抄録
A new fracture criterion of the shear failure for the geomaterials is presented which enables to predict a straight extension of a crack in the elastic plastic materials under the compressive loads. It is an application of the Coulomb fracture criterion to a crack extension criterion called “The maximum frictional shear stress criterion”.
We examine the criterion by using both the singular and the constant terms in the asymptotic expansion of the crack tip stress fields for a linear hardening Drucker-Prager elastic plastic material. As a result, we find that the confining pressure, the frictional coefficient of the crack surface, the small hardening parameter, and the dilatancy effect is the lowering of the extensive hoop stress causing the crack kink, which contribute the frictional shear stress extending a crack straight to maximum.
