Changes in Pore-Water Pressure and Deformation of Saturated Frozen Soil with Rising Temperature and Constant Loading

Abstract

In frozen soil engineering, the foundations of structures are particularly susceptible to uneven settlement and cracking due to changes in external temperature and load, posing threats to the safety of structures and increasing maintenance costs. Pore-water pressure plays a critical role in the water-heat process of frozen soil induced by temperature gradient or loading. However, existing research primarily focuses on constant static and dynamic load studies under isothermal conditions, with limited research on pore-water pressure changes under incremental warming in frozen soil, failing to meet practical engineering needs. This study conducted a series of warming tests on frozen specimens made of quartz powder under constant loading. The variation behaviors of pore-water pressure at varying depths and the deformation of the samples were investigated. The results demonstrate that an incremental increase in soil temperature led to the stepwise developments of pore-water pressure and deformation amplitude, which corresponded to the increase in unfrozen water content. Load size is positively related to the pore-water pressure and deformation amplitude of frozen soils with consistent temperature and dry density. Furthermore, the pore-water pressure and deformation amplitude of the thawed quartz powder far exceed those of the frozen state. At the varying depths of the frozen specimen, the pore-water pressure exhibited a consistent variation pattern, thus providing a basis and reference point for the analysis of pore-water pressure variations at different depths in actual frozen soil engineering foundations.