The effect of soil freezing and thawing behavior on slope stability

This paper deals with the effect of freezing and thawing of soil behavior on the progressive failures of slope along the A-Li-San highway in central Taiwan Subsurface investigations through in situ boring tests and soil sampling, clay mineralogy determinated by X-ray diffraction, soil mechanical properties variation measuring under different temperature of freezing and thawing processes in laboratory and slope stability analysis by using PC-STABL II program are critical and necessary for this study. The results of inclinometer monitoring show that the potential sliding zone should be 9 similar to 12m & 21 similar to 24m in depth on the downslope of highway. This was identified by conducting slope stability analysis and boring hole tests in the field. The factor of safety (F.S) drops from 1.12 to 0.83 when the soil strength parameters (Cg;dt) being used at different conditions of freezing and thawing effect tests. It was found that the slope being monitored at high altitute of 1800m in elevation should be in potential unstabilization. This was verified by the effect of soil freezing and thawing fluctuation during the seasonal change of warm spring and cold winter in the studied area.