| For thick coal seam mining technology in our country,the application of fully mechanized mining with large mining height has been widely applied,and the corresponding mining machines and equipments has been developed successively.There are a few mines used fully automatic mechanized mining method with large mining height.Many experts and scholars have carried out in-depth study on the occurrence regularity of the mining pressure in the working face and obtained very valuable research conclusions.However,there is less research on the roof movement of automatic working face with large mining height.Based on Yanzhou mining group Dongtan coal mine 6304 automatic mining face,the law of strata behavior in the working face,the roof movement rule and the adaptability of hydraulic support system are analyzed.The main conclusions are as follows:(1)The large mining height direct roof is divided into the lower direct roof and the upper direct roof,and the calculation formula of thickness and pressure step is given.(2)The effect of the support on the lower direct roof and the upper direct roof is analyzed by the "given load" scheme.The effect of the support on the basic roof is analyzed by the "given deformation" or”limited deformation" scheme.(3)The movement Iaw of the roof,the distribution Iaw of abutment pressure and the distribution of plastic zone on the working face at different driving distances are obtained by using the UDEC numerical simulation software.(4)A series of roof control techniques are presented and field tests were carried out.Then the results were analyzed.The distances of first weighting and periodic weighting of different roo fstrata were measured.The influence range of the working face supporting pressure is obtained.At the same time,the adaptability of the support was analyzed.In this paper some references are provided for the roof control of the same tvpe of mechanized large mining height working face. |
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