Bridges
Flatiron-Dragados Team Completes Midspan Closure for Corpus Christi Harbor Bridge
Making the mid-span closure of the Corpus Christi Harbor Bridge's 1,661-ft main span was one of the project's most significant challenges, the contractors say.
Photo courtesy Harbor Bridge Project
Crews working on the $1.2-billion Harbor Bridge replacement project in Corpus Christi, Texas reached a milestone when they completed the main span closure in February. The new Harbor Bridge is now the longest concrete segmental cable-stayed bridge in North America and is set for a ribbon-cutting next month once remaining work is completed.
The 3,295-ft-long bridge spanning the Corpus Christi Ship Channel is planned to replace the aging Harbor Bridge, which officials with the Texas Dept. of Transportation (TxDOT) say no longer provides enough navigational clearance for large modern shipping vessels and presents some safety issues for those crossing it as it lacks shoulders and access for pedestrians or cyclists, and features a steep grade.
The new bridge includes 698 precast concrete box girders and 84 delta frames. It has a 205-ft clearance over the water and features six lanes plus a median, shoulders and a shared use path for cyclists and pedestrians. With 538-ft-tall towers, it is the tallest structure in South Texas, according to Flatiron/Dragados LLC, the joint venture leading construction for TxDOT. More than 10 million labor hours have gone into the project.
“It was truly remarkable to witness how the extensive months of design coordination across all teams culminated in a seamless execution, with the bridge responding exactly as predicted during alignment and jacking,” says Francisco Sarria, deputy construction manager with Flatiron/Dragados.
Making the mid-span closure of the 1,661-ft-long main span was one of the project’s most significant challenges, says Lynn Allison, project spokesperson for Flatiron/Dragados. The team used a pair of strongback beams to achieve vertical and horizontal alignment, and installed a pair of struts at the top and bottom of the cross-section to resist axial and bending forces. Crews temporarily stressed some of the permanent tendons across the open joint to manage top deck stresses adjacent to the closure joint, and installed eight 3-in.-dia. post-tensioning bars through the bottom struts to address tension under some scenarios.
The team used continuous geometric monitoring to ensure the cantilever tips met within a few inches of the planned vertical alignment and within a fraction of an inch horizontally, both falling within the allowable tolerances and operational range of the temporary works, according to Allison. Once the cantilevers were aligned, crews jacked apart their tips to a specified axial force.
Construction of the Harbor Bridge is nearing completion. Photo courtesy Harbor Bridge Project “The connection and meeting of the two spans within a fraction of an inch shows the amount of precision, care and expertise taken with the design and construction of the bridge,” says Joseph Briones, TxDOT deputy district engineering for the Corpus Christi area. “The fact that this was accomplished with each cantilevered span over 800 ft long and at a height of over 200 ft provides further certainty as to the safety and integrity of this structure.”
The project team overcame several hurdles to reach this point. TxDOT halted work twice over concerns with design work by FIGG Bridge Engineers following the 2018 collapse of a FIGG-designed pedestrian bridge in Florida. Flatiron/Dragados selected a team of Arup and CFC to replace FIGG as the engineer-of-record on the project, and TxDOT also required a slate of changes to the design based on an independent review by International Bridge Technologies. TxDOT and Flatiron/Dragados ultimately settled the remaining disputes in 2023.
With the main span complete, crews are completing lighting illumination on the upper pylons and delta frames and installing barriers and railing, drainage and stay dampers. TxDOT plans to hold a dedication ceremony and inaugural crossing on May 10, and Allison says it will permanently open to traffic later in May.
Demolition of the old Harbor Bridge is planned to follow the new bridge’s opening. The new bridge is designed to last 170 years.
