|THE RIVERGATE||title page | contents | appendices | cd-book cover|
of the rivergate and
early construction of the casino
by michael rouchell
|I.||Friday The 13th Doomsday For The Rivergate|
|II.||Deconstruction Given To Out-Of-State Contractor|
|III.||Rivergate Poses Unusual Demolition Challenges|
|IV.||Wrecking Ball Bounces Off The Rivergate|
|V.||Cementitious Dust Storm Sweeps Central Business District|
|VI.||Demolition Behind Schedule, Casino Rises At A Frantic Pace|
|VII.||Rivergate Debris Dumped At Lakefront Park|
|VIII.||Construction Of The Casino, A Stationary Assembly Line|
|IX.||Enormous Parking Garages Built On Prime Real Estate|
|X.||Tunneling Under Poydras Street|
|XI.||The Buck Stops Here! Politicians Done Deal Turns Into A Dumb Deal!|
I. Friday The 13th Doomsday For The Rivergate
The official "wall-breaking" ceremony was Friday the 13th of January 1995. On this occasion, a back hoe equipped with a claw toothed bucket and a "Harrah's" banner draped on its back climbed up the steps at the Canal-South Peters Streets entrance and began wrecking the underside of the cement plaster entrance canopy. The spectacle for the news media lasted only a half an hour!
A TV news reporter interviewed the wrecking machine operator who coincidentally had been involved in the construction of the Rivergate. When asked about his feelings concerning demolishing something he had helped to build, his response, "It's just a job."
Although the North Hall was scheduled to be demolished first, demolition crews started on the Mississippi River side under the porte-cochere, punching holes in the Rivergate's concrete walls with a back hoe mounted jack hammer. It was 11 January 1995, two days in advance of the official "wall-breaking" ceremony, when construction crews began attacking the structural system of the Rivergate. Interior asbestos abatement, which had started in December, was still in process on the main, barrel vaulted roof structure.
Much of the Rivergate's two-level basement and foundations were retained. Excavating so much construction would have been too costly, even for Harrah's. The promoter, Christopher Hemmeter had, however, initially proposed to demolish the Rivergate down to its pile caps to build a partly underground casino that encompassed the entire site. Hemmeter wanted to implode the building, bringing over 42 million pounds of concrete and steel crashing down in a matter of seconds.
Because the existing basements and foundations were to be reused and were not capable of withstanding such an impact, implosion was ruled out. This relieved many who feared that such an enormous blast would produce a tremor that could damage nearby historic buildings, such as the U.S. Custom House and the nineteenth-century block of buildings across Poydras Street, and could possibly undermine the levee and Woldenberg Park, built on piles at the edge of the Mississippi River.
It is unlikely that any adjacent modern buildings would have been affected by the tremors of any implosion because of their deep foundations and monolithic concrete sructures. However, there was legitimate concern for the old buildings at the corner of South Peters and Poydras Streets because their unreinforced masonry walls rest on spread footings. Furthermore, old buildings are not tied together like modern buildings. Wood joists, for example, are set into pockets within the masonry wall with only the floor load and the dead weight of the masonry above to secure the joists in place.
The masonry facades of
this nineteenth-century group of buildings are currently out of plumb, convexing outward
at the second level. It is possible that a large blast could send these facades into the
The Friends of Rivergate brought the issue of safety in the demolition to the attention of the City Council. As a result, the City Council in a meeting of 15 November 1994 discusssed the plans for demolition.
Florian Barth, an engineer from California who specializes in demolition of post-tensioned concrete structures, discussed his proposed demolition procedure to crush the concrete into small pieces that could be scooped up and hauled away. The building would be shored up to prevent collapse, while two hydraulic concrete pulverizers attached to seventy-foot booms would crush the concrete and steel. The jaws on the pulverizers earned it the nickname of "Pac Man" after the popular video game. One machine would operate on the Poydras Street side, the other on the Canal Street side; somewhere in the middle they would meet. The demolition process, the "deconstruction," was the construction of the building in reverse.
The main roof is a long-span post-tensioned concrete structure. It features a series of six thin shell concrete barrel vaults that span sixty feet between seven-foot deep concrete beams at the valley of each of the vaults. The barrel vaults and valley beams are in a camber, or slightly arched, to span over the 253-foot wide exhibition hall. The camber is reversed over the secondary span that covers the entrance, meeting rooms, and porte-cochere. The roof structure cantilevers an additional thirty feet on all four sides. This cantilever is stiffened by a seven-foot parapet wall. To prevent buckling, large concrete stiffeners are located at the column lines, the mid point of the secondary span, and the mid and quarter points of the main span.
