Study On The Slope Deformation Mechanism Under Open- Pit And Underground United Mining

Conditions of open-pit and underground united mining,the open-pit slope is located in the underground mining affected area,two types of mining effect interaction, overlap and interact with each other,thus constitute a composite superimposed effect,The slope rock mass performance for superimposed deformation mechanism of the open-pit mining and the mining effect. This paper based on the engineering background of Zijin mountain gold-copper mine open-pit and underground united mining, the use of theoretical research and numerical simulation methods to study the deformation mechanism of slope under open-pit and underground mining conditions, and slope stability evaluation. The main research contents are as follows:1.Midas GTS software is used to build three-dimensional slope body model under open-pit and underground united mining, and using FLCA-3D numerical simulation software to simulate the deformation mechanism of open-pit slope. Due to two types of mining effect,the open-pit slope deformation evolution has three-dimensional properties,the open-pit slope emerged two typical class movement and deformation characteristics, one deformation is moving down along the slope and the other deformation is moving to the underground mined area. the size and scope of the deformation depends on the relative spatial relationship between the open-pit slope and underground mining area, the mining progress and advance of the two kinds of mining method, the relationship between the underground mining direction and open-pit slope, etc.2.Based on the research of spatial properties that underground mining on the impact of open-pit slope deformation, And by the numerical simulation comparative analysis of three different mining timing scheme of underground mining area shows that when the direction of the mining face is the same as the direction of the slope the underground mining has minimum impact on open-pit slope stability.3.Using the sliding field theory to search the slope slip of on four main section, on the basis of the selected the most dangerous slope slip, respectively use the JanBu method, residual thrust method, Morgenstern-Price method and Bishop calculation method to evaluate the slope stability.obtained that the local region of the open-pit slope under the influence of underground and open-pit united mining is in an unstable state. Thus it is need to take appropriate measures to control the slope of these areas, and to ensure that the slope in a stable state and safe production.