Saudis Planning To Build World's Tallest Skyscraperv - PiFFko news!

If a Middle East prince has his way, Saudi Arabia will someday be home to the world's tallest building. Alwaleed Bin Talal Bin Abdulaziz recently unveiled a scheme for a 5.3-sq-kilometer city north of Jeddah that would include a mixed-use supertower designed to reach more 1 km above the desert floor.

Kingdom Tower, under design by Adrian Smith + Gordon Gill Architecture, with structural engineer Thornton Tomasetti, would enclose 530,000 sq m. The skyscraper is expected to cost $1.2 billion. The main contractor on the project is the Saudi Binladin Group. According to the architect, the foundations are designed, and the contract for the piles is already under tender. The Kingdom City development is expected to cost $20 billion.

Martin Luther King Memorial Dream Becomes Reality

The decades-long dream to create the Martin Luther King Jr. National Memorial in Washington, D.C., will become a reality on Aug. 28. Fifteen years in the making, the memorial faced challenges—ranging from an extensive approval process to a site on the National Mall made of fill from the Potomac River—before construction could start in late 2009. Two years later, the design-build team, the first use of the delivery system for a memorial on the Mall, will deliver the $120-million vision within walking distance of the spot where Dr. King delivered his “I Have a Dream” speech 48 years ago.

First authorized in 1996, the high-profile memorial has a mix of significant private and public stakeholders, including the Federal Commission of Fine Arts (FCFA), the National Park Service, the National Capital Planning Commission and the Martin Luther King Jr. National Memorial Project Foundation. Dr. Ed Jackson, executive architect with the foundation, says after ROMA Design Group of San Francisco won the design competition in 2000, negotiations began in earnest.

 “Once the design competition had been completed and we had identified a winner, everyone thought the game was over. But for those of us who [know] the process here in Washington, that’s just the beginning of the game,” he says.

The project went through a trying series of approvals, including concerns raised by the FCFA in 2008 that the original sculpture concept of Dr. King was “too confrontational.” Security enhancements were also a sticking point. Plans to use a series of bollards to block vehicle entry were scrapped in favor of trees, a stone wall and bollards.

Once consensus was reached, the National Park Service signed off on the project in October 2009, allowing work to begin.

Darien Grant, project executive with Turner Construction, New York City, credits the design-build process for getting the project through the final years of approvals and getting the project on-track for its August delivery. Turner Construction partnered on the project with McKissack & McKissack, Washington D.C.; Gilford Corp., Beltsville, Md., and Turner subsidiary Tompkins Builders, Washington, to form the design-build team, which was selected in June 2007. The MLK memorial is the first memorial on the Mall to use a design-build procurement method, Grant says.

 “The [design-build] process really panned out,” he says. “If you look at the numerous stakeholders and their specific functional requirements, with the design-build process, the team brought to the table the proper intellectual horsepower to balance the desires of the owner with the requirements of the other agencies involved.”

The artistic vision for the memorial stems from the Dr. King quotation, “Out of a mountain of despair, a stone of hope,” which was part of his “I Have a Dream” speech. Upon entering the memorial, visitors will pass through a 30-ft-tall granite Mountain of Despair. Beyond the passageway, visitors will see the “Stone of Hope,” another 30-ft-tall piece of granite, carved as if it had been removed from the Mountain of Despair. A sculpture of King, created by Chinese artist Lei Yixin, is carved into the Stone of Hope, which is on the face opposite the entrance.

Additional elements include a 2,350-cu-ft, 194-ton granite inscription wall and 47,000 sq ft of granite pavers. The 450-ft-long, crescent-shaped wall displays 14 quotations from Dr. King. Landscaping includes 185 Yoshino cherry trees, 32 American elm trees and 16,835 Big Blue Liriope plantings. Two large waterfalls are served by below-grade pump rooms with a 175-ft access tunnel.

Kauffman Center for the Performing Arts Pulls Strings For Kansas City Music-Goers

In addition to a swooping, stepped concrete and sloped stainless-steel roof-line, the Kauffman Center for the Performing Arts in downtown Kansas City, Mo., features a radial glass atrium that hangs on finely tuned steel cables. The privately funded, $413-million job is set to open Sept. 16 after more than a decade of planning, design and construction.

