Distribution Pattern of Anchorage Stress and Water Sensitivity Analysis of Red Clay

Lifeng Li,Huilin Deng,Gan Li,Weili Gong,Xiaohu Zhang

doi:10.1155/2020/6272576

Lifeng Li, Huilin Deng + Show 3 more

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https://doi.org/10.1155/2020/6272576

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Abstract

Red clay is a special soil layer with complex engineering properties distributed in tropical and subtropical regions. An anchor cable support is a common form of red clay slope support. The effectiveness of the anchor cable support is mainly determined by the anchoring force provided by the red clay stratum. Increase of the water content will lead to the rapid deterioration of the mechanical properties of red clay, which will lead to the reduction of the anchoring force of the slope anchor cable and lead to the failure of the support. Based on the classical Phillips and uniform anchorage shear stress distribution theory, this paper puts forward a uniform-exponential distribution pattern of anchorage shear stress according to the specific characteristics of red clay by using the characteristics of the peak shear strength and residual shear strength of the rock and soil mass. With increasing anchorage force, the dynamic evolution (single exponential distribution ⟶ double single exponential distribution ⟶ uniform index exponential complex distribution ⟶ uniform distribution) of the anchorage shear stress is analysed. Based on the peak and residual test of the cohesive force and internal friction angle, the relationship between the anchoring force and buried depth and water content is established by analysing the factors influencing the anchoring force. It can be found from the field test that, according to the relationship established, the limit anchorage force of the anchor cable in the red clay stratum can be calculated and the water sensitivity of the anchor cable’s limit anchorage force can be quantitatively analysed.

Highlights

Red clay is mainly distributed in the hot and subtropical climatic zones between latitudes 30° north and 30° south
Taking the anchorage shear stress of the red clay formation as the research object, the change of water content as the influencing factor, and the shear strength as the approach, this paper mainly studies the distribution law of the anchorage force and water sensitivity of the red clay formation
The failure of the anchorage is a bond failure between the anchorage body and the rock-soil mass, or the failure of the rock-soil mass itself. e interface strength of the anchorage body and the soil mass affected by grouting infiltration is greater than that of the soil mass. e shear failure of the anchorage body and soil mass in red clay is marked by the shear failure of the soil mass

Summary

Introduction

Red clay is mainly distributed in the hot and subtropical climatic zones between latitudes 30° north and 30° south. According to the classical molar Coulomb theory, the shear strength of red clay is determined by the normal stress of the soil layer, the cohesion of the soil mass, and the angle of internal friction [16]. With the increase of water content, its engineering mechanical properties deteriorate sharply, which is mainly manifested in the deterioration of the soil cohesion and internal friction angle. Taking the anchorage shear stress of the red clay formation as the research object, the change of water content as the influencing factor, and the shear strength as the approach, this paper mainly studies the distribution law of the anchorage force and water sensitivity of the red clay formation

Anchorage Stress Distribution Theory

Classical eory of Anchorage Shear Stress Distribution

II III

Conclusion