| The scholars in China proposed the concept of strip mining with backfilling based on advantages of strip mining and backfilling mining, strip mining with backfilling technology is a new green mining technology, it has the remarkable characteristics of cost control and resource recycling, and it meets the basic requirement of low cost, high recovery rate and high security to have promotive and applicable prospect.Through theoretical analysis, mechanical test, similar material simulation test and numerical simulation experiment, the paper analyzes the stability of filling body and coal pillar for strip mining with paste backfilling. The main research results are as follows:(1) The paper analyzes bearing mechanisms of the composite support pillar and puts forward to determining the strength formula for the filling body, the action mechanism of the filling body in composite support pillar and influence factors for the stability of composite support pillar is introduced.(2) Mechanical experiments were carried out for the coal pillar, filling body and combinations for the composite support pillar. The compressive deformation characteristics of coal samples, filling body and combinations were obtained, and the difference between the compression characteristics of coal body and the filling body is compared and analyzed.(3) The physical simulation experiment is used to analyze the stability of different isolated coal pillars in width for composite support pillar, the stress distribution characteristics of the composite support pillar and the characteristics of overburden rock movement are obtained, coupling support movement system for the composite support pillar and overburden rock is summarized.(4) The changes of stress and plastic zone of the composite support pillar in different stages are studied,The different influence factors on stress and plastic zone of composite support pillar under the static conditions is studied with numerical simulation experiment, the relationship between different factors and stress increasing coefficient is got, and and through regression analysis the stress increasing coefficient formula of isolated coal pillar and filling body are obtained, According to the grey theory, the grey relational analysis program is developed by using VBA, by the use of the grey theory different influence factors on the stability of isolated coal pillar is analyzed.(5) By the dynamic module the characteristics of dynamic response and the stress and plastic zone of composite support pillar under the effect of the horizontal, vertical and bidirectional seismic wave are summarized.The research results of this paper provide basic data and theoretical support for the study of the stability of the composite support pillar for strip mining with backfilling, and improve and enrich the theoretical system of strip mining with backfilling. |
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