A Precedent-Setting Case

Miami Federal Courthouse Project Faced Uniquely Demanding Criteria

By Scott Judy

Scheduled for completion in July, the 577,000-sq.-ft., 14-story federal courthouse will complement an adjacent existing federal courthouse square complex in downtown Miami.

With its strict building code and tight labor market, South Florida can be a demanding environment for designers and builders.

In addition to those usual hurdles, the construction groups building the new $163 million Wilkie D. Ferguson Jr. U.S. Courthouse in downtown Miami also had to overcome other design and construction issues - including impacts from four hurricanes and criteria that at times were in direct opposition to each other.

Designed by Miami-based Arquitectonica and national architecture firm HOK, the new courthouse features curving lines and a glass exterior - a material chosen to reflect today's judicial system.

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Dennis Wilhelm, archivist for Arquitectonica, said the glass was selected to make the building "primarily transparent and open, reflecting the integrity of the court while emphasizing equality before the law."

The 14-story courthouse is further designed to be viewed as two opposing towers that are separated, yet connected, by a bridge. "The opposing towers represent the two sides of each case heard before the courts," Wilhelm said. "The transparent bridge represents the truth that is being sought by the court and which lies somewhere between the two opposing sides."

The two towers are connected by a lobby-type area that repeats on every floor. A conical glass atrium hangs down through the center of the building. It decreases in size as it rises through the building and terminates in a skylight.

The facility will house 14 district courtrooms, 16 chambers for the U.S. District Court, space for the U.S. Marshals Service, the federal public defender, the U.S. attorney and the building's owner, the General Services Administration.

It will complement the adjacent existing Federal Courthouse Square complex, which includes the existing U.S. District Court, the Dyer Building Courthouse, the Federal Detention Center and the James Lawrence King Federal Building.

Outside

Dick Corp. of Miami is serving as construction manager-as-constructor, and is currently heading toward a July completion. The value of the company's contract is roughly $125 million. EllisDon Construction, with offices in Miami, is serving as the construction manager-as-advisor to the GSA.

The building's nonlinear design - concave on one side of the building, convex on the other - brought with it construction hurdles.

"There aren't a lot of straight lines in the building," said Gene Budler, vice president of operations with Dick Corp. "It's shaped like a boat, so the layout was quite a challenge."

Capform of Texas performed all of the structural concrete work and finished on time just as concrete shortages and inflation started impacting the South Florida area.

"We lucked out in that our concrete finished weeks before (prices) took off," Budler said. The project's timing also allowed the contractors to avoid similar availability and price issues with steel.

A more demanding issue surrounded the design and installation of the curtain wall exterior. Here, the project's location and function as a federal facility combined to provide the engineers and contractors with a major issue - how to design a curtain wall system that could meet the sometimes-opposing criteria of local wind-load requirements as well as federal specs for blast resistance. This was believed to be a unique set of criteria for such a project.

"Hurricane resistance says you've got to be really rigid, and if a coconut gets thrown at (a window) it doesn't break," Budler said. "Blast criteria requires the membranes blow out first, and the structure remains behind, so there's no massive implosion that causes massive damage. So we had two sets of conflicting requirements."

The contractor chose an internationally known subcontractor, Antamex International of Canada, to handle this work.

"It was more an engineering challenge than a fabrication challenge," Budler added.

Gary M. Mote, chief and public information officer with GSA in Atlanta, said his agency developed a performance specification requiring the builder to meet both criteria. "The performance criteria were developed by our blast consultant (Weidlinger Associates of Tallahassee, Fla.) and through wind tunnel studies," he added.

Mote said the Arquitectonica/HOK team conducted wind-tunnel studies using a scaled mock-up of the building to establish the wind loads that were to be accommodated on each part of the exterior wall system.

"Our blast expert developed load tables based upon building standoffs to establish the required blast resistance for glass, mullions and precast elements from the ground to the top of the structure," Mote said. "Extensive mock-up tests were conducted in Miami to establish the performance of the exterior wall for large and small impacts. Any opposing criteria were resolved by the engineers working for the building contractor to meet the performance specifications."

Once the curtain wall was engineered, the installation proceeded quickly. Antamex started the installation in early March of 2004 and had the building enclosed by August.

Inside

The other design highlight, the interior atrium cone, was another construction hurdle. Measuring roughly 130 ft. tall, it starts at the seventh floor and continues to the ceiling. Some of the most demanding installations for this element, within the atrium space, involved sound baffles (perforated metal panels) that were specifically placed to eliminate any unwanted acoustical effects from the circular piece.

Erection of the cone was performed by first erecting the skylight to dry-in the building. Erection then proceeded, starting at the seventh floor and proceeding upwards to tie the element into the skylight. Antamex also performed this work.

"Putting all of this trim in was extremely challenging because you had to rig it from the top and drop down level by level," Budler said. In all, this task took about five months to complete - longer than the team had anticipated. However, the work didn't impact any other trades and did not delay the project.

Budler said Dick Corp. phased the project to progress on two "fronts" at once: floors five through nine and then from the 10th floor up. This was done because five through nine are office floors and 10 through 13 are court floors, with each set featuring redundancies - and therefore efficiencies for the interior trades. The 14th floor is a judges' congregation/lunchroom/library area.

"As soon as the structure was up and the building was dried in, we started on level five going up and on level 10 going up," Budler said.

Decision

Dick Corp. has worked on numerous federal projects, including the Sandra Day O'Connor U.S. Courthouse in Phoenix, and several of the contractor's staff were involved with that project and other GSA projects throughout the country.

Budler, who was not involved in the Phoenix project, said the combination of blast and wind-load criteria on the Miami job may have made this one more daunting.

"I'd think everybody would say this is more challenging," he said. "It's just very unique."

As for his own experience, Budler said this courthouse was among the more trying he's worked on, but was not the most difficult.

"I wouldn't say this was the toughest, but it's not the easiest," he added. "It had its own set of unique challenges - a lot of them completely impossible to anticipate. No one knew four hurricanes were coming."

Notably, GSA appears pleased, with Mote indicating Dick Corp. has "performed well" to date.

"The building will be very dramatic and we hope it will become a well-received landmark," Mote said.