Study Of Overlying Strara Movement Law And Selection Of Support In Fully-mechanized Working Face

The exploitation of(extra) thick coal seam plays an important role in the development and utilization of coal resources across China, and the fully mechanized caving mining is one of main methods in mining thick coal seam. The effective support is the primary task and fundamental guarantee in fully mechanized caving mining safely and efficiently. Hydraulic support, as the core equipment in fully mechanized caving mining, which investment accounted for 60% of the whole working surface coal mining equipment, not only can effectively guarantee the safe operation space, but also can ensure the movement of comprehensive mechanical equipment. Therefore, the correct selection of hydraulic support not only determines whether the working face is safe and efficiently, but also determines whether the investment id reasonable. Therefore, the preliminary selection of hydraulic support and the determination of other parameters must be reasonable in order to keep safe, efficient and intensive mining. With the large promotion of fully mechanized caving mining technology across China, the relationship between the movement of overlying strata and the support-rock interaction should be well known, which will help us to understand the stress characteristics and deformation law in rock strata around the fully mechanized caving face and will be important in guiding the safe mining.The selection of hydraulic support and the determination of parameters in working face No.1312 of Sanyuan coal mine is chose as the engineering background. Firstly, the data were collected and the characteristics of roof strata and floor strata were analyzed based on the peep results. Then, the crushing mechanism of top coal, the factors influencing the cave of top coal, the rock structure of roof and rib, the strength-stiffness-stability coupling of rock strata and hydraulic support were explored. Thirdly, the hydraulic support was selected according with the geological conditions. The center distance, support strength, working resistance, initial support force, the maximum and minimum support height were calculated based on different theories. And some attention items were advised in the operation of hydraulic support. Finally, the vertical stress distribution rules as well as the vertical distribution characteristics of force and deformation were studied with the numerical simulation software FLAC3 D. Meanwhile, the moving deformation regular were explored with different supporting strength to verify the correctness of the supporting strength theoretically. With the above factors, the model of hydraulic support in working face No.1312 was determined, which will provide favorable conditions for the safe and efficiently mining and will bring well economic benefits for Sanyuan coal mine.The researches in this paper can provide a certain reference value for studying the movement deformation of rock strata and selecting the proper hydraulic support in fully mechanized caving mining...