Warm frozen soil is widespread in foundations during warm and cold seasons. Due to its low shear strength and high compressibility, warm frozen soil severely endangers the stability of construction projects. 

Therefore, scientists tried to find an effective method to stabilize the warm frozen soil. However, current research tested solidified soils at around 20℃, so experimental results cannot be directly applied to warm frozen soil in permafrost regions. 

Recently, a research group from Northwest Institute of Eco-Environment and Resources (NIEER) of the Chinese Academy of Sciences conducted laboratory experiments to investigate the changes of physical and mechanical properties of treated and untreated warm frozen soil. 

To improve the mechanical strength of warm frozen soil, the ionic polymer soil stabilizers (IPSS) were adopted for reinforcing the warm frozen soil from the Beiluhe region of the Qinghai-Tibetan Plateau. 

To evaluated the effects of IPSS on warm frozen soil and analyze the mechanisms of actions, scientists measured the physical, chemical and mechanical properties of warm frozen soil, both untreated and following treatment with IPSS. 

The research shows that the soil treated with IPSS or additives effectively improves the mechanical strength of soil and causes changes in its physical properties. 

The addition of IPSS to the soil resulted in a significant decrease in the plasticity index, freezing temperature, and cation-exchange capacity of soil. 

However, IPSS improved the shear strength and reduced the compressibility of warm frozen soil, but could not maintain the mechanical properties of warm frozen soil after thawing. 

The study entitled “Effectiveness of Ionic Polymer Soil Stabilizers on Warm Frozen Soil” was published in KSCE Journal of Civil Engineering.