptions:  results must be time dependent  results must allow the creation of joints in the rock mass before and during the study of the event and they have to allow for the movement of rock along joints, the opening of joints and the creation of new joints. The direction of the modelled joints must be similar to the reality, i.e. their direction and inclination must be the same as in reality. These measures make it possible to create a structure of modelled rock mass similar to the real one. The filling of cracks must be equivalent to those in reality. The scale of physical models was used as a basic method of study of geotechnical problems from equivalent materials and a mathematical solution. Keywords: failure mechanics, physical model, mathematical model, pile defence of slope slip.

Keywords

failure mechanics, physical model, mathematical model, pile defence of slope slip