Results of Long-Term Infiltration Tests on Unsaturated Swelling Clay

Results of two long-term infiltration tests conducted in a triaxial cell are presented. Results of the testing are examined to assess mechanical and hydraulic behavior of an unsaturated swelling clay. In one test, radial flow is enforced with water pressure applied at the perimeter and drainage is allowed at the center of the specimen. In the second long-term test, vertical flow is applied with water pressure at the base and drainage is allowed out the top of the specimen. In both cases water flow into specimens and air flow at the downstream side is measured along with volume changes. Suction at the center of the specimen is measured in the vertical flow test using an embedded sensor. Water flow, volume change and suction responses are discussed to assess how flow and boundary conditions affect behavior. Differences in behavior during infiltration are noted due to anisotropy in the compacted specimens. Final distributions of water content, bulk density, dry density and degree of saturation are presented and discussed. Results show that these infiltration tests are important for understanding the physical movement of water through unsaturated swelling clay materials.