Combined method limiting shrinkage-swelling behaviours of expansive soils in Huai'an, China

Controlling swelling and shrinkage deformation of the expansive soil is essential for the design of earth structures surrounding by expansive soils. The swelling and shrinkage deformation could induce severe damages (i.e., cracks and/or distortion) to infrastructures, for example, embankments, pavements, pipelines, etc. In this study, a series of laboratory tests and a field trial on the Huai'an expansive soils were conducted to investigate its shrinkage-swelling cycle characteristics. A technology of combining quicklime-stabilization and surcharge pressure was proposed to limit Shrinkage-Swelling deformation of the Huai'an expansive soil in a highway embankment project. The experimental and field test results show that (1) the swelling potential of the Huai'an expansive soil increased with an increase of number of drying-wetting cycles without surcharge pressure; (2) the swelling potential decreased with an increase of magnitude of surcharge pressure; (3) adding quicklime into the Huai'an expansive soil combining with surcharge pressure could reduce the swelling potential significantly; and (4) the shear strength of expansive soil samples decreased as the number of drying-wetting cycles increased. The measured settlement from the field test indicated that the proposed technique can reduce the swelling potential and control the heaving of the Huai'an expansive soil effectively.