Introduction

1.1 Problem Statement And Motivation

The present book concerns temporary structures, in particular the most commonly used temporary structures: scaffolds, shoring, bridge falsework systems made of slender vertical and horizontal steel tubes connected by special couplers. The design of scaffold structures made of bamboo is also discussed, as well as specialised equipment used in modern bridge construction, often named bridge construction equipment (BCE).

Failures involving these structures are amongst the most common types of accidents in civil and construction engineering, and often lead to disproportionate consequences. This reality calls for a paradigm change regarding the design and use of temporary structures systems.

The book will present and explore the most recent advances in research and innovation in the field of civil, construction and structural engineering applied to temporary structures.

There are various types of structural systems available in the market: from towered systems made of steel or aluminium built-up members, frame systems of steel beams and columns with structural profiled sections, to proprietary modular 3-D frame systems of metallic elements connected by special couplers. There are many applications of these structural systems ranging from the construction, rehabilitation to the retrofit of bridge and buildings structures. Figure 1 illustrates some examples of temporary structures systems.

Figure 1.

Examples of temporary structures

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There are several stakeholders directly or indirectly concerned with temporary structures: researchers, designers, producers, clients, consultants, insurers, contractors, sub-contractors and workers. In this context, the assemblage, use and dismantling of temporary structures systems is usually done by a specialised sub-contractor, in accordance with a standard design project or with a specially developed design project, depending on the work complexity.

Since the industrial revolution, the construction industry and in particular temporary structures have been experiencing new challenges and some fundamental changes. The International Federation for Structural Concrete (fib) has stated that through time the role of temporary structures in the cost, construction rate, safety, quality, durability, efficiency, utility and aesthetics of any engineering project has increased in a consistent fashion (fib, 2009). Therefore, it is not surprising that a correct choice of temporary structure, good planning, design and operation of the temporary structures are keys for the success of every engineering project. In particular, it is vital that synchronised planning and continuous knowledge exchange exists between the structural designer, the contractor, the temporary structures designer, the temporary structures contractor and others.

Unfortunately, this is not always a reality. The framework of engineering construction consists of complex interactions between all the above mentioned stakeholders who have different backgrounds and can have different priorities, perceptions and goals, some of which can even be contradictory (fib, 2009). Despite the construction phase being the most critical stage of a structure’s lifetime – most failures occur during construction rather than after projects have been completed, see Ratay (2009) and Scheer (2010) for examples – some stakeholders still do not recognise the importance of these systems: they are “temporary” and, therefore, their role is considered to be minor compared to that of the permanent structures. Consequently, the design and use of temporary structures are not usually treated as carefully as in the case of permanent structures. Furthermore, they do not receive the same level of research attention and research funding as occurs in permanent structures.