Effect of Prior Cyclic Loading on Triaxial Compression Strength of Sliding Zone Soil of the Huangtupo Landslide

Qiong Chen,Yu Chen,Wei Xiang,Xianyu Tao,Deshan Cui,Yang Wu

doi:10.1155/2021/9924995

Abstract

Earthquakes or cyclic loadings cause significant changes in the strength characteristics of soil. These changes, especially for sliding zone soil, can lead to catastrophic landslides. Taking into account this characteristic, this paper investigates the effects of prior cyclic loading on the consolidated undrained triaxial compression strength of sliding zone soil with the KTL triaxial automated system. Our experimental results indicate that the prior cyclic loading has a significant effect on the strength behaviour of saturated sliding zone soil. Under different confining pressures, cycle periods, and number of cycles, the samples exhibit the characteristics of strain-hardening. Deviatoric stress under cyclic loading condition is smaller than that with monotonic loading condition under different confining pressures, cycle periods, and number of cycles. As the confining pressure and cycle period increase, the failure stress ratio decreases. The axial strain exhibits a steep rise first and then stays stable under a cycle period of 90 s, while the axial strain shows a linear increase with an increase in the number of cycles under a cycle period of 10 s under confining pressures of 100 kPa and 400 kPa, respectively. The logarithmic relation correlates well with the failure stress ratio in the cyclic loading tests, which preliminary validates the applicability of logarithmic relation for sliding zone soil influenced by prior cyclic loading, providing a theoretical basis and guidance for the further understanding of strength characteristics of sliding zone soil.

Highlights

Introduction e Hubei Yangtze River EconomicBelt, located in the center of the Yangtze River basin, is the demonstration zone for the emergence of ecological civilization in central China.erefore, it is essential to study the catastrophic mechanism and prevention technology of landslide disasters in the ree Gorges Reservoir Area (TGRA) of the Hubei Yangtze River Economic Zone. e cyclic stress amplitudes and loading sequences on soil did affect the characterization of soil [1,2,3,4]
Earthquakes or cyclic loadings cause significant changes in the strength characteristics of soil. ese changes, especially for sliding zone soil, can lead to catastrophic landslides. Taking into account this characteristic, this paper investigates the effects of prior cyclic loading on the consolidated undrained triaxial compression strength of sliding zone soil with the KTL triaxial automated system
In the confining pressure of 400 kPa, the pore water pressure decreases to a negative value, indicating that the sliding zone soil is in the state of dilatancy, and the effective shear strength becomes 253.88 kPa

Summary

Introduction

Introduction e Hubei Yangtze River EconomicBelt, located in the center of the Yangtze River basin, is the demonstration zone for the emergence of ecological civilization in central China.erefore, it is essential to study the catastrophic mechanism and prevention technology of landslide disasters in the ree Gorges Reservoir Area (TGRA) of the Hubei Yangtze River Economic Zone. e cyclic stress amplitudes and loading sequences on soil did affect the characterization of soil [1,2,3,4]. Erefore, it is essential to study the catastrophic mechanism and prevention technology of landslide disasters in the ree Gorges Reservoir Area (TGRA) of the Hubei Yangtze River Economic Zone. There is an urgency to investigate the catastrophic mechanism of landslide under cyclic loadings, such as atmospheric rainfall, the rise or fall of reservoir water levels, and especially, traffic loadings and earthquakes. E influence of periodic rainfall infiltration on sliding mass is mainly reflected in the dynamic process of increasing bulk density and attenuated matric suction, both of which lead to a lowered landslide stability safety factor [5]. For a slowly sliding landslide, the sliding zone soil is in the state of residual strength, which is generally 70% of the shear strength [17, 18]. For a slowly sliding landslide, the sliding zone soil is in the state of residual strength, which is generally 70% of the shear strength [17, 18]. e residual

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