A fracture damage constitutive model for fissured rock mass and its experimental verification

A constitutive model for fissured rock mass is established based on the deformation characteristics of microcracks under compression. The method to determine the model parameters is given. Comparative analyses between the proposed model and experimental results of siltstone indicate that this model can describe the whole process from the initial state to failure state of fissured rock mass well; this model can also simulate the initial phase in the process of fissured rock under compression well. At the same time, this model can also reflect the property of strain softening as well as the damage evolution process. Compared with previous models, this model is better able to capture the general trend which is observed experimentally. The strain energy and damage revolution of fissured rock under compression are also discussed; and the proposed model is capable of predicting the energy and damage behavior, which are in reasonably agreement with the experimental observations.