Abstract
In the previous report, based on the results of corrosion survey of steel sheet pile structures, corrosion tendencies of steel sheet piles have been divided into three types, (a), (b) and (c), according to the condition of corrosion under H. W. L. But due to the further corrosion surveys, it has been proved that there are other two types of corrosion tendencies of steel sheet pile structures. Namely, the tendency in which corrosion concentrates only at concave surface of steel sheet piles directly under residual water level is called corrosion tendency (d), while another tendency in which concentrated corrosion occures both at convex and concave surfaces of steel sheet piles directly under L. W. L. is called corrosion tendency (e). Corrosion rates (both sides) at the portion in which corrosion concentrated were 0.5 to 1.0mm/yr.
On the other hand, investigating the relations between corrosion tendencies and conditions of steel sheet pile structures based on the corrosion survey results of 83 examples, it is supposed that corrosion tendencies of steel sheet piles are affected by water depth, tide level difference, presence of fresh water, kind of backfill, shape of cross section of steel sheet piles, residual water level difference, and so on. Damage caused by concentrated corrosion are flow-out of backfill and settling or subsidence of superstructures of steel sheet pile structures.
