DETERMINATION OF THE MATRIX SUCTION OF LOW-PLASTICITY SILTS AND ITS CORRELATION WITH THEIR COLLAPSE POTENTIAL

Abstract

Soils are usually in a partially saturated state, meaning that both air and water occupy their voids. This condition can affect the stability of structures because it is closely related to wetting deformation (collapse). A low-plasticity silt (ML) composed of 45% kaolin with a liquid limit of 36% and a plasticity index of 10% was used in this study. In this study, the soil suction matrix was determined using the filter paper method established in ASTM D5298, correlating it with the moisture content and percentage of deformation induced by wetting. It was concluded that, as the moisture content decreases, the suction and the percentage of deformation by wetting increase, since, for a moisture content of 9% the suction is 14901.6 kPa and the deformation is 0.58%, while for a moisture content of 21% the suction is 1028.1 kPa and the deformation is 0.07%. Thus, a change in the slope of the SWRC was evident starting at 9%, which indicates a greater effect of suction and deformation below this moisture content.