Detailed numerical simulation of experiments on masonry arch bridges using 3D FE

Abstract

Masonry arch bridges which are one of the oldest forms of bridges constitute a big part of the railway and roadway network of Europe. Thus the economical, functional and social value of these structures is of great importance. Moreover, because of their esthetic and technical value they constitute part of our cultural heritage which needs to be preserved. The durability of these bridges which rises from the materials used for their construction but also from their structural behavior is remarkable. Nevertheless, they were not designed to carry the increased loads of the modern service demands. This is the reason why a big number of masonry arch bridges need to be assessed and then repaired or strengthened in order to be functional under the new necessities. It is therefore necessary to understand the constitutive structural elements of the masonry arch bridges and how each of them contributes to the overall structural behavior of the bridge. In this way, experimental methods as well as analytical ones which can predict the behavior of these structures are needed. Aiming to the better understanding of the structural behavior of masonry arch bridges, the Technological Laboratory of Structures of the Construction Engineering Department of UPC carried out an experimental campaign on real-scale bridges focusing mostly on the ultimate capacity and the collapse mechanisms. This thesis is dealing with one of those experiments on a semi-circular masonry bridge. Firstly, the structural behavior as well as the current analytical methods used to evaluate the condition of masonry arch bridges are presented. Next, a summary of the design and the construction of the bridge is described as well as the instrumentation used to record the results and the loading until failure of the structure. Then, experimental results are compared with those results provided by different analytical methods. Limit analysis using RING 2.0 was the first approach of interpreting the results. But the actual objective of this thesis is to present a finite element model able to predict the behavior of the masonry arch bridge and which can help us understand the contribution of each structural element. The results of the finite element analyses are compared with the experimental ones and some important conclusions are reached regarding the capabilities of different analytical approaches that have been used. Finally based on the gained experience some recommendations for future analytical study are given.