Strategier för reduktion av tvärkraftsarmering i brobaneplattor - Modelleringsval och regelverksjämförelse för plattrambroar
(2025) In 0349-4969 VBKM01 20251Division of Structural Engineering
- Abstract
- The national construction and civil engineering industry contributes significantly to Sweden’s total carbon dioxide emissions. Meeting the United Nations’ global sustainability goals will require intelligible, measurable and structural changes within the industry. Notably, modern bridge designs often demand greater material use than those built half a century ago, albeit the structural types are fundamentally the same.
In concrete bridge construction, various types of reinforcement are required to enhance the load-bearing capacity. Shear reinforcement, typically in the form of stirrups, must be installed if the shear forces exceed the concrete’s inherent capacity. However, engineers generally aim to minimize shear reinforcement due to... (More) - The national construction and civil engineering industry contributes significantly to Sweden’s total carbon dioxide emissions. Meeting the United Nations’ global sustainability goals will require intelligible, measurable and structural changes within the industry. Notably, modern bridge designs often demand greater material use than those built half a century ago, albeit the structural types are fundamentally the same.
In concrete bridge construction, various types of reinforcement are required to enhance the load-bearing capacity. Shear reinforcement, typically in the form of stirrups, must be installed if the shear forces exceed the concrete’s inherent capacity. However, engineers generally aim to minimize shear reinforcement due to environmental impact, labour-related challenges, and economical cost. This master’s dissertation aims to provide practical guidance for engineers designing shear reinforcement in portal frame bridges.
A comparative study focused on computational differences between SS-EN:1992-1-1, 2005 and SS-EN:1992-1-1, 2023 is conducted, using the fib Model Code 2010, 2013 as a supplementary benchmark for broader comparison. Key areas of investigation include the introduction of new parameters, advancements in calculation procedures,and assumed material behaviours in the most recent standards. The findings indicate
that while shear reinforcement quantities in the ultimate limit state are similar across the codes, results for the fatigue limit state vary more significantly, hence no clear conclusion can be drawn. The tiered design methodology known as Levels of Approximation has the potential to streamline calculations and, in some cases, reduce the required amount of shear reinforcement.
To highlight the consequences of different modelling choices two alternatives strategies are evaluated, point load dispersion and the use of Free Body Cut, using the finite element software Brigade/Plus. The utilized distribution widths are based on literature and current research. Multiple distribution widths and loading areas are tested for both approaches to evaluate their impact on shear intensity within the bridge deck. The aim is understanding the overall structural behaviour resulting from these choices, rather than capturing every individual force component with numerical precision. The analysis is based on a case study of a portal frame bridge at the Eriksberg interchange,
located in rural Sweden. In the original model, traffic loads are applied as concentrated point loads representing wheel pressures. Combined with load enveloping, this approach can produce unrealistically high shear intensities simulating vehicle stepping,
leading to excessive shear reinforcement requirements.
The results show that both methods lead to smoother shear force diagrams and lower design shear intensities, thus reducing the amount of reinforcement required. Each method has its advantages and limitations, and the choice of approach should be guided by the specific objectives and constraints of the project. (Less) - Popular Abstract (Swedish)
- Bygg- och anläggningsindustrin har en betydande påverkan på Sveriges totala koldioxidutsläpp. För att uppnå FN:s globala mål krävs tydliga förändringar. Broar som byggs idag kräver mer material än broar som byggdes för 50 år sedan, trots att brotyperna är likadana. Tvärkraftsarmering i form av skjuvbyglar är något som konstruktörer generellt sett strävar efter att minimera av miljömässiga, arbetsmiljömässiga och ekonomiska skäl. Det visar sig att mängden skjuvbyglar i plattrambroar kan minska ifall konstruktören lyckas navigera rätt bland normtolkningar, modelleringsval och missvisande resultat.
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9192902
- author
- Samuelsson, Jakob LU and Darvelid, Emilia LU
- supervisor
- organization
- alternative title
- Strategies to reduce shear reinforcement in bridge decks - Choice of modelling parameters and comparison of design codes for portal frame bridges
- course
- VBKM01 20251
- year
- 2025
- type
- H3 - Professional qualifications (4 Years - )
- subject
- keywords
- Tvärkraftsarmering, Brigade/Plus, Levels of Approximation, Utmattningsdimensionering, Brobaneplatta/farbana, Singularitet/toppvärde
- publication/series
- 0349-4969
- report number
- 25/5307
- other publication id
- LUTVDG/TVBK/25/5307
- language
- Swedish
- additional info
- Examinator: Miklos Molnar
- id
- 9192902
- date added to LUP
- 2025-06-09 10:53:57
- date last changed
- 2025-06-09 10:53:57
@misc{9192902,
abstract = {{The national construction and civil engineering industry contributes significantly to Sweden’s total carbon dioxide emissions. Meeting the United Nations’ global sustainability goals will require intelligible, measurable and structural changes within the industry. Notably, modern bridge designs often demand greater material use than those built half a century ago, albeit the structural types are fundamentally the same.
In concrete bridge construction, various types of reinforcement are required to enhance the load-bearing capacity. Shear reinforcement, typically in the form of stirrups, must be installed if the shear forces exceed the concrete’s inherent capacity. However, engineers generally aim to minimize shear reinforcement due to environmental impact, labour-related challenges, and economical cost. This master’s dissertation aims to provide practical guidance for engineers designing shear reinforcement in portal frame bridges.
A comparative study focused on computational differences between SS-EN:1992-1-1, 2005 and SS-EN:1992-1-1, 2023 is conducted, using the fib Model Code 2010, 2013 as a supplementary benchmark for broader comparison. Key areas of investigation include the introduction of new parameters, advancements in calculation procedures,and assumed material behaviours in the most recent standards. The findings indicate
that while shear reinforcement quantities in the ultimate limit state are similar across the codes, results for the fatigue limit state vary more significantly, hence no clear conclusion can be drawn. The tiered design methodology known as Levels of Approximation has the potential to streamline calculations and, in some cases, reduce the required amount of shear reinforcement.
To highlight the consequences of different modelling choices two alternatives strategies are evaluated, point load dispersion and the use of Free Body Cut, using the finite element software Brigade/Plus. The utilized distribution widths are based on literature and current research. Multiple distribution widths and loading areas are tested for both approaches to evaluate their impact on shear intensity within the bridge deck. The aim is understanding the overall structural behaviour resulting from these choices, rather than capturing every individual force component with numerical precision. The analysis is based on a case study of a portal frame bridge at the Eriksberg interchange,
located in rural Sweden. In the original model, traffic loads are applied as concentrated point loads representing wheel pressures. Combined with load enveloping, this approach can produce unrealistically high shear intensities simulating vehicle stepping,
leading to excessive shear reinforcement requirements.
The results show that both methods lead to smoother shear force diagrams and lower design shear intensities, thus reducing the amount of reinforcement required. Each method has its advantages and limitations, and the choice of approach should be guided by the specific objectives and constraints of the project.}},
author = {{Samuelsson, Jakob and Darvelid, Emilia}},
language = {{swe}},
note = {{Student Paper}},
series = {{0349-4969}},
title = {{Strategier för reduktion av tvärkraftsarmering i brobaneplattor - Modelleringsval och regelverksjämförelse för plattrambroar}},
year = {{2025}},
}