Dimensioning Concept for Integral Composite Bridges with Sheet-Pile Abutments

Integral composite bridges with sheet-pile abutments represent a modern approach to bridge construction, combining the benefits of appropriate material choice (steel in tension and concrete in compression) and integral bridge design. This method eliminates the need for conventional expansion joints and bearings, this reducing the maintenance requirements and enhancing structural integrity. Especially for medium spans up to 45 m, the use of prefabricated elements such as VFT®-girders, helps to increase the economic feasibility as well as construction speed. Using sheet-piles as permanent foundation elements allows for greatly reduced carbon emissions and excellent soil retention capabilities near waterways, where sheet-piles are commonly used as pit-protection systems during construction. For a widespread application of integral bridges with sheet-piling abutments, a generalized approach to dimensioning is currently lacking, preventing engineering acceptance. Within the scope of FOSTA research project P1521 “Integrale Spundwandwiderlager von modularen Verbundbrücken für einen zeiteffizienten Bauablauf” various investigations on the load bearing behavior of a modular frame corner in composite construction have been performed to identify load paths and capacities of different elements used. Based on these investigations, the following paper proposes a simple dimensioning concept for spans up to 45 m using mostly modular construction while considering all relevant loads and structural effects from temperature and soil-structure interaction. The assumptions of the concept are cross-checked by numerical calculations using detailed FE-simulations to confirm load paths and section utilization.