  A new experimental set-up using a differential pressure transducer was
developed, that enables the monitoring of volume changes in cyclic triaxial
tests on unsaturated soils. Calibration tests were performed in order to
analyze the performance of the set-up, especially in terms of loading
frequencies. Based on calibration results, a low frequency of 0.05 Hz was
adopted for the tests carried out on the unsaturated loess from northern
France. Five water contents were considered in the tests. The obtained results
have confirmed the efficiency of the new system for volume change monitoring
under cyclic loading. The effect of water content on the cyclic behavior of
loess was clearly evidenced. Finally, some suggestions were made to improve the
accuracy of the system.
