Abstract:

Using the freeze-thaw cycle apparatus combined with electrical resistivity observation for whole process , repeated freeze-thaw tests in a closed system(i.e. no water supplied) are performed for the saturated silty clay in Beilu River with dry density of 1.62 g/cm3, in which the complete testing data for the deformation versus time curve, temperatures in different layers and the associated electrical resistivity-time curve are obtained. The experimental results indicate that the changes of resistivity, temperature and deformation during freeze-thaw cycles are real-time and synchronical, which also proves that it is feasible to study the change of soil structure during freezing and thawing by using electrical resistivity method. The resistivity of frozen soil decreases and that of thawed soil increases exponentially with increasing of freezing-thawing times. The amount of frost heave, thaw collapse and average dry density in every cycle rise with increasing of freezing-thawing times, and they trend to be stable after 5 freeze-thaw cycles.

Key words: repeated freeze-thaw cycles, electrical resistivity, frost heave, thaw collapse, temperature, freezing soil, thawing soil