Brazilian disc splitting tests and numerical simulations on coal samples containing bedding planes

Abstract

In this paper, Brazilian disc splitting tests on coal rock specimens with bedding planes and corresponding simulations by combined finite/discrete numerical method(FDEM) were carried out.The results show that the angle of bedding plane have a significant influence on fracture pattern and tensile strength of coal.It is clear that as the angle of weak plane increases, the fracture pattern of models can be classified into four types, including stretching failure perpendicular to weak bedding planes, complicated sketching and shear mixed pattern, shear failure along the bedding planes, and sketching damage along weak bedding planes.As for the difference of tensile strength values, it is observed that when the load is perpendicular to the bedding plane, the effect of bedding structure on calculating tensile strength is negligible and the tensile strength value decreases with the angle rising up to the minimum value as angle reaches vertical.In addition, with respect to dissipated energy of coal samples, it is concluded that the dissipated energy gradually decreases when the angle of bedding planes are increased, which have a relationship with varied fracture patterns and strength values.

Keywords

• coal
• brazilian disc splitting test
• bedding plane
• fracture pattern
• tensile strength
• numerical simulation