Award-winning papers in 2019

The Baker Medal, presented to the third best paper overall, was awarded to Wiggins et al. (2019).

Brougham Castle Bridge is a three-span masonry arch highway bridge that has suffered significant scour damage to foundations and substructure with referred damage through the superstructure. This paper presents an engineer’s account of the appraisal, investigation, assessment of structural action and the design and execution of repairs for stabilising the structure. The analytical tool employed to interpret the flow of force was a thrust-line graphical equilibrium analysis. It will be demonstrated that this analytical approach accords with the observed structural pathology, thus giving a clear understanding as to where the loads are going, that they may be effectively grappled with. Through thrust-line analysis, continued stability could be demonstrated despite substantial changes in the foundation conditions. It seems fitting that this efficient, robust and confidence-building tool is the same used by the engineers who originally designed many of these bridges. Using this ‘historical approach’, a successful intervention was executed; initially emergency stabilisation work to save the bridge from collapse and latterly permanent rehabilitation works to bring the bridge back into service in advance of the upcoming winter floods.

The Tso Kung Hsieh Award, presented to the best paper on structural dynamics (nominated by SECED), was awarded to Xie et al. (2019).

The Dou-Gong system in Asian timber structures plays an important role in resisting seismic action. Traditional carpentry in Asia uses timber pegs to connect components, which enables relative movement between components and hence provides friction to dissipate energy in an earthquake. This method, however, has some shortcomings, such as inadequate stiffness to resist a large lateral force, and, therefore, the structures tend to exhibit permanent deformation after earthquakes. This study proposes a new technique by using super-elastic alloy bars to replace conventional wooden peg connections to enhance the seismic performance of the structures. Static pushover experiments were conducted on full-scale two-tiered Dou-Gong systems, and high-strength steel and conventional wooden pegs were used as benchmarks. The ultimate stiffness of the Dou-Gong system has shown an increase when both high-strength steel and super-elastic alloy bars were used, but only super-elastic alloy can provide a consistently high damping ratio. This technique also involves pre-strain of the super-elastic alloy, and the outcomes of this series of experiments have shown that pre-strain of the super-elastic alloy can significantly increase the damping ratio in the structure, and, hence, more energy is dissipated. The results of this paper can be used in projects of timber structures using the Dou-Gong system.

The Thomas Telford Premium Prize, presented for the best paper published in Engineering History and Heritage, was awarded to Wilde (2019).

The aims of this paper are to record how the Connaught Tunnel was surveyed, assessed and repaired by Crossrail for use for the new Elizabeth line in London, UK. The challenges and changes involved with implementing the repairs required to bring an example of Victorian engineering back into use again were based on Network Rail guidance and other current practice. The repairs will reduce future maintenance requirements, which will benefit railway operations in the future. Groundwater leakage remains within the tunnel as the cost of rectifying the leaks, if successful, would have been prohibitive. Prior to the Crossrail Act of 2008, consideration was given to the whole-life costing of reusing the tunnel as opposed to boring new tunnels, and the cost of new tunnels was considered to be higher than the costs of repairs, maintenance and ongoing drainage requirements to reuse the existing tunnel.