long span bridges
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David Collings BSc CEng FICEMaking the complex simple
LONG SPAN BRIDGES
Making the complex simple.
Summary Presentation by
David Collings BSc CEng FICE
University of Surrey, UK; Feb 2015.
Long Span Bridges
Arches, trusses and box girder bridges have
reached the economic limits to span, the
maximum spans in figure 1 (previous slide)
are fairly flat with time. The span of cable
stay and suspension bridges is still
increasing and technology still developing.
And so, the main focus of the long span
bridge (LSB) course is on SuspensionBridges and Cable Stay Bridges.
David Collings BSc CEng FICEMaking the complex simple
Chaotian Bridge over the Yangtze
River, Its 520m trussed span is the
longest arch span in the world.
However its form is similar to those
built almost a century ago.From 5
Long Span Bridges
Summary presentation of the MSc Module for 2015.
Full details of the course can be found at:
http://www.surrey.ac.uk/postgraduate/bridge-engineering
Tutors
David Collings BSc CEng FICEIndependent Consultant
Professor Gerry Parke BSc MSc
PhD CEng FICE FIStructE EurIngHead of Civil & Environmental Engineering University
of Surrey
The Course
The course consists of 6 Units:
• Introduction to LSB
• Suspension and Stay Systems
• Box Girders
• Aerodynamics
• Stays and Hangers
• Towers and Pylons
Introduction to LSB
This outlines the history and development,initial design and construction of Cable-stayand Suspension bridges. The initial designexamples use a simple method based on adata-base of past structures (figure 2) toallow the student to work within currentnorms. Some failures [ref 4] are alsodiscussed. The construction of LSB isillustrated with historical and currentstructures (figure 3).
David Collings BSc CEng FICEMaking the complex simple
Figure 2 Note: 11.8 is taken from Collings [ref 2] which outlines the behaviour of cable stay and extradosed bridges in the context of steel-concrete composite construction.
Suspension and Stay Systems
This outlines the classic theory of the
Catenary, Cable Deformations, the
Rankine Theory and the Elastic Theory of
Suspension Bridges. Preliminary Analysis of
Cable Stayed Bridges. The initial design
examples are revisited to determine cable
and stay forces by analysis (figure 4).
Box Girders
Steel box girders are used on all LSB above500m span (fig 5) The the behaviour ofplates, plates in compression, plates inshear , plates under in-plane bending,panels under lateral loading, plates undercombined in-plane stresses are all importantfor the design of Box Girders (fig 6), thedesign of web stiffeners and diaphragmdesign.
Aerodynamics
Throughout the history of LSB wind hasbeen a major consideration (fig 7) andcaused many failures [ref 4]. This Unitoutlines the Basic Wind Loads, theDynamics of LSB, Basic Aerodynamics,Wind Tunnel Testing, the use of BD 49-01and an Example of the design decisionsneeded to avoid instability and limitmovements are discussed.
Stays & Hangers
Cables, Stays and hangers can beprefabricated or built on site, Installation,Maintenance, Strengthening and replacementare important considerations. Cabledehumidification is reviewed. Cables, Staysand Hanger Analysis and design issues suchas fatigue, progressive collapse, etc. arereviewed.
The special issues associated with multi-spanLSB and footbridges are discussed (fig 8).
Towers & Pylons
Types of Pylons and Towers, Loading andConceptual Design, Cable Connections toPylons and Towers, Pylon and TowerConstruction.
Towers and Pylons are a key visual feature,the aesthetics of LSB are discussed (fig 10).
.
References
1. Parke & Hewson (2009) Manual of Bridge Engineering,
second Edition, ICE Publishing..
2. Collings D, (2011) Steel-concrete composite bridges,
second Edition, Thomas Telford, London.
3. Collings D, Santiago A S, (2013) Extradosed and cable
stayed Bridges: Exploring the boundaries, Proc ICE BE 166,
Dec 2013, pp 231-239.
4. Collings D (2008) Lessons from historical bridge failures,
ICE Proceedings, Learning from Failures - a Civil
Engineering special issue, Thomas Telford Ltd.
Long Span Bridgeshttp://www.surrey.ac.uk/postgraduate/bridge-engineering
Other Summary presentations on Slideshare:http://www.slideshare.net/DavidCollings/cable-stay-bridges-presentation-summary-
of-a-lecture-delivered-at-uni-of-surrey
http://www.slideshare.net/DavidCollings/extradosed-bridges-exploring-the-
boundaries
http://www.slideshare.net/DavidCollings/chinese-arch-bridges-timber-stone-
concrete-steel
…making the
complex simple…
http://www.slideshare.net/DavidCollings/david-collings-bsc-
ceng-fice-personal-careerdc-summary
David
Collings
大衛
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