Undrained Stress-Strain Behavior of Unsaturated Sands. Volume 1.
Pagination or Media Count:
This final report provides the details of an investigation on the undrained stress strain behavior of partly saturated sands under controlled laboratory conditions. A new triaxial test setup was developed during the previous years of this research study. Thus, the two purposes of the investigation reported in this report were a to evaluate the usefulness of the new soil test procedure, and b to determine the behavior of the unsaturated sand samples. An axis translation technique was used to monitor pore water pressure changes during the tests and this appeared to work well. A special ceramic porous stone was used to be able to measure pore water and air pressures separately. The conclusions drawn from this research are that the stress-strain behavior changes little with respect to saturation level until the level approaches about 95. The initial tangent modulus decreased with an increase in saturation. For lower saturated samples, there seems to be no difference between an undrained and a drained test. The dilation potential of the sand increased with strain rate. The strain rate had some effect on the initial modulus of only the dense samples of sand.
- Soil Mechanics