Structural health monitoring (SHM) of civil engineering structures (buildings, bridges, wind turbines, dams, masts etc) aims to assess their structural integrity and performance and to detect potential damage induced by i) daily service loads, ii) exposure to environmental effects over the years and/or iii) extreme/accidental loads, either natural (e.g. floods, hurricanes and earthquakes) or man-made (e.g. explosions and traffic accidents).
As identified in the UK's 2011 National Infrastructure Plan, investing in civil infrastructure is a key priority to achieve Nation-wide financial growth and prosperity, a statement which applies globally. Developing new SHM tools to facilitate better informed decisions by civil infrastructure owners, local authorities, National agencies, and Governments on taking refurbishment, retrofitting, upgrade, or replacement actions for existing infrastructure is of utmost importance to appropriately channel investments in civil infrastructure.

In this context, the proposed research considers concepts from the emerging field of compressive sensing (CS) to develop novel structural condition assessment and damage detection algorithms for vibration-based SHM of civil engineering structures. These SHM algorithms support the use of arrays of sensors incorporating CS-based data acquisition hardware equipment which has not been considered before in wireless SHM of civil engineering structures. Such equipment is not commercially available yet, but the few existing prototypes showcase that it yields simpler, more affordable, and less obtrusive sensors. Therefore, this project paves the way for transformative technological advancements towards a new breed of wireless sensors enabling i) cost-effective routine/periodic SHM for ageing infrastructure, and ii) rapid integrity assessment of large number of structures in the aftermath of natural and man-made disasters.

Potential Impact:
Structural health monitoring (SHM) of civil engineering structures (buildings, bridges, wind turbines, dams, masts etc) aims to assess their structural integrity and performance and to detect potential damage induced by i) daily service loads, ii) exposure to environmental effects over the years and/or iii) extreme/accidental loads, either natural (e.g. floods, hurricanes and earthquakes) or man-made (e.g. explosions and traffic accidents).
As identified in the UK's 2011 National Infrastructure Plan, investing in civil infrastructure is a key priority to achieve Nation-wide financial growth and prosperity, a statement which applies globally. In the same document, an estimated pipeline of planned investment in UK infrastructure worth over £250 billion between 2011 and 2015 is announced by the Government. Developing new SHM tools to facilitate better informed decisions by civil infrastructure owners, local authorities, National agencies, and Governments on taking refurbishment, retrofitting, upgrade, or replacement actions for existing infrastructure is of utmost importance to appropriately channel such investments.

The novel SHM algorithms to be developed in this research support the use of arrays of sensors incorporating compressive sensing-based (CS-based) hardware equipment, addressed for the first time in wireless SHM of civil engineering structures. Such equipment is not commercially available yet, but the few existing prototypes showcase that it yields simpler, more affordable, and less obtrusive sensors. Further, the proposed algorithms are tailored to minimise energy consumption at these sensors. Thus, the need for energy harvesting and/or frequent battery replacement and consequently the overall cost for their deployment and maintenance is reduced. Therefore, this project, though theoretical and computational in nature, paves the way for transformative technological advancements towards a new breed of wireless sensors enabling i) cost-effective routine/periodic SHM for ageing infrastructure and ii) rapid integrity assessment of large number of structures in the aftermath of natural disasters. Consecutively, owners of infrastructure will benefit as SHM will add value to their assets and reduce insurance costs, since health and safety issues will be better addressed, with the level of structural integrity of instrumented structures being in any case readily assessed.

To this end, the proposed research will spark, in short term, considerable new technological R&D and commercialisation opportunities for national and international specialised instrumentation companies and electric equipment manufacturers to address the global market needs for cost-effective, mobile, and prompt SHM solutions relying on CS-based sensors. This is a growing global market as the inventory of infrastructure and their rate of decay due to climate change increase world-wide.

Further, this new CS-based technology might influence policy makers setting frameworks for the periodic inspection regimes of the large stock of decaying infrastructure. For example, there are almost 600,000 bridges in the US Highway system, which have been rated with a "C" by the American Association of Civil Engineers (ASCE) in 2009. UK's inventory of bridges is in better shape at the moment, rated as "B" by the Institute of Civil Engineers (ICE) in 2009. However, Highways Agency spends about £800million per year for maintenance. A portion of it concerns routine visual bridge inspections undertaken every second year which can be quite subjective. Adopting wireless CS-based sensors for routine SHM inspections in the case of highway bridges may offer a better option for early warnings of structural underperformance and/or deterioration in order to avoid collapse of structures (e.g. I-35W Minneapolis bridge, USA) and operation disruptions of lifelines (e.g. closure of M4 in West London in July 2012), at a reasonable additional annual cost.