Experimental investigation of matric suction in compacted fine-grained soils

ABSTRACT

This paper presents the results of laboratory tests performed to study the effect of compaction properties on the development of matric suction in four different soils (three soils were classified as silty clay and one was classified as silty sand). The soils were compacted at the optimum water content (OWC) and wet and dry of optimum according to the standard Proctor procedure (ASTM D698-12). For each sample, matric suction measurements were made using the filter paper technique. When the silty clay soils were compacted at a water content less than the OWC, a significant increase in matric suction was observed. For all the soils tested, matric suction values were very low when the compaction water contents were greater than the OWC. Plots of matric suction vs. compaction water content [ranging from (OWC-2%) to OWC] were developed for the compacted silty clays. The test results indicate that there is a direct relationship between the compaction properties (i.e. compacted dry unit weight and water content) and the matric suction values retained in compacted silty clays. Preliminary relationships were proposed between the matric suction of compacted silty clays and water content based on the data collected in this paper.

KEYWORDS:

• Compacted silty clays
• matric suction measurement
• filter paper technique
• standard Proctor test
• compaction plane