Chapter 2 overviews the historical development and past research into temporary structures from 1970 up to 2016 and describe the various problems that have occurred necessitating changes to traditional design and construction techniques. The survey covers tubular, proprietary and modular scaffolds, bridge falsework as well as bridge construction equipment. Particular areas emphasised are the changes introduced by the use of advanced structural analysis techniques and the need for changes in procedures following the analyses of collapses of temporary structures. An overview of various solutions is presented, including the use of different materials (steel, aluminium, timber and bamboo). The chapter shows that same analysis procedures are used for these different materials. The chapter then overviews the actions acting on temporary structures such as permanent loads and variable construction loads and finishes with an introduction to failures of falsework and scaffolding structures.
Top2.1 Introduction
This Chapter presents a brief review into the history of temporary structures and overviews the development of new systems.
There are many types of temporary structures; the long list includes scaffolding, falsework, and bridge construction equipment. These are the most commonly used temporary structures and the bulk of this book concerns them. This Chapter will also review the management of temporary structures projects but more detail of this is covered later in the book, particularly in Chapter 8.
The Chapter first describes the types of temporary structures commonly used, from tubular scaffolds, through proprietary and modular scaffolds, bamboo and timber structures to bridge construction equipment. During the overview, developments in modelling from the use of effective lengths to full nonlinear finite element models are described. Of particular importance to structural analysis is the incorporation within the models of the material’s elastoplastic behaviour, of accurate connection models and of various types of imperfections, such as connection looseness.
The Chapter also describes the different types of actions that can be applied to temporary structures: from permanent actions due to self-weight and imposed vertical loads, to variable actions such as wind loads. Design recommendations to improve the safety of temporary structures are also introduced.
Finally, the Chapter summarises the research in collapses leading to an introduction to Chapter 7 that will present a forensic analysis into temporary structures collapses with methods to avoid failure.
On the basis of this Chapter it is expected that the reader will acquire knowledge on the following topics:
- 1.
Different types of temporary structures and their main characteristics.
- 2.
Historical evolution of temporary structures, their design and their role in construction.
- 3.
How temporary structures fit in the construction project.
- 4.
Type of actions to which temporary structures are exposed.
- 5.
Examples of temporary structures collapses.