Abstract: A triaxial cell apparatus for conducting constant lateral stress tests, constant volume tests and zero lateral strain tests on particulate materials. Pressure and volume measuring devices are in communication with a flexible inner specimen cylinder and with a rigid outer cylinder mounted on the apparatus frame. A control panel permits the compressed air confining stress to be regulated as axial stress is applied through a piston assembly having the same cross-sectional area as the specimen cylinder. The different tests are conducted by various combinations and hookups between the pressure and volume measuring devices and the control panel. The tests can be performed on a specimen so that the stress history of that material may be determined for later use in confining structure design.

Abstract: An apparatus for testing soils by measuring the rate of moisture loss from soil or sediment samples is disclosed, comprising a test chamber, a fan, a heater-thermostat, a chilled water humidity control device, an automatic balance scale connected to a continuous chart recorder, a shield around the balance pan, and a magnetic damper for the balance pan. The heater-thermostat maintains a constant temperature within the chamber, while the chilled water humidity control device maintains a constant relative humidity. The fan circulates air in the chamber, and the magnetic damper and shield around the balance pan allows the soil sample to be weighed without air currents causing the balance pan to vibrate. The balance scale continually weighs the sample, with the weight being recorded on the chart recorder, thus providing a record of the rate of moisture loss. A bell jar allows the testing to be done under vacuum conditions.The method of this invention comprises the steps of:1.