Study On The Simulation Experiment Of Rock Beams Deformation Failure

The coal measure strata is dominated by sedimentary rock, whose main characteristic is bedding development. A significant beam structure exists in the stope overlying stratified rock. So the analysis of stresses and deformation failure of the beam is the research foundation of stope overburden structure.By using physics resemble simulation and theoretical analysis method the thesis researches the breakdown forms of rock beam under weight force. Choosing appropriate simulation materials and suitable ratios it tests the physical and mechanical parameters of the specimen and determines the experimental model and method. It takes the breakdown experiments for different materials and thickness.Through experiments the thesis gets conclusions as below. The stress and strain in the top and bottom surfaces of simple supported single layer beam increase with the increase of beam span under self-gravity effect. The span limit increases with the increase of the beam strength and thickness. The beak characters of simple supported two equal-thickness beams under self-gravity effect relate to the composite style. The upper beams break after the lower in upper hard and lower soft condition, and the bending and subsidence appear in lower beams before breaking. The break span of lower soft beam is slightly larger than that of the soft single layer, which is opposite in upper hard beams. In upper soft and lower hard condition both beams bend and break with the increase of suspended span, and the break span is less than that of the hard single layer, which indicates that the upper soft beams have transformed to loads to the lower hard ones.The theoretical analysis shows that the stress value increases with the increase of beam span, and the beam breaks forced by the lower tensile stress when the suspended span reaches limit.The theoretical analysis of beam limit span and maximum bending value basically tally with experimental value.The research has important reference value for the further study to rock beams.