Study on the Creep Constitutive Model of a Sandstone Rock under the Water-Rock Interaction

Zuosen Luo,Jingyu Zhang,Jianlin Li,Zuoxiang Zhu,Huafeng Deng,Eleyas Assefa,Lehua Wang,Qiao Jiang,Xingzhou Chen

doi:10.1155/2021/6648421

Abstract

With the continuous construction of large-scale geotechnical engineering, more and more attention has been paid to the long-term stability of rock mass engineering, especially the problem of rock creep under the influence of water. Combined with the author’s previous research on the triaxial creep characteristics of sandstone under water-rock interaction, a nonlinear creep constitutive model was established to capture the degradation behavior of a sandstone rock due to cyclic wetting and drying of the reservoir water. Due to the limitations of the visco-elastoplastic model, a thorough modification was done to account the effect of the water-rock interaction on the mechanical degradation of the sandstone rock. Finally, the predicted results were proved to be in a good agreement with the experimental results. Moreover, the strong correlations between the predicted results and the experimental results show the effectiveness of the modified model to scrutinize the nonlinear creep behavior of sandstone rock. Relevant research results have important theoretical significance for the accurate prediction and effective control of the long-term stability of rock mass engineering under the influence of water-rock interaction.

Highlights

After the completion of the ree Gorges Hydropower Project, the reservoir water level has been fluctuating by 30 m. e ree Gorges reservoir has 600 km length
It inundates 4 counties in Hubei Province and 16 counties in Chongqing. e reservoir bank slope in the hydrofluctuation zone is subsequently altered by the wetting and drying cycles. is phenomenon has an adverse effect on the mechanical properties of the rock mass [1,2,3,4,5]
For the evaluation of the long-term strength of the rock mass under the action of water, it is very important to consider the damage of the water-rock interaction. erefore, this paper introduces the water-rock interaction damage variable and establishes the consideration of the water-rock interaction damage creep model

Summary

Introduction

After the completion of the ree Gorges Hydropower Project, the reservoir water level has been fluctuating by 30 m (between 145 m and 175 m). e ree Gorges reservoir has 600 km length. E deformation and the failure of the reservoir bank slopes are mainly due to the effect of the water-rock interaction on the creep mechanical properties of the rock mass [7,8,9,10]. Zhu Hehua and Ye Bin [18] conducted uniaxial creep tests on dry and saturated tuff rock. According to their finding, water has a significant impact on the ultimate creep behavior of tuff rock. The degradation effect of water-rock interaction on the mechanical properties of the rock was considered, the sandstone creep constitutive relationship considering the water-rock interaction was established, and the research results can provide references for specific engineering calculations and analysis

Creep Characteristics of Sandstone under Water-Rock Interaction

Creep Constitutive Model

E1 σ η1 σs σ η2

Incorporating the Effect of Water into the Creep Model

Conclusion