ABSTRACT
The paper describes various case studies of defects and failures of bridges located in Poland taking place over the past several years. Classification of the observed damage types is proposed and their relationships to structural type and material of a bridge are given. Those defects occurring most often as well as the types of structures especially prone to be damaged are indicated. For these two issues potential causes of the defects are discussed. Attention is paid to some specific features of the considered damage cases important for determination of a method for bridge robustness evaluation including: damage intensity variation, types of loads acting on the damaged structure and required to be still carried after the failure, potential ways of the internal force redistribution due to damage or possibility of generalization among different damage types. Some of the presented damage scenarios are selected for evaluation of the bridge structural robustness. A deterministic energy-based approach is applied in case studies of three bridge structures to measure its robustness in a strict way. An initial approach to development of a uniform procedure of bridge robustness evaluation is proposed. On the basis of the evaluation results some general conclusions are provided.
