Experimental study on the effect of boundary hydraulic pressure on frost heaving of soil [补水压力对土体冻胀的影响]

作者：Hao X.; Feng W.; Ma W.^*; Wen Z.; Zhang L.; Wang Y.; Shen M.; Huang Y.

来源：Journal of Glaciology and Geocryology, 2022, 44(2): 708-716.

DOI：10.7522/j.issn.1000-0240.2022.0070

• boundary hydraulic pressure
• cold-end temperature
• frost heave
• frost heave susceptibility
• soil group
• water migration

In order to study the influence of cold-end temperature, soil group and boundary hydraulic pressure on soil frost heave and the applicability of the current methods on assessing frost heave susceptibility of soils. Three factors and three levels of orthogonal experiments are carried out. The sequence of influencing frost heave ratio of soils is obtained by using the gray correlation method. The results show that the correlation among boundary hydraulic pressure, cold-end temperature and frost heave ratio is relatively larger, and the correlation between soil group and frost heave ratio is relatively smaller. Therefore, the factors affecting the frost heave ratio of soil from strong to weak are boundary hydraulic pressure, cold-end temperature and soil group. The ice lenses are formed in sandy soil samples during freezing under boundary hydraulic pressure, and the frost heave ratio of some sandy soil samples were larger than that of silty clay samples. Therefore, it can be concluded that it is not reasonable to assess the frost heave sensitivity of soil under the condition of boundary hydraulic pressure by fine particle content, and the frost heave susceptibility of soils should be assessed according to the actual situation. It is generally believed that the influence of soil group on frost heaving is strong, while it is found that the effect of soil on frost heaving is the weakest under boundary pressure. The relationship among frost heave susceptibility, thaw weakening susceptibility and frost susceptibility were discussed. It is found that although the sandy soil can frost heave under boundary hydraulic pressure, it can rapidly discharge water during thawing, which can reduce the frost damage caused by soil thawing. Therefore, coarse-grained soil should be replaced with fine-grained soil when treating the frost damage. In order to ensure the safe operation of engineering structures in cold regions under boundary hydraulic pressure, it is proposed that the effect of boundary hydraulic pressure on soil should be solved firstly. Moreover, constructing drains to drain water and employing replacement method.

• 单位
  中国科学院大学; 冻土工程国家重点实验室