Measuring Pore Water Pressure Variation Inside Saturated Triaxial Specimens of Low-Plastic Composite Clay under Strain-Controlled Cyclic Loading

As a step forward in an ongoing investigation on behavior of composite clay, which is used as the core material of some large embankment dams all over the world, a series of experiments were conducted to explore the distribution of excess pore water pressure along saturated triaxial clay specimens during cyclic loading. As the predominant feature of the composite clay behavior is the increase in excess pore water pressure in both monotonic and cyclic loadings as a consequence of increase in inclusion content, this paper focuses on formation of such pressure distribution inside the specimens in cyclic loading, by utilizing a miniature inner pressure transducer inside triaxial specimens. Specimens of pure clay and mixed material containing 40% (volumetric) ceramic beads and 60% clay were tested. Under strain-controlled cycles of 1.5% single amplitude, the expected increase of excess pore water pressure was captured at both ends and also inside the sample, which is in agreement with previous findings in this regard.