Author(s)

Fei Huang^1,2, Lichun Zhuo³, Keneng Zhang⁴

¹CCCC Fourth Harbor Engineering Institute Co., Ltd., Guangzhou, China.
²Laboratory of Environmental Protection & Safety of Transportation Foundation Engineering, Guangzhou, China.
³Guangzhou Rising Geotech Ltd., Guangzhou, China.
⁴School of Geosciences and Info-Physics, Central South University, Changsha, China.

The red clay in Chenzhou, Hunan province is mostly in unsaturated state. Simply applying the mechanical properties that derived from classic saturated soil mechanics often leads to slope failures in this region. In order to study the shear strength characteristic of unsaturated red clay in Chenzhou and to explore a shear strength equation that can be easily applied in engineering practice, a series of triaxial tests of saturated and unsaturated red clay samples were performed using the regular triaxial testing apparatus. The testing results show that the peak strength of red clay drops slightly before the moisture content of 30% but decreases sharply after that. The friction angle of red clay under unsaturated state is basically equal to the effective friction angle under saturated state, while the cohesion of unsaturated red clay is far much bigger than that of saturated one, which indicates that the matric suction makes a great contribution to the cohesion. By fitting the testing results with appropriate curves, the relationships between total strength parameters  and  with moisture content were obtained. The total  increases logarithmically before the moisture content of 35% then decreases linearly, while  decreases cubically with increasing moisture content.

Unsaturated Soils, Red Clay, Shear Strength, Triaxial Tests

Huang, F. , Zhuo, L. and Zhang, K. (2022) A Study on the Shear Strength Characteristic of Unsaturated Red Clay. World Journal of Engineering and Technology, 10, 714-727. doi: 10.4236/wjet.2022.104046.