Experimental Investigation on the Shear Behavior of Interface between High Plastic Clay and Concrete

Yumeng Zhu,Guoying Li,Kuangmin Wei,Ziyu Chen,Zhankuan Mi,Shengwen Tang

doi:10.1155/2022/9313881

Abstract

The Lianghekou earth core rockfill dam to be built in China will be the third highest rockfill dam in the world. This study presents the results of a series of direct shear tests between high plastic clay and concrete to study the shear behavior of contact clay-concrete cushion interface of Lianghekou dam. Results showed that water content and normal stress are significant factors affecting the shear behavior of the interface. The higher shear strength is related to lower water content and higher normal stress, and the shear strength can be formulated by the bifold-line type Mohr–Coulomb strength criterion. It is also found that the interface exhibits mainly two kinds of shear failure modes, that is, sliding failure along the concrete surface and shear failure in the clay matrix nearby the interface. Moreover, a nonlinear elastic model is proposed to simulate the shear behavior of the interface, of which parameters can be quickly estimated by water content. The simulation of the model is compared with the experimental results, and the results show that the model is reasonable and practical.

Highlights

Earth core rockfill dam (ECRD) is widely used in the world due to its low cost, adaptability to complex geological conditions, and fewer restrictions in climate conditions
For the ECRD, concrete cushion roughness, stress state, soil density, and water content have a great influence on the shear behavior of interface, so it is necessary to test the behavior of high plasticity clay-concrete with different water content
Higher water content is related to lower shear strength, especially for higher normal stress

Summary

Introduction

Earth core rockfill dam (ECRD) is widely used in the world due to its low cost, adaptability to complex geological conditions, and fewer restrictions in climate conditions. Liu et al [36] developed an elastoplastic constitutive model for the soil-structure interface that uses critical state concept and generalized plasticity approach. Ese results showed that interface shear behavior during monotonic and cyclic loading could be predicted reasonably. All the aforementioned constitutive models are based on the twodimensional behavior of the interface, whereas there are many soil-structure systems that can undergo complex three-dimensional loading [37]. For the ECRD, concrete cushion roughness, stress state, soil density, and water content have a great influence on the shear behavior of interface, so it is necessary to test the behavior of high plasticity clay-concrete with different water content. E aim of this study is to comprehensively analyse and clarify the frictional behavior between high plasticity clay and concrete and the influence of water content on contact clay-concrete cushion interface shear behavior. A nonlinear elastic model is modified to simulate the shear stress and normal deformation of the interface. e aim of this study is to comprehensively analyse and clarify the frictional behavior between high plasticity clay and concrete and the influence of water content on contact clay-concrete cushion interface shear behavior. e current study is helpful to better understanding of clay-concrete interface in ECRD

Description of Tests

Test Results

Determination of Constitutive Model Parameters

Discussions