In geotechnical engineering

fractured rock mass is often in the post-peak deformational state. It is important for predicting stability of structure to study post-peak stress-strain relationship of fractured rock mass. Based on the evolution of post-peak strength parameters

firstly

a method for solving the relations of post-peak stress-strain of rock and stress-shear displacement of crack is proposed. Then using Mohr-Coulomb strength criterion

regarding maximum principal strain of rock and shear displacement of crack as softening parameters

assuming the strength parameter as a piecewise linear function of softening parameters

in the two cases that the rock mass fails along the fracture and through the rock

the method for solving relation of post-peak stress-strain of rock mass with multiple penetrative crack sets is presented. Finally

in case study

the post-peak stress-stain curves are given in the two cases that the rock mass fails along the fracture and through the rock; and the effects of mean space

normal stiffness and shear stiffness of cracks on post-peak strain are discussed. The results show that the smaller the mean space

normal stiffness and shear stiffness of cracks are

the larger the axial strain of fractured rock mass is.