Improving mechanism of expansive soil by weathered sand and
slope stability analysis
1.Civil and Architectural Institute, China Three Gorges University, Yichang, Hubei 443002, China; 2.Yichang Transport Bureau, Yichang, Hubei 443002, China; 3.Xiaoxita to Yaqueling FirstClass Highway Rebuilding Engineering Project, Yichang, Hubei 443002, China
Abstract： The improving mechanism of expansive soil by weathered sand was investigated through the indoor experiment. The physical and chemical reactions between weathered sand and expansive soil were revealed to discuss the relationship between weathered sand content and swelling shrinkage characteristics of expansive soil. Based on laboratory experiments, for the firstclass highway rebuilding engineering construction project from Yichang Xiaoxita to Yaqueling, the overall stability analysis of embankment with 10 m height was conducted by strip method. The results show that the safety coefficient of embankment with natural expansive soil is small, which can not meet the specification requirements. Compared with the embankment with undisturbed expansive soil, the slope stability coefficient of embankment with weathered sand improving expansive soil was significantly improved, which can meet the code requirements. With the increasing of sand mixing ratio, the safety coefficient of subgrade is increased first with later decrease. When the sand ratio reaches 20%, the maximum safety coefficient of improved expansive soil filling roadbed is achieved.
2014, Vol. 35 
