PURPOSE: To prevent freezing damage on superstructures by a method in which a solid lubricant is coated over a range slightly longer the thickness of an active layer or a seasonal frozen soil layer on the surface of a pile body being driven to the active layer or the seasonal frozen soil layer.
CONSTITUTION: Since the frictional coefficient between the surface of a lubricant 11 coated on the surface of a pile body 1 and soil or frozen soil is smaller than that with the surface of the pile body 1, even when the active layer 6 is heaved by freezing in the winter season, the frost heaving force to be applied to the pile 10 is reduced beyond that to be directly applied to the pile body 1 because of the generation of slippage. Since negative friction to be applied to the pile 10 in thawing and settlement of the active layer 6 in the summer season is likewise reduced, the pile 10 can be protected from frost damage and the superstructure can be protected.
NAKAGAWA SHIGERU
TAKEDA TAKASHI
OOMORI KATSUMI
OOKUMA TOSHIYUKI
