On Wear Thickness of Rust Layers of Steel Structure due to Ice Impact Load

Abstract

Abstract Rust layers on the surface of corroded steel are removed due to sea ice action in ice-infested sea, subsequently leading to increased wear due to further corrosion. Damage to coastal structures and training levees comprising steel sheet pile seawalls on the Sea of Okhotsk occurred sooner than expected, since large wear rates had not been considered in their design. This paper investigates the degradation mechanism of steel structures through indoor tests focusing on sea ice impact. The effect of wear thickness is examined based on parameters such as sea ice temperature, sea ice impulse, sea ice momentum, ice impact load, sand inclusion in sea ice, angle of ice impact load, and real contact area of ice impact load. It is shown that wear thickness can be estimated from maximum ice impact pressure on the real contact area between sea ice and rust layer. This implies that the uni-axial compressive strength of sea ice, which relates to maximum ice impact pressure, plays an important role in the estimation of wear thickness. These results also lead to the estimation of thickness of sacrificial (additional) steel walls in addition to the original steel structure as a countermeasure against wear.