|
Summarized by Bruce Thomas
Church's 22,000-Seat Hall Is an Open and Shut Case
Engineering News-Record pg63 17Apr00 B1
by Stephen H. Daniels
SALT LAKE CITY, UTAH -- "A waterfall plunges through a 'canyon.'
Aspens and evergreens grow to the edge of a three-acre alpine "meadow."
The setting sounds bucolic but it is not. It is the rooftop of a 1.5-
million-sq-ft conference center smack in the middle of Salt Lake City.
The $240-million building for the Church of Jesus Christ of Latter-day
Saints houses a 22,000-seat hall, described by church officials as the
world's largest.
"The building opened briefly April 1 for the church's general
conference. Construction then resumed toward a formal opening and
dedication in October.
"Temporary completion stretched Legacy Constructors, a consortium of
the three largest local contractors: Layton Construction Co., Okland
Construction Co. and Jacobsen Construction Co. 'It's been crowded,
very hard and very fast,' says Harvey E. Wright, Legacy's manager of
construction.
"Not only is the expansive roof flat, but 'we are building to seismic
zone 4 requirements,' adds James G. Peterson, Legacy's project
executive. The building was also designed with a 25% safety factor, to
give it a 150-year life, he says.
"The roof garden emerged because LDS President Gordon B. Hinckley told
the Portland, Ore.-based architect Zimmer Gunsel Frasca Partnership to
avoid another big box, like the nearby Delta Center arena, in the heart
of Salt Lake City.
"The church leader also wanted to be assured the roof would not leak.
He did not, he told ZGF principal-in-charge Robert Frasca, want the
building to be remembered as 'Hinckley's Folly.'
"A 'greenhouse' roof, with a layer of liquid rubber, covers a composite
metal deck with a 6-in.-thick concrete topping. Beneath planters,
contractor Utah Tile and Roofing, Salt Lake City, installed root
barriers -- roofing membranes and an egg-crate-like drainage system
filled with gravel. Walking surfaces are pavers atop Styrofoam in the
irrigation systems underneath.
"The auditorium roof is a quarter circle in plan. A 30-ft-deep
proscenium king truss spans 152 ft and bears at its ends on a
reinforced concrete column at either side of the stage. Ten tapered
radial trusses, also 30 ft deep, fan across the hall. Each 300-ton
truss bears on the king truss at one end and on the radius wall at the
other end, says Charlton.
"The weight of the king truss, says the steel erector, grew to 600 tons
as the structure was revised, which played havoc with steel fabrication
and erection. 'We turned our whole company over to this project, and it
went crazy,' says Scott Schuff, president of steel contractor Schuff
Steel Co., Phoenix. "The job stressed everybody," he says.
Schuff says 'a $9-million structural steel contract became a $37-
million job.' Schuff threatened to go to court. Church officials said
this week the dispute has been settled, but Schuff could not be reached
to confirm.
To meet this month's opening date, the design schedule was whittled,
the main hall was fast-tracked and working drawings were produced
piecemeal. 'We struggled early to get the building out of the ground,'
says Thomas E. Hanson, the church's director of special projects.
"A 75-ft height restriction imposed by City code meant sinking the East
end of the building 75-ft, then soldier piling and lagging the entire
site, a 660-ft-square city block. Once out of the ground, the team ran
into trouble with concrete walls and buttresses so heavily reinforced
that ironworkers stumbled, says Hanson. Legacy resorted to increasing
wall thickness by 2 in. and using a fine aggregate to get around the
inordinately dense rebar.
"Additionally, 'at every turn, we were frustrated by changes and were
consumed by changes and were consumed by trying to respond to the
rooftop garden and other moving targets,' Hanson says. Complicating
matters, a tornado touched down Aug 11, shredding the Delta Center's
roof and tipping a tower crane onto the conference center's roof.
"The area's Interstate 15 project and a flurry of Winter Olympics
construction created shortages among several trades, especially
ironworkers. 'What had been a stable labor market for years was
suddenly stretched,' Hanson says.
"For construction, the Legacy partners divided the site geographically.
As Okland built the underground 1,300 space parking garage, Layton
began work on the radius wall. At the same time, Jacobsen was building
the buttresses and the wall behind the stage.
"Design details never quite caught up with construction and the
complicated steel work fell six months behind schedule, throwing the
April assembly hall pre-opening into doubt, says Wright. But the team
prevailed. 'The only thing I ever lost sleep over was the granite
facade,' says Hanson.
"During design development, the church decided on a local granite it
had used for adjacent Salt Lake Temple. But the quarry had long been
inactive, so the cladding supplier had to go through the process of
reactivating it. 'Some larger fabricators didn't want to get involved
in that kind of adventure,' says Hanson.
"Idaho Travertine Corp., Idaho Falls, took the job. People ask if
there were any miracles on this job, says Hanson. 'I tell them it was
the stone.'"
The article has a few pictures of the building during construction. I
thought the insight about the building was interesting from a
construction standpoint.
|
