Author: C. Blackett-Ord (CARE + Blackett-Ord Conservation Limited)
4th January 2016
First published: 4th January 2016
Standard: £9 + VAT
An IStructE account gives you access to a world of knowledge. Create a profile to receive details of our unique range of resources, events and training.
Added to basket
C. Blackett-Ord (CARE + Blackett-Ord Conservation Limited)
The River Tyne has been a major discharge port for coal from the UK’s Northumberland and Durham coalfields for centuries. Staiths were constructed near the mouths of navigable rivers as a means of discharging coal from railway wagons into ships, and the Dunston Staiths were the largest timber structure in Europe at the end of the 19th century. Their repair history has been reasonably well documented and so they provide a good case study for timber deterioration, selection of repair species and strength analysis.
This short article describes the rehabilitation of an office building in Baghdad damaged by a missile strike during the 2003 Iraq War. The author briefly sets out the damage to the building’s steel frame, explains how a structural model was created to enable the design of a supporting steel frame, and describes the installation of the temporary supporting frame and new steel columns using hydraulic jacks to raise the building’s upper stories.
A tuned damping solution was developed to mitigate walking induced vibration of joist-framed floors in 25 rectangular, trapezoidal and irregular-shaped rooms in an educational facility. The make-up of the floors was concrete on metal deck, supported by open-web steel bar joists. The floors came in various sizes (800–1200sq.ft) and shapes, with the first resonant frequencies in the 6.5–7.5Hz range.
Following the measurement of vibration and finite element analysis of the floors, 50 tuned mass dampers
(TMDs) (two for each room) were designed, manufactured and installed to effectively address the vibration
challenges of the first structural modes of the floors they were designed for.
After installation of the TMDs, the effectiveness of the tuned damping solution was evaluated via further
measurements. TMDs effectively dampened the first structural modes of the floors in various rooms and
lowered their walking-induced vibration to acceptable levels.
Letters this month raise concerns about the the forces cited in an article published in May 2015 on assessing the capacity of the Grand Parade stone balustrade in Bath, UK; as well as considering structural safety margins and code discrepancies in relation to steel web buckling.