Texas DOT “Tunes” One-of-a-Kind Network-Tied Arch Bridge

After opening to the public last fall, the cables of the unique Northaven Trail Bridge in Dallas, Texas, needed some “tuning.”

The only known network-tied arch bridge with a doubly-curved deck and skewed supports, the structure – which spans the U.S. 75/North Central Expressway – has 64 cables that require precise tightening to properly support the nearly half-mile, 800,000-pound bridge. The unique bridge was built off-site and moved into place over one weekend, opening to traffic in late 2023. (To watch the bridge's move, check out the Texas Department of Transportation video at the end of this story.) 

In fact, bridge design firm HNTB, which designed the Northaven Trail Bridge, used a specialized matrix calculation table of its own design to twist and adjust each cable properly.

“If you change one spoke or cable, you change the load on all the others,” said HNTB’s Chief Bridge Engineer Ted Zoli. “We’re adjusting the spokes in such a way to not only get the bridge deck in the right position, but also to make sure the cables are best able to share the loads.”

Designed to withstand a pedestrian load of approximately 445,000 pounds, HNTB’s website states the bridge’s cable arrangement “was carefully designed to increase the stiffness of the structure by a factor of 10, making it incredibly resilient to accidental overloads.” 

Building the Northaven Trail Bridge was a collaboration among the Texas Department of Transportation, the City of Dallas, Dallas County, the North Central Texas Council of Governments, HNTB and construction contractor Ragle Inc.

To watch the weekend bridge move, check out TxDOT's video below: