Abstract: The numerical simulations for the Truckee-I80/Truckee River Bridge Structure, California in USA, were conducted in different damage scenarios in platform of OpenSees. In this study, the damage status of the model was evaluated by using the improved direct stiffness method with consideration of single and multiple damaged locations under measurement errors or not, push-over analysis, and seismic damage evaluation. The results show that the improved direct stiffness method is valid and efficient for damage detection in bending-type bridge structures.