Locals have likened architect Moshe Safdie's design to the Sydney Opera House—or to a pair of armadillos. The atrium was envisioned to resemble a cello's strings fanning over a bridge and fret-board. The cables span the 300-ft-long, 105-ft-wide glass lobby to support 48,300 sq ft of high-performance glass panels, each roughly 1.5-in. thick. To keep the ceiling and walls from caving in, a series of 27 threaded rods and corresponding cables are tensioned to an average 400 kips, or 400,000 lbs, creating the effect of a 250-mph wind load as they pull against the building superstructure.

“The cables were by far the dominant force that we needed to consider,” says G. Kelley Gipple, principal of locally based Structural Engineering Associates Inc., the main building's engineer of record.

Though most work was smooth, the project hit a snag in 2009 when a 125-ft-tall boom lift failed, tipping over and killing the operator. The family is suing the manufacturer, JLG, and others for wrongful death in Jackson County court.

Double Yolk

Organized like two egg yolks within a single shell, the building contains 4,500 tons of steel brace frames and curved box trusses. They support a precast concrete and stainless steel outer structure, which encases two cast-in-place concrete bowls: a 1,800-seat proscenium theater and a 1,600-seat orchestral hall. For acoustics, each space is isolated from each other and the over-arching canopy.

Like a stringed soloist in concert, the elegant cable-glass atrium, built by Germany-based Novum Structures LLC, took center stage during a key period of construction last year, forcing the general contractor, locally based JE Dunn Construction, to carefully sequence work around the delicate glazing operation.

“It's a one-of-a-kind structure, so there was a lot of cutting-edge planning that had to go into it,” says Kyle McQuiston, project executive for JE Dunn.

For eight weeks last summer, as the cable system was tensioned (from the center grid outward), Dunn had to stage the finishing of the building's exterior precast concrete walls, interior walls and elevators as the pulling job was done. Once the tensioning work was complete, the building's steel members had shifted 2 in. to 6 in. from their original locations. Workers were then clear to finish the build-out.

The big pull took place outside the glass atrium, across a driveway that lies underneath the stringed fanfare, where 27 rods anchor into a 50-ft-tall, 4-ft-thick concrete wall bolted into bedrock. On one side of the wall are the below-grade portions of the performance halls; the other is a 1,000-space parking garage.

At about 50 ft high at their opposite ends, the rods pull against articulating, 20-in.-thick mast tubes that frame out the glass-wall's radius. Inside the atrium, one cable follows the roof slope while another curves downward, forming a truss shape. Both cables pin to 70-ft-high brace frames, which bear on columns.

Arup, the building's design engineer, chose hardier rods outside for safety. Fire models showed that a bus exploding in the driveway would pose more risk to melting connections than would an interior fire.

The enclosure's vertical load is taken by the massive concrete wall. For extra support, concrete struts attached to the wall tie back into the main structure. This supports the driveway slab and resolves the horizontal tension with compression forces. “If you can provide a building a circular load path—keep all of the forces from the tensioned net within the building—then the foundation is much smaller,” explains Brian Markham, an associate and structural engineer in Arup's New York City office. “We could take this building and pick it up off its foundation, and the cable nets and the glass atrium would maintain their integrity.”

Seattle Voters Approve Alaska Way Viaduct Replacement Tunnel by Wide Marginм

A $2-billion deep-bore tunnel along Seattle’s downtown waterfront appears to have overcome what may be its final obstacle to construction, garnering the approval of nearly 60% of voters in a referendum on whether the city should give the notice to proceed with the project.

The tunnel, scheduled for completion in 2015, is the centerpiece of a $3.1-billion Washington State Dept. of Transportation program to replace the seismically suspect double-decked Alaskan Way Viaduct. That thoroughfare carries approximately 110,000 vehicles each day along one of Seattle’s primary north-south arteries. Damage from the 2001 Nisqually Earthquake sparked a decade-long, often-controversial effort by WSDOT to find a suitable strategy for replacing the Viaduct and the aging seawall that supports its backfilled foundation soil.

In 2009, the 1.7-mile, 57-ft dia tunnel emerged as WSDOT’s top replacement alternative compared with constructing a new above-ground structure, and doing away with an express route entirely in favor of a beefed-up street system. State and local officials assembled a funding plan that draws on federal funds, state gas tax money, a contribution from the Port of Seattle, and toll revenue from the completed tunnel. That funding also covers upgrades to the Viaduct’s less-controversial southern section, already under way.

Earlier this year, WSDOT awarded the tunnel’s design-build contract to Seattle Tunnel Partners, a joint venture of Dragados USA and Tutor Perini Corp. Other team members include Frank Coluccio Construction, Mowat Construction, HNTB, and Intecsa.

