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The Structural Engineer

The City of Manchester Stadium was constructed as the central venue for the 2002 Commonwealth Games. After the games, and following some additional construction work, it became the new home to Manchester City Football Club for the start of the 2003 – 2004 season. The completed stadium is a monument to the skill and professionalism of the Structural Engineers involved in designing it. Constructing a cable structure of this form is particularly challenging and requires solutions to difficult engineering problems, or issues of stability that are often lost or forgotten in time as they are only temporary and disappear as the structure is completed. Iain G. Hill, BEng (Hons), CEng, MIStructE, MICE Design Director, Watson Steel Structures Ltd

The Structural Engineer

The paper describes the demolition of Bernard House, an office building in the centre of Manchester, which was a necessary enabling operation for the redevelopment of the Piccadilly Plaza. The Piccadilly Plaza is a 1960s development of two multi-storey office buildings alongside a multi-storey hotel, all sitting on a plinth of car parking, shops and basement storage. At 10 storeys high, Bernard House was the smaller of the two office buildings, its floors were supported by a central core and above the third floor by perimeter reinforced concrete window mullions. The third floor was a post-tensioned prestressed concrete slab which supported, at its perimeter, the structural concrete mullions and therefore the upper floors. Demolition of the slab is this paper’s main subject. The main technical difficulty was linked to the slab’s post tensioning. However, the demolition process was generally made harder by the city centre location and the adjacent busy bus/metro station. G. Sellors, CEng, FIStructE Principal Engineer, Babtie Group Ltd Sale, Cheshire

The Structural Engineer
The Structural Engineer
The Structural Engineer
The Structural Engineer

Cast iron is very strong in compression and remained the preferred material for columns in buildings throughout the nineteenth century. Today, the safe load capacity of cast iron columns, struts or arch ribs in existing buildings or bridges is usually estimated using a form of the nineteenth century Gordon–Rankine formula. This is a semi-empirical fit to the results of a series of pioneering experiments begun in Manchester in the 1830s by Eaton Hodgkinson (Fig 1). The paper presents an overview of Hodgkinson’s work, describes the background to the obsolescence of cast iron columns in buildings, gives details of some present-day problems in their structural assessment, and describes some recent full-scale laboratory tests. Thomas Swailes, BSc (Hons), CEng, MIStructE, MICE Eduardo Aja Fernandez de Retana, BEng (Hons), MSc Manchester Centre for Civil and Construction Engineering, UMIST

The Structural Engineer
The Structural Engineer