Degradation of weak sandstone and continuum damage model

Abstract

The study experimentally simulates in-situ degradation mechanisms to investigate the degradation of weak sandstone. Following different artificial degradation processes, the specimens are subjected to uniaxial compression. From the experimental results, it is noted that degradation of the tested weak sandstone results in a marked reduction in strength and elastic modulus and an increase in the failure strain. On the basis of the experimental results, a constitutive model is proposed to describe the mechanical behavior of weak sandstone. The presented constitutive model-contains a hyperbolic pore/crack closure model and a continuum damage mechanics model. By comparing the simulated and experimental results, it is demonstrated that the proposed model can closely simulate the stress-strain relation of weak sandstone with very limited material parameters.