ABSTRACT
On the railway and highway network – including culverts – there is a great number of such structures. It is important to mention that the majority of the arch bridges has short spans: approximately 80 % of the structures are under 5 m and only 8.5 % exceed 10 m in span [Leonhardt, 1994]. Most of them are simple supported arches. During service bridges are subjected to wear. In the last decades the initial volume of traffic has increased. Therefore many structures require a detailed investigation and control. The examination should consider the age of the bridge, all repairs, the extent and location of any defects etc. A continuous maintenance which generally must increase in time is important in order to assure the safety in operation of the existing structures. Careful inspection of the structure is the most important aspect in evaluating the safety of the arch. On the accuracy of the in situ inspection depends the level of operation: the check of existing structures should be based on the complete bridge documentation; however in the majority cases this documentation is missing. But this information can be recovered due to careful investigations and inspections of the arches, experimental determination of material characteristics and stresses in structural elements, full scale in situ tests (static and dynamic) calibration of the structure and computer aided analysis. Arches gain their strength from the shape; the form of the majority of arch bridges is the segmental arch (semi-circular).
