| Filling mining technology is a green mining technology that actively protects the ecological environment.It is widely used in medium thick coal seams and has rich experience.However,in the thin coal seams accounting for 20% of the coal reserves,due to the constraints of special conditions such as narrow mining height space,the benefits of thin coal seam filling mining are poor and the development progress is slow.Based on the problems of limited sight distance and low filling effect encountered in the application of filling mining technology in thin coal seams,a breakthrough is found in the structure of solid filling hydraulic support.On the basis of the structural characteristics and basic working principles of the filling hydraulic support,a new type of vertical guide pillar hydraulic support suitable for high-efficiency filling and mining in thin coal seams is designed through literature research,theoretical design,simulation and other research methods,which increases the visual distance space of the filling and mining hydraulic support and improves the filling and mining effect and efficiency in thin coal seams.The main research results are as follows:(1)Based on the literature of support design,according to the working demand of thin coal seam solid filling hydraulic support,a vertical guide pillar balance system is proposed to meet the problem of insufficient visual space of thin coal seam solid filling hydraulic support;(2)The process of solving the roof load by the mechanical model of "roof and coal wall support backfill" and numerical simulation is studied,and the support strength of hydraulic support is determined;(3)According to the mechanical characteristics of the vertical guide pillar solid filling hydraulic support,the mechanical models of the top beam,the balance jack,the vertical guide pillar,the pushing device and the base are established respectively,and the basic parameters of the main structure of the support are determined;(4)In view of the fact that the support should meet the strength requirements,the support structure is checked for the four basic working conditions by the method of loading in the support,which ensures that the maximum stress of the support under the four working conditions is within the yield strength of the material,and at the same time,the occurrence position of the maximum stress and deformation of the support is obtained,which provides a favorable reference for further structural strength optimization;(5)The relationship between the inclination of the working face and the instability of the support is analyzed.Using the center of gravity measurement function of SW software,the free,initial bearing and working states of the support are calculated in detail from the transverse and longitudinal directions.The mathematical models of the inclination of the support,the friction factors and the support force of the column are established.The analysis results show that the support is suitable for coal seams with the inclination of the working face less than 16 ° and meets the use requirements,At the same time,it meets the conditions of moving the rack with pressure;(6)Considering that the support is controlled by the hydraulic system,a simulation model of the support hydraulic system is built by AMESim.Based on the design requirements of the support control system,the influence of internal leakage of different pump flows on the performance of the column is analyzed,the impact resistance characteristics of the support are tested,and the pressure loss of the hydraulic control system is estimated.The results show that all the data of the support are within the allowable range,which provides an important reference for the further optimization and improvement of the support hydraulic system. |
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