As being the confining tension increases, the rise in resistance to longitudinal crack propagation leads to a gradual transition of shale failure method from longitudinal to inclined shear failure that demonstrates an escalation in rock plasticity. If the confining strain reaches 30 MPa, there are still neighborhood shear microcracks https://vertechs1.blogspot.com/2025/12/mastering-depths-how-vertechs-is.html