Strength Characteristics Of Fractured Rock Mass

In this paper,the influence of rock mass structure on strength is studied by indoor test and theoretical analysis.The strength,deformation and failure characteristics of rock mass formed by different angles and different numbers of fracture combinations,different broken grain sizes and different strength filling materials have been studied,and the following results have been obtained.(1)Through investigation and abstract,two kinds of 10 groups of rock mass simulation tests are designed.With the similar material as the base material,the rock structure is controlled by the artificial fracture and rock mass gradation,and the basic data of the relationship between rock mass structure and strength and deformation are obtained.(2)As the number of fractures increases,the strength curve of rock mass gradually changes to isotropy,and the strength of rock mass is mainly affected by the most unfavorable cracks.The strength of rock mass can be reduced by different fractures.Filling materials can enhance the peak strength of rock mass and change the slip of the structure surface,but it can not change the failure mode of rock mass.(3)The deformation modulus and deformation capacity of fractured rock mass are anisotropic.There are 3 possible failure modes of fractured rock mass: tensile failure through structural plane,shear failure along the structural plane and crushing of intact rock.(4)Regardless of the high or low rock fragmentation,the higher the strength of the fill,the higher the strength and deformation modulus of the rock mass.When the filling strength is the same,the strength of the rock mass with smaller crushing degree is higher;the strength of the filling plays a leading role in the strength of the rock mass.(5)For low fractured rock mass,the higher the strength of the filling,the higher the residual strength.There are 2 failure modes of fractured rock mass: the fracture of cementation surface of rock and fill and the crushing of rock blocks themselves.