Creep deformations for unsaturated-saturated soils with consider suction and pore-water pressure

¹ Ashikaga University, Department of Civil Engineering, Tochi, Japan
² Geotechnical Engineering General Institute, Tochigi, Japan

^* Corresponding author: Nishimura.tomoyoshi@g.ashikaga.ac.jp

Abstract

This study conducted an out creep test for both unsaturated soil and saturated specimens using a microporous membrane, which has high hydro conductivity comparison to high air entry disc (i.e., ceramic disk). The membrane was installed in an unsaturated triaxial compression apparatus. In order to interpret the changing both suction and axial deformations through creep tests. The triaxial compression apparatus consisted of a double cell, and pore water and pore-air pressure transfers were installed. The pressure transfers and highly accurate sensitivity regulators contribute to controlling and measuring small suction ranges. Various dry densities were prepared at a constant water content, which have a subjection of investigate the influence on creep deformation properties was investigated. The developed unsaturated triaxial compression apparatus makes it possible to change from an unsaturated to saturated condition through seepage application. After saturated specimen, observing creep deformations compared with unsaturated specimens shows that it is significantly different. In addition, the applied suction was controlled to a saturated specimen at 20 kPa. As mentioned above, this study focuses on creep behaver for unsaturated specimens in which control of matric suction is presented as an advantage. Interpretation in this study is that effort of reminding unsaturated condition and matric suction are obviously through suction deletion, such as saturation.