Effect of drought and partial seepage on stability of expansive soil canal embankments
To investigate the influence of surface air drying,groundwater level rising and side slope seepage on the expansive soil embankment,and prevent the on-site disasters caused by them,a laboratory model test was conducted to study the influence of fluctuations in water content of the expansive soil on the deformation and crack development of the embankment of the South-to-North Water Diversion Project.The relationships between slope deformation,crack length,crack width and water content,time and seepage location were analyzed.The disaster-causing process and spatio-temporal development law of water content fluctu-ation of expansive soil were revealed.The test results showed that:① Evaporation causes the first V-shaped cluster of vertical longitudinal cracks on the slope surface at a depth of 200 mm,and then the cracks gradually develop horizontally with a maximum settlement value of 4 mm,while reach stability after 15 days.② Elevation of the water level at the foundation in the rainy season cause significant expansion of the expansive soil at the bottom,and the embankment is elevated by 3.32 mm.③The water content of the soil near the seepage center on latera canal slope increases by more than8%.Free water in the embankment spread uneven-ly along the vertical and horizontal direction,causing the uneven expansion and deformation of the soil in all directions.And a wide crack of 400 mm in length and 14 mm in width was generated.④The calculation formula of foundation deformation based on the expansion coefficient can better predict the deformation at each location after the canal embankment submerged in water.It helps to discern the deformation state at each point based on the moisture content of the soil and provides a reference for the anal-ysis of embankment stability.
expansive soil canal embankmentmodel testwater contentdeformation of canal slopecrack developmentSouth-to-North Water Diversion Project
国家科技期刊平台
NSTL
万方数据
维普
