Analysis of structural effects due to ice formation inside hollow steel foundations

Abstract

This master thesis is written on behalf of Statnett SF, which is the system operator of the Norwegian power system. Statnett has developed a new type of foundation which requires less time to assemble and is more convenient to transport than a typical concrete foundation. The foundation consists of a tubular section mounted on top of a steel pad. In soils with high water content, water fills the tubular section and freezes inside when the temperature drops below 0 (°C). The thesis investigates if the water that freezes inside the tubular section of the foundation has a damaging effect. The theory of heat transfer, the behavior and the properties of ice were studied. Based on the theory, a set of analyses and calculations were conducted. The analysis revealed the amount of water that can freeze inside the tubular section and the strength capacity of the section. The conclusion based on the research and the analysis results indicates that the force exerted by ice is within the strength capacity of the foundation.