Abstract:

The plastic characteristics of the coal seam floor has been explored with the finite element strength reduction software of ANSYS; and its plastic area perforation process is given; and that the slip lines given by this methods are much close to theoretical solution; the plastic failure fields depth of the coal seam floor similar to Prandtl type; some parameters are compared with that by theoretical solution; the error is less than 10% so as to show that used the finite element intensity reduction method to solve floor damage situation is feasible. The scope of its plastic area can be used to reserve the safe thickness in water inrush from coal seam floor and the maximum effective spacing of liberated seam; then further utilizes in liberated seam to obtain its plastic area and slip lines.

Key words: finite element strength reduction method, slip lines, coal floor, protecting coal seam