Advertisement
  1. Archive

Tests bode poorly for Crosstown

The bad news keeps piling up for the new elevated lanes of the Lee Roy Selmon Crosstown Expressway.

Ongoing tests of soil and rock beneath the bridge's supports have confirmed that most of them are resting on unstable ground. Of the 35 supports on which analysis has been completed, as many as 31 will need additional work ranging from simple to complex, Pat McCue, executive director of the Tampa-Hillsborough Expressway Authority, said Wednesday.

And there are more problems: The authority had hoped to borrow some of the repair funds from the Florida Department of Transportation, on top of the $100-million borrowed for the project initially. But now that the DOT faces an estimated $1-billion in expenses repairing roads and bridges damaged by four hurricanes, additional financial aid for the Selmon Expressway is problematic.

While much of the hurricane repair money is reimbursable from federal sources, the work could leave the DOT spread thin in the short term.

"A few months ago, we were the only ones looking to FDOT for help, but now there's a whole bunch," McCue said. "We have no reason to think they won't give us some help, but not as much."

These are just the latest in a deluge of setbacks for the $350-million project, which had been on schedule to open next summer. Now, the worst-case scenario is that it will cost $70-million to reinforce the columns supporting the 6-mile long bridge if most of the 224 columns need shoring up.

Meanwhile, in an effort to husband funds, the authority wants to "lay off" one contractor, PCL Civil Constructors Inc., for up to six months while the rest of the support columns are tested and repairs begun. PCL is responsible for building and installing the support columns.

No one is blaming PCL for the project's problems, but all work on the elevated lanes has ceased. It is costing the authority $100,000 a day to keep PCL and its employees on the job with little to do.

"We are continuing work on the nonelevated portions of the project, but it could be anywhere from four to six months until we're ready to start work on the elevated lanes again," McCue said.

The Expressway Authority is holding URS Construction Services, the general engineering consultant on the project, responsible for the column problems since URS designed the structures based on its soil testing.

McCue has said in the past that URS was not sufficiently conservative in gauging the strength of the rock under the columns.

The problems became apparent in April when one column near 50th Street dropped 11 feet into the ground, taking a section of roadway with it. Then, in July, a second column settled 1.3 inches, which is beyond the project's safety tolerance. Both were found to have inadequate underground support.

The authority is negotiating with URS on the question of who will pay to fix the problems.

"To date, URS has agreed to pay for the field-testing and design of foundation repairs, and they are presently working with their insurance company to determine their financial participation in the construction of the repairs," McCue wrote in a report to the authority board.

URS has insurance policies that exceed $100-million, McCue said.

Suzie Boland, president of RFB Communications Group in Tampa, the outside spokeswoman for URS, confirmed that the company already has agreed to pay some of the costs of repairs.

"URS has agreed to pay for geotechnical studies of all supports, which includes necessary design work (on repairs) and for dynamic load testing of representative foundations," Boland said.

The load testing involves the transport from California of a large piece of equipment that will tamp on columns that do not have roadway built on them to determine if the columns can withstand intense downward force.

But Boland said it is too early to discuss what URS's insurance might cover.

"This question is premature until we get the results of testing," she said.

The geotechnical tests, which involve seismic testing of the soils around and under each column, are being conducted by foundation specialists Ardaman & Associates. They should be completed within the next four months, although repairs will begin in October with column No. 97, the first that sank.

That pillar has been removed to ground level. Two additional supports will be built on either side of the original, much deeper than the original. Then a platform will be built across all three, so that the weight of the column above ground, and the roadway it cradles, will be distributed across all three below-ground pillars.

The Expressway Authority's insurer will pay for this repair.

Other columns might require the same extensive repairs, McCue said, though in some cases it might be enough to pour grout into the unstable soils around columns to solidify the ground.

In December, McCue said, the authority will sell additional bonds to finance the rest of the project while negotiations with URS proceed.

"While the authority ultimately intends to recover all costs from URS, some of the costs already have been incurred, and others are likely to be challenged by URS," McCue said in his report. The authority will have to cover the costs of the repairs until they can be recovered through a settlement or lawsuit, he wrote.

When if finally opens, the elevated expressway will provide three express lanes for SunPass customers from Brandon to Tampa in the morning rush. The lanes will reverse for the outbound rush in the evening.

Fixing the pillars

One way to strengthen foundation pillars for the elevated lanes of the Lee Roy Selmon Crosstown Expressway is to put to smaller pillars on each side of the original and drill them deeper into solid bedrock limestone.

The original foundation pillar is 6 feet diagonally. The two new pillars would be 4 feet each.

A cap would cover all three pillars like a tabletop on which the above-ground bridge support would stand to distribute the weight of the roadway and stabilize it.

Source: Tampa Hillsborough Expressway Authority

YOU MIGHT ALSO LIKE

Advertisement
Advertisement