抄録
In order to use scallop shells of a fishery by-product effectively for the back-fill material of a quay, we are investigating the internal friction angle of the sand which mixed the crashed scallop shells by consolidated-drained tri-axial compression test. In our first report, we checked that the sand which mixed the crashed scallop shells is applicable to back-fill material to some extent. This time we investigated the internal friction angle of the mixture sand which changed kind of both scallop shells and sands. As a result, when the maximum grain size of crashed shell is 5-10mm and the rate of shell mixture is about 25%, the internal friction angle of the sand which mixed the crashed scallop shells is degree the same as sand, and it is thought that we can use the sand which mixed the crashed scallop shells for the back-fill material, although some scallop shells are crushed.