In this episode of the series The young structural engineer, we meet Emilia Andrade Borges. She discusses her PhD research on precast girder bridges and shares her thoughts on the structural engineering profession.

This article is also available in Dutch.

Experimental research on precast girder bridges

Precast girder bridges have been constructed in the Netherlands since the 1960s. Originally designed as simply supported, they can be made continuous by adding a cast-in-situ top layer and crossbeams at the intermediate supports. Currently, the Dutch highway system includes over 100 precast girder bridges, while provinces and municipalities collectively own approximately ten times as many. As many of these structures approach the end of their service life, their structural assessment has become increasingly important.

This assessment poses a significant challenge: when evaluated against current standards, a relevant percentage of these bridges do not comply with the minimum required shear reinforcement. To better understand the capacity of these shear-critical structures, a research program including a full-scale experimental campaign is underway at Delft University of Technology since 2022. This campaign investigates several influencing parameters, including shear reinforcement ratio, prestressing level and layout, interface reinforcement ratio and detailing, and longitudinal reinforcement.

The experimental and analytical investigations in this project have three main objectives: (i) to develop accurate models for evaluate shear capacity, (ii) to establish reliable strategies for non-linear finite element modelling, and (iii) to generate models that describe the interface behaviour between the precast girders and the cast-in-situ top layer. Ultimately, the aim is to provide models that complement existing guidelines and support improved decision-making regarding the future of these structures.