Damage localization in crack weakened rock mass is closely related to the crack growth pattern. Bifurcation of the alternative evolution of cracks occurs when the cracks grow to some extent

then some cracks keep on growing while other ceased evolving. It is found that damage localization in crack weakened rock mass is caused by bifurcation of the crack growth pattern

and the initial location is also determined by the crack growth pattern. Based on the analysis on the bifurcation of crack growth pattern

the critical length of wing crack and the critical stress of damage localization in crack weakened rock mass are obtained. Subsequently

the onset location of damage localization is determined by using the eigenvalue and eigenvector of coefficient matrix

and crack interaction is also taken into account in this model. Finally

the relationship between the interval between columns and rows

the orientation of crack

confining stress and the critical stress of damage localization is defined in the example.