Experimental Study on Compressibility of Frozen Saturated Chinese Standard Sand

The compressibility of frozen soil must be taken into consideration when the deformation of highway and high-speed railway is strictly controlled in permafrost regions. In this study, the frozen saturated Chinese ISO standard sand was taken as the study object, and step load tests under different temperatures were carried out using a self-developed confined compression apparatus for frozen soils. Tests were conducted at the loads of 1, 2, 3, 5, 10 MPa and under temperatures of −0.5, −1.0, −2.0, −3.0, −5.0 °C. The coefficient of compressibility was obtained according to the e-σ_z curves for both unfrozen and frozen samples under different temperatures. The experimental results of temperatures ranging from room temperature to negative temperature were then obtained. The test results indicate that the compression curve of the frozen material are similar to that of the samples under room temperature; for warm frozen samples, the compressibility is considerable; the compressibility of frozen soil is closely related to temperature, i.e., the coefficient of compressibility increases with the increase of temperature in a form of exponential function.