The cross-Interstate pedestrian bridge being built between a residential complex and Creighton University is a "very safe, sturdy structure" and apparently a different design than the Florida pedestrian bridge that collapsed Thursday, two engineers for the Nebraska Department of Transportation said Friday.
Mark Traynowicz, senior bridge engineer, and Khalil Jaber, deputy director of engineering, said the bridge being built over the North Freeway by NuStyle Development uses a "traditional steel truss structure," not the concrete structure apparently used in the Florida bridge.
"It's a very safe, sturdy structure that they're putting up," Traynowicz said. "We've been building trusses for hundreds of years. We're always interested to find out what happened with the one in Florida, but it really has no relevance to what they're doing here."
The NuStyle bridge will have two piers, with the span crossing the North Freeway and a tower on the east end, landing at a pedestrian mall on the Creighton campus. NuStyle's redevelopment at the former Creighton University Medical Center is at the west end.
The trusses are being built away from the piers and will be hoisted into place and bolted together, with a temporary pier at the point where they join. Jaber said there will be an overnight traffic closure to swing the trusses into place.
"Once it's up, they'll take that temporary pier out, and then it will be free-standing between the two permanent piers," Traynowicz said. Then other work — pouring a concrete deck and installing railings and a roof, will take place.
"The truss is the backbone," he said. "Once the truss is in place, that really is the structure."
Some reports have criticized the construction method of the Florida bridge, which is called Accelerated Bridge Construction. That bridge was built off-site and put into place five days before the collapse.
Traynowicz said the term is imprecise because assembling a truss off-site also speeds up the building process, but the NuStyle bridge is not considered an Accelerated Bridge Construction project.
The bridge over Highway 2 near 27th Street in Lincoln is a truss structure, he said, as is the Missouri River bridge at L Street, although on a much larger scale.
Jaber said the department reviewed the plans for the NuStyle bridge and has people inspecting it as construction proceeds. The department has authority over the bridge because it crosses a public roadway.
State highway engineers will exchange "lessons learned" once the cause of the Florida collapse is known, Jaber said.