Bridgesin the U.S. are in disrepair, not for lack of funds, but because of obsoleteinspection methods
By Rajika Jayatilake
Every government experiences a “feel good” sensation uponannouncing infrastructure spending plans. President Joe Biden too recentlypresented an infrastructure budget. Like earlier infrastructure plans, it includes significant funding for “transportation infrastructure,” such as bridges.
True enough, statistics point to an increasingly grave situationconcerning the bridge network in the U.S. The 2021 Bridge Condition Report producedby the American Road and Transportation Builders Association (ARTBA) states that according to thelatest federal data analysis, 220,000 bridges in theU.S., amounting to 36% of bridges in the country, need repair, while another 79,500 bridges require replacement. This doesn’t take into account county and smaller bridges in your neighborhood.
Statistics such as these, of deteriorating or collapsing bridgesare oft quoted to emphasize the need for more federal funding.
However, the reality is that colossal budgets are already beingspent, year in year out, on inspection, repair and maintenance of America’saging bridge system. In fact all of the major bridges in the national bridge inventory system over 600,000 are scheduled to be inspected every 2 years.
Then, why are bridges continuing to deteriorate and collapse despite all themoney spent in repairing them?
The reason is stark and undeniable.
America’s bridges are collapsing not due to a lack of budget, but topersistent use of obsolete bridge inspection methods.
It is a fact that while advocating repair and maintenance ofbridges, policymakers continue to ignore the need for technology-based bridgeinspection. And it is nothing if not tragic that the technology is readily available, but theU.S. continues to rely on subjectivejudgements of manual inspection methods which are at least 50 years old.
Over fifty years ago, U.S. federal and state guidelines for bridgeinspections focused on what was seen through the naked eye, and discovered bypinging the bridge’s surface with a hammer, or dragging a chain across the bridge surface. And all the while, traffic would be continuously speeding along an open lane a few feet away, hindering accurate diagnosis.
Yet, inspections are critical to understand the health of bridges,as various factors contribute to weakening their serviceability, and shorteningtheir lifespan; among them are material deterioration, fatigue, vibrations, foundation integrityissues, design flaws and consistent loads and overloads on the bridges. Moreover, extreme weather conditions exacerbate underlying issues. Intense heat can warp concrete and steel, while salting of bridges in harsh winters corrodes steel.
While archaic manualinspections can only expose problems conspicuous on the exterior, the issues,by that time, would have become dangerous and expensive, sometimes even too late to fix. It is then usually at a point that the entirestructure has to be replaced at tremendous cost.
On the other hand, robotics can detect issues early in the bridge lifecycle, and Nondestructive Testing Technology (NDT) can penetrate the interiorof a bridge structure, uncoveringwhat is invisible to the naked eye. Technologycan record quantitative data which is invaluable to bridge inspectors toanalyze in real time, the condition of the bridge. The slightest anomaly will draw attention to a condition which may not have yet turned into a problem. The data recorded will pinpoint the exact location where a problem is in the making, which in turn will allow inspectors to use their extensive knowledge and experience to brainstorm viable options to arrest the problem at fledgling stage.
Moreover, when deterioration is discovered early in the bridge lifecycle, asset managers can budget more efficiently,prioritize early repairs, with public safety in mind, and extend the service life ofthe structure, saving billions of dollars in untimely replacements.
With this goal, a Florida-based robotic engineering firm,Infrastructure Preservation Corporation (IPC), has trailblazed technology-basedbridge inspection methods that directly contrast with the ancient ones currently in use.
IPC engages NDT “Nondestructive Testing” in robotic systems toidentify deterioration in concrete and other structural material at the initialstages. In fact, IPC has taken modern technology to another level, by producing custom-built robotics that enable quantitative results. With these results, With IPC’s data, asset owners are able to provide an action plan for repairs before deterioration spreads and compromises the safety of bridges or other infrastructure. Moreover, IPC has shown how robotic devices are able to provide more precise quantitative data for more of the critical infrastructure than ever seen before.
Despite this, President of IPC, Doug Thaler, is frustrated by theapparent refusal of some federal and local authorities, as well as giantcompanies, to incorporate technology in inspections.
He asks, “How can you repair something when you don’t understandwhat is wrong, to begin with?”
As Thaler has observed, manual inspections are so subjective, that10 different inspectors could give 10 different reports upon inspecting thesame bridge.
Thaler explained that modern technology and robotics provide morequantitative data for less money and exceed the requirements of Federal HighwayAdministration (FHWA) and American Association of State Highway and Transportation Officials (AASHTO), the two agencies that set the standards for these inspections.
He said, “Typically, and unfortunately change only takes placeafter a catastrophe. After the I-35 collapse of 2007 in the US, new regulationswere released.”
In the I-35 bridge collapse of 2007, 13 people died, 145 wereinjured, and 111 vehicles were destroyed. Investigations revealed a designanomaly in the bridge that went unnoticed because locating design errors is not standard practice for manual bridge inspections. Yet it was an accident waiting to happen since the bridge opened for business, because what should have been the strongest part of the bridge, was, in fact, one of its weakest. The Ponte Morandi(Viadotto Polcevera) in Italycollapsed in 2018 killing 43 people and the list goes on. The damage to human life, neighboring homes, cars and on the ongoing economy are devastating. What if a bridge collapsed on your watch and the technology Bridge inspection existed that could have exposed the problems before they became catastrophic.
If, instead of manualinspections, engineering firms utilize advanced robotic systems like IPC’s BridgeScan™engineers would be instantly alerted by abnormal data in specific areas. Immediate action could be taken, well ahead of any catastrophe. Further, Ground Penetrating Radar(GPR), is a geophysical locating method employing radio waves to capture underground images in a minimally invasive manner.
As Thaler points out, IPC has developed a range of sophisticatedequipment based on modern technology, software and robotics to help take infrastructureand bridge inspections to a level as to improve the safety and potential for catastrophe worldwide. For instance,CableScan® inspects bridge cable stays, not just the sheathing that surrounds the steel that holds up the bridge which is now the inspection method being utilized. TendonScan® locates corrosion and loss of metallic area inside the post-tension tendons that hold up our bridges and box girder overpasses, while RopeScan is able to inspect suspender cables, broadcast towers, flare stack guy wires and transmission towers while PoleScan® is a high mast light pole inspection service with an additional robotic repair service.
And all this is possible with existing Department of Transportationbudgets. What is needed is not more funds, but a fundamental change inperspective.
This makes it imperative that the entire concept of inspectionchanges immediately. It is only when the federal government recognizes theurgency of using technology that engineering firms will employ technology to obtain data which will then be given to inspectors for analysis and recommendations otherwise tax dollars and safety will continue to be compromised.
The money currently spent on bridges is bad economic managementand, ironically, is water under the bridge.
Billionaire business magnate, Michael Bloomberg said, “You don’tmake spending decisions, investment decisions when you don’t know what’s goingto happen.”
America’s bridges can be meaningfully repaired and maintained onlyby understanding what goes on within the bridge. Such quantitative data can onlybe obtained by employing technology.
