Guido Bolle

Load Testing of Concrete Structures in Germany – General Practice and Recent Developments

In 2000 the Deutscher Ausschuss fur Stahlbeton (DAfStb) published his guideline for load testing of existing concrete structures and therewith the experimental proof of the load bearing capacity became a widely accepted method in Germany. Since then over 2000 proof load test have been carried out and so a lot of experience exists in the usage of the Guideline. Nethertheless there are still reports about load tests carried out with mass loads or using mechanical measurement techniques. To prevent a misuse of the Guideline in future, to take into account the great experiences existing in the evaluation of the measuring results and the bearing condition, the DAfStb decided to revise the existing Guideline. In the last years there has also been an increased research activity focusing the development of evaluation criteria for possible brittle failures in shear and to extend the safety concept for the evaluation of not-directly tested elements. These results shall also be considered in the new Guideline.

Monitoring of Railway-Bridges – An Advanced Component of Maintenance and Sustainability

A lot of the older German railway bridges are made of steel and have reached or exceeded the planed duration of use. Because it’s impossible to renew all these bridges at once, concepts for extension of duration of use without a decrease of safety are necessary. The paper shows the determination of load capacity of railway bridges using a combination of measurement and calculation procedures, that includes the detection of bearing reserves. Special procedures of short and long time measurements, which are contained in the standard of German Railway, will be explained. Based on a current project, the structural monitoring of a railway bridge in Chemnitz, the use of measurement procedures in combination with statically calculations is demonstrated. Particularly the concept for realistic determination of remaining life is explained and significant results are presented.