Durchlaufbrücken

Durchlaufbrücken, also known as continuous bridges, are a type of bridge superstructure that is continuous over two or more supports. Unlike simply supported bridges, which have separate deck structures for each span, a durchlaufbrücke's deck acts as a single, unified structural element across multiple spans. This continuity offers several advantages, including increased stiffness and the ability to distribute loads more effectively.

The structural behavior of a durchlaufbrücke is characterized by the development of both positive and negative moments within the deck. Positive moments occur over the spans, while negative moments develop over the piers or abutments. This distribution of moments can lead to a more economical design, as it reduces the maximum bending stresses compared to simply supported bridges of equivalent span lengths. The continuity also provides a higher degree of redundancy, meaning that the bridge can still carry loads even if one support is damaged.

Common types of durchlaufbrücken include beam bridges, slab bridges, and box girder bridges, constructed from materials such as steel, reinforced concrete, or prestressed concrete. The design and construction of durchlaufbrücken require careful consideration of factors like thermal expansion and contraction, as well as the effects of settlement of the supports. Despite these complexities, their efficient load-carrying capacity and improved structural integrity make them a popular choice for many bridge projects.