Structural Assessment of an Existing Concrete Box-Girder Bridge, According to the German and the Dutch Standards

In Western Europe the majority of the road bridges are built in the post-war building period up to the eighties. Most of these bridges are made of concrete and many are prestressed. Over the years the traffic has increased tremendously, with more and heavier vehicles. In the design of the bridges this increase in traffic wasn't anticipated on by a trend factor. Besides the knowledge of structural engineering has evolved, which has resulted in more reliable design and verification rules. Based on this the actual structural safety of most existing bridges isn't known. Therefore there is a need to perform structural assessments of existing road bridges. To do so countries such as the Netherlands (RWS 2013; NNI 2011) and Germany (BMVI 2011) have drawn up own standards, complementary to the Eurocode for existing structures. These standards determine how existing structures can be recalculated. To make clear the similarities and differences between the standards, Royal HaskoningDHV performed a pilot project in which a post-tensioned box-girder bridge in Germany is structural assessed. In this assessment both the German and Dutch standards for existing structures where taking into account. In this paper the similarities and striking differences between the German and Dutch regulations are presented and discussed.