Underslung cable structures – a feasible alternative?

This paper examines the behaviour and feasibility of under-slung cable structures. Consideration is given to their structural behaviour, their dynamics, their cost-effectiveness and the practicality of adopting such structures. The parameters that govern the behaviour and response of these structures are investigated and structural arrangements and details are proposed, which it is suggested would make the construction of such structures feasible. The aim of the paper is to generate discussion of this novel form of construction and to identify opportunities for the exploitation and development of such a concept. This paper discusses how underslung structures, when combined with a radical trussed stiffening girder, can provide an innovative but more sympathetic structure, which is stiff, stable and economically viable for both medium and long-span structures. It is shown that when there is a need to minimise the number or limit the location of the foundations required, such structures provide a means of adopting relatively large spans, while restricting the height of the cable supports and hence minimising the impact of the structure. The paper concludes by summarising the benefits that can be obtained from such structures both during construction and in use, and seeks to identify the opportunities and challenges that must still be met to facilitate the exploitation and development of such a concept.