Research on residual shear strength of surrounding rock base on elastic-plastic softening model

Heng Zhou,Heng Zhou,Peng Huang,Ying Zhang,Ying Zhang,Bo Liu,Bo Liu,Shengjie Di,Shengjie Di,G Yang,M Ziegler

doi:10.1051/e3sconf/202019801034

Heng Zhou, Heng Zhou + Show 9 more

Open Access

https://doi.org/10.1051/e3sconf/202019801034

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Abstract

With the rapid development of infrastructure construction, the edge shape analysis of underground chamber excavation in water conservancy and hydropower projects has received more and more attention. This paper takes an underground chamber of a hydropower project as the research object and uses an ideal elastoplastic stress-strain softening model to study the relationship between deformation, stress, plastic zone and strength parameters. The results show that the value of each shear strength parameter has a significant effect on the distance of the plastic zone, and the calculation result may provide a basis for the design.

Highlights

In the fields of water conservancy and hydropower engineering, underground water storage engineering, etc., it involves reasonable support design for underground cavern excavation [1]
The underground powerhouse caverns of hydropower stations in mountainous and valley areas have the characteristics of large caverns, large buried depths and complex geological conditions
The deformation and failure of the surrounding rock of large underground caverns mainly occurs under the action of rebound stress and redistributed stress caused by excavation unloading

Summary

Introduction

In the fields of water conservancy and hydropower engineering, underground water storage engineering, etc., it involves reasonable support design for underground cavern excavation [1]. The deformation and failure of the surrounding rock of large underground caverns mainly occurs under the action of rebound stress and redistributed stress caused by excavation unloading. The nature of the rock mass, the size and shape of the cavern, the size of the stress conditions (the initial stress of the rock mass), and even the construction method will affect it. The combination of these factors is unpredictable. During the unloading failure process, the deformation and strength parameters of the rock mass are significantly weakened [4]. It is necessary to consider the weakening of rock mass strength parameters during unloading failure. The stress-strain relation curve of rock can be approximately linear at the beginning, that is, the elastic property of rock [5]

Constitutive model

Calculation analysis and sensitivity analysis

Conclusion