Effects of Moisture and Compactness on Uniaxial Dynamic Compression of Sandy Soil under High Strain Rates

Abstract

The interaction of moisture content, strain rate, and dry density affects the dynamic mechanical properties of sandy soils with certain cohesion at high strain rates but this effect is rarely quantified. According to the dimensionless uniaxial compressive strength relationship obtained by similarity analysis, the common engineering parameter ‘compaction degree’ is used as a substitute for dry density. The effects of moisture content and compaction degree on the high strain-rate (600 s−1 to 2100 s−1) mechanical properties of sandy soil were characterized by a series of split-Hopkinson pressure bar (SHPB) tests. The results show that the uniaxial compressive strength of sandy soil can always be enhanced by increasing the compaction degree while the reduction of its moisture content usually weakens it. The compressive response of sandy soil is also sensitive to strain rate at the same time. Based on the experimental data, an empirical model is established, which shows the relationship between the dimensionless uniaxial compressive strength and the strain rate, moisture content, and compaction degree of sandy soil.