The mechanical behavior and mechanism of the interface between structure and coarse grained soil with slurry were investigated through conducting monotonic and cyclic tests of both interfaces with and without slurry. The interface with slurry between structure and coarse grained soil can be thought as the one between structure and slurry if the slurry is thick enough. Whereas

the behavior of the interface with slurry would be similar to that of the interface between structure and coarse grained soil if the slurry is not thick enough

which is only affected quantitatively by the slurry. For example

the shear strength would be reduced and the compression would be increased if the slurry becomes thicker. The behavior and thickness of slurry as well as the behavior of structure material and soil are main factors to the behavior of the interface between structure and coarse grained soil with slurry.