Above: a plan of The V&A Exhibition Road Extension foundations, (image credit Arup)
Institution Fellow, Ed Clark, is a Director at international engineering consultancy, Arup. A structural engineer for 20 years, Ed is also a member of our Structural Futures Committee, which considers those factors which may impact on the engineers of the future, and reports their findings to the profession. Here he discusses how electronic sensors might change the way we build and maintain the buildings of the future.
As a student I was inspired by the engineering avante-garde of the time - engineers like Peter Rice and hi-tech structures like Stansted Airport. The expressive use of structural systems from that era was really exciting, and perhaps explains why I was happy to join the Institution’s Structural Futures Committee, which reports on cutting-edge technologies which have the potential to change the way we think about engineering.
One such future technology is the use of sensors – that is wired sensor networks which report on the structural integrity of a building. The possibilities are really exciting: far off in the future it might be possible for buildings to largely maintain themselves, using sensors to automatically diagnose their own defects, and deploying drones to make repairs.
Of course such a world is a very long way off, but the idea of adaptive structures is not so far away; that is, leaner and more dynamic structures that are able to change their geometry or stiffness to respond to different loads in real time – for instance a bridge that actively damps out footfall vibrations to maintain pedestrian comfort. Active vibration control systems have been used in the automotive and aerospace industries and could become more common in civil/structural applications, with actuators responding to sensor data by providing a force that will effectively cancel out vibrations.
Very few structures are currently being constructed with built-in sensor networks – for the moment they are most common in large infrastructure projects like bridges, where they provide structural integrity data (measuring the effects of strain and acceleration) as part of a strategy to monitor the health of the structure.
A big barrier to their more widespread use is cost, but as wireless systems develop and handle increasingly large amounts of measured data, they should become more economically viable over the next few years.
How we use those sensors will vary according to the structure. For example, one of my current projects is the Exhibition Road Extension to the V&A Museum in London, where we have embedded fibre-optic sensors into some of the piled foundations (which are designed to resist tension forces in heaving soil). The interaction between piles and soil is complex, and the sensor data will allow us to closely monitor the way our current design performs and create better piles based on what we learn from the sensor data.
(Above: installing pile sensors at the V&A project)
Sensors also have the potential to diagnose problems early, enabling us to prevent serious damage, better plan future maintenance and extend the lifespan of structures as a result.
So, what will such technologies mean for future engineers? In general, we should only think of them as a useful tool to facilitate an engineer’s expertise, not a replacement for them. As the guardians of public safety, structural engineers are required to have a remarkable depth of knowledge. Combined with their human judgement and experience, our professional expertise could never be adequately replaced by technology alone.