But despite a planned September groundbreaking, tunnel opponents refused to give up. Seattle Mayor Mike McGinn, a longtime tunnel skeptic, regularly battled with the pro-tunnel city council, contending that downtown property owners would be on the hook for potential cost overruns arising from the uncertainties of the waterfront’s soils. Opponents also worried that the tolls would divert traffic to already clogged city streets.

Though the city council dismissed those concerns, McGinn backed the effort to put the question to Seattle voters—did they support the city’s already negotiated agreements on utility relocations, street use, design review, and liability, allowing the project to begin on schedule?

While the city council could have kept the project moving in the face of a “no” vote by passing a new ordinance, that outcome would have almost certainly led to a new round of efforts to slow or block the project. 

In conceding the outcome of the vote, which was conducted entirely by mail, McGinn stated, “I worked to give the public a direct vote on the tunnel. The public said move ahead with the tunnel, and that’s what we’re going to do.”

Architect-Contractor Team Converts Joplin Structures to Schools in Time for Aug. 17 Opening

It took just minutes for a tornado packing 200-mph winds to level a third of Joplin, Mo.'s public schools last spring. In a remarkable turnaround, it took less than three months to bring the schools back on line in time for the new school year.

On  Aug. 17, classroom sessions resumed on schedule in Joplin, even as construction crews continued cleaning up from the May 22 tornado, an EF5 event that cut a mile-wide swath through a six-mile stretch of the city, killing more than 150 residents and injuring another 1,000. 

The tornado destroyed six of 19 school buildings and severely damaged three others, leaving school administrators scrambling to locate and renovate replacement facilities, some of which will function as fully operating schools for up to three years.

Many of the facilities initially were constructed for uses far different from schooling. Joplin High School houses 11th- and 12th-grade students in an 80,000-sq-ft Shopko store that stood vacant for 10 years, while East Middle School is operating in a 50,000-sq-ft warehouse in an industrial park.

“There was huge demand for space in the days following the tornado,” recalls assistant superintendent Angie Bessendorfer. “People find it interesting we've converted a Shopko to a high school, but the reality is, the store was the only 80,000-sq-ft space available. We didn't want our students returning to trailers in a field.”

Once FEMA agreed to fund 75% of project costs, the decision to proceed with replacement facilities was immediate, with contracts calling for work to conclude no later than Aug. 10. To help expedite construction, Missouri Gov. Jay Nixon waived the bidding requirements required for public projects.

Bessendorfer says the majority of designers and builders involved in the projects were closely associated with Joplin's school district as a result of past or pending projects.

Kevin Greischar, principal with Overland Park, Kan.-based DLR Group, design architect for the high school, arrived in Joplin on June 3 and, with a staff of six, set up shop in a classroom in one Joplin's remaining school buildings. Schematics for the $5.5-million project were performed on June 8 and the morning of June 9, then presented to administrators that afternoon. 

“We supplied a simplified floor plan, knowing we were flying the airplane at the same time we were building it,” says Greischar. Columbus, Kan.-based general contractor Crossland Construction began demolition of storage and back-office space on June 11.

“All we had were four walls and a roof,” says Crossland project superintendent Aaron Shnurbusch. “A similarly scaled school would have required a year to a year and a half to complete. Here, we had about eight weeks, so we handpicked subcontractors we'd had long relationships with and who we knew had the manpower and expertise to pull it off. The floor plan allowed us to begin by building out interior walls, with the understanding that the locations of doors and such might later be modified.”

Final design documents were completed three weeks after schematics, on June 30.

Scheduling for the $4.5-million middle school was no less forgiving.“We first learned about the project on June 3, a Friday, and developed schematics over the weekend,” says Kyle Denham, principal with Joplin-based PLJBD Architects, the project's designer. Crossland, also contractor for middle school, began work on June 13.м

The World Trade Center's Tower Crews Get the Royal Treatment

For workers raising the Western Hemisphere's soon-to-be tallest skyscraper, “fast food” has an extra dollop of meaning.

With hundreds of eateries in Lower Manhattan, crews erecting the frame of the $3.2-billion One World Trade Center—on schedule to stand 1,776 ft when substantially complete in fall 2013—have only two options when the lunch bell rings: They can frequent a Subway sandwich shop on high or “brown bag” it. However, they can't leave the premises.

The 36 shipping containers that house the shop are dubbed “the hotel” because they also contain lockers and restrooms. The hotel scheme not only minimizes vertical commute times, it prevents hoist congestion.

