Bridge Inspection: What We Learn From Bridge Failures And Repairs

[This article was first published on October 28, 2021, and has been updated and revised.]

Bridges are the lifelines of our transportation infrastructure, carrying millions of vehicles, pedestrians, and cyclists daily. While most bridges are built to last, the relentless forces of nature, traffic, and time can take a toll on even the most robust structures. Bridge failures, though rare, highlight the critical importance of regular inspections and maintenance.

The fracture and subsequent closure and repairs of the Hernando DeSoto Bridge over the Mississippi between Arkansas and Tennessee made national headlines for months.

As we noted the events here in previous articles and, since August 2, 2021, the bridge has been reopened to traffic along I-40. 

But what did we learn?

 

 

 

A Possible Catastrophe Diverted, But Many Structurally Deficient Bridges Remain

A story published by The Washington Post after the bridge fully reopened noted, 

The bridge became a national example of the risks posed by the nation’s decaying infrastructure. The emergency repairs on the closed span created major traffic disruptions in the Memphis area while traffic was diverted to another bridge nearby.

“We know having the bridge closed has been incredibly inconvenient,” Tennessee Transportation Commissioner Clay Bright said in a statement. “We appreciate the public’s patience while our team made the repairs and performed extensive inspections to ensure it’s structurally sound for many years to come.”

The 3.3-mile bridge, built in the late 1960s to early 1970s, carries about 60,000 vehicles daily, according to the Tennessee Department of Transportation, which shares responsibility for the span with the Arkansas Department of Transportation.

Inspectors working for a private contractor discovered the crack May 11 during a routine inspection. 

They were so alarmed by the prospect of a catastrophic failure that they called 911.

Prior to the repairs being fully completed, the Tennessee DOT noted on their website that following the completion of repairs, the damaged steel will be preserved for detailed forensic investigation.

 

One Lesson: Quality Bridge Inspections Matter

While there seems to be a bit of controversy over who, exactly, should have been held to account for allowing this particular situation to go unnoticed for so long – possibly more than two years – the bottom line is that several inspectors failed to see the growing fracture.

All of which underscores the need for bridge inspection efficacy.

In theory, no major structural damage should go undetected for more than the period between routine inspections, every two years. And there are other inspections that can occur in the interim depending on the age of a bridge or other circumstances. 

But bridge inspections that are not carried out properly or are done so in a less than professional manner can potentially put lives at risk.

The Importance of Bridge Inspections

Bridge inspections are essential for identifying potential problems before they escalate into catastrophic failures. These inspections involve a thorough examination of the bridge’s superstructure, substructure, and deck, looking for signs of deterioration, cracks, corrosion, or other damage. By catching issues early, engineers and contractors can implement timely repairs, preventing costly and dangerous collapses.

 

Lessons Learned from Bridge Failures

Tragic bridge failures, though uncommon, serve as stark reminders of the potential consequences of neglecting bridge maintenance. In addition, these incidents often reveal underlying issues such as:

• Material Fatigue: Bridges are subjected to constant stress from traffic, wind, and temperature fluctuations. Over time, materials like concrete and steel can weaken, leading to cracks and fractures.
• Corrosion: Exposure to de-icing salts, moisture, and other environmental factors can accelerate corrosion, compromising the structural integrity of bridge components.
• Design Flaws: In some cases, bridge failures can be attributed to design errors or inadequate construction practices.
• Insufficient Inspections: Regular and thorough inspections are crucial for identifying potential problems before they become critical.

Bad Things Happen to Good Bridges

Sometimes perfectly sound bridges can be damaged extensively, requiring a shut down and unplanned repairs. This happened in July 2021, a few weeks before the Hernando de Soto bridge reopened.

In Georgia, a local highway overpass was struck by the raised bed of a dump truck passing underneath. 

According to the Georgia DOT, the bridge was dislodged from its concrete base after it was hit by a big rig towing a dump trailer raised in its dumping position. As a result of the impact, the center of the bridge was pushed back nearly six feet and the section of the bridge over the westbound lanes below was hanging lower.

While this type of incident is unfortunate, the DOT and contracted inspectors could do nothing to prevent it.

Stress damage, progressive weather damage, and other common bridge stability issues can and should be identified by competent inspectors.

Proactive Bridge Maintenance: A Harder Lesson to Learn

It’s not that the concept is novel or new. Anyone working on or with highway bridges understands that the best approach to bridge safety and maintenance is a pre-emptive one. But a myriad of factors often stand in the way of implementing it, including lack of funds.

But the fact remains that, to ensure the long-term safety and reliability of bridges, a proactive approach to maintenance is essential. This includes:

• Regular Inspections: Conduct thorough inspections at recommended intervals, using advanced technologies and equipment when available.
• Early Intervention: Address any identified issues promptly to prevent further damage.
• Load Management: Monitor bridge loads to prevent overloading and excessive stress.
• Material Selection: Use high-quality materials that are resistant to corrosion and other forms of deterioration.
• Proper Design: Ensure that bridges are designed to withstand expected loads and environmental conditions.

