With rock sample of coal seam roof as matrix and steel wire as bolt and steel sheet as steel strip

anchored rocks have been experimented by means of three-point-bend. Testing results show that: as the differential properties on compressive and tensile of rock，the speed of tensile strain growth is greater than that of compressive and cracks begin to extend on the lower surface of rock and gradually propagate upward in the bending process. The flexural behavior of bolt anchored specimen has been enhanced

while the mechanical properties of rock are improved in anchorage zone

and a certain amount of tensile stress is shared by steel belt and bolt. The cross section stress distribution of specimen could be divided into three stages in accordance with the failure process. The first is elastic stage. Crack generation and propagation is the second stage. The bearing capacity of rock start to deteriorate

and tensile stress gradually shifts to the steel belt

bearing capacity of anchored increases dramatically because crack propagation of rock is limited. The third is failure stage

bolt lost function

deflection increases while bearing capacity of the specimen tends to be stabled.