Title: Case study: Value engineering of cast-in-place box-girder bridges into a precast concrete superstructure
Date Published: November - December 2026
Volume: 71
Issue: 6
Page Numbers: 28 - 46
Authors: Hany Nasr, Mohamed Gawdat, Sam Valmassoi, Ahmed A. Rawdan, and Maher Tadros
https://doi.org/10.15554/pcij71.6-02
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Abstract
Multicell box-girder bridges are traditionally constructed using precast concrete segmental or cast-in-place methods. Although cast-in-place construction accommodates complex geometries, it can involve lengthy schedules, traffic disruptions, and substantial on-site labor. Fully precast concrete systems offer an attractive alternative by accelerating construction and improving quality control. This paper presents prestressing, erection, and assembly considerations for unsymmetrical precast concrete box-girder components assembled to form full-bridge-width multicell box girders. The approach enables construction from manageable precast concrete components while maintaining the structural efficiency and appearance of a closed box-girder system. Key construction challenges include prestressing unsymmetrical sections, lifting and placement stability, torsional behavior during erection, alignment of adjacent segments, temporary support requirements, and sequencing of bottom closure pours to achieve a continuous flat soffit. Practical methods for addressing these challenges are discussed based on their implementation in several bridges, including the King Abdullah Financial District access road network project in Riyadh, Saudi Arabia.