Because the main roof was a monolithic system spanning in two directions, the underside had to be shored up during demolition operations, using tall scaffolding structures similar to those used to support the formwork during the building's construction. Cutting into post-tensioned cables without shoring would have reduced the structure's ability to carry its own weight and would have caused large segments of the roof structure to collapse all at once, damaging the substructure and posing a danger to the workers.
The demolition of the vaulted roof structure required sophisticated engineering and a specialized demolition contractor with experience in demolishing post-tensioned concrete structures. The Times-Picayune article, "Delicate touch needed for roof," reported that a similar size building of conventional construction would cost $500,000 to demolish, but knocking down the Rivergate was estimated to cost $4.2 million or about eight times as much (Bridges 1995).
Before the main roof structure could be demolished, the peripheral structures, including North Hall, that are independent of the main roof structure, had to be demolished first to allow wrecking equipment easier access to the main roof structure.
The demolition of these peripheral structures was accomplished by two jack hammers, each attached to the end of the boom of a back hoe that punched holes into the concrete walls until they were unable to carry the roof and second floor framing. When the floor and roof framing collapsed, the debris was scooped up and loaded into trucks. Problems arose during the demolition of North Hall when a large section of long-span bar joists collapsed all at once damaging a whole bay of the floor structure below, necessitating its replacement. After this occurrence, demolition crews exercised greater caution, removing one bar joist at a time. During the construction of the Rivergate, a fatal accident occurred when these same bar joists were not properly secured during construction.
In spite of the effort made to retain the existing foundations, the former exhibition floor was overloaded beyond its designed live load. After being crawled upon by the concrete crushing machines and rolled over with fully loaded scrap trucks and concrete mixers, the floor slab sustained severe cracking. Most of the cracks outlined the locations of the bell capitals of the concrete columns below indicating excessive shear loading. Bell capitals are often used for flat slabs that span in two directions. They resemble inverted cones and are used to distribute shear forces over a larger sectional area of the cylindrical concrete columns below.
Demolition of the Rivergate's main roof structure was supposed to take sixty days with crews working from seven o'clock in the morning until nine in the evening, seven days a week. The demolition crews eventually found out that this time table was, as Friends of Rivergate predicted, impossible. Crews worked seven days a week, including Mardi Gras and Easter Sunday, with jack hammering operations taking place as late as midnight, despite the five major hotels surrounding the site. Still, the demolition took more than a month longer than estimated.
On 16 February 1995, a crane began to swing a wrecking ball against the parapet at the Poydras Street and Convention Center Boulevard corner. The jaws of "Pac Man" could not position themselves to bite down on top of the parapet. The wrecking ball, when suspended from a crane along side the mammoth Rivergate, took on the scale of a bowling ball. It is hard to imagine that this seemingly small device could take on such a large building. The 4,000-pound wrecking ball bounced off the parapet for fifteen minutes, spalling bits of concrete, until the reinforcing cage was exposed. The sound could be heard for several blocks, resembling the noise of distant cannon fire.
After cutting away the reinforcing, the "Pac Man" jaws were then able to chew into the thin concrete shell of the main roof structure. Often, the "Pac Man" jaws would chew away the thin shell behind the parapet, leaving a portion of the parapet to cantilever out as much as thirty feet. The wrecking ball then repeatedly hit this cantilevered chunk of concrete, and each time the parapet shook like a spring board. It took twenty minutes before the concrete finally broke away.
"Pac Man" was used for the thin shell only. It took trial and error to determine the most effective way to demolish the large beams between vaults and the stiffeners transversing the vaults. First, demolition crews tried to use a concrete cable saw, a continuous cable with abrasive cutting bits wrapped around the beam or column and strung around a pulley hooked to an electric motor, to cut the beams away from the columns. Dismembered beams were then lowered to the ground by a crane where they were jack hammered into smaller pieces.
The cable saw proved to be too time consuming; it took over an hour to cut through one of the beams. Finally, one of the "Pac Man" jaws was removed and replaced with a jack hammer. This proved to be more effective at breaking up the beams and stiffeners. The concrete beams were jack hammered until all that remained were the twenty steel post-tensioning tendons draped across the temporary shoring, and they were later cut off with a welder's torch.
the wrecking ball proved to be the most effective way to demolish the
parapet. At one time a similar concrete pulverizer suspended from a crane
was employed but was soon abandoned for the wrecking ball. The wrecking
ball was also dropped onto the top of the thin shell roof to break it
away from the stiffener at each of the column lines.
days, downwind from the demolition site, pedestrians had difficulty walking
on the street without getting dust particles in their eyes. To cope with
the migrating dust, the nearby Windsor Court Hotel screened off its garage
with polyethylene sheets.
