David Collings presented on long span bridges at the University of Surrey in February 2015. He discussed the history and development of suspension bridges and cable-stayed bridges, whose maximum spans are still increasing due to advancing technology. The main focus of the course is on these two bridge types. It consists of six units covering topics like suspension and stay systems, box girders, aerodynamics, towers and pylons. Case studies of historical and current bridges are used to illustrate concepts. Full course details can be found online at the University of Surrey's website.

1. David Collings BSc CEng FICE
Making the complex simple
LONG SPAN BRIDGES
Making the complex simple.
Summary Presentation by
David Collings BSc CEng FICE
University of Surrey, UK; Feb 2015.

2. David Collings BSc CEng FICE
Making the complex simple
Figure 1

3. 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 Suspension
Bridges and Cable Stay Bridges.

4. David Collings BSc CEng FICE
Making 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

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

6. Tutors
David Collings BSc CEng FICE
Independent Consultant
Professor Gerry Parke BSc MSc
PhD CEng FICE FIStructE EurIng
Head of Civil & Environmental Engineering University
of Surrey

7. The Course
The course consists of 6 Units:
• Introduction to LSB
• Suspension and Stay Systems
• Box Girders
• Aerodynamics
• Stays and Hangers
• Towers and Pylons

8. Introduction to LSB
This outlines the history and development,
initial design and construction of Cable-stay
and Suspension bridges. The initial design
examples use a simple method based on a
data-base of past structures (figure 2) to
allow the student to work within current
norms. Some failures [ref 4] are also
discussed. The construction of LSB is
illustrated with historical and current
structures (figure 3).

9. David Collings BSc CEng FICE
Making 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.

10. David Collings BSc CEng FICE
Making the complex simple
Figure 3

11. 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).

12. David Collings BSc CEng FICE
Making the complex simple
Figure 4

13. Box Girders
Steel box girders are used on all LSB above
500m span (fig 5) The the behaviour of
plates, plates in compression, plates in
shear , plates under in-plane bending,
panels under lateral loading, plates under
combined in-plane stresses are all important
for the design of Box Girders (fig 6), the
design of web stiffeners and diaphragm
design.

14. David Collings BSc CEng FICE
Making the complex simple
Figure 5

15. David Collings BSc CEng FICE
Making the complex simple
Figure 6

16. Aerodynamics
Throughout the history of LSB wind has
been a major consideration (fig 7) and
caused many failures [ref 4]. This Unit
outlines the Basic Wind Loads, the
Dynamics of LSB, Basic Aerodynamics,
Wind Tunnel Testing, the use of BD 49-01
and an Example of the design decisions
needed to avoid instability and limit
movements are discussed.

17. David Collings BSc CEng FICE
Making the complex simple
Figure 7

18. Stays & Hangers
Cables, Stays and hangers can be
prefabricated or built on site, Installation,
Maintenance, Strengthening and replacement
are important considerations. Cable
dehumidification is reviewed. Cables, Stays
and Hanger Analysis and design issues such
as fatigue, progressive collapse, etc. are
reviewed.
The special issues associated with multi-span
LSB and footbridges are discussed (fig 8).

19. David Collings BSc CEng FICE
Making the complex simple
Figure 8

20. Figure 9

21. Towers & Pylons
Types of Pylons and Towers, Loading and
Conceptual Design, Cable Connections to
Pylons and Towers, Pylon and Tower
Construction.
Towers and Pylons are a key visual feature,
the aesthetics of LSB are discussed (fig 10).
.

22. Figure 10

23. David Collings BSc CEng FICE
Making the complex simple

24. 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.

25. Summary

26. Long Span Bridges
http://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

27. …making the
complex simple…
http://www.slideshare.net/DavidCollings/david-collings-bsc-
ceng-fice-personal-careerdc-summary
David
Collings
大衛

29. Presentation by CRD and Wolf productions.
The full lectures are available on Surreylearn.