When the westbound Washington Bridge was suddenly shut down in December 2023, never to re-open, many wondered if the crisis could have been prevented. An investigation by Rhode Island PBS and The Public’s Radio found that the Rhode Island Department of Transportation (RIDOT) may have failed to perform crucial inspections of the span that could have warned of the bridge’s deterioration.
A report commissioned by RIDOT in the aftermath of the shutdown found a laundry list of deficiencies, including within components that can’t be seen during the routine visual inspections to which the bridge was subject. However, it is often possible to assess the health of these components via special inspections using technology like radar, engineers told Rhode Island PBS and The Public’s Radio.
It does not appear that RIDOT conducted inspections using these methods, according to documents obtained through multiple public records requests.
Problems with the post-tensioning system
Many of the problems with the bridge relate to what’s called the post-tensioning system, which involves steel cables called “tendons” running through ducts in concrete.
“The cables … act like a rubber band that squeezes the concrete and keeps it in place,” said David Lattanzi, an associate professor at George Mason University. He’s a former bridge engineer and inspector. One issue, he said, is that many important components found in the westbound Washington Bridge are buried in concrete.
“You’re trying to look inside these ducts to see what is going on, but visually we can’t inspect them,” Lattanzi said. “And so we need to use other technologies to verify that we’ve got a good seal or whether or not there’s water inside. And this has been a longstanding problem for those kinds of components.”
The bridge opened to traffic in the late 1960s. While its closure was a shock to Rhode Islanders, corrosion in post-tension tendons is not a new issue in the world of bridge engineering. It’s a problem that’s been known for decades.
“These post-tension ducts and especially at this era, became something that engineers across the country have dealt with,” Lattanzi said. “It was just really hard at that time because you could create an air gap in the duct and you wouldn’t – you can’t see it.”
Gaps can allow water, and road salt applied in cold-weather climates, to corrode steel components.
In 1999, a bridge in the Florida Keys was found to have a post-tension tendon failure caused by corrosion; the tendon went on to be replaced. Other bridges in Florida, as well as Pennsylvania, Virginia, Minnesota, Indiana and South Carolina – and bridges in Europe – have also had these kinds of problems, according to a report by the Federal Highway Administration.
“If anything happens to that post-tensioning cable or rod … in terms of fracture or corrosion, [then] you can have a very sudden failure,” said Andrew Smyth, a professor of civil engineering and engineering mechanics at Columbia University. “You can also have just weakening if there’s cracks or other deterioration of the grout that’s holding the post-tensioning cable. It just allows a sort of relaxation and then you run the risk of the sort of sudden catastrophic failure.”
Rhode Island PBS and The Public’s Radio asked RIDOT for an interview with director Peter Alviti. A spokesman declined the interview request, citing the ongoing lawsuit the state filed against 13 companies that did work related to the bridge. When the organization followed up and asked RIDOT if the department was aware of tendon failures in post-tensioned bridges across the country, a spokesman again declined to answer because of the litigation.
According to the state’s lawsuit, engineering firms failed to identify red flags that compromised the structural safety and integrity of the bridge. However, attorneys representing Rhode Island also said in filings that issues with the post-tensioning system, including concerns about corrosion from moisture and salt exposure, were first brought to the state’s attention in 1992.
Kansas-based engineer Casey Jones has been following the abrupt bridge closure from the start. He has released more than two dozen YouTube videos on the Washington Bridge.
“Rhode Island DOT’s Bridge Inspection Manual says that the ultimate responsibility for conducting and documenting these bridge inspections lies with Rhode Island DOT,” Jones said. “I’m sure if there’s some culpability with the design consultants that should be exposed and investigated, but the main person in charge is Rhode Island DOT.”
Special inspection methods
The engineers who Rhode Island PBS and The Public’s Radio spoke with said RIDOT could have been monitoring the post-tensioning components for years using special inspection methods.
“That means that you’re going to watch this thing and you’re going to use more advanced technologies and you’re going to increase the frequency of the inspections,” Lattanzi said.
Lattanzi and others point to bridge inspection technologies that operate like an X-ray and offer an internal scan of bridge components, detecting issues like bad grouting and pockets of moisture.
“The broad term that we use for this kind of thing is what’s known as non-destructive evaluation or non-destructive testing. Sometimes we call this NDE, and that’s a blanket term for any kind of special non-visual technique that we use to assess a structure,” Lattanzi said. “The two that are the most common were something called ground penetrating radar, which is just what it sounds like. It’s a way of sending radar pulses that, you know, you bounce back and then they get received.”
The other, he said, is magnetic flux leakage, which tests how much magnetism there is in a metal component. And there are other NDE techniques that could have been used.
“There’s impact echo and ultrasonic techniques that can also detect the presence of voids and cracks or delamination in different systems,” Smyth said. “One can also measure the humidity in these post-tensioning ducts. And so if the air is more humid than it indicates an infiltration of water into those areas.”
