The construction team broke ground in summer 2009. The senior project manager for Big-D Construction, Leon Nelson, says while final designs for the more complicated exhibit spaces were still being completed, the team began work on the north side of the building.

To stabilize the hillside and allow for site excavation, Big-D first constructed a solider-pile wall with timber lagging. The wall was then sprayed with shotcrete to extend its functional life. To reach the final height of 45 ft, the solider pile was topped with mechanically stabilized earth with tiebacks into the hillside.

“It was one of our first challenges on the job,” says Nelson. “It wasn’t easy construction-wise, but it was not insurmountable.”
David Dunn, of Salt Lake City-based structural engineering firm Dunn Associates, said isolating the building from the pressures on the hillside was important in order to create large open spaces inside the museum.

“You have to have the soil forces resolved either through a shear-wall or through the building,” Dunn says. “If we hadn’t done the solider pile, it would have required more shear-walls through the building space. This way we saved costs and got the spaces inside we were looking for.”

The Right Mix

Nelson says another significant challenge for the contractors was finding the right concrete mix, which would become both a structural and a visual feature throughout much of the building.

Schliemann wanted a horizontal layered and textured look for the concrete. To reach LEED goals (designers are aiming to achieve Gold certification), a self-consolidating concrete with a high-fly ash content was utilized. Nelson says the team went through eight mock-ups using different wood forms and concrete mixtures before finding one that worked. Eventually, the team used forms made from Douglas fir, which provided the look designers wanted.

“Doing this board-form concrete is kind of old style, but we needed that texture with the grain of the wood. It leaves impressions like a fossil,” says Schliemann. “The wood could also be recycled after several uses. The mix of concrete ended up with this soft gray, which I think looks great. The contractors did a great job and they should be proud.”

One of the sections of the building without large expanses of exposed concrete is the canyon, where the walls are mostly drywall and plaster with multiple angles recalling the sandstone canyon walls of southern Utah’s red-rock deserts.

Nelson says constructing and finishing the walls required building a suspended work platform (dance floor) that filled the canyon space, allowing carpenters and drywall finishers to create the surfaces.