Ultimate Deflection Capacity of Lightly Reinforced Concrete Intake Towers

The authors are to be congratulated on their experimental research performed to assess the seismic performance of lightly reinforced intake towers. These concrete structures are unique in that they have extremely low reinforcement ratios. The authors indicate that displacement ductility results for the ITS-2 and ITS-3 models are counterintuitive to that expected because the more heavily reinforced ITS-3 exhibited lower displacement ductility than did ITS-2. No discussion, however, was provided with respect to the important influence stress-strain properties of the different reinforcing steels used may have on displacement ductility capacity. Although the displacement ductility for ITS-2 may be greater than that for ITS-3, it should be recognized that, under similar earthquake ground motion conditions, ITS-3 would perform better.