ABSTRACT
The immediate roof, coal seam (foundation) and the main roof (rectangular plate) in longwall stope, for the first time, are drawn separately as elastic, elastoplastic, viscoelastic and viscoplastic foundation plate structures. The boundary element method (BEM) for bent thin plate combines individually with elastic, elasoplastic, viscoelastic and viscoplastic BEM to solve the above mentioned structures. The results show that fractured patterns of the foundation plates are all flat X type or an half of flat X type; Fractured main roof forms a regular or an oblique arch structure with three-gripping; In the transitional process of the foundation from elasticity to viscoplasticity the distance between the fractures of the main roof and the coal wall, and roof convergence rate increase, and the stress concentration factor(k), the dynamic loading coefficients of primary weighting (q’) and of periodic weighting (q”), and the amount of reverse elastic movement of the main roof and foundation system decrease.