By investing in bridge inspection and maintenance, we can protect lives, reduce traffic disruptions, and extend the lifespan of our critical infrastructure. By utilizing advanced equipment like under bridge platforms and inspection units, contractors, engineers, and inspectors can perform their jobs more safely and efficiently, helping to build a safer and more resilient transportation network.

 

The Promise of Change: Innovations in Bridge Construction and Inspections

The field of bridge engineering and inspection is constantly evolving, driven by the need for safer, more durable, and sustainable infrastructure. Advances in materials, design, and technology are transforming how bridges are built and maintained.

Innovations in Bridge Construction

• Advanced Materials: The use of composite materials like carbon fiber reinforced polymers (CFRP) is gaining traction in bridge construction. These materials offer exceptional strength-to-weight ratios, corrosion resistance, and durability, leading to lighter and longer-lasting bridges. Additionally, self-healing concrete, which can repair microscopic cracks, is being explored to extend bridge lifespan.
• Innovative Design: Engineers are pushing the boundaries of bridge design with concepts like cable-stayed bridges with asymmetrical configurations and long-span arch bridges that utilize high-strength concrete. These designs offer aesthetic appeal while enhancing structural efficiency.
• Accelerated Bridge Construction (ABC): This method involves prefabricating bridge components in controlled environments, reducing construction time and minimizing disruptions to traffic.

Innovations in Bridge Inspections

Technology is revolutionizing the way bridges are inspected.

• Drones and Robotics: Unmanned aerial vehicles (UAVs) equipped with high-resolution cameras and sensors can access hard-to-reach areas, providing detailed visual data of the bridge’s condition. Robotic systems can perform underwater inspections and collect data on submerged structures.
• Sensor Technology: Advanced sensors embedded in bridges can monitor structural health in real-time, detecting early signs of distress and allowing for proactive maintenance.
• Data Analytics and AI: Artificial intelligence can analyze vast amounts of inspection data to identify patterns, predict potential failures, and optimize maintenance schedules.
• 3D Scanning and Modeling: Creating detailed 3D models of bridges helps engineers assess structural integrity and plan repairs more effectively.

By embracing these innovations, the bridge industry can build safer, more resilient, and cost-effective infrastructure while minimizing environmental impact.

 

Another Lesson: Under Bridge Inspection Equipment Matters

The equipment used by bridge inspectors to gain access to the underdeck regions of highway and railway bridges are critical. 

Without the use of some of the large capacity under bridge inspection units (UBIUs) that are available, getting eyes on many areas under some bridges would be next to impossible. While the use of under bridge scaffolding can be implemented, along with teams of rope riggers, the versatility and ease of access provided by UBIUs can’t be matched.

And, as exemplified during the highly publicized repairs made on the Hernando de Soto bridge over the Mississippi, the same equipment can be utilized for extensive repair work as well as routine maintenance and upkeep.

We also learned that, with more than 617,000 bridges across the United States – over 40 percent of which are at least 50 years old – the potential exists for many other damaged bridges to be discovered. 

And this is especially true for the more than 46,000 of the nation’s bridges that are considered structurally deficient, or in “poor” condition.

 

The Role of Under Bridge Platforms and Inspection Units

To effectively inspect bridges, professionals need access to all areas of the structure. Under bridge platforms and inspection units provide safe and efficient access to hard-to-reach areas, such as the underside of the bridge deck and piers. These specialized pieces of equipment are essential for performing detailed inspections, collecting data, and conducting necessary repairs.

Key Benefits of Using Under Bridge Platforms and Inspection Units:

• Improved Safety: These platforms and units provide a stable and secure working environment for inspectors, reducing the risk of falls and other accidents.
• Increased Efficiency: By providing easy access to all parts of the bridge, inspection and repair work can be completed more quickly and efficiently.
• Enhanced Data Collection: These platforms often come equipped with features that allow inspectors to collect detailed data on bridge conditions, aiding in the development of repair plans.
• Cost-Effective Solutions: Early detection of problems through regular inspections can help prevent costly emergency repairs.

 

 

For Under Bridge Platforms We Provide the Best – From the Plains to the Best

Under Bridge Platforms serves all of the Western States, including California, Washington, Oregon, Idaho, Nevada, Montana, and Wyoming to provide quality under bridge equipment.

Our large and expanding inventory of under bridge access platforms includes state-of-the-art self-drive access platforms such as the versatile Truck Mounted Hydra Platform HPT43 and the Aspen Aerials A-30 Bridge Inspection Unit.

There are a variety of different bridge inspection platform vehicles featuring multiple capabilities. In addition, determining the best choice for your work or project also depends on both the structure and the terrain.

So, while cost is certainly important, the vehicle capabilities and your specific project needs should be the dominant deciding factors in your equipment rental decision.

With a professional firm you can rely on to guide you through the process, buying or renting the right under bridge inspection vehicle and bridge inspection platform equipment for your project means we are here to help you make the proper selection.

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