Research On Failure Laws Of Overlying Rock And Support Resistance In Fully-mechanized Face In Shallow Seam Of Thick Clay Layers

In this paper, the law of the appearance of strata pressure, overlying strata movement and reasonable force of the supports in shallow seam mining under thick clay layers are studied in details with three methods as following: simulating model test, numerical simulation and theoretical analysis.Proceeding with the engineering geological character of the laterite and loess, and connect with the geological conditions of the first fully mechanized coal mining face (20115face) in NanLiang coal mine. Two models of equivalent material are established, a suit of Emulational control system of simulating bracket with constant resistance mechanics character is devised and used in Field Simulation Experiment at the fisrt time.thereby the relationship between the support and the surrounding rock with different supports is efficiently analyzed. Through analyzing the supporting resistance, influence of laterite on the main roof structure and falling height of overlying rock, it is revealed that the huge thick clay layers is key affecting strata which control the occurrence of intensive appearance of strata pressure accompanying the overlying strata full-thickeners cutting-off along the seam wall.Theoretical Analysed the roof without voussoir beam structure in shallow seam mining under thick unconsolidated layers, thus, cann't use voussoir beam theory to compute the force of supports. By study on equilibrium condition of key rock in the fractrue rockpillare, The mechanical model of key rock structure is established, Theoretical formulas of therational support resistance in fully mechainzed coal mining face in shallow seam mining under thick clay layers gained at the same time.Applying the numerical simulations program RFPA^-2D to analyze the law of strata pressure appearance under the mining condition of thick clay in shallow seam, Due to the...