Built to Last

The role of construction standards and innovation in building stronger, safer bridges

On June 14, 2024, ironworkers from Canada and the US working on the Gordie Howe International Bridge shook hands across the border as the remaining edge girders that allow for the final deck gap to be built were installed. Once completed in 2025, this bridge will be the longest cable-stayed bridge in North America and tenth longest in the world. It will enhance connectivity between Detroit and Windsor and facilitate the efficient flow of traffic and goods.

Bridges are vital connectors within the transportation network, linking cities, regions, countries, and economies. Industry puts a lot of trust in bridges to support the smooth functioning of the North American supply chain.

When a bridge fails, that trust is eroded.

There are numerous examples of bridge collapses in the last century: the Tacoma Narrows Bridge (1940), the Point Pleasant (Silver) Bridge (1967), the Mianus River Bridge (1983), and the I-35W Mississippi River Bridge (2007). The Francis Scott Key Bridge in Baltimore is the most recent example. In March 2024, a container ship struck one of the piers of the bridge. The bridge collapsed, leading to the deaths of six members of a roadway maintenance crew. The collapse halted shipping to and from the Port of Baltimore for 11 weeks, with serious economic impacts. The cost to replace the bridge is estimated at up to $1.9 billion.

Some bridge collapses are the result of collisions, while others are caused by structural flaws, inadequate inspection, environmental or operational stressors, or material faults and failures. Many tragically lead to fatalities and injuries, and all impact the economy and public trust in infrastructure.

Responses to bridge collapses have led to stronger regulations, improved engineering and construction practices, better oversight, and enhanced resilience. Even though bridges are safer than they’ve ever been, maintaining safe structures that the public can trust is an ongoing responsibility.

When it comes to the welded components of bridges, that responsibility has two dimensions: stringent regulation of codes and standards governing fabrication and construction, and the relentless pursuit of innovation and excellence to improve quality and resilience.

Standards help ensure public safety

In Canada and the US, welding-specific standards are vital for ensuring the safety and reliability of steel structures like bridges. In the US, the American Welding Society (AWS) establishes comprehensive welding standards, such as AWS D1.5, which is widely recognized as the standard for bridge welding. AWS D1.5 provides guidelines for welding processes, inspection, and quality assurance. It specifies requirements for materials, welder qualifications, and inspection procedures, ensuring that welded connections meet the necessary strength and durability criteria. Compliance with these requirements minimizes the risk of weld failures that could compromise the structural integrity of bridges.

In Canada, the Canadian Standards Association (CSA) offers standards like CSA W59, which covers welded steel construction and CSA S6, the Canadian Highway Bridge Design Code. CSA W59 and CSA S6 outline requirements for welding design, procedures, and qualifications, promoting high-quality welds that can withstand the stresses and loads encountered in bridges. The standard emphasizes the importance of welder certification and regular inspection to maintain safety and performance.

“Welding standards contribute to the overall safety of bridges by ensuring components are welded to code, mandating rigorous testing and inspection, and identifying and preventing defects to reduce the risk of failure,” said J. Craig Martin , Chief Operating Officer, CWB Group . “Through the CWB certification process, which involves a thorough review of an organization’s personnel qualifications, welding procedures, documentation, and quality control programs, we can ensure an organization complies with the applicable CSA standard. This is a critical aspect of the long-term safety and durability of bridges and other critical infrastructure.”

Innovating for strength and durability

Constant innovation also supports public safety and public trust in bridges to stand the test of time. Research into new innovations in welding and materials joining can significantly enhance standards and engineering practices for bridges. Advancements in these areas contribute to stronger, more reliable bridges, reducing the risk of failures and improving safety.

Welding technologies introduced over the last few decades, such as friction stir welding and laser multi-pass narrow-gap welding, offer enhanced efficiency, precision, and strength. These techniques and improvements in processes reduce defects and improve the quality of welds, leading to more durable joints. Research into high-performance materials, such as high-strength, low-alloy steels and advanced composites, can lead to the development of lighter, stronger bridge components. These materials offer improved resistance to environmental stresses, such as corrosion and fatigue, extending the lifespan of bridges and reducing maintenance costs. Incorporating these innovations into relevant standards can enhance safety by promoting the use of superior welding methods that ensure structural integrity.

Innovations in non-destructive testing (NDT) and inspection techniques, like innovative ultrasonic testing equipment and digital radiography, enable more accurate detection of flaws in welds and materials. These methods provide data and insights into the condition of bridges, allowing for proactive maintenance and repair. That way, potential issues are identified and addressed before they lead to failures.

“Innovation in materials and joining methods allows current bridges to be repaired effectively and new bridges to take advantage of new opportunities for effectively connecting across transportation gaps,” said William Mohr , Principal Engineer, EWI . “The rapid improvement and adoption of digital radiography can be a model for other technology areas.” EWI offers comprehensive engineering services based on their deep expertise in materials joining, forming, testing, and modeling to help manufacturers take advantage of innovations like these.

Reinforcing public trust is a continuous effort

The Francis Scott Key Bridge collapse and other disasters have highlighted the integral role bridges play in the economy. Lessons learned from these incidents, along with oversight of standards and ongoing research and innovation, will help ensure the lasting safety of new structures like the Gordie Howe International Bridge and other critical infrastructure projects. Incorporating research-driven innovations into welding and materials joining standards can lead to safer, more resilient infrastructure, ultimately protecting public safety and infrastructure investments.

In 2022, EWI, of Columbus, Ohio, and CWB Group, of Milton, Ontario, announced a strategic alliance to serve and promote materials joining and allied technology services (MJATS) in Canada, the United States, and beyond. Unified in their mission, CWB, EWI, and the CWB Foundation work to advance workforce development, champion public safety, and deliver innovative and meaningful solutions that contribute to a strong economy and a better world.

Learn more: cwbgroup.org? |? ewi.org? |? cwbweldingfoundation.org