弱面を有する異方ぜい性材料の破壊特性に関する研究

抄録

In order to investigate what different types of anisotropy (Foliation, stratification or shistosity) in rocky materials will have influence on their ultimate strength and failure pattern, a series of uni-, bi- and tri-axial compression tests were performed using the mortar specimens with construction joints.
The results obtained are as follows:
(1) The in fluence of the inclination of jointed plane on strength is maximum for α≈30°(α: angle between max. principal stress σ₁ and jointed plane). The decrease in strength is descending as confining pressure is high; for 30°-specimens there occurs respectively 80% and 15% decrease in strength under confining pressure 0kg/cm² and 200kg/cm².
(2) Fracture criterion can be approximated by Jaeger's theory.
(3) Fracture surface in the principal stress space is a slightly bulged pyramidical convex surface, being crooked in σ₁>σ₃>σ₂ (σ₃: principal stress parallel to the jointed plane).