Swell Behavior of Expansive Soil with Free Lateral Movements

Expansive soils are characterized by volume increase upon saturation. Extensive damages to structures may occur as a result of soil heave. Prediction of field expansion is essential prior to foundation construction. Experimental tests using oedometer equipment are used to predict field swell. However, in these tests, full lateral expansion is restrained which does not represent the actual field behavior where part of volume increase is consumed in the lateral direction. To improve the quality of field swell estimation, different testing techniques must be adopted. In this paper, experimental testing program is carried out on expansive soil with no lateral restraint. It is found that the lateral swell constitutes about one third of the total swell. More attention should be directed to such unconventional testing procedure to replace the oedometer tests for more accurate heave prediction. Keywords: Expansive soil, Swell pressure, Swell index, Lateral restrain