Exploring the Water and Temperature Regimes’ Mechanical Characteristics of a Plain Concrete Pile Composite Foundation under Freeze–Thaw Cycles: A Model Testing Study

Abstract

In this paper, through extensive on-site research of the plain concrete composite foundation for the Jiuma Expressway, the study conducted proportional scaling tests. This study focused on the temperature, moisture, pile–soil stress, and deformation of this foundation under freeze–thaw conditions. The findings indicate that the temperature of the plain concrete pile composite foundation fluctuates sinusoidally with atmospheric temperature changes. As the depth increases, both temperature and lag time increase, while the fluctuation range decreases. Furthermore, the effect of atmospheric temperature on the shoulder and slope foot is more significant than on the interior of the road. During the freeze–thaw cycle, the water content and pore-water pressure in the foundation fluctuate periodically. The pile–soil stress fluctuates periodically with the freeze–thaw cycle, with the shoulder position exhibiting the most significant changes. Finally, the road section displays pronounced freeze–thaw deformations at the side ditch and slope toe. This study provides a valuable basis for the construction of highway projects in cold regions.