Influence of grout-filled flaws on strength properties and fracture modes of coal petrography

In order to study the influence of grout-filled flaws on strength and fracture modes of coal petrography, based on the test results of indoor cracked rocks, the fractured rock containing different geometric arrangements were investigated experimentally using the parallel particle flow model. The results show that the peak stress and peak strain of cracked sandstone decrease first and then increase with the increase of ligament angle. In addition, with the increase of the flaw inclination angle, the strain energy and slip friction energy of the fractured rock increase to some extent under the same ligament angle. The failure mode of the specimen mainly includes tensile failure, shear failure and tensile-shear mixture failure.