Discussion on the frost susceptibility of sandy soil under hydraulic pressure: Fid-Bau Portal

Discussion on the frost susceptibility of sandy soil under hydraulic pressure

Hao, Xiaoyun / Ma, Wei / Feng, Wenjie / Wen, Zhi / Zhang, Lianhai / Gao, Yu

Abstract A non-frost susceptibility soil is generally not considered to generate significant frost heave. However, recent researches indicate that significant frost heave occurs in coarse fill in engineering, which implies that the frost susceptibility classification based on fine content and particle size may be not reliable. To investigate the frost susceptibility of sandy soil under hydraulic pressure, nine groups of 1-D freezing tests based on the orthogonal array are conducted considering the combination of hydraulic pressure, cooling temperature, fine content and dry density. The results indicate that considerable frost heave occurs in freezing sandy soil. A multivariate regression model is developed to predict the frost heave ratio and to assess the frost susceptibility of sandy soil. From the regression equation, the hydraulic pressure has the largest influence on frost heave ratio of sandy soil, followed by fine content, and the effect of cooling temperature and dry density on sandy soil frost heave can be ignored. In addition, it is found that the reliability of the current standards is poor when assessing the frost susceptibility of sandy soil. The invalidation for frost susceptibility classification is owing to the increased saturation and the increased driving force for water migration. It is proposed that the PWP at the base of freezing front can be used as an indicator for assessing the frost susceptibility of soil.

Highlights • A significant frost heave occurs in freezing sandy soil under hydraulic pressure. • A multivariate regression model is developed to predict the soil frost heave. • The reliability of standards for assessing frost susceptibility is discussed. • The method for assessing the frost susceptibility of sandy soil is presented.