Press Clippings
Concrete Construction
November, 2001

California Concrete Adventure
Concrete helps Disney create a new theme park.
By: K. Susan Casey

During the fall of 2000, radio, TV, and print ads announced the impending openings of Disney's California Adventure theme park, Downtown Disney (an adjacent pedestrian mall), and the adjoining Grand Californian Hotel. Excitement and curiosity were growing among the general public. The concrete contractors working on these projects, however, had markedly different feelings.

“It was like a Chinese fire drill,” says Shawn Devine, vice president and chief of operations for Sullivan Concrete Textures, Costa Mesa, Calif., the company placing the architectural concrete for the hotel. “When we came on, the roofer was up top, other guys were putting lath on, the windows were going in, and we were below finishing the concrete. We were out there morning, noon, and night, 7 days a week in order to finish.”

Building California Adventure, the $1.4 billion expansion of Disney's Anaheim resort, not only was done within severe time restrictions but it also challenged contractors to create the park within a confined space. Concrete contractors from Southern California were entrusted with projects ranging from the construction of the Mickey and Friends parking structure, to a variety of architectural and decorative concrete, to the creation of a concrete mountain shaped like a grizzly bear. The completed California Adventure is like a showroom for the latest methods and techniques used in modern concrete construction.

Parking structure

Since the area surrounding the existing Disneyland resort is heavily developed, when Disney Imagineering wanted to create a new theme park in the parking lot of the existing resort, thousands of parking spaces were lost. The first step in the expansion, then, was construction of a parking structure. With Disney, functionality goes hand-in-hand with image. This was to be not just an enormous parking structure—now being hailed as the largest in the United States—but unique in its design, construction methods, safety, and security.

“Architecturally, the underlying theme was to express the structural elements of the building,” says Tom Romine, project manager for Walker Parking Consultants and the project's prime designer. “The actual structural finishes and shapes are intended to express the fact that concrete can be crafted by skilled people to create an appealing result. One example is at the pedestrian walkway where a Vierendeel truss was used in place of a typical moment frame. In this way we were able to use the frame as a seismic-resisting element and also take advantage architecturally of the colonnade separation of the pedestrian area from the vehicular drive.”

Another example was the floor finish. “It was mandated that the floor be specially finished to eliminate the possibility of tire squealing being heard by the neighbors. Every square foot of floor surface was hand finished with a notched trowel in a uniformly scalloped pattern.”

The six-level, 3.8-million-square-foot structure can hold 10,225 cars. The rooftop is the size of fourteen NFL football fields. A flyover from the southbound freeway leads directly into the structure, and vertical circulation (cars moving from one level to another) is facilitated by speed ramps—inbound and outbound. Cars enter one of 10 lanes leading to five tollbooths on the first level. The design allows parking of up to 3600 vehicles per hour. A ventilation system operated by carbon monoxide sensors monitors air quality, sucking out excess exhaust if a large number of cars is waiting. Ramps have magnetic strips that detect the number of cars entering each level, information that is displayed in the parking office allowing officials to steer the flow of traffic to empty areas. A closed-circuit TV with 220 surveillance cameras is part of the security system. The canopied escalator from the fifth floor to ground level is the largest of its kind —118 feet long and 54 feet high.

Vierendeel truss frame

To accommodate buses at ground level and a column-free pedestrian walkway on the east end, the structure uses a cantilevered bay supported by a Vierendeel truss frame (see box on page 54). When designing the structure, engineers looked at the two principal directions in which the building would move when subjected to earthquake loads, and they determined the support needed. “A Vierendeel truss is good not only from the aesthetic point of view in that you see a lot of open space, but it also addresses the seismic load-resisting challenge,” says Mohammad Iqbal of Walker Parking Consultants.

While the structure as designed was within the code requirements, to dispel concerns Walker took extra steps to assure and enhance performance using a new type of analysis. “You have to go to a newer push-over analysis in which you push the structure in the computer and see how it works in order to find the weakest link in that structure. Then you design that link and make sure the columns are not the weak link,” says Iqbal.

Conventional spread footings support interior columns within the body of the parking structure. For seismic-resistance, drilled piles support the shear walls and all perimeter foundations. The spaces between the columns are 50 feet by 54 feet. Between the columns are beams running north and south; girders running east and west pick up the beams and frame into columns eventually. Cast-in-place, post-tensioned concrete helps resist the loads. The design is based on a maximum credible earth quake of a magnitude eight. “It is interesting engineering-wise because of the seismic requirements and the amount of reinforcing required,” says Sanjay Pandya of Walker Parking Consultants. “The challenge was to keep all the elements and the mass in the structure nomimal and still allow the builder to be able to put some concrete in there with room to flow and work.”

Construction challenges

Disney's design also requested architectural features to be incorporated within the structural concrete components. The exterior walls of cast-in-place architectural concrete use a special Type 3 cement. Decks used a different concrete mix. The upturned beams and shear walls on the exterior were installed after the decks were cast. Shores were constructed to support the deck for the 21 days until placement of the perimeter elements.

“Not always does the architectural requirement meet the structural requirement, nor do the structural requirements make an architectural finish,” says Tracy MacDonald, project director for McCarthy Building Cos., Newport Beach, Calif. McCarthy, the general contractor on the parking structure, is one of only a few GCs that does its own concrete work. “We had to develop a mix design using Type 3 cement and various admixtures to meet the requirements of the structural engineers and the architect in terms of color, finish, and consistency, and also to satisfy our need to use and work a mix in order to place it. Accommodating three necessary elements was the real challenge.”

