Issue 10

All articles published in the October 2012 issue.

The construction of the Northern Ticket Hall (NTH) formed part of the overall redevelopment of London Underground’s King’s Cross/St Pancras station. A static tower crane was required to service the largely top down construction works. Due to the limited access and particular site constraints, the tower crane had to be located within the area to be excavated. To address the specific site requirements, an innovative foundation was developed comprising a single large diameter (2.1m) steel tubular mono-pile installed from the existing ground level and founded principally into the underlying London Clay. As the steel tube would be eventually exposed down to the underside of the ticket hall base slab, the pile was designed as a free-standing cantilever with limited allowable movements that would meet the crane’s safe operating requirements. This paper describes the geotechnical and structural design challenges of an unusual tower crane foundation, as well as the particular construction and operational requirements.

This article covers how to understand whether a material is hazardous, what it can do to the health of humans and under what circumstances.

Falling objects

This note explains how steel elements are restrained against buckling and what the structural engineer should consider when analysing steel structures with respect to buckling resistance.

This note shows how to size elements, prior to detailed design. This process allows the engineer to gain an appreciation of structural form.

This paper presents the results from a comparative embodied carbon assessment of new commercial buildings focusing particularly on different structural forms. The assessment is based on five recently-constructed steel-framed commercial buildings and also on redesigns of those buildings in alternative structural forms. All building and structural options analysed have been independently costed. The embodied carbon assessment was undertaken using the life cycle assessment (LCA) model CLEAR which is based on ISO standards and has been peer-reviewed by Arup. The results presented are a subset of a more comprehensive dataset generated under the Target Zero programme. In addition to the embodied carbon results, other findings relating to operational carbon and BREEAM, which may be of interest to structural engineers, are presented. This paper describes Target Zero and the five buildings studied; the assessment methodologies employed and presents the principal findings and conclusions.

"Sandwich slab" construction is a novel bridge slab system, which provides substantial economic savings in the construction of steel bridges. The advent of the sandwich slab has allowed engineers to design new forms of steel bridge construction, which cannot be achieved by conventional concrete slabs. It has been more than 10 years since the technology was developed by Sumitomo Metal Industries, Japan and a number of composite steel bridges have been constructed using sandwich slabs in Japan. The products are now being supplied by Yokogawa-Sumikin Bridge, Japan. The technology was also independently assessed and has been officially registered in the civil engineering technology database system 'New Technology Information System' (NETIS) provided by the Ministry of the Land, Infrastructure, Transport and Tourism (MLIT), Japan. Despite its excellent track record, the sandwich slab has never been used outside Japan. This paper describes the sandwich slabs and the new forms of steel bridge design that have been realised by the sandwich slab technology.