TxDOT Provides Update on Harbor Bridge Work


Following delays over design safety concerns last year, the Texas Department of Transportation recently provided an update on the ongoing progress for the new Harbor Bridge. According to reports, “overlapping construction” has aided the Department contractor Flatiron-Dragados in moving the project forward.

TxDOT also reportedly plans to release new information about the construction flaws later this month.

Project Background

Beginning in 2015, joint venture Flatiron/Dragados LLC was chosen by TxDOT for the design-build contract for the new Harbor Bridge.

The new bridge is slated to carry U.S. Route 181 across the Corpus Christi Ship Channel off Corpus Christi Bay, replacing the current Harbor Bridge, a through arch bridge that was built in 1959. Once completed, the bridge will be the longest cable-stayed bridge in the United States. According to TxDOT at the time, the total cost of the project—including the construction of the new bridge and the demolition of the current one—would be approximately $802.9 million.

In March 2017, construction activities began on the project, and by February 2019, crews had completed concrete placement on the first lift of the south tower.

The following month, Flatiron/Dragados announced that the project would likely not meet its April 2020 completion deadline. However, the first span had been put into place on the north side of the ship channel, marking a significant milestone. Company officials attributed the delay to weather conditions and permitting issues.

In November 2019, TxDOT declared the suspension of design work for the Harbor Bridge. The announcement arrived after the National Transportation Safety Board released its findings related to the FIU bridge collapse in October, revealing that the probable cause was related to load and capacity calculation errors made by the Harbor Bridge project’s designer FIGG Bridge Engineers Inc.

Consequently, at the beginning of 2020, TxDOT requested that Flatiron/Dragados LLC replace FIGG. FIGG had overseen designs for the Harbor Bridge’s main spans—which are included in the cable-supported section of the bridge that will cross the Corpus Christi Ship Channel.

Due to the suspension and previous delays, the Harbor project’s original completion date—slated for 2021—was pushed back to early 2023, increasing the project’s total to $930 million.

In July of last year, TxDOT halted construction on the new span due to safety concerns, only impacting construction regarding the new cable-stayed portion of the project. In a letter released to the public, which dated the same day construction was halted, TxDOT wrote to Flatiron/Dragados Project Manager Keith Armstrong in response to the upcoming installation of delta frames and the suspension of work over safety issues.

Eariler in the year, the department had consulted bridge design and engineering service International Bridge Technologies to independently review the designs. The company concluded that there are “significant design flaws that raise serious concerns about the safety of the New Harbor Bridge.”

While IBT found “numerous technical findings and observations” to be addressed, the department explained that the five areas of primary concern include:

  • Inadequate capacity of the pylon drilled shafts;
  • Deficiencies in footing caps that led IBT to report that the bridge would collapse under certain load conditions;
  • Delta frame design defects, primarily related to the connections between the delta frames and the adjacent precast box units;
  • Significant uplift at the intermediate piers; and
  • Excessive torsion and other stresses related to crane placement during construction.

The letter also adds that Flatiron/Dragados, as well as its Engineer of Record Arup-CFC, have failed to “adequately address the nonconforming design,” continuing to deny any problems with the design “despite ample evidence to the contrary.

Flatiron/Dragados also sent a letter to TxDOT, acknowledging full responsibility for a safe design and construction of a safe bridge. The contractor committed “to do whatever needs to be done, including any changes to our teams’ culture as necessary, to assure that the FDLLC and the TxDOT teams are able to work collaboratively toward the successful conclusion of this project.”

As part of the commitment, Flatiron/Dragados would provide design and install the items of work to resolve the concerns listed in the report at its expense.

On Aug. 30, Armstrong provided a follow-up letter outlining a preliminary schedule and action plan regarding the bridge’s design concerns. The plan defines the following proposed design changes:

  • Extend the footings adjacent to the tower legs and add additional drilled shafts to each tower;
  • Add longitudinal and transverse reinforcement to the top of the in-situ concrete joint between the delta frame and adjacent precast segment and make continuous into both precast units;
  • Modify the bridge design to prevent bearing decompression from occurring at strength-limit state;
  • Establish limiting values of tension strain in the bottom flange of the superstructure above the temporary pier and monitor during construction; and
  • Restart meetings and dialogue to resolve any other items of concern.

Then, in November, work partially resumed on the bridge as a design fix for the delta frames was approved by the project’s engineer of record. The Caller Times reports that, as of October, the north approach was 81% complete and the south approach was 87% complete. Roadworks for the north and south approaches were 91% and 84% complete, respectively, and utilities were at 95%.

According to FDLLC, all of the concrete approach segments have been completed. The main span segment casting was reportedly 59% finished, with the delta frame casting at 77% completion.

Reports indicated that deficiencies in the bridge's main span design, including elements of the bridge's foundation and stability in certain wind conditions, and the specific crane placements during the construction process of the main span, had yet to be addressed at the time.

Additionally, the project was pushed back once again, with a tentative completion date in 2025. An official timeline was expected to be provided when design concerns were resolved.

Latest Progress

Currently, according to reports, the foundation footing is going up for the bridge to support the structure of the tower that will hold the cables and the bridge deck.

“The drill shafts of the foundation that go underneath the footings—we'll complete those on the north tower this month,” said TxDOT District Engineer Valente Olivarez Jr. “And then we'll move over to south tower and work on those.

“And while we're working on the ones at the south tower, Flatiron Dragados’ team will continue to work on expanding the footing to go and encompass over the drill shafts that have been ports.”

Olivarez said that the overlapping construction schedule has helped the project move forward. Additionally, roadwork and bridge work has been happening around Interstate 37.

"Hopefully what we're looking at here, as far as Flatiron Dragados and their schedule, is that we may be able to shift traffic sometime in March on Interstate 37, which will open up a lot more areas to work underneath that interchange for the roadway and bridge crews to continue construction in those areas," he said.

Olivarez reported that TxDOT plans to release information about the specific construction flaws that caused the recent delay after the fifth item is addressed this month.

Routine painting on the existing Harbor Bridge also began earlier this month, with work including coating steel truss members above and below the bridge deck. The project will reportedly require lane closures on the bridge in March.

Weather permitting, the painting project is expected to be completed this summer.


Tagged categories: Bridges; Bridges; Contractors; Contracts; Department of Transportation (DOT); Design; Government contracts; NA; North America; Ongoing projects; Program/Project Management; Safety

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