PROBLEMS OF ASSESSMENT THE STABILITY OF PIT EDGES OF THE KIYEMBAYEVSKY DEPOSIT

Abstract

According to normative documents, for definition and grounding the parameters of pits edges and benches the calculation of of stock stability coefficient by means of classical methods of extreme balance has to be executed. These methods don't consider such factors as modern geodynamics and parameters of structural disturbance in the rock mass that exert negative impact on stability of pits edges and benches. The results of researches on stability of pit’ edges s of the Kiyembayevsky field where there was a collapse of benches on the western board are given in the article. Updating physic mechanical properties of
composing rock mass is made for determination the reasons of collapse. In terms of the obtained data calculation the coefficient of stock stability for the actual contour of a pit is executed. The results of calculations have shown that edges and benches of a pit are in a steady state, but in reality it isn't confirmed. Not low strength properties of rock mass, and formation of the extended cracks of shift character caused by processes of deformation in the conditions of the increased compression in one direction and a depression in the second with violation of primary structure of rock mass is the main reason for violation. As accounting of this factor is almost impossible, for ensuring safe functioning of a pit it is necessary to carry out monitoring of deformations of rock mass in the course of mining. Taking into account geo-mechanical conditions of working off the Kiyembayevsky pit, the design of observing station has been developed for monitoring the deformation processes of rock mass. It includes two traditional profile lines and two local observing stations. Observations of rock mass condition not always give the chance to prevent collapses and landslides, but allow to reduce possible damage from them and especially the risk for people who are in the pit.