A seismic damage prediction method of reinforced concrete water tanks in a water supply system based on wallboard crack width was modified. When the tensile stress of bars on wallboard exceeded its yield stress, the crack-width-based seismic damage rating system was no longer applicable. By adjusting the unreasonable influencing factors in the model, an empirical statistical regression model is proposed. Based on the analysis of the Tangshan earthquake, Haicheng earthquake and Wenchuan earthquake damage example, the results of the evaluation of the seismic damage grade of the clean water tanks based on the empirical statistical regression model showed that the empirical statistical regression model solves the defect that the system based on the crack width would no longer be applicable when the tensile stress of the wallboard reinforcement exceeds its yield stress.
