Methodology for determining robust cross-sections for monolithically connected reinforced concrete piers of semi-integral viaducts

• Applicant: Professor Dr.-Ing. Steffen Marx
• Subject Area: Structural Engineering, Building Informatics and Construction Operation
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 559325203

The overall aim of the proposed project is to develop a methodology for the reliable identification of robust cross-sectional configurations for monolithically connected piers of semi-integral viaducts. This methodology will contribute to more durable, slimmer bridge structures with minimized maintenance costs. For this purpose, the knowledge regarding the load-bearing behavior is expanded This project begins with a systematic compilation of all limit criteria and empirical values concerning the design and dimensioning of integral column structures, which define the framework for the further steps. The next step is to develop a replacement model that reduces the column in the frame structure to a single column. Based on engineering principles, the model will be used to analyze the structure under investigation without any loss of safety. The specific effects considered include the normal force loading through the superstructure and the displacement of the pier head. Afterwards, parametric studies are conducted to examine the influences of the controllable cross-sectional parameters and their sensitivity to the stress variables. In the first step, extensive numerical simulations are carried out using three different models, utilizing the parameter range derived from the previous analysis of the limit criteria. The first model only considers behavior at the cross-section level. Further investigations are performed at the component level using substitute models with increasing levels of complexity: a bar model and a shell model with crack formation simulation. On the one hand, these three different investigation models allow the results to be verified against each other. On the other hand, a sufficiently precise model complexity is determined in this way. These theoretical investigations are followed by experiments at different scales to validate the numerical simulations. The results are also used to calibrate the numerical models. The aim of the numerical and experimental research is to identify suitable parameter spaces with regard to cross-section dimensions, reinforcement quantity and position. Finally, a design methodology is derived to accurately determine the cross-sectional configuration of a monolithically connected column of semi-integral valley bridges, which reacts robustly with regard to any fluctuations in impacts and effects.

• DFG Programme: Research Grants