2020 Volume 76 Issue 1 Pages 77-87
As has been reported since old times, a berm ditch installed in a cut slope in a snowy cold region is deformed due to frost heaving. The purpose of this research is to elucidate the rotating mechanism of the berm ditch by frost heaving. We constructed a 1/10 scale model of an actual berm to conduct an indoor model experiment for reproducing the frost heaving, thawing, and settlement behavior of a berm ditch. Meanwhile, we used a U-shaped ditch installed in the berm of a road slope in service and conducted onsite measurements of the temperatures and displacements of the ground around the ditch. The results show that the berm ditch moves up due to adfreeze and frost heave occurring in the extreme surface layer of the flat part of the berm and turns to the mountain side due to nonuniform frost heave occurring in the transverse direction. In addition, results of a simple water transmission test confirm that the water transmission performance of the berm ditch three years after the installation was significantly degraded by accumulation of sediment and fallen leaves, which had been promoted by the step of the joint caused by the rotation.
