By the end of January 2019, it was reported that one of the anchor bolts holding the main cable in place had cracked as a result of hydrogen embrittlement and the local roads authority were carrying out daily inspections. Since then, the decision has been taken to replace all of the 300-plus bolts to prevent further damage and fractures.
Structural defects can often go undetected and sometimes may even be dismissed as a non-safety issue if the bridge has passed a stress test. The problem is that, even if all the required tests are carried out and there are safety measures in place, some defects can be difficult to spot. Manual inspections and maintenance can involve scaffolding, ropes, specialised equipment, and a head for heights.
Enter drones that can be used to carry out inspections through the use of 3D mapping.
“Drones for construction make the identifying and reporting of any defects easier, safer and quicker,” said Pae Natwilai, CEO and founder of Trik, who was an engineer in the energy sector before she set up her enterprise drone software company.
“With a drone needing a sole, experienced operator to fly it, those on the ground can focus on using realtime insights to improve their decision-making. Engineers can carry out maintenance and any necessary repairs without delay,” added Natwilai.
A big advantage of using drones is that they can map even the hardest-to-reach parts of a structure and, thanks to thermal imaging, can spot defects that aren’t visible to the naked eye.
Links to software
While drone technology can transform how buildings, megastructures and utilities are mapped, its true value can arguably only be realised when integrated with enterprise asset management (EAM) and enterprise resource planning (ERP) software. Then its impact can be felt throughout a construction supply chain.
According to Jens Roehrich, professor of supply-chain innovation at the University of Bath, any technologies that are powered by artificial intelligence, computer vision and machine learning can drive productivity, sustainability and general performance throughout supply chains.
In the construction industry, this could mean using drones to keep visual logs of all cracks and faults and concluding that there is a pattern in the events that occur that points to a pre-existing defect in a part being sourced from a supplier. The EAM and ERP software can be used to manage procurement and supplier contracts and improve inventory control.
Spare parts are typically kept well-stocked in order to reduce downtime when carrying out maintenance events and repair jobs. By identifying which particular part is faulty, defect-free replacements can be sourced quickly.
If the supplier is alerted to a defect in a part it sells, which for whatever reason wasn’t picked up during quality checks, the supplier can escalate a recall up the supply chain. On those sites the affected part has unwittingly found its way onto, construction companies can then use drones to inspect the structure and get to work carrying out the required maintenance and repairs.
Building a business case
The consultancy PricewaterhouseCoopers predicts that there will be a significant increase in the number of drones being deployed on construction sites – for inspecting structures and collecting 3D information – over the next 10 years. By 2030, drones are set to have boosted productivity in the UK’s construction and manufacturing sectors by 3.1%, creating efficiencies worth £3.5bn in the process.
Although 4,800 drones are expected to be in use in these two sectors by 2030, there is still the challenge of convincing construction companies that new digital technologies can empower decision-making.
“Often those in the boardroom will want to see a return on investment before they purchase any technology,” said Roehrich. “Key stakeholders need to be presented with a business case. It’s unlikely they’ll be persuaded to invest in drones simply because the technology is there and it’s exciting.”
In the case of constructing bridges, there is a clear business case: drones can be used to detect defects and potentially avoid collapses and deaths, damage to the construction company’s reputation and even avoid any legal battles.
Moreover, when integrated with EAM and ERP software, the information captured by drones can be used to inform the engineering team effectively on what maintenance and repair work needs to be carried out. Engineers can then do their job with minimal disruption.
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Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.