Abstract
The new type roadbed using the slug materials is adopted in the tunnel under the Shirasu ground water level on Kyushu Shincansen under the construction. The water-resistant structure is generally selected under the high water pressure on Shirasu ground. But it is found that the water-resistant structure can not completely prevent against the mud-pumping by trainload because the resistant of water erosion on Shirasu ground is weak. The new type roadbed using the slug materials is designed in order to decrease the ground water pressure.
This paper describes the examination results of permeability and durability under cyclic load of the new type roadbed. The coefficient of roadbed permeability is the grade of 10-3cm/s in case of addition the 10% cement to the slag materials. The roadbed settlement is very small under the 2×106 times cyclic load.
