Taking into account the spatial variability of the physical and mechanical properties of a hydraulic dump when flushing it
Authors:   Kuzbassgiproshakht, Kemerovo, Russia, Karablin Mikhail M. , Prostov Sergei M. ,   T. F. Gorbachev Kuzbass State Technical University, Kemerovo, Russia
Published: April 2021

Introduction. Slope stability analysis reliability depends on the level of schematizing the results of engineering-geological survey, hydrogeological monitoring, electrical sounding, and mine surveying data generalization. In order to improve the stability analysis accuracy, it is relevant to use the geomechanical models, which take into account the spatial variability of the adjacent rock mass physical and mechanical properties, with further search for the most hazardous section in the plan. Research aim is to substantiate the relevance of slopes physical and mechanical monitoring by the methods of downhole control and further stability analysis with the use of the geological and geophysical models. Methodology includes the search for the most hazardous section of the rock mass by the ratio of the shearing and restraining forces within the limits of the established zones characterized by the variability of physical and mechanical properties. Results. As a result of generalizing the databases of the engineering and geological study, hydrogeological monitoring, electrical sounding and mine surveying, the volumetric geological and geophysical models were built of the technogenic massif formed at the dump, as well as the slopes of the hydraulic overburden face, represented by the three-level fill of dry overburden. Test areas stability has been analyzed for the actual position, and the comparative analysis of the results was made. Conclusions. When building volumetric geological and geophysical models of man-made rock masses formed at the areas of filled hydraulic waste diposals, in addition to the results of the traditional survey measurements and direct engineering and geological study, it is important to create informative databases on spatial and temporal variations of physical and mechanical properties of alluvial rock conditioned by their fluid loss and consolidation, which with in details at cross hole intervals may be obtained based on the statistical dependences on electrical conductive properties variation by the methods of electrical sounding or tomography; and when making enclosing embankments (bridges) of dry rocks – information about excess pore pressure under these facilities. When using the hydromechanized method for the alluvial rocks, relatively homogeneous in strength properties, the hydraulic overburden face slope stability is determined to the greatest extent by the absolute values of the accumulated strength indicators in the mined area and the unfavorable combination of the edge shape (the presence of protruding sections and face unevenness in the plan) with the entry height. The established range of the stability coefficient was n = 1.03–3.76. The stability of the enclosing structures made of dry rock to the greatest extent depends on weak alluvial layer depth and thickness and the absolute value of excess pore pressure in this layer. The established range of stability coefficient variation for this rock mass section is much narrower and amounted to n = 1.29–1.59.