Test Research On Frost Heave Of Soils Under Different Artificial Freezing Conditions

As following merits, more flexible adaptability to complicated hydro-geologic conditions, high-intensity, well water-resisting property, non-contamination to environment and so on, artificial ground freezing is more and more recognized in subterranean projects recent years. As for present technology, there is certain hazard, especially frost heave, so that the test study on soil is extremely significant, under different artificial ground freezing conditions.According to test requirement, author has develops the frost heave-thaw collapse apparatus, and adopted advanced type ST5405 high-low temperature freezing and thaw cycle test device, DT615 data taking system, displacement sensor, type T thermo-element etc, all of them are in good working order in this test. Through adjusting the temperature scheme of top plate, bottom plate and box body, moreover, with or without external water supply, this paper carries out test research on the frost-heave character of manipulated soil and undisturbed soil under different artificial freezing test engineering-conditions, then analyzing the test results with such factors as temperature field, temperature gradient, frozen front, frost-heave amount, rate of frost heave, water content and dry density (density).In terms of artificial freezing conditions and soil types of samples, the test consists of four units.23 samples in all are researched in the study process, gaining massive test data and developing law of frost heave.The major results indicate that the frost heave developing of samples frozen under constant temperature freezing model is fast than that under sine temperature freezing model; the changing of temperature field and temperature gradient is respectively synchronous with the temperature variation and lagged to half phase under sine temperature freezing model; there is moisture redistribution in all frozen samples. In the laterally artificial freeing test, the frost-heave amount of manipulated soil samples with water supply is lager than that without it. When external water isn't supplied, the frost-heave amount of manipulated soil samples with bottom-top freezing model is maximal, but the one with top - bottom freezing model minimal. The frost-heave amount of undisturbed soil...