Deformation Characteristics and Load-Bearing Capacity of NO.21 Coal Seam’s Mudstone Floor in Western Henan

Abstract

Through the floor specific pressure test, the floor specific pressure was obtained. The rock mass of mudstone, under the loading perpendicular to the weak plane, was in brittle-plastic failure state, and the bearing capacity of mudstone was equal to the Ⅲa grade floor. The brittle-plastic transition mechanism of the mudstone was revealed: Firstly, the more size, the more heterogeneity. The mudstone body was bigger than its rock samples, so there were more planes of weakness, which caused the macroscopic plastic deformation. Secondly, the directions of the load and the weak plane influenced the strength of the mudstone floor. During the plastic deformation, the compressive failure occurred layer by layer under the loading perpendicular to the weak planes, and the post peak load-bearing capacity of mudstone floor was decided by the layer’s strength.