RC piers of semi-integral viaducts

Project data 

Short description

© MKP / Burzik

The majority of road and railway bridges in Germany are constructed using reinforced concrete and prestressed concrete. In addition to viaducts with conventional bearing systems, semi-integral bridges are also increasingly being used. This construction method offers several advantages, particularly in terms of a larger load-bearing capacity, lower maintenance costs, and increased durability of the structures. Semi-integral bridges are statically indeterminate systems, which means that more complex calculations are required. In addition, superstructure shortening and lengthening cause pier head displacement, which leads to constraining forces in the piers. To date, there is no generally accepted design and dimensioning model for the design of monolithically connected piers, which means that approvals in individual cases or investigations in the approval process are often required.

The aim of the DFG-funded research project MonoPier is to develop a design model for monolithically connected reinforced concrete columns of semi-integral bridges. This model is based on deformation-induced design, in which the normal force and the pier head displacement in particular are taken into account as decisive effects. To simplify the complex system relationships, the problem is reduced to a suitable substitute model. On this basis, a linear, iteration-free design process can be developed that enables practical and efficient application in the design.

To investigate the system behavior, extensive numerical analyses are performed at the cross-section and component level, both in the ultimate limit state and, in particular, in the serviceability limit state. This is supplemented by experimental investigations to determine the moment-curvature relationship. Furthermore, the actual load-bearing and deformation behavior of columns under combined normal force and displacement effects is experimentally mapped and evaluated.