The architectural requirement was for an as-cast finish—a shiny, marble look. PVC-coated plywood was used for the forms for the architectural concrete to get that finished look. Button holes where ties were used to hold the forms together were left in place as part of the architectural look.

The structural requirements for the perimeter elements demanded concrete of 7000 psi compressive strength. Inexperienced in using Type 3 cement at that strength, McCarthy did 40 mock-ups before finding the right mix design. The first mix had 900 pounds of cement per cubic yard, which gave the required strength but had heat problems. The final mix was down to 600 pounds. “We looked at different admixtures to see how they reacted and what they did to the architectural look and structural characteristics and what worked best for a pumpable mix. Adjustments were made, and every time we did an adjustment we did a mock-up,” says MacDonald.

Another challenge was deck-to-deck access. Since the ramp system was external to the decks and installed after them, during construction the crew did not have the luxury of moving between the decks with the ramps. Instead they had to move everything by crane from one level to the next.

Aggressive schedule

Because of the amount of concrete to be poured—140,000 cubic yards for 120 decks—McCarthy had to devise a sequence of events and a beam-forming system that allowed the workers to complete a deck every other day. Some deck pours were in excess of 900 cubic yards. They started off on the first elevated deck with one set of beam forms. After reaching a certain point, they introduced a second set of beam forms on a second level and soon a third set on the third level—a tiered forming sequence. “At one time we had all five beam systems in operation, forming and pouring all five levels at any given time,” says MacDonald.

“To handle that we had an onsite batch plant,” he says. “There was a tremendous amount of construction in and around Anaheim, and we couldn't be hampered by traffic problems. In order to alleviate traffic congestion for the surrounding neighborhoods, we had the aggregates and cement delivered to the jobsite by 10 trucks dedicated to the site. Trying to accomplish the schedule requirements and come up with a sequence of events and a beam form system that allowed us to turn a deck over every other day is pretty significant,” he says.

Hotel decorative concrete

If image was paramount with the parking structure, it was all the more important within the theme park and adjacent hotel. Incorporation of architectural and decorative concrete was an important part of the design plan. Sullivan Concrete Textures was contracted for projects in areas of the theme park called Paradise Pier and Hollywood Backlot and for the Grand Californian Hotel, a 750-room resort hotel built in the turn-of-the-century California craftsman style.

“Disney has its own team of engineers, managers, and art directors who run each job,” says Devine. “They give you the finish, the color, and the stamp [pattern], but they don't give you the means and methods. That's what we determine in mock-ups.” For the three areas, Sullivan made 150 to 200 mock-ups— 10, 5, or 3 feet square—which were judged on color, finishing technique, size, width and depth of the joint, and color and size of the aggregates. “It's like dealing with an artist,” he says. “The art directors have an eye for color, and maybe the color hues are wrong, finishes are not what they wanted. It's kind of a see-feel-touch thing.”

What tip does Sullivan offer to other contractors? “Never put anything down without a mock-up,” says Devine, “something that will set the precedence for the quality of workmanship. It should be standard practice, though sometimes schedules don't permit. Disney required them.”

A bear mountain

Disney also required extraordinary performance from Rock & Waterscape Systems Inc. (RWSI) of Irvine, Calif. RWSI created the concrete bear mountain that is now called Grizzly River Run. Disney designed the rebar matrix that forms the skin of the mountain on a computer that ultimately controlled a machine that bent the individual bars to within 1 /2 inch of the final dimensions. Rebar cages then were assembled onsite and plastered to form the overall shape. Eight cages were assembled to form just the bear's head. The bulk of the bear is supported by steel framing, with the lower portions encapsulated by retaining walls.

Below the bear's head the ride flume winds around and through the body of the bear. The ride flume itself is a poured-in-place concrete structure constructed by Clark Construction Group, Irvine, Calif. The decorative edge of the ride flume as well as several streams were constructed with a structural pea gravel shotcrete mix. The rockscape is composed of a #3 rebar mat with galvanized lath backing and cement mortar coating. The final application of mortar is hand carved and textured to create the variety of shapes and images that ultimately make the structure recognizable as a bear. “The ongoing day-to-day challenges were the schedule and pleasing Disney's art directors,” says Tom Real, project manager for RWSI. “Every day there were changes due to changes in personnel, taste, or landscaping.”

Today as visitors approach the park, the bear, at 250 feet (6 feet higher than Disneyland's Matterhorn) is the highest point in the resort and the first thing to catch their attention— literally the high point of Disney's new resort. Visitors enjoy the easy parking access, the detail of the decorative concrete, the fantasy attached to a bear mountain, and the fun of the river raft ride without realizing all that went into the construction— something the contractors know all too well.

Vierendeel truss frame

A Vierendeel truss is a framed beam and column structure with vertical webs connected rigidly to parallel top and bottom chords—like a series of interconnected boxes. There are no diagonal members in the truss. A Vierendeel truss is not a true truss, because its members are subjected to nonaxial bending forces. In a true truss, the members that make up the truss experience only axial compression or tension, no moments. “It is a frame to resist lateral loads, a frame that acts like a truss,” says Sanjay Pandya of Walker Parking Consultants in Newport Beach, Calif. “There were seismic demands that required a stiff lateral-load-resisting element within this portion of the structure, so this was the choice.”

Publication #C01K050 Copyright © 2001 Hanley-Wood, LLC All rights reserved

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