Experimental Investigation of Sand Subjected to High Stress Levels in Wet and Dry Conditions.

This work aimed to understand the mechanical behavior of siliceous and calcareous sand materials under uniaxial confined compression loading at high stress levels. For this purpose, a series of quasi-oedometric compression tests were conducted on sand materials, to examine the effects of grain size, nature, and moisture contents on the soil crushability and the compression behavior, using an upgraded thick pressure vessel device that can reach mean stress up to 500 MPa. All samples were prepared using an aspect ratio of 1:1 (diameter: height), placed inside a high strength steel vessel, and compressed at a uniform axial displacement rate of 5 µm/s.

A peek into the origin of creep in sand.

This paper presents the results of an experimental study of the particle scale mechanisms that underpin creep, on-going deformations under constant external load, in dry non-cemented sand under 1D oedometric compression loading at 2500 kPa. Traditional observations on the boundary of the sample are complemented with simultaneous measurements of the 3D kinematics of both the entire grain assembly and details of grain-scale mechanisms using synchrotron based X-ray tomography at two different spatial resolutions. Both the continuum response and the local grain scale response are captured using two spatial resolutions, i.