ABSTRACT

The use of circular hollow section members in bridge design is a relatively new concept. The application of such constructions is strongly influenced by the design and manufacturing of the joints. In general, there are two possibilities: either to use cast steel joints or welded joints.

This contribution tries to give an overview about the advantages and disadvantages of both possibilities concerning the aspects of resistance, fatigue, manufacturing and economy in order to help practical engineers in their decisions and to allow for a further application of circular hollow sections in bridge design.

As a crucial question, special considerations are given to the fatigue assessment of welded circular hollow section joints. For an example of a recently completed bridge with a typical spatial CHS truss and cast steel joints it has been shown that also welded connections would have been a possible alternative. This conclusion is drawn from numerical studies based on FE calculations applying the hot-spot stress approach for the fatigue assessment of the welded joints.