“The goal is to make the whole tower job move up as if workers are on the ground,” not 900 or 1,200 ft in the air, says Mel Ruffini, project executive for the local Tishman Construction Corp., a unit of AECOM Technology. The construction manager is under contract with the Port Authority of New York & New Jersey to build 1 WTC's $2.1-billion core and shell.

The hotel is novel in its own right, but it serves more than one purpose.

As part of its $256-million contract, local steel contractor DCM USA Erectors Inc. also designed the hotel to stabilize the tower's steel perimeter-tube moment-resisting frame. Under Tishman's “steel first” scheme, the hotel minimizes the needed erection-steel until the structural concrete core, 10 floors behind the steel, catches up.

There's more. Each half of the three-level hotel sits in the core void like two square donuts, each with a tower-crane mast that rises through the donut's center. The location puts a protective roof over Collavino Construction Co.'s concrete crews, who work below the ironworkers.

The roof is also a shield that allows the slower concrete operation to continue in the rain, allowing the concrete to keep pace with the steel. And hatches in the hotel floors let crews install risers on weekends, when the steel and concrete operations are idle.

The hotel is but one prop in a meticulously staged play to meet a demanding schedule for the 3.5-million-sq-ft 1 WTC, originally named the Freedom Tower. Having two tower- crane hooks for two steel operations is another prop that lets DCM jump each crane separately, followed by each hotel half. And that avoids a shutdown of steel erection. “It's like a vertical freight train,” says Ruffini.

A sky-lobby hoist system is another part of Tishman's efficiency plan. To avoid disruptive exterior-hoist shutdowns when winds exceed 30 mph, Atlantic Scaffolding, LaPorte, Texas, is providing hoists inside the building. The hoist scheme had to be planned with the structural engineer because creating a 70-story shaft to floor 100 required leaving out permanent floor beams temporarily and adding temporary beams.

Staying Out of Each Other's Hair

Tishman also developed a tactic to keep the core and curtain-wall operations out of each other's hair. A “slider” crane, which cantilevers off the tower's sloping-in northwest corner, is used exclusively for concrete rebar and lumber. The slider and its mast travel up just above the curtain wall.

These strategies facilitate the erection of two floors every two weeks. The pace is needed to keep the steel frame, currently at 960 ft, on course for topping out in March at 1,386 ft.

Tishman, which reports no deaths or major injuries to date, is obsessed with worker safety. To protect crews, expected to peak at 1,500 this year, Tishman devised another first for a steel frame in New York City: A two- story, lightweight-steel traveling system, called a “cocoon,” wraps the upper limits of the frame in heavy netting and drapes nets down 16 to 20 floors. The cocoon, lifted by crane as the steel grows, contains work platforms that hang off the steel. Ironworkers no longer have to balance on beams.

The skyscraper sits in the northwest corner of one of the world's busiest and most congested construction sites: the 16-acre WTC replacement for the 10-million-sq-ft office complex destroyed by terrorists on Sept. 11, 2001. The port authority's PATH rail tunnel crosses under the site. Construction gates have to be shared with seven major projects under way, complicating deliveries. Security is tight. Deliveries are screened.

Before construction began in 2006, Tishman spent months plotting operations, schedules and logistics to determine how to deliver a 1,368-ft office tower, topped by a 441-ft spire, on time, on budget and safely. “We micromanage to the max,” says Tishman's Ruffini. Any delay has a cascading effect on the rest of the operations coming up behind it, he adds.

At New York's New World Trade Center, Uncommon Cooperation

The $19-billion redevelopment of the original World Trade Center, destroyed on Sept. 11, 2001, by terrorists, is loaded with memories of the tragedy. But for the thousands rebuilding the 16-acre site, the work also is loaded with patriotism, indomitable spirit and a collective will to succeed.

That's fortunate because, depending on who is counting, there are at least seven major projects currently under way, each with its own team and schedule but not its own site, at least not below grade. All the projects overlap in a four-level basement.

Consequently, the work is also loaded with challenges.

“To have the opportunity to work on this project is deeply emotional but also something we're proud of,” says Nicholas Holt, a director of Skidmore, Owings & Merrill, which is the architect for the site's iconic skyscraper, the up- and-coming 1,776-ft-tall One World Trade Center.

“We knew there would be lots of opinions and that it would be politically charged. But now that the building is visible, there is “a sense of optimism” in the air, he says.

