Issue 5

All articles published in the May 2012 issue.

(NB Technical Guidance Note Level 1, No. 8 contained within this issue was updated in October 2016. For the updated article, see the individual article entry for this issue.)

The United States Air Force Memorial (USAFM), overlooking the Pentagon in Washington DC, comprises three stainless steel spires which evoke an image of aircraft in a ‘bomb-burst’ manoeuvre. The elegance and simplicity of their architectural form belies the complexity of their engineering design. Structurally they consist of a stiffened stainless steel shell with the lower two thirds of each filled with concrete. A second component, essential to the integrity of the structure, is also hidden by the steel skin; a series of large, steel-coated spheres, free to roll in oversized padded boxes, are located inside each spire. The purpose of these ‘impact dampers’ is to stabilise the motions of the spires in high winds. This article provides an overview of the spire structures and focuses on the challenges encountered during the design, development and test of the damping devices.

Employees are expected to have the appropriate knowledge, skills and experience for the tasks assigned to them, unless they are under competent supervision. This article focuses on the schemes for individuals.

Aging car parks - a cause for concern. Structural-Safety.org’s Alastair Soane draws on three recently submitted CROSS reports to highlight an urgent need to review current practice.

Robert Kilpatrick (Kilpatrick International Search & Selection) highlights the issues facing employers and candidates and provides guidelines on how to avoide the pitfalls.

This note concerns the assessment of loads that apply to retaining structures, typically generated from soil. These forces primarily come into play during the design of retaining wall structures, but they can also be found in water-retaining structures and storage vessels.

It is essential for structural engineers to be able to express their ideas clearly through their designs. This note describes two common techniques used to draw in three dimensions.

This paper discusses a study undertaken by Arup on behalf of The Concrete Centre to investigate the embodied CO2 in typical structural frames for non-residential buildings. The study used the designed and measured schemes produced for the cost model studies published by The Concrete Centre in 2007-2008. The study explored the variations in embodied CO2 predictions. Two sources of variation were considered: the method of the analysis and the speciifcation. The study found that, within the uncertainties of the available data, there was little difference between the embodied CO2 of the different types of structural frames, but that once the frame type had been chosen, there was a significant opportunity for the structural engineer to reduce the embodied CO2 of the final structure by careful specification.

This paper presents an experimental programme conducted to investigate the behaviour of bonded-in BFRP bars loaded parallel to the grain of glulam members. Tensile pull-out tests were conducted to examine the effect of bonded length and bond stress-slip on the structural capacity of the connection. An analytical design expression for predicting pull-out capacity is proposed and the results have been compared with some established design equations. It was found that pull-out load increased approximately linearly with the bonded length, up to maximum which occurred at a bonded length of 15 times the hole diameter, and did not increase beyond this bonded length. The most significant failure modes were failure at the timber/adhesive interface followed by pull-out of the BFRP rod. Increased bonded lengths resulted in higher bond slip values compared to lower equivalent bonded lengths. The proposed design model gave the best predictions of pull-out capacity compared with other existing models.

Topics of importance openly discussed...

One of the Institution's largest Regional Groups places strong emphasis on CPD...