en Seismic Geotechnique Seismic Geotechnique Research Paper Research Paper <p>A series of tests and also numerical analyses were conducted to explore the mechanical behavior of a mixture of coarse gravelsize<br> particles floating in a matrix of silt, sand or clay. The research is a step forward in an ongoing investigation on behavior of<br> composite clay, which is used as the core material of some large embankment dams all over the world. After providing the reader<br> with an overall image about behavior of such materials through the literature, the paper focuses on a predominant feature of the<br> composite soil behavior: increase of non-deformable solid inclusions in a mixture leads to formation of heterogeneity of stress<br> field, excess pore water pressure and strain distribution along the specimens. This paper mainly probes formation of such<br> heterogeneity by the aid of special experiments and also numerical analyses. In addition to loading details, it is clarified through<br> the paper that position of inclusions relative to loading direction also affects heterogeneity of stress/strain and excess pore water<br> pressure distribution through the mixture. Despite the former, the latter redistributes with a rate proportional to material<br> hydraulic conductivity.</p> Composite soil, Mixed material, Heterogeneity, Torsional hollow cylinder, Cyclic triaxial, Finite element analysis 124 138 http://ijce.iust.ac.ir/browse.php?a_code=A-10-318-2&slc_lang=en&sid=1 J. Jalili j.jalili@iiees.ac.ir 180031947532846009677 180031947532846009677 Yes Ph.D. candidate, Geotechnical research center, International Institute of Earthquake Engineering and Seismology M. K. Jafari jafari@iiees.ac.ir 180031947532846009678 180031947532846009678 No Professor, Geotechnical research center, International Institute of Earthquake Engineering and Seismology A. Shafiee ali_shafiee_iiees@yahoo.com 180031947532846009679 180031947532846009679 No Assisstant professor, Geotechnical research center, International Institute of Earthquake Engineering and Seismology J. Koseki koseki@iis.u-tokyo.ac.jp 180031947532846009680 180031947532846009680 No Professor, Geotechnical Engineering Laboratory, Institute of Industrial Science, The University of Tokyo T. Sato tsato@iis.u-tokyo.ac.jp 180031947532846009681 180031947532846009681 No Private sector collaborative researcher, , Geotechnical Engineering Laboratory, Institute of Industrial Science, The University of Tokyo