Weak infrastructure can turn natural hazards into catastrophes, but it isn’t immediately visible when a a bridge or tunnel has damage. Some clues help engineers identify them faster, so… what methods are used to know if a structure is still safe? How can robotics help to prevent catastrophic infrastructure disasters? Let’s find out in this article.
Risk: A simple event or the “lives at stake” concept?
Each year, the World Economic Forum creates the Global Risks Report (GRR) and the Global Risk Index (GRI) in order to analyse the vulnerability of more than 170 countries to the effects of natural disasters. In this way, specific risk areas (hotspots) are identified and risk indicators are developed, emphasizing aspects such as the probability of a natural disaster occurring, vulnerability and resilience (ability to face disasters) at each point analysed, as well as possible preventive measures to adopt. In principle, particular regions in each country are at greater risk of suffering disasters related to natural phenomena, such risks also grow with regional environmental degradation and climate change.
Risk is also changing globally due to the role that vulnerability plays. It is not just a matter of assessing the intensity of natural disasters but of seeing how susceptible societies are when affected by those events: how capable are communities of dealing with these risks in the short and long term.
Infrastructure plays a key role for a natural phenomenon to become –or not– a disaster. First of all, it is of utmost importance for relief and response work. In the event of a flood, for example, reliable access roads, bridges and airports are needed so that aid gets where it needs to be quickly. For this reason, infrastructure plays an increasingly important role in levels of vulnerability.
What should we prevent in any infrastructure?
Concrete constructions have to withstand everything: bridges must withstand the passage of heavy trucks; industrial factories must house heavy machinery and dance hall floors have to withstand hundreds and even thousands of people circulating at the same time. The climate also has a great impact on this type of structure. Due to the above, a detailed review of the building facilities will ensure that all services work correctly and safely (mechanical systems, ventilation, drinking water, fire systems, sewage, rain, access gates, etc.).
Concrete is generally a very stable material and can support a huge weight. However, there are certain elements that can negatively influence its stability: water, acid, rust and weight. Water in particular may be able to penetrate structures and oxidize them; if steel beams rust, the concrete will lose its strength and give away; worse the case if you use road salt or any other more aggressive chemicals that rust the frame faster. Acids attack not only metal, but also concrete itself; the calcareous components of the cement dissolve, the concrete softens and becomes brittle. Even rainwater can cause such effect, especially if the concrete is rough and the surface is rough, which favors water penetration. Likewise, enormous amounts of weight are a hazard to the structure; this includes, for example, the large amounts of snow that sometimes accumulate on roofs. Recurring vibrations, such as those caused by trucks on bridges, are also dangerous.
During an inspection, engineers first look at the structure in detail from the outside: are there any visible water spots? Have stalagmites formed under the structure? If so, this would mean that the water has long penetrated the concrete and removed the lime scale. Is there chipped concrete? Are the reinforcing parts that have oxidized visible? Is the surface covered with moss? These are some aspects that engineers look for when conducting the inspection.
After the visual inspection, the engineers proceed to search for the supporting structures. For this, old building plans are useful. For this, old building plans are useful. Inductive magnetic gauges are then used, similar to metal detectors that use DIY devices to search for cables and pipes in the wall or like those used by treasure hunters. The devices can detect metals that are up to approximately four inches deep under concrete, even steel can be located deeper. In addition, there are radar devices that can detect water retention. All this state of corrosion of a steel structure in a building can be initially estimated non-destructively.
Especially in prestressed concrete structures, reinforcements play a very important supporting role. We should remember that preventive maintenance always will be better than corrective maintenance.
How to inspect wire ropes and cables with robots?
Cable ropes ensure that the long pieces of a bridge, for example, remain stable, usually composed of high-strength carbon steel. To find out if tension cables can break, engineers use a procedure where each cable acts like a bar magnet and measures its magnetic field with probes. Where a magnetic field ends and a new polarity begins, there is definitely a break in the steel. Now that task could be done by robots, as well as other activities.
The applications of robotics in the construction field allow the future path to continue in order to obtain a quality sustainable building, reducing costs, time and production processes. It is estimated that in five years around 20% of the work done in this sector will be carried out by used industrial robots because it is necessary to recognize technological change and begin to establish a transformation strategy towards it.
Robotics technology helps to pinpoint conditions and deterioration of the study structures, such as bridges, roadways and infrastructure, allows to better protect public safety, repeat processes faster than humans without making many changes, optimize repair and maintenance expenses for facilities and equipment, to obtain a much higher efficiency at a reduced cost, as well as complete the inspections without exposing workers to dangerous conditions. It is safer for the traveling public, workers and inspectors. They do exactly the same than the engineers mentioned before, but with all these benefits.
Infrastructure Preservation Corporation (IPC) utilizes modern technology and robotics for many tasks and it has the following services:
- BridgeScan®: Comprehensive bridge deck assessment.
- CableScan®: Robotic Cable stayed bridge inspection service.
- PoleScan® & PoleScan®: High mast light pole robotic inspection and repair services.
- RopeScan®: Robotic wire rope inspection service.
- TendonScan®: Comprehensive post tension tendon inspection service.
- CrackScan®: Concrete and bridge crack inspection service.
- ColumnScan®: Robotic column & shaft inspection.
Utilizing the latest in robotic non-destructive testing and robotic engineering Infrastructure Preservation corporation (IPC)provides the latest infrastructure inspection services. Many of IPC’s service do not require personnel to work from heights, they don’t require lane closures or heavy equipment disrupting traffic on the bridge. Not only can these robotic services provide more quantitative data at a reduced cost so less taxpayer dollars with more useful information to help asset owners better budget for maintenance and repairs.