Documents provided by RIDOT show the westbound Washington Bridge was inspected annually from 2015-2023. In 2023, a typical instance, inspectors from engineering consultancy AECOM submitted a 25-page inspection report, complete with 300 photos. According to the report, they used ladders, 60- and 80-foot lifts and air monitoring equipment to document pages of notes on the bridge’s condition. The report makes no mention of any NDE technology.
Dana Tawil, a structural engineer and a PhD student at the University of Ottawa focused on corrosion in concrete bridges, said routine visual inspections can lead to recommending NDE inspections.
Tawil said a bridge owner should engage in a non-destructive evaluation “once there are signs of damage” including cracking and what’s known as spalling — when pieces of concrete deteriorate and chip away or fall off.
A review of inspection reports from 2015-2023 revealed numerous examples across the years of cracked concrete, deep spalling and broken rebar in piers connected to the post-tension system, as well as structural elements that were supposed to be encased in concrete but had been exposed after concrete apparently chipped away. Tawil and other engineers said photos illustrate how the bridge could have benefitted from a non-destructive evaluation.
“When you have this much damage in the structural elements or components around the tendons … I would definitely move forward to do some non-destructive evaluation of the tendons,” said Tawil, referencing photos taken during a 2021 inspection.
Professor Andrew Bechtel is the chair of the department of civil engineering at the College of New Jersey. He looked at photos taken during a 2016 inspection and was struck by the amount of corrosion on one of the bridge’s beams and the area behind it.
“Water will destroy every civil engineering creation that there is,” Bechtel said. “We drain the bridge to the abutments, so keeping them clear and controlling the water will ultimately control the corrosion of the abutments.”
Engineer Casey Jones said it appears that “people weren’t putting eyes on certain aspects of the bridge on inspection after inspection. And that should be – the reason for that should be addressed.”
Rhode Island PBS and The Public’s Radio asked if RIDOT had used any NDE techniques to inspect for corrosion in the post-tensioning system prior to the bridge’s emergency closure. A spokesman for RIDOT said the department couldn’t answer that, citing the ongoing lawsuit. Rhode Island PBS and The Public’s Radio also asked RIDOT for a list of special inspections done on the bridge since 2014 – none of the reports they shared included NDE techniques. A public records request for contracts for special inspections of the westbound span yielded only contracts for bridge inspections dated after the bridge had been closed.
According to the Federal Highway Administration, it’s up to bridge owners, in this case RIDOT, to decide what type of special inspection it conducts.
Documents obtained by Rhode Island PBS and The Public’s Radio do show evidence of one instance of NDE tests: In the engineering report released in March 2024, three months after the bridge was closed, the consultants described using ground-penetrating radar and ultrasound technology to assess the condition of some of the post-tension tendons following the emergency closure of the bridge.
Replace or repair?
Given the numerous problems found by engineering consultants following the shutdown of the westbound Washington Bridge, it’s not clear the closure could have been averted. However, inspections using NDE techniques may have given the department more time to prepare, according to Lattanzi.
“One of the problems with this type of component is that it is extremely hard to repair,” Lattanzi said. “[RIDOT] could have done things that would’ve provided an extra 10 years, 20 years, and that would’ve … allowed them to do better capital allocation and better planning for a new bridge replacement.”
RIDOT would not say how long it initially expected to keep the bridge in service, but it shut down the structure more than 50 years after it opened. The department had already spent $34.5 million dollars rehabilitating the bridge since October of 2021 – a project that was expected to cost a total of $78 million, raising questions about whether repairing an old bridge was a wise use of taxpayer money.
“Foresight would’ve had me say, ‘Do you know what? This is going to cost us too much money in the long term,” said College of New Jersey’s Andrew Bechtel. “We need to replace it before it becomes an issue.’”
Ultimately, Lattanzi said Rhode Island is extraordinarily lucky that an engineer spotted the broken anchor rods nearly a year-and-a-half ago.
“The tie rods didn’t cause a major safety issue, but they triggered a deeper investigation that found a worse issue,” Lattanzi said. “It’s kind of the analogy of you go to the doctor because you’ve got heartburn, and then that triggers the doctor to do blood work and it comes back that you have some sort of a serious issue, and it’s only because you went to the doctor for something else that they were able to see you and make that assessment.”
That shouldn’t stop RIDOT and engineers around the country from learning from the Washington Bridge’s failure, according to engineer Casey Jones.
“There are important lessons, I think, that need to be learned and I don’t see any will within the leadership of Rhode Island DOT to answer such questions,” Jones said.
On June 6, RIDOT plans to announce who will build the new westbound bridge and how long it will take. State officials have said it won’t include the problematic components that forced the closure of the old bridge.
This story is part of Breaking Point: The Washington Bridge, a community-centered project from Rhode Island PBS and The Public’s Radio.
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