Abstract:
The dispersive soil and expansive soil are widely distributed in Heilongjiang area which are sensitive with water. Those problematic soils can cause serious threat to canal engineering safety. Based on the analysis of physical and chemical properties and mineralogical composition, the expansibility, dispersivity and mechanical properties in Longtouqiao, Hamatong, Tangyuan irrigation canal were studied by swelling ratio tests, crumb tests, pinhole tests, double-hydrometer tests, pore water soluble cations tests, exchangeable sodium percentage tests and direct shear, and futher investigations on the treatment effect of expansibility and dispersivity with lime. The experimental analysis results indicate that, those soils have the expansive properties, and the Longtouqiao soils are the strongest among those soils. The Hamatong soil is the dispersive soil, but the others are not. The shear strength of the soil samples in the three irrigation areas is not high, the cohesions of soil samples in the Longtouqiao irrigation area are higher than others, which is between 13.62 and 49.60 kPa, and the internal friction angles are lower than others which is between 1° and 24.5°for high organic matter content from 12.3 to 15.3 g/kg. There were obvious modification effect with low lime, which could eliminate expansibility and dispersivity. This method could be used for the poor canal foundation treatment.