DEVELOPMENT OF A NEW DUMPING SYSTEM FOR STEEL SLAG-DREDGED SOIL MIXTURE

Abstract

 Steel slag-dredged soil mixture is widely used as a construction material for tidal flats and shallow areas, as a reclamation material, and as a refilling material for subaqueous borrow pits.

 Grabs are often used when dumping steel slag-dredged soil mixture into the sea. However, in construction using a calcia drop-mixing vessel, it is considered efficient to use a tremie pipe, which can reduce the transportation and dumping of calcia-improved soil, into the sea. On the other hand, when steel slag-dredged soil mixture is dumped into the sea using a tremie pipe, turbidity may occur and the tremie pipe may be clogged.

 Therefore, we developed an underwater dumping system for steel slag-dredged soil mixture, which consists of a tremie pipe with slits on the side and a hopper with a V-shaped drop part for the steel slag-dredged soil mixture. Through experiments, it was confirmed that the newly developed tremie pipe can reduce turbidity and increase strength by dropping and mixing the steel slag-dredged soil mixture. The maximum turbidity of the tremie pipe with slits was reduced to about 40%, and the amount of turbidity generated was reduced to about 10% compared to the normal tremie pipe.