Deformation Behaviors of Saturated Clay under Intermittent Cyclic Loading with Cyclic Confining Pressure

• Published in: International journal of geomechanics 2024-07, Vol.24 (7)
• Main Authors: Huang, Juehao, Sun, Xuebing, Li, Xiaolong, Gao, Yunlong, Chen, Jian, Fu, Xiaodong, Liu, Shuai
• Format: Article
• Language: English
• Subjects: Axial strain; Clay; Confining; Cyclic loading; Cyclic loads; Deformation; Dynamic loads; Empirical analysis; Hydrostatic pressure; Mechanical loading; Pore water pressure; Pressure; Shear stress; Soft clay; Soil analysis; Soil investigations; Soils; Strain; Stress distribution; Stress ratio; Technical Note; Technical Notes; Water pressure
• ISSN: 1532-3641; 1943-5622
• DOI: 10.1061/IJGNAI.GMENG-8927

Abstract The dynamic behaviors of subgrade soil are usually investigated by use of continuous loading mode in most studies; however, the dynamic loading induced by traffic loading is composed of cyclic loading and intermittent periods. Moreover, the existence of cyclic deviator stress, cyclic confining pressure, and shear stress has been already observed in the stress field induced by traffic loading. Recognizing this, intermittent cyclic loading was applied to saturated soft clay for this study. The impacts of cyclic deviator stress, cyclic confining pressure, and drained condition during intermittent periods on the deformation behaviors of soft soil were analyzed. The variations in strain increment were similar in all cases: as the number of loading stages increased, the strain increment decreased, and the difference in strain increment was more significant in the first loading stage although it could be ignored in subsequent loading stages. Furthermore, the strain increment increased with increasing cyclic stress ratio (CSR) and decreased with increasing cyclic confining pressure. Moreover, the dissipation of excess pore-water pressure induced during the cyclic loading period resulted in the increase of accumulated axial strain under intermittent partially drained conditions, while the recovery of specimen deformation during intermittent period led to the decreasing of accumulated axial strain under undrained conditions. In addition, an empirical formula of accumulated axial strain under intermittent cyclic loading was established, and the calculated results were consistent with the measured data.