Steel Designers Manual - TheBestFriend.org

This material is copyright - all rights reserved. Reproduced under licence from The Steel Construction Institute on 12/2/2007
To buy a hardcopy version of this document call 01344 872775 or go to http://shop.steelbiz.org/
Steel Designers' Manual - 6th Edition (2003)
must be a commitment made by all concerned to understand why the links are there,
and how best to enhance speedy information exchange.
33.10 Special structures
All structures are, to some extent, special. However, there exist particular structures
which, by their complexity, require special consideration when designing and planning
their erection. The length, height and relative mobility of a completed structure,
or the depth of individual members, may bring forward particular design
problems.
Temperature differentials over the depth of bridge box girders will produce
changes in the camber of the girder. Temperature differentials over the width of a
structure will produce changes in verticality. Temperature changes will affect the
vertical orientation of the columns at each end of a long single-storey factory building
or bridge. Some of these effects can be, and commonly are, accommodated by
the provision of expansion joints. Others must be addressed in the planning and execution
phases.
The construction of suspension (see Fig. 33.23) or cable-stayed bridges provides
good examples where movement and change to the shape of the structure become
increasingly apparent as the construction process progresses. A radio telescope is
the best example of a special structure which is designed to move and yet must maintain
very close tolerances as the extremities of the structure are reached. Other
structures move as they grow, and their temporary supports can fail as a result.These
failures are too often the result of a lack of appreciation of construction movements,
vibrations from wind, or local loads from erection plant.
References to Chapter 33
References 1011
1. HMSO (1995) The Construction (Design & Management) Regulations 1994.
2. Health and Safety Executive (1984) Guidance Note 28 (Parts 1–4), HMSO.
3. The British Constructional Steelwork Association (2002) National Structural
Steelwork Specification for Building Structures, 4th edition, BCSA/SCI.
4. British Standards Institution (1990) Building setting out and measurements. Part
1: Methods of measuring, planning and organisation and acceptance criteria. Part
2: Measuring stations and targets, Part 3: Check-lists for the procurement of
surveys and measurement surveys. BS 5964, BSI, London.
5. CIMSteel (1997) Design for Construction. The Steel Construction Institute,
Ascot, Berks.
6. Cheal B.D. (1980) Design Guidance Notes for Friction Grip Bolted Connections.
CIRIA Technical Note 98. Construction Industry Research and Information
Association, London.