Model test research on creep characteristics of discontinuous structural surfaces slope

Abstract

The rock slopes in nature are mainly cut by joints, which are in a non-persistent state in the rock mass. The creep mechanical characteristics of discontinuous structural surfaces have a significant and complicated influence on slope stability. Based on the analysis of the characteristics of a rock slope in Western Hubei before and after instability, the geological prototype of the slope is generalized, and the mechanical model of the discontinuous structural surfaces is established. Based on the uniaxial compression creep test, the phase creep characteristics of discontinuous structural surfaces are analyzed. The instantaneous strain in the creep process of discontinuous structural surfaces decreases greatly, and then increases slowly. The creep strain increases with the increase of stress. A viscoelastic-viscoplastic element that can describe the viscoelastic and the viscoplastic properties and damage variables are introduced, and an improved Nishihara damage creep constitutive model is constructed. The Levenberg-Marquardt (L-M) algorithm and global optimization method are used to verify the improved Nishihara damage constitutive model. After verification, comparing the experimental values and the predicted values of the damage constitutive model, the results show that the improved Nishihara damage constitutive model can better simulate the creep process of discontinuous structural surfaces. The author hopes that this study can provide reference for the study of creep characteristics of discontinuous structural surfaces in the future.