All articles published in the December 2012 issue.
Publish Date ‐ 30 November 2012
Chief Executive Martin Powell reflects on some of the Institution's activities and accomplishments over the last 12 months and looks ahead to the exciting projects and plans in place for 2013 and beyond.
John Nolan reviews the Institution’s achievements and challenges within the context of his Presidential theme.
We read about (and maybe unfortunately witness) people being hurt or killed; these events have an immediate effect on a company or project. Accidents may be recorded and analysed, often within a short time of their occurrence. It is no surprise therefore that traditionally, the industry has seen the improvement of accident statistics as representing a true measure of improvement in health and safety performance.
Three reoccurring themes (communication issues, quality assurance and lack of appreciation for the importance of stability) continue to emerge from reports to CROSS detailing incidents on site. Alastair Soane provides examples.
Whilst, for most projects, contractors and temporary works designers are the lead players, permanent works designers will always play at least two important roles: a technical one (the design of the permanent works determines what temporary works are needed and what the primary loads will be) and a managerial one (ensuring that appropriate contractual provision and arrangements are in place). John Carpenter outlines the important (and often unsung) role that temporary works play in a construction project.
Sean Brady stresses the importance of managing 'human factors' to reduce human error within bridge projects, citing international examples from which lessons can be learned.
The chosen form of any substructure is entirely dependent on what the site investigations reveal. It is typically up to the structural engineer, with the aid of geotechnical engineers and specialists, to determine the extent of this investigation and interpret its results.
The twisting of elements within structures due to eccentric loading is best avoided. Such actions develop torsion forces - which the elements were not designed to withstand. This note shows structural engineers how to avoid problems that can lead to significant remedial works and/or failures.
There is potential to reduce both operational and embodied greenhouse gas emission from buildings. To date the focus has been on reducing the operational element, although given the urgency of carbon reductions, it may be more beneficial to consider upfront embodied carbon reductions. This paper describes a case study on the whole life carbon cycle of a warehouse building in Swindon, UK. It examines the relationship between embodied carbon (Ec) and operational carbon (Oc), the proportions of Ec from the structural and non-structural elements, carbon benchmarking of the structure, the value of ‘cradle to site’ or ‘cradle to grave’ assessments and the significance of the timing of emissions during the life of the building. The case study indicates that Ec was dominant for the building and that the structure was responsible for more than half of the Ec. Weighting of future emissions appears to be an important factor to consider. The PAS 2050 reduction factors had only a modest effect but weighting to allow for future decarbonisation of the national grid energy supply had a large effect. This suggests that future operational carbon emissions are being overestimated compared to embodied.
Exposure trials on timber cladding are valuable sources of information for façade designers. Key material, fire, and structural issues affecting timber cladding design are assessed and robust construction details derived alongside a framework for the emerging sub-discipline of timber façade engineering. The timber used was UK grown Sitka spruce (Picea sitchensis).
The work was undertaken because timber is an increasingly common cladding material in the UK, being used on low-rise residential buildings and for medium-rise and non-domestic buildings. The associated risks have, therefore, increased but this is not reflected in published guidance.
Around 40 construction details were produced and a selection are shown in this paper. They integrate, for the first time, all of the performance requirements applicable to low- and medium-rise timber façades in the UK. The work’s key benefit is that the guidance arising from this study rationalises and improves façade design.
Jon Morris advocates seeing beyond initial embodied CO2 figures and to think in terms
of whole-life carbon content when considering the sustainability of a project.
Topics of importance openly discussed...