A parametric numerical study of factors influencing the thermal icepressure along a dam

The uncertainty regarding size and variation of the ice pressure constitute one of the mainsignificant sources of concern for condition assessment of concrete dams in cold regions. Inmost current dam safety guidelines, the design ice load is determined solely from thegeographic location of the dam. However, factors such as variation in temperature and waterlevel, the slope of the banks, wind etc. may also influence the size of the load. Previousmeasurements indicate that the pressure on a dam varies along the dam line during the sametime and that the average ice pressure decreases as the area of the ice-structure interface isincreased. This paper presents numerical studies on how the ice pressure varies along the damwall. A finite element model that includes several dam monoliths, the ice and the beaches ofthe reservoirs are used to simulate thermal ice loads. The pure elastic load caused by therestrained expansion of an ice sheet subjected to a change in thermal gradient are greater thanthe design ice load in current dam safety guidelines and the loads measured. The simulationsshow that the ice load vary significantly along the dam, and the variation in cross-sectionstiffness along the dam greatly influence the magnitude of the total ice pressure. Theparameter study shows that the elastic thermal ice load increases with an increased slope ofthe banks, reservoir length, and ice thickness and decreases as the angle of the connectionbetween the dam and bank increases. However, the difference in ice load between theindividual monoliths with the same geometry and temperature change are in several cases ofthe same magnitude as the variation in the external factors.QC 20210907