After a fatal tragedy last year, transportation officials aren’t taking chances with the girders over Interstate 70.
Last May, a 40-ton steel girder killed a family driving under a bridge where C-470 crosses over Interstate 70. The Colorado Department of Transportation is planning to return to work on the girder next week, but officials said they are taking more precautions this time around. They delayed the project this week because of a safety issue.
William, Anita and Koby Anne Post were killed in the accident. The deaths prompted an investigation which won’t be concluded until next summer, said CDOT spokeswoman Stacy Stegman. In the meantime, CDOT will be more involved in the bridge-building process than they were before, she said.
“We didn’t have specifics in place that required formal planning of our contractors for bridge installation,” Stegman said. “It was much less formal. We would maybe talk about sequencing, or traffic control, but it was left up to the contractors to determine the best method for installing girders.”
Because there is no federal standard for monitoring bridge construction, Stegman said procedures range from state to state. Stegman said CDOT surveyed other states and decided to take a middle route with their new requirements.
“There were other states like us that relied only on the expertise of contractors and some where the state has to actually approve the plan,” she said. “We now require our contractors to submit an erection plan and we don’t approve it, but review it. If there is anything lacking, we ask them to revise it. We’re somewhere in the middle, where we require a plan that needs to be stamped by an engineer.”
Jalisco International of Commerce City was contracted by CDOT for a project currently underway at eastbound I-70 and C-470. Nine girder segments will be installed as part of the interchange improvement project, which is scheduled to begin next Monday.
The project was delayed this week because a bearing plate did not pass final CDOT inspection.
Jalisco International safety officer Antonio Ledezma said a subcontractor, Rocky Mountain Structures of Englewood, will work on the bridge and will install two segments at a time, simultaneously, to ensure structural integrity.
“The possibility of them tipping over is essentially zero because it is like you are creating a box instead of a column,” Ledezma said.
Stegman said weather delays were part of the reason that only one segment was put in place in 2004.
“They installed one line of girders, making it inherently unstable,” Stegman said. “They put temporary braces that time. This go-around they have to install two lines together and the braces they put in between the girders are permanent, not temporary, so they can’t wobble and move.”
Stegman said CDOT is also erring on the side of safety, even if it means additional closures on a major highway.
“We believe in this process,” she said. “If something goes wrong, if we have to take something down or keep the road closed to move toward to another step, we will.”