The demolition of the Rivergate was to be completed by mid March 1995 according to an article in the Times-Picayune. Demolition of the Rivergate's superstructure was completed by 22 April, over a month behind schedule. Coincidentally, on the same date, architectural historian Dr. Richard Longstreth of George Washington University lectured on the significance of preservation of the recent past to the members of the Louisiana Landmarks Society at the annual Martha Robinson Memorial Lecture.
During the later phases of the Rivergate's demolition, pilings were driven around the perimeter of the building to support portions of the casino foundations that lay outside the Rivergate's footprint. Where the casino utilized the Rivergate's foundations, new steel columns were supported at the intersection of huge cruciform concrete beams. Built during the later phases of the Rivergate's demolition, these beams transferred the exhibition floor loads to at least four of the columns below. These cruciform beams, some on the upper basement level and some on the lower basement level, significantly changed the utility of the basement areas. The steel skeleton of Harrah's casino went up soon after the Rivergate came down.
Demolition of the basement levels at the Poydras-South Peters Streets corner continued well into May. The entire two-level basement was demolished and excavated. A solid concrete mat was poured over this corner of the building in lieu of the network of cruciform transfer beams used everywhere else in the basement.
the concrete debris was hauled to West End at Lake Pontchartrain to be
used as fill for enlargement of a park off Breakwater Drive. Although
only reinforced concrete was supposed to be dumped there, other debris
was mixed in. The nature of the debris stirred environmentalists and their
protests stopped the dumping at the West End site.
As soon as the steel erection had been
completed on the Canal Street side, it was enclosed with a metal stud
wall followed by a crew of bricklayers. A fast-track method of installing
interior finishes before the exterior of the building was closed in caused
many of these finishes to be exposed to the weather indefinitely while
the project was tied up in bankruptcy court.
Construction also began on the "Casino Support Facility" -- the huge parking garages across Poydras Street from the casino. These structures, built on Squares 4 and 5 in an historic district, close to the Convention Center, are the gateway to the Warehouse Historic District. Politicians permitted garages to be built on this prime property as if parking garages were a status symbol for the city!
The parking structures were built like two book ends. The Poydras Street facade simulates twelve stories and decreases to nine stories on Lafayette Street. The up-river building, which extends from Lafayette Street to Girod Street, appears to be five stories but is so incomplete it is impossible to say definitely. The top two floors of the Poydras Street side of the garage were built for the cooling towers for the casino building. Huge chilled water lines run down the inside of the parking garage and through the Poydras Street tunnel to serve all the air conditioning for the casino.
Both parking garages are built of post-tensioned concrete construction. Unlike the Rivergate, where post-tensioned concrete engineering and architecture were perfectly married in the expressive barrel vaulting, the parking structures are mass produced engineering. Taken to the extreme, the garages employ the "flying form" construction method in which an entire bay of formwork can be used over and over. After the concrete has set, the forms' supporting jacks are lowered, and the whole assembly is lifted up to the next level. The "flying form" method could not have been used at the Rivergate because of the complexity of the undulated barrel vaulted formwork required for the job.
garages remain unfinished as a result of Harrah's bankruptcy. Precast
concrete panels partially clad the unfinished structure. The lower two
levels are waterproofed in anticipation of a brick veneer.
Left over from the 1960s riverfront expressway controversy is a $1.3 million tunnel, paid for by taxpayers' money. It is six lanes wide and thirty feet high and transected the Rivergate site. Constructed before the Secretary of Transportation John A. Volpe canceled the planned Vieux Carré riverfront expressway, the tunnel remained unused during the lifetime of the Rivergate.
controversial tunnel, this one under Poydras Street, links two elements
-- parking garages and casino -- to prevent gamblers from experiencing
the city while enroute to and from their cars. The tunnel was built in
three phases. The first phase included excavating the median and rerouting
all the utilities that lay in the way of the tunnel. The second phase
was excavation and construction of a segment of the tunnel nearest the
casino with traffic rerouted to the other side. After that section was
built, it was covered over with a road bed and used to reroute Poydras
Street for construction of phase three, the other half of the tunnel nearer
the parking garage. The original plan called for an overhead pedestrian
bridge to connect the nearer garage to the casino, but was abandoned early
On 1 May 1995, the temporary casino opened. "Let the Games Begin!" proclaimed Mayor Marc Morial at the opening ceremonies. Green lasers shot beams of light into the night sky during the month of May.
On 21 November, Bankers Trust canceled its line of credit to Harrah's prompting them to stop work at the permanent casino. Merrill Lynch advised its bond holders to sell. The day before Thanksgiving all construction ceased; hundreds of construction workers were laid off. Harrah's Jazzville filed for Chapter 11 bankruptcy. The unfinished casino stood in limbo for several months before action was taken to close the exterior to prevent further weather damage; interior construction was put on hold.
of the casino would not be realized until 28 October 1999, three years