Author(s): Rikard Hellgren; Richard Malm
Linked Author(s):
Keywords:
Abstract: The uncertainty regarding size and variation of the ice pressure constitute one of the main significant sources of concern for condition assessment of concrete dams in cold regions. In most current dam safety guidelines, the design ice load is determined solely from the geographic location of the dam. However, factors such as variation in temperature and water level, the slope of the banks, wind etc. may also influence the size of the load. Previous measurements indicate that the pressure on a dam varies along the dam line during the same time and that the average ice pressure decreases as the area of the ice-structure interface is increased. This paper presents numerical studies on how the ice pressure varies along the dam wall. A finite element model that includes several dam monoliths, the ice and the beaches of the reservoirs are used to simulate thermal ice loads. The pure elastic load caused by the restrained expansion of an ice sheet subjected to a change in thermal gradient are greater than the design ice load in current dam safety guidelines and the loads measured. The simulations show that the ice load vary significantly along the dam, and the variation in cross-section stiffness along the dam greatly influence the magnitude of the total ice pressure. The parameter study shows that the elastic thermal ice load increases with an increased slope of the banks, reservoir length, and ice thickness and decreases as the angle of the connection between the dam and bank increases. However, the difference in ice load between the individual monoliths with the same geometry and temperature change are in several cases of the same magnitude as the variation in the external factors.
Year: 2020