...track behavior under quake loads, results in better performance and $1.5 million in savings, says the engineer.

Design mixed low- and high-tech tools. Piano, based in Genoa, Italy, first made sketches. Wood models of increasing size came next. Then, the team built 40 full-size mock-ups of different elements.

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California Academy Of Sciences

The designers used only 3D parametric digital modeling for the most complex geometries. With the undulating roof profile, something as mundane as drainage would have been more difficult to do in 2D. “The 3D software gave us the slope at any point,” says Stantec’s Kiang.

Webcor developed a construction 3D model for logistics and as a visual aid before it became known as building information modeling. “We teamed with [software developer] Graphisoft and that was how its [BIM] product Constructor was born,” says Pedersen. Webcor eventually added schedule (4D) and some pricing (5D) to the model.

Webcor Webcor team finished the base building on time.

BIM helped with routing exhibit-hall sprinkler pipe. Running 4-in. mains along curving roof steel while maintaining the allowable penetration through roof steel, and conforming with the layout of acoustical panels and other infrastructure was difficult to envision, says Matt Rossie, a Webcor project director who was a senior project manager on the academy job.

After standing in the field and trying to use hand gestures and sketches, Webcor invited the pipefitter foreman from Northstar Fire Protection, Eagan, Minn., into the jobsite trailer’s conference room and projected the BIM onto the white board. The architect and pipefitter proceeded to sketch possible solutions on the board. “We cut through the model to expose all of the varying conditions,” says Rossie.

Webcor

Webcor Rain forest ramp, with changing radii, was supplied by roller-coaster maker.

Mock-ups were used to prevent field muck-ups. In the competitive bidding for the publicly funded job, contractors that had worked on mock-ups had the best bids, says Kiang. “There was a certain amount of risk taken out,” he adds.

One early mock-up, set on the old roof for six months, helped with plant selection and taught the team that erosion control was needed for the slopes. “We built a 20 x 8-ft ‘plant torture chamber’ with four slopes,” says Kiang.

Other testing was done off-site. The museum collection 20 million specimens in 2 million to 3 million jars filled with flammable alcohol needed stringent fire protection. A foam suppression system would have required rooms with large evacuation chambers. Instead, the team wanted to use a high-pressure fog system that cost a lot less and made clean-up easier, says Pedersen. But it was not approved in the U.S. Tests, run at a facility in Texas, helped win approval.

Webcor built a roof mock-up at its Hayward yard to help with roof slopes of up to 55°. From there, the team, including Salt Lake City-based SME Steel Contractors, worked out a way to pick the curved beams at three points so they wouldn’t flop over. The team also used the mock-up to design the soil support system.

Another mock-up helped with expressed concrete shear walls. After viewing the work, Piano opted to use the same system on some of the exterior, instead of stone. “We saved money on stone but worked overtime to produce the as-cast concrete,” says Pedersen.

Arup Dome cantilevers over coral reef exhibit on lower level.

Value engineering helped keep a lid on cost. One switch was to a roof with members curved one way and faceted in the other, instead of curved in both. To deal with price escalation, Webcor bought much of the job early, including the rain forest enclosure and skylight.

When prices came in too high for the rain-forest visitor ramp, a helix with changing radii, Webcor’s Rossie turned to roller-coaster makers. Fabriweld Corp., Clearfield, Utah, offered a down-to-earth price. It became a sub to SME.

Webcor began demolishing the old building in fall 2004 and started letting contracts in mid-2005. It finished the base building last fall when interior work, exhibit installation and commissioning began.

The roof is now completely planted, the rain forest is 90% complete and the coral reef is 25% complete. Dioramas are 75% complete. Solar panels are commissioned. The academy staff, which will reach 400, has moved in with 20% of the 38,000 live animals, among them penguins, sharks, turtles and fish.

Says Arup’s Lassetter, “Don’t misunderstand, there were very difficult times. But for me, there has never been another project like this.”