Quasi-static and high-strain-rate experiments on sand under one-dimensional compression

This paper investigates the effect of strain rate on the behaviour of dry and partially - saturated sand at very high stresses, seekin g to clarify the existence of a strain - rat e dependence and how this is affected by changes in moisture content. Dynamic one - dim ensional compression tests on a fine quartz sand have been carried out to axial stresses of 4 00 MPa using a split Hopkinson pressure bar, alongside quasi - static tests to 8 00 MPa using the mac 2T multi - axial test rig at The University of Sheffiel d . Specimens were prepared at moisture contents of 0.0%, 2.5% and 5.0%, and were laterally confined using a steel ring or steel loading box to ensure one - dimensional test conditions. Lateral stresses were recorded to allow the three-dimensional stress state of the specimens to be analysed. The results show that knowledge of both the axial and radial stresses is important for understanding the response of sand at higher strain rates, where an increase in stiffness is observed axially when compared to the quasi-static results.