Abstract: According to the failure mode of expansive soil slope induced by expansion effect and the monitoring result of on-site simulation test, we summarize the techniques of expansive soil slope treatment. Furthermore, we compare and analyse the effectiveness of four treatment measures (cement soil modification, geogrid reinforcement, geomembrane, and geotextile bags filling) by evaluating the slope deformation and the variation of moisture content. Results reveal that cement soil (replacement of non-expansive clayey soil) has the best performance, whereas geogrid reinforcement is featured with complex techniques, and the compaction degree of geotextile bags filling is hard to control. Finally, we put forward the principles of expansive soil slope treatment.

Key words: South-to-North Water Transfer Project, expansive soil, construction technique, slope, deformation, water content, effectiveness assessment