DOT Engineers Get Creative To Test Strength Of Bridge
Posted June 10, 2003 11:50 a.m. EDT
RALEIGH, N.C. — The North Carolina Department of Transportation said drivers were never in danger as engineers spent Tuesday testing the strength of a new bridge design.
The Highway 401 bridge over the Neuse River in northern Wake County opened two years ago. But Tuesday, it was the center of a first-of-its-kind test.
A dump truck carrying a 40-ton load pulled up to the bridge, creating quite a scene as traffic was blocked and technicians hustled into place. The big truck then slowly pulled forward over the bridge, stopping at designated test points.
The bridge is the first of its kind in North Carolina. It uses a high-performance concrete with fewer support beams. Tuesday's test was performed to see how sturdy the bridge design was.
The bridge was wired with lines that went to sensors under the bridge. The senors fed into computers. Engineers then were going to analyze the data.
"We're trying to learn from the bridge so that we can apply it to all the other bridges in the state," engineer Tom Koch said. "There are 18,000 bridges in the state that either need to be replaced or repaired at some point in their lives."
The Highway 401 bridge is a cheaper, more efficient bridge that is supposed to last longer. But is it safe? Engineers said they would need two weeks to answer that question.
What they are hoping for is a bridge life of 75 to 100 years if the bridge passes the test.
The bridge appeared to pass the test. But the final word on whether the design goes statewide is in the computers.
When asked if taxpayers could feel good about Tuesday's test, bridge engineer Paul Zia said: "Absolutely.
"If the test is successful, it proves that the bridge is designed well."