An investigation on effect of inclusions on heterogeneity of stress,excess pore pressure and strain distribution in composite soils

A series of tests and also numerical analyses were conducted to explore the mechanical behavior of a mixture of coarse gravelsize particles floating in a matrix of silt, sand or clay. The research is 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. After providing the reader with an overall image about behavior of such materials through the literature, the paper focuses on a predominant feature of the composite soil behavior: increase of non-deformable solid inclusions in a mixture leads to formation of heterogeneity of stress field, excess pore water pressure and strain distribution along the specimens. This paper mainly probes formation of such heterogeneity by the aid of special experiments and also numerical analyses. In addition to loading details, it is clarified through the paper that position of inclusions relative to loading direction also affects heterogeneity of stress/strain and excess pore water pressure distribution through the mixture. Despite the former, the latter redistributes with a rate proportional to material hydraulic conductivity.