| Mineral resources are nonrenewable and the comprehensive utilization of residual ore resources has drawn more and more attention under the situation of increasing shortage of mineral resources. In order to mine residual ore maximally, reserved barrier pillars between goafs need to be explored on a large scale. Blasting not only effects on barrier pillar but also disturbs on roof and floor of adjacent goaf, which makes a certain influence on stability of goaf group. Therefore, it makes sense for reduce mine disasters to carry out research on dynamic rensponse and control technology for instability of horizontal goaf group under the condition of scale residual ore mining.By taking residual ore mining engineering of a large underground gold mine as research object, this thesis makes a research on dynamic rensponse of horizontal goaf group under the condition of scale residual ore mining through rockmass mechanics, structural dynamics and numerical simulation. At last active and passive control technology are put forward to prevent the dynamic failure of horizontal goaf group. The main work and research results are as follow:(1) The stability influence factors of horizontal goaf group under scale residual ore mining have been systematically analyzed including factors of unit goaf, barrier pillar, horizontal goaf group combination structure and scale mining.(2) Similar nonlinear model of dynamic response for horizontal goaf group was creatively established to analyze the dynamic response of horizontal goaf group, which was investigated and verified based on cases. Similar nonlinear model effectively respond to instantaneous, continuous and sectional dynamic load; quantitative method of similar nonlinear factor p is more accurate compared to qualitative method; similar nonlinear model better fits the results of numerical simulation compared to linear model, which to some extent reveals the dynamic response law of horizontal goaf group.(3) Similar nonlinear model of dynamic response and numerical model of FLAC3 D for horizontal goaf group of complicated combination structure were built to investigate the dynamic response and stress response law under condition 2( Pillar 1 was mined out). When structure was changed, the dynamic response of rock mass m3-1 and m3-2 varied the most under the dynamic load while the remaining rock mass within a narrow range. Blasting load made apparent influence on stress distribution of the rock mass that blasting load effects. Field engineering application verified similar nonlinear model of dynamic response and numerical simulation.(4) The response characteristics and distribution law of displacement field, velocity field and stress field of single-layer and multilayer horizontal goaf group were analyzed via similar nonlinear model of dynamic response and numerical model of FLAC3 D. The results of dynamic and static stability indicate that Plan Ⅱ for single-layer and Plan Ⅳ for multilayer are more reasonable. Plan Ⅱ for single-layer were verified by in-situ monitoring.(5) The maximum charge amount of single-deck blasting was confirmed on the basis of similar nonlinear model of dynamic response. And by dynamic response comparison analysis, control technology such as multi-deck millisecond blasting, multi-pillar opposite blasting and key goaf filling can effectively reduce blasting vibration effect. |
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