Study On Floor Of Deformation And Damage And Floor Stress Field Under Different Lithology Environments

Combined with slope stress distribution characteristics, the paper established an elastic semi-infinite stress distribution computational mechanics model of floor in the triangle strip load, a materials mechanical model of floor beam structure, and an elastic thin plate mechanical analysis model of mined-out area floor, given the floor stress, internal forces formula, deformation and damage judgment basis. Using Flac3d numerical simulation software, the paper simulated deformation and damage law of floor plate direction, tendency and depth during drilling working face under three kinds of rock environment of hard-top and soft-bottom, hard- bottom and soft-top, similar circumstances of top and bottom, including stress distribution characteristics, displacement characteristics and plastic zone of floor plate. Then it summarized the similarities and differences of floor plate deformation and damage law under these three kinds of rock environment.It proposed floor plate stress area criteria, that is working face near the floor will be divided into mining pressure appeared sudden change region and weak region by maximum vertical stress gradient normal. That is to say, floor plate mine pressure behavior such as floor heave deformation and shear breaking occurred in the stress peak to the direction of mined-out area while floor plate front of the peak has only small changes of substrate deformation; floor plate will be divided into tensile stress region, stress reduction region and stress increase region by tensile stress lines and the original rock stress lines. The paper also defined the Attenuation coefficient of focused stress field front of working face spreading of floor plate, which can vividly depicted the stress field distribution characteristics of floor plate depth orientation combined with the maximum vertical stress gradient normal.The paper does the mechanics analysis and calculation study of deformation and damage law of Suntuan 1028 working face mining floor, gives plastic region of the stress, displacement and floor plate, at the same time gives floor damage depth. Finally, combined with on-site measurement, the paper verifies mechanics analysis results and numerical simulation results accuracy.