Introduction to new steel bridge design method using sandwich slab technology

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.

All articles published in the October 2012 issue.

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.