Modeling the influence of water content in Callovo-Oxfordian argillite compression test

Abstract

A unified elastic–plastic model is presented for argillites in this paper. Emphasis is put on the description of hydromechanical behavior of argillite under saturated and unsaturated condition in compression test. Base on the experimental investigation, the material’s behavior is characterized by important plastic deformation coupled with damage on the short-term scale. Furthermore, the water content has an important impact on mechanical behavior of argillite at different saturation degree. Using the unified approach proposed by Matallah and Christian La Borderie (2016), a general constitutive model is proposed for the poromechanical behavior of argillites in both saturated and unsaturated conditions. Main features observed in experiments are taken into account, particularly the elastic degradation due to microcracks, coupling between plastic deformation and induced damage and influence of water content on plastic flow on different time scales. The performance of the model is examined by simulation of plasticity tests with different hydraulic states. Finally, the model is applied to study the hydromechanical coupling in a resaturation–desaturation test.