동결 및 동결-융해작용을 받는 점성토의 강도와 그의 변형거동

Experimental Studies of Characteristics of Strength and Deformation Behaviour of Frozen and Cyclic Frozen-thawed Clayey Soils

Some experiments were carried out to investigate the effects of freezing and thawing on the strength and strain characteristics of alluvial silty clay under the different temperatures, loading and moisture conditions. The results were as follows; 1. The soil used was proved to be consisted of silty clay with honey-combed structure, and showed higher dilatancy, frost activity and lower stability in natural state. 2. Soil treated with freezing and thawing cycles showed lower compressive strength compared with the non treated, The strength decreased with incement of freezing and thawing cycles. It's shapes of stress-strain curves were flat and did not formulate a peak while the peak strength of higher moisture content soil decreased with the increment of moisture content. It's decrement ratio was most distinctly shown at the first one cycle of freezing and thawing. 3. The cohesion decreased due to freezing and thawing cycles but internal frcition angle was not changed. 4. The liquid limit decreased with increment of freezing and thawing cycles, and became almost constant after three cycles of freezing and thawing. 5. The strength under simple loading at failure mode was appeared to be higher compared with the cyclic loading after freezing and thawing but initial moisture content effect was not observed. 6. Ice lense was not observed within 50% of ice content ratio but observed over 100%. The higher the ice content ratio, the higher the peak strength. As a matter of fact, it seems that an optimum ice content ratio exists for plastic mode and the least compressive strength.