How Does Simulation Support Bridge Assessment and Rehabilitation?

Simulation-based investigations of existing structures regarding load-bearing capacity and serviceability are a core area of expertise at Geodynardo GmbH in Weimar. Compared with traditional engineering models commonly used in structural engineering, these analyses offer significant advantages. Entire structures or representative sub-models can be analyzed, allowing interactions between different structural components as well as dynamic or exceptional loading scenarios, such as earthquakes, impacts, or fire, to be considered. This enables rehabilitation and strengthening measures to be planned and implemented in a highly targeted manner. Two examples illustrate this approach:

Case Study: River Main Bridge in Marktheidenfeld, Germany

For a realistic assessment of the load-bearing capacity of the Main bridge in Marktheidenfeld under ship impact, it is essential not only to consider the three-dimensional structural behavior but also to simulate the dynamic response of the structure. Figure 1 shows the complete FE model of the bridge, including its different structural components and materials. A transient dynamic analysis goes beyond simplified quasi-static calculations and reveals additional load reserves. The chart (Fig. 2) shows the temporal evolution of the reaction forces resulting from a frontal ship impact on the second pier of the bridge.

 The structural response is clearly visible: the maximum reaction force at pier 2 does not coincide with the peak load amplitude. Instead, it occurs at the end of the first impulse phase, which exhibits a significantly steeper gradient. The simulation also shows the plastic strains at the end of the impact event. It becomes evident that the permanent deformations, approximately 5 mm at pier 2 and 1.5 mm at pier 3, are primarily caused by plastic strains in the subsoil.

By simulating ship impact dynamically using the full model of the River Main bridge in Marktheidenfeld, Germany, additional load reserves can be identified, enabling a realistic assessment of the serviceability and load-bearing capacity of the existing structure.

Structural Health Monitoring of a Reinforced Concrete Bridge

 A simulation model developed by Geodynardo enables the condition of a canal bridge with three-hinged reinforced concrete arches, as well as its historic bearings and joints, to be monitored throughout the year. Figure 3 shows the structural deformations based on the three-dimensional simulation model, which has been calibrated using on-site measurement data collected over the course of a year. In addition to self-weight and water loading, seasonal temperature variations are also incorporated into the model.

On the one hand, the model allows new measurement data to be evaluated and their impact on the structural stress state to be determined. On the other hand, the calibrated model makes it possible to predict further seasonal scenarios, analyze appropriate maintenance strategies, and derive targeted strengthening measures for the structure in service.