Early-Stage Design of Concrete Girder Bridges Using Set-Based Design: Parametric Exploration of Design Alternatives Considering CO2 Emissions, Cost, and Buildability
Publicerad
Författare
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
This thesis investigates the application of parametric multi-criteria optimization in the
early-stage design of reinforced concrete girder bridges using a set-based design (SBD)
approach. As the construction industry faces increasing pressure to reduce greenhouse
gas emissions in line with Sweden’s 2045 net-zero targets, methods that allow sustainable
solutions in the initial stages of a project are encouraged. However, minimizing the
use of carbon-intensive materials, such as concrete, can present challenges for buildability,
particularly when more geometrically complex structures are introduced. To address
this situation, the study incorporates both environmental impact and buildability into the
optimization criteria, enabling identification of solutions that balance these potentially
conflicting objectives. A developed parametric Python algorithm was used to generate
a wide design space based on geometry parameters from a reference project. The study
focused on cross-sections with two main girders—either of rectangular or I-shaped profiles.
Each alternative was structurally verified by the algorithm through finite element
analysis using BRIGADE/Plus, and subsequently evaluated in terms of investment cost,
CO2 emissions, and buildability. The analysis of over 100,000 cross-section alternatives
revealed groups of material-efficient solutions that reduced both emissions and cost, although
some with buildability that was negatively impacted due to increased production
complexity. The results underscore the trade-offs between key criteria and demonstrate
the ability of the SBD method to identify solutions that meet multiple performance targets.
Overall, the study highlights the value of SBD in supporting early-stage decisionmaking,
enabling more informed trade-offs, and reducing risk in tendering processes
aimed at sustainable infrastructure development.
Beskrivning
Ämne/nyckelord
set-based design, parametric modeling, multi-criteria optimization, girder bridge, reinforced concrete, buildability, environmental impact