Assessment of slopes endangered by groundwater

摘要

In many cases of deposits like tailings from open pit mines, the environment is damaged by the long extension of the slopes. Steeper slopes have a better influence on the landscape. On the other hand, the basic problem is caused by ground water, which a posteriori, after completing the construction of these structures, seeps through the foundation of the slopes. It is very important that no reclaim helps to solve this problem. If the deposits are founded in the wrong way, i.e. in the foundations where no disturbances of capillary water are applied, new methods have to be employed in order to stabilize the slopes. Before this, studies concerning the influence of ground water on the slope stability of the deposits have to be carried out. Natural slopes cannot practically be assessed, as the expanses involved in such tests are enormous. This is why scale models are prepared, together with numerical analysis based on coupled modeling. The influence of water is simulated by free internal parameters, which describe the extent of the hydration. On the other hand, geotechnical parameters change according to rules determined in the laboratory. Such a complex discussion can then be a starting point for several improvements of the slopes. The coupled modeling (scale and numerical) is applied to prepare a parametric study of tailing dams in Northern Bohemia, where large problems occurred because of the moving of current slopes against existing villages in this region. Scale models have been created in compliance with real situations and the results from them implemented in mathematical models. A parametric study was carried out using the numerical models.