Constitutive Modelling of Joints under Cyclic Loading. Part 2. Further Development of Hierarchical Plasticity Model for Joints

摘要

Discontinuities or joints play a significant role in the behavior of structures founded on discontinuous rocks (or soils) which contribute an important source of weakness. Although modern computational techniques make numerical analysis possible, proper constitutive relations for discontinuities must be used in order to obtain reliable and useful results. Discontinuity, by definition, is the boundary region between two materials. Usually it is weaker compared to surrounding intact materials. The geometry and roughness of the joint walls play a significant role in the shear strength and deformation of the joint. The opposite walls of the discontinuity have only finite contacts, air, liquid and filling materials are often present, and it possesses negligible strength in tension. As a consequence, its behavior is quite different from that of continua surrounding it. This model represents a generalized and modified development of the model presented in Part A of this report. The proposed generalized model allows for detailed consideration of the normal and shear components of the joint response, and is verified for both normal stress and normal stiffness controlled conditions. (mjm)