Slide breaking of shearing wedge block often occurs to elastic and plastic wall rockes around the circular roadways within the non-static head siress field in the direction perpendicular to its principal stress.

Under the condition of general shear failure of soil, this paper offers the expression of Nr , discusses the formulas when soil cohesion C transformed into equivalent overload and makes comments on ultimate bearing pressure of Taylor and Vesic respectivel.

Based on the different conditions,the styles of soil nail pull-out failure can be classified as column shear failure on the interface between soil nailing and soil,soil shear failure around soil nail,composite shear failure and material yield failure of soil nail.

Methods Based on the two failure mode of plane and wedge sliding destruction of the limit equilibrium theory,rock slope stability is analysed.

Anisotropy of shear strength of layered rocks and determination of shear failure plane;

Research on point safety factor of shear failure geomaterials

Based upon shear strain gradient plastic theory of rock deformation localization, it is assumed that the failure pattern of rock in the shear band is shear failure.