Dive Brief:

• A length of road near the Gordie Howe International Bridge jobsite reopened on June 23 following an 18-day closure after a 100-foot-long section of the street collapsed inward during construction of the $4.5 billion bridge connecting Detroit and Windsor, Ontario. 
• Construction crews had been driving sheet piling in the area earlier, according to CBC, but no workers were on site at the time of the collapse on June 5 and no one was injured. An investigation into the cause is ongoing, project builder Bridging North America, a consortium of ACS Infrastructure, Fluor and Aecon, said Thursday. The Michigan DOT and the Windsor-Detroit Bridge Authority are assisting with the investigation.
• Bridging North America said it will keep monitoring the situation and won't work near the collapse area until further notice, but said it currently poses no danger to the community. The six-lane span will supplement what is currently the countries’ busiest land border crossing when it’s finished, likely by the end of 2024.

Dive Insight:

Four main components make up the Gordie Howe project, which broke ground in 2018 and aims to boost vehicle capacity and border processing in the congested crossing area:

• Gordie Howe International Bridge. 
• U.S. and Canadian ports of entry.
• The Michigan Interchange, a 1.8-mile section of Interstate 75 and surrounding local roads. 

The collapse happened on West Fort Street at Cavalry Street, not directly on the site where the bridge is being built but closer to the Michigan Interchange construction, according to CBC. Bridging North America said it would cover repair costs for the street if it was found responsible.

There are a wide variety of factors that could have contributed to the problem, including utilities with a leaking water line or old water lines that were preventing drainage, according to Maria Lehman, American Society of Civil Engineers president-elect.

“There are all kinds of things that could have been happening there,” according to Lehman. “Major collapses are not as frequent, but I think minor — you know, having areas open up — happens on a lot of construction sites all the time.”

Sometimes maps to old utilities get lost, particularly in historic urban areas, and builders may not know there’s a problem until they’ve hit it. In this case, workers driving sheet piling nearby could have shifted something that was holding things up or caused disruptive vibrations, according to Lehman. 

“We’re always happy when no one gets hurt, and then doing the forensics to figure out what happened so that you can write some of that information into future codes so it doesn’t happen again,” Lehman said. “It’s important that you really get to the root cause for the future, so you don’t encounter that again when you’re not as fortunate and have loss of life or someone gets hurt.”

American roads are in bad shape with a D grade, according to ASCE’s latest infrastructure report card, and bridges are the only type of infrastructure that have gone down in grade since the last report card, to a C. The $1.2 trillion Infrastructure Investment and Jobs Act aims to help address the problem, with $350 billion toward federal highway programs over a five-year period, including $12.5 billion for bridges specifically through the IIJA’s Bridge Investment Program.

Unfortunately, the country is not doing a good job of reconstructing the structures it builds, according to Lehman. She said what’s needed is systematic replacements and improvements for infrastructure, and not just fixes that will only last a few years.

“We’ve been starving this problem so long, I kind of laugh that we’re not in a middle age crisis with our infrastructure, we’re at an old age crisis,” Lehman said. “And it’s all coming due at the same time.”