Properties of compacted soil as a function of dry density and the degree of saturation

Abstract

The conventional fill compaction procedure controlling the dry density ρd and the water content w has several limitations due mainly to significant effects of compaction energy level CEL and soil type on the ρd vs. w relation of compacted soil despite great difficulty in the prediction of in-situ CEL and soil type. The optimum degree of saturation (Sr)opt defined as Sr where (ρd)max is obtained for a given CEL and the ρd/(ρd)max vs. Sr-(Sr)opt relation of compacted soil are independent of CEL and insensitive to soil type variation. The unsoaked and soaked strength and stiffness and the saturated coefficient of hydraulic conductivity k are controlled by ρd and "Sr during compaction" and can be represented by empirical equations with variables of ρd and compacted Sr, not including CEL. A new compaction control method achieving compacted Sr close to (Sr)opt and compacted ρd large enough for the soil properties required in design of a given soil structure, with pre-compaction control of water content, is proposed.