Field response characteristic test of expansive soil engineering behavior under effect of atmosphere

The swelling-shrinking deformation, deformation modulus and permeability of expansive soil are tracked and measured in Nanning, Guangxi considering the effect of atmosphere. The test results are just as follows. Firstly, a low rainfall may lead water content and swelling state to the limit value, and the influence depth of infiltration is finite while raining. Secondly, the deformation modulus is decreased with the increase of water content following the forms of power function. Finally, when the water content is low, the fissure is developed and the permeability is improved greatly; meanwhile, the permeability is also strengthened with the vegetation covered, which is useful to recognize the disastrous mechanism of expansive soil slope.