Experimental study on frost heaving characteristics of silty clay in Qiqihar region

Heilongjiang Province is affected by cold winter negative temperature, which is easy to cause channel leakage, foundation subsidence, track irregularity and other problems, which increase the difficulty of engineering construction. In order to solve the practical problems, taking the silty clay in Qiqihar region as the research object, the artificial freezing test in the closed system was carried out, and the frost heave test data were measured and analyzed, to investigate the freezing process of soil and the change of the frost heaving ratio under different moisture contents, dry densities, cold end temperatures and freezing rates. The test results show that: under the conditions of high moisture content, high dry density, low cold end temperature, and low freezing rate, the phenomenon of soil frost heaving is more significant, and the frost heaving ratio has a good correlation with the four factors. The results of frost heave orthogonal analysis show that the influence of cold end temperature on frost heaving rate is the weakest, the influence of dry density is strong, and the effect of moisture content is the most severe. Using SPSS statistical analysis software, a multiple linear regression model of frost heave rate is established under the comprehensive influence of moisture content, dry density and cold end temperature. The model has the advantages of good fitting effect, high reliability, high accuracy, meeting the actual needs, simple operation, and can be used for the correlation calculation and prediction of silty clay.