Study On Hydraulic Support Technology Of Large Resistance Cover Top Coal Caving Under Shallow Deep Caol Seam

The bedrock of shallow deep coal seam is thinner,the loose layer is thicker,the working face generally appears the phenomenon of step sinking,and the mine pressure appears violently,so the common hydraulic support used in the working face of shallow buried deep coal seam is apt to have insufficient working resistance.The problems such as poor supporting effect,complicated structure design and complicated operation seriously restrict the mining of shallow deep coal seam.In this paper,the working characteristics of two pillar shield hydraulic support for shallow coal seam are studied to improve the performance of the support and to solve the problem of safe and efficient mining in shallow coal seam.According to the existing condition of coal seam in the working face,this paper designs and selects the hydraulic support of two pillar shield caving coal caving,combined with the coupling relation between support and surrounding rock stiffness,and the influence of top coal hardness and coal caving technology on the support,determines the working resistance of the support.Secondly,calculate the key technical parameters of the hydraulic support,determine the selection type of the key structural parts of the support,and according to the stress condition of the support,establish a three-dimensional force model,analyze the interrelation between the various internal and external forces of the support,start with the functional characteristics of the support.Design the hydraulic control system of the integral cover type top coal caving hydraulic support,use the AMESim simulation software to analyze the four main control loops:column,balance,tail beam and insert plate,and to verify the rationality of the hydraulic system,and put forward the improvement measures.Finally,combining Creo3.0 and ANSYS Workbench simulation software,by comparing and analyzing the stress and displacement characteristics under different working conditions,analyzing the mechanical characteristics of the cover type top coal caving hydraulic support,finding out the weak link of the support,and putting forward the feasible optimization measures.In this paper,the working resistance of the support is determined by studying the coupling relationship between the support and the surrounding rock,the working resistance of the support is determined by designing the electro-hydraulic control system of the hydraulic support,the operation mode of the support is simplified,the rationality of the hydraulic system design is verified by virtual software,and the improvement measures are proposed.In order to improve the reliability of the hydraulic system of the support and to simplify the structure of the two-pillar sheltered coal caving hydraulic support under the premise of ensuring the reliability of the structural design by using the spatial mechanics analysis and the structural finite element analysis the effect of roof control of the support is improved.The research of this paper has certain guiding significance to solve the problems of large working resistance and intense mine pressure in shallow deep coal seam.