Stimulating Tulsa’s IDL

The recently completed $75 million project along the Tulsa Inner Dispersal Loop (IDL) included traffic lane and bridge reconstruction of I-244’s west and north loop segments around downtown Tulsa. The most critical work for the IDL centered on reconstruction and paving of the 44 bridges.

A majority of these bridges were rated as structurally deficient. Reed Wood, general superintendent for Manhattan Road & Bridge , explained, “Every bridge required deck removal to the top of the beams, and we fixed some of the substructure on those in worse condition.”

The bridges along Tulsa’s IDL closely mirror bridge conditions throughout the U.S. With most built in the 1960s, they were in rough condition. “On an NBI (National Bridge Inventory) rating of 0 to 10 with 4 being structurally deficient, a majority of the bridges on the IDL were rated at 4 or less,” added Travis Smith, resident manager–Tulsa Residency for ODOT.

Facing a $20,000 per-day disincentive for missing deadlines of the 540-day contract, Manhattan had to make sure every project detail was meticulously planned. To ensure a smooth and efficient bridge-paving process, Wood met with his Terex Bid-Well representative prior to starting the project. Larry Eben (the southeast area manager for Terex Bid-Well ) and I reviewed bridge lengths, widths, crowns and flares, so we had the right equipment to pave all the decks,” he said.

The two noticed the designs presented multiple challenges for the crews and bridge pavers. Several of the decks transitioned from a left slope to a crown to a right slope. Others had a continuous span that had to be poured by skipping segments. Additionally, “one deck measured 16 ft wider from one end to the other, and the total bridge length was only 150 ft,” recalled Wood.

Nearly half of the bridges were designed at skew angles reaching 50 degrees. In order to pave the crown at the skew angle to get the proper finish, Manhattan purchased a skew bar kit. “The kit offsets the paving carriage, so it hits the same crown points on the deck from the front to the rear of the machine,” explained Eben.

The preplanning and paver helped Manhattan execute a smooth bridge reconstruction process. The 20 bridges of contract Phase 1 were completed in May 2010, and Phase II was complete within the contracted time.

The final phase included several complex bridge designs. A long continuous-span design that flared from 53 to 65 ft, Bridge 52 twisted from a 3.2% left slope to a crown at the center to a 6.2% right slope. The 1,050-ft-long Bridge 53 started at a flat grade and 2-ft crown, but at a distance of 300 ft from the header, this crown expanded to a lane width, which required adding a longitudinal joint from the abutment to Pier 2.

Yet even with these challenges, Manhattan’s crews paved exceptionally smooth decks.