The Mohr-Coulomb model is based on plotting Mohr's circle for states of stress at failure in the plane of the maximum and minimum principal stresses.

It is suggested that on the same seismotectonic zone, the directions of principal compressional stress of fault plane solution of small earthquakes are consistent.

This paper USES principal curvature, plane stress and structure filtering to evaluate the development of fracture at geology shape, mechanical and signal handle facet.