Compressibility Influence Rule of Subgrade Soil in Cold Area Under the Condition of Freeze-Thaw Cycles

Through determination of the thawing settlement coefficient of remoulded soil specimens with different water contents and different freezing temperature under different number of freeze-thaw cycles, the paper tries to find the main factors and rules influencing the thawing settlement coefficient changes. Experiments found that the most adverse condition of frozen soil thawing settlement should be one cycle of freeze-thaw cycle from the third time to the sixth time. So it is unsafe to perform design according to thawing settlement coefficient obtained by one melting in the project, which would also bring some hidden troubles to the normal work of future subgrade. Based on indoor experimental data, the paper draws the relationship curve between relative compressibility and pressure, finds the influence rule of freeze-thaw cycle on the compressibility changes of thawed soil, and puts forward the concept of compression modulus loss, to measure the damage of soil compressibility by freeze-thaw cycles.