Effect of parallel joint interaction on mechanical behavior of jointed rock mass models

To better understand the interaction of parallel joints and its effect on the mechanical behavior of jointed rock mass models, the results of a physical experiment program undertaken in the laboratory were present in this manuscript. The joint spacing and joint overlap are varied to alter the relative positions of parallel joints in geometry. Accordingly, four basic failure modes identified from the testing results are tensile failure across the joint plane, shear failure along the joint plane, tensile failure along the joint plane, and intact material failure. The wing cracks from tensile failure across the joint plane mode represent the interaction between parallel joints which depends on the joint dip angle, joint spacing and joint overlap. With the increment of parallel joint interaction, the corresponding normalized strength and maximum displacement at peak stress of jointed rock mass models reduced generally except at α=0°.