A statistical damage constitutive model with damage threshold based on Mogi-Coulomb criterion

摘要

Because of the limitations and deficiencies of rock damage model based on Lemaitre's strain equivalence.Our study is firstly concerned with the evolution rule of damage variable during the process of rock strain softening,considering the influence of damage threshold.Secondly,as Mogi-Coulomb strength criterion can better describe the failure features of rocks under high geostress and rock micro-unit strength obeys the Weibull distribution,a new statistical damage constitutive model is established.Then,comparing the new model based on Mogi-Coulomb criterion with the Drucker-Pmger model and Mohr-Coulomb model,the new model can fit well experimental data.Finally,the new model is applied to the study of sudden change in rock permeability.Theoretical prediction is in good agreement with experimental result and is better than the existing results through a comparative analysis.The validity and feasibility of the model are verified.