Role of Matric Suction in Collapse of Compacted Clay Soil

This paper examines the influence of variations in matric suction on the collapse behavior of compacted Bangalore clay soil. The ASTM filter paper method measured the matric suctions of the compacted soil specimens. The matric suction of the compacted clay soil specimens ranged between 50 and 8,000 kPa at the as-compacted Sr values of 90 and 35%. Comparison of the matric suction-gravimetric water content relations of various compacted soils showed that the soil with a higher liquid limit has a higher matric suction at a given gravimetric water content. Variations in as-compacted degrees of saturation at a constant relative compaction or variations in relative compaction at a constant as-compacted degree of saturation notably affected the matric suction of the Bangalore clay soil. Experimental results also showed that the influence of matric suction on the collapse behavior of this compacted clay soil greatly depended on the relative compaction of the specimens and the pressure at which they were inundated.