Seasonal Permafrost Zone Silty Clay Frost Heave Test

This paper focused on soil frost heaving of seasonally frozen soil region and chose typical silty clay with frost heaving in Harbin as the research object to study the frost heaving response characteristics of the soil under the condition of three factors that include different freezing temperature, moisture content and dry density in closed system. This paper made a detailed analysis on frost heaving of the silty clay the influence of three factors, which can provide the reference for controlling freezing disaster in engineering.Main research achievements include:(1) The test simulated frost heaving process of the remoulded soil by freeze-thaw test instrument, temperature and displacement sensor, data acquisition system, then acquired the changes of the test index include that temperature, temperature gradient, freezing rate, frost heaving amount, frost heave ratio and frost heaving rate.(2) It analyzed the soil's frost heaving under the different influencing factors by the method of single factor experiment, and acquired changes of frost heaving with in the scope of threshold under the influence of different freezing temperature, moisture content and dry density. It acquired the biggest combination of the frost heaving in test range by analyzing the results of the orthogonal experiment, and also compared the size of contribution degree of the frost heaving based on these three factors.(3) It made the multivariate linear regression analysis based on the least-square principle by comprehensive test data, and established the frost heave prediction statistical model that took the freezing temperature, moisture content and dry density in consideration. It acquired good fit between model's calculated value and experimental value.