| With the development of society,mineral resources which needed by people are gradually increasing.While the current situation that the total amount of resources is decreasing determines the change of resource exploitation mode,in which,Coordinated open-pit and Underground Mining mode has been paid attention to and applied because it can realize the optimal mining of resources.Although Coordinated open-pit and Underground Mining mode has its advantages,the interaction between open pit mining and underground mining in time and space is inevitable.So the stability control of open slope under Coordinated open-pit and Underground Mining becomes a new problem to be solved urgently.That’s to say,it is great theoretical significance and practical value for the stability control and disaster early warning of open-pit slope to study the influence of open-pit slope stability under underground mining.In this paper,taking Coordinated open-pit and Underground Mining of Anjialing Open Pit Mine and the Jinggong No.2 Mine in Pingshuo mining area as the background,applying the comparative analysis of the theoretical,experimental,numerical simulation results and the field test results,the law of strata movement and stress distribution of open pit mining slope under near horizontal condition was revealed and the mechanism of slope deformation and instability under the influence of key control layer was proved.Based on the rheological theory and limit equilibrium analysis theory,the nonlinear rheological model of coal and rock slope and the bending creep model of rock layer were constructed,the key control layer concept of deformation and failure of open slope under Coordinated open-pit and Underground Mining was put forward,and the comprehensive control technology of slope stability under Coordinated open-pit and Underground Mining was formed by optimizing the stopping line position of underground mining and adjusting the mining plan of open pit mining.And the rationality and feasibility of the comprehensive control technology were verified by field monitoring.Applied the research results in Anjialing Open pit mine and analyzed the effects,the following conclusions were obtained:the improved original rheological model of coal body and rock body is consistent with the test results;the main key control layer of overburden rock near the working face of Jinggong No.2 Mine is 16.3m siltstone with a sub-critical control layer of 11m coarse sandstone;the reasonable stop line at 29210 working face is 341m away from the slope foot,the reasonable stop line at 29211 working face is 288m away from the slope foot;using the comprehensive control technology of slope stability by optimizing the stopping line position of underground mining and adjusting the mining plan of open pit mining,in addition to the effective control of slope safety,it also realizes the maximum mining of coal resources under the slope.There are 73 figures,6 tables and 121 references in this paper. |