That optimism is keeping others, still in the trenches, going. The most intense conditions are out of sight, in the warren of the basement that fills the site's expanded “bathtub,” formed by the site's 90-ft-deep perimeter walls. In the four-level structure, different projects share the same mechanical spaces, both horizontally and vertically. In effect, one team's ceiling is another's floor.

“We build to one point, and the next stakeholder builds to another,” says David Worsley, senior vice president for Silverstein Properties, the developer of 2 WTC, 3 WTC and 4 WTC, which together represent a $7-billion investment.

“The idea was to disburse all the facilities through the site to make it extremely difficult to knock out the services,” says Gary J. Negrycz, a vice president of the local Turner Construction Co., which is building the 88-story 2 WTC.

Things are even more complicated because of the recession. Two WTC's basement is home to the power supply for all three Silverstein towers. However, because of the economy, Silverstein is building only the basement at this time.

The Port Authority of New York & New Jersey—the landowner investing $11-billion in the project—is responsible for the entire site. This work includes the agency's own projects: the $3.4-billion World Trade Center Transportation Hub, the $3.2-billion 1 WTC, the WTC Vehicle Screening Center and the shared WTC infrastructure and utilities, among them. The port authority is also keeping tabs on Silverstein's buildings.

Complicating matters further, there is a major effort in the immediate area to improve streets and transit services, centered on the $1.4-billion Fulton Street Transit Center.

The hub and the office buildings flank the complex's heart and soul: the $700-million National September 11th Memorial and Museum. The local Lend Lease is building the memorial and museum. Currently, all other project teams are standing aside so that 80% of the eight-acre memorial will be able to open on Sept. 11.

Low on Gas Taxes, Florida Accelerates Contractor Financing

Despite uncertainty over future funding, the Florida Dept. of Transportation is banking on low bids and private-sector financing as it accelerates an estimated $1.2 billion in projects in an effort to boost the state's stagnant jobs situation. At the same time, the agency is rolling out a plan to aggressively expand the use of tolls to add capacity throughout the state’s network of interstate highways and major bridges.

Calling the stream of revenue derived from gas taxes “not sustainable,” Florida Secretary of Transportation Ananth Prasad announced the plan before a gathering of the Florida Transportation Builders’ Association in Naples, noting, “We must identify creative financing alternatives to get more projects through the production pipeline.”

The first of those alternatives to be put to use will be contractor-obtained financing. An estimated $1.2 billion in projects are part of the acceleration, with 11 projects totaling about $900 million dependent upon contractor financing.

Secretary Prasad says recent contractor bids have been coming in at about 25% below DOT estimates. He expects the bids for the accelerated projects to be similarly priced, making the financing costs acceptable.

 

The model for this approach is the $394.4-million Interstate 4/Selmon Expressway Connector in Tampa. On that ongoing project, joint-venture partners PCL Civil Constructors and Archer Western Contractors provided $180 million in gap financing to help get the contract rolling.

The pool of contractors able to deliver financing for these projects is a concern and was taken into consideration in crafting the initiative, Prasad said.

“We’re going to make sure the size of these jobs is such that the vast majority of the contractors are going to be able to participate,” he said.

The group of accelerated contracts that will use contractor financing varies significantly, ranging in size from a $13-million U.S. 27 project in Polk County to the $172-million expansion of the Veterans Expressway in Hillsborough County, a part of Florida’s Turnpike Enterprise. Another roughly $300 million in projects not yet identified by FDOT also will be accelerated but will not use private financing.

BURLESON

Bob Burleson, president of the FTBA, Tallahassee, said his group applauds the measure  but is concerned about the ability of some contractors to compete for the jobs.

“The association recognizes the need to try to come up with some sources of capital that are available to more than just the megacompanies,” Burleson said. To that end, FTBA is attempting to line up investors in an effort to “open up a lot more [firms] for the opportunity to bid the work. I think we’ll be able to do that.”

There should be no shortage of investor interest, says Michael Likosky, a senior fellow at the New York University’s Institute for Public Knowledge and author of "Obama's Book: Financing a Durable New Deal." 

“There’s an enormous amount of money sitting in funds right now,” Likosky says. Pension, private-equity and other types of funds, he says, “have money, and they want to put it in these projects rather than in, for instance, U.S. Treasuries right now, as long as they think they’re going to get a revenue stream. That’s very appealing to them.”

The timing of repayment will be negotiated on a contract-by-contract basis, says Dick Kane, agency spokesman.