Tampa toll say settled major claims on URS for 2004 collapse of El for $74.75m

Tampa Hillsboro (Toll) Expressway Authority (THEA) say they've settled with URS' insurer on $74,750,000 in compensation for flawed design work revealed in a collapse of their Selmon Expressway elevated ('El') while under construction in April 2004. URS, THEA's managing engineers on the El, failed to accurately characterize ground conditions and failed to design adequate pilings for the elevated structure, according to geotechnical specialists Ardaman & Associates who were called in by THEA after the collapse.

14 months into construction around 7:15am Tuesday April 13 2004 one pier of 218 subsided. It dropped 3.3m (11ft) into the ground as the structure swayed and rumbled. No one was hurt although debris rained onto the heavily trafficked surface lanes of the Selmon Crosstown Expressway below the structure, and workers on the deck on top scrambled to get clear.

Initially the theory was that the collapse of Pier 97 was due to an anomaly or unusual 'sinkhole' beneath the pilings of this one pier. 

But then in June another pier was found to have settled a few inches, and Ardaman declared a systemic problem.

Construction was halted. Investigation found the bridge builder Figg Engineering was building the structure to specifications and there had been no failures in the structure.

The specifications written by URS for the pilings were wrong, badly wrong. (Pilings are the underground concrete shafts drilled or driven down to provide upward resistance to the downward weight transmitted through the piers or above-ground columns of the structure.)

Ardaman concluded that of 204 piers built only 39 had adequate pilings. 60 were marginally adequate, but 105 needed elaborate 'sister' shafts to be built on either side of the pier and huge collars or caps built to join the extra shafts to the top of the original pilings.

This made it a major rebuild job.

14 piers weren't yet started asnd could be built with beefier pilings from scratch.

URS said they would stand by their work and initially participated in the repair program.

But URS engineers said that the recommendations of Ardaman for repairs were excessive, going well beyond what was necessary.

Firings

In December 2004 URS were dismissed from the job, and HNTB hired to replace them as general engineering consultants. 

Pat McCue the executive director of THEA who had been the driving force behind the El had been sacked in October 2004 and a Florida DOT engineer Ralph Mervine installed in his place.

Testing and shafts for sister piles were driven through the first half of 2005 and work resumed on the prefabricated concrete box girder superstructure that formed the elevated roadway.

Success in operation

July 18 2006 the El finally opened to traffic. It has been a big success. There hav been no further structural problems.

3-lanes reversible over most of its 15km (9 miles), with the pair of surface lanes it provides 5 lanes in the peak direction to the central business district morning and evening. 20+ minute journeys were made into 10 minute trips.

Traffic is well ahead of preconstruction forecasts.

$120m claimed

But the halt in construction, the testing program and the supplementary pilings added about $100m to the $320m cost of the project and it opened 18 months late.

THEA initially claimed $120m in compensation for the repairs and lost revenues.

There were law suits, attempts at arbitration and mediation.

THEA has got small amounts of compensation from Figg Engineering, the builder, and $6.5m from its own insurer. With $74.75m from URS' insurer it now has $82m and is pursuing a further $5m.

http://www.tampa-xway.com/

TOLLROADSnews 2009-06-30