research details

Application of Hollow Sections in bridge structures


FOSTA project P816: Optimal application of hollow sections and cast steel nodes in bridge building with the usage of steel S355 up to S690

In this research project, the positive findings in terms of design and design advantages from the FOSTA project P591 "Economic construction of road and railway bridges made of hollow steel sections" were continued and expanded.

The P816 project carried out extensive research on the economic use of hollow sections in bridge construction. The focus is on the investigation and optimization of fatigue-stressed truss joints and connections with bridge-specific dimensions. These investigations were carried out on welded joints as well as on joints made of cast steel and their connections.

A repair concept was developed and further fatigue tests involving samples from S690 were carried out in order to broaden the statistical evidence base. Thus, new notch classes according to Eurocode 3 for repair welded details and higher strength steels could be proposed.

At the same time, economic considerations and recommendations were developed. In particular, the influence of engineering-architectural aspects on the efficiency of bridges made of hollow steel sections was investigated.

All this contributes to the promotion of lightweight and aesthetic composite bridges with trussed circular steel hollow sections (S355 to S690).

The project was funded by the Forschungsvereinigung Stahlanwendung e.V. (FOSTA) and by the Research Institute for Steel, Timber and Masonry of the Karlsruhe Institute of Technology (KIT), KoRoH GmbH, the office for engineering architecture Dipl.-Ing. Richard J. Dietrich and ICOM Steel Structures École Polytechnique Féderale de Lausanne (EPFL)

Competence Center

Thanks to the many years of experience of our employees and the active participation in standardization and international committees, we have been able to build up solid and extensive competences in hollow profile applications.


Engineering services

Our services include verification of stability, fatigue design, dimensioning and optimization of steel structures including offshore constructions. We carry out investigations to clarify damages and residual life and prepare damage analyzes and expert opinions.



Konzept, Layout und Programmierung von