January 29, 2009

Some steel trusses in the futuristic structure of the Canadian Museum for Human Rights will be exposed to visitors, but most of the building’s steel won’t be visible.

Models replace drawings in Canadian Museum of Human Rights project

DON PROCTER

Correspondent

Five years ago, any dream of designing and engineering such a complex structural steel job as the Canadian Museum of Human Rights (CMHR) set to rise in Winnipeg in the near future would be just that: a dream.

Today, it is a reality for project engineer Neb Erakovic, executive engineer Barry Charnish and the rest of the team of the project’s consulting structural engineer Halcrow Yolles.

The challenge is a big one. The iconic museum — described by its architect, New Mexico’s Antoine Predcock, on the firm’s website as “a symbolic apparition of ice, clouds and stone set in a field of sweet grass” — is essentially a series of shapes and forms. The architect must work closely with Halcrow Yolles to ensure those shapes and forms can be built.

“You don’t measure this building by square footage but rather by volumes and forms,” says Erakovic. “It is a sculpture, and is unlike any traditional building design.”

3D computer software such as Form Z, CATIA and Revit Architecture are required to create the volumes and shapes of the building. “This job can’t be done through traditional engineering methods,” points out the engineer. “Drawings are rather useless. The documents on this project are models.”

Among the engineer’s unusual challenges is calculating floor loads because of the complex geometry and space planning requirements. To engineer a traditional building such calculations are a snap.

“Here, with every floor plate we have to create charts and diagrams to clearly describe the loads and finishes.”

Determined by a wind tunnel study, 18 structural wind load cases on the building were calculated. Without sophisticated computer software to make the calculations, it could have taken months to arrive at the numbers.

For the engineering team to arrive at a design that can realistically be built, it has to break down the architectural design into segments, or individual “structural concepts.” Each segment (including the Tower of Hope, the Cloud, offices, the Wedge/Canyon, Mountain Galleries and the Great Hall) must go through a complex engineering process. All the while, engineers must keep in mind that the steel design is to be closely co-ordinated with the poured-in-place concrete sections.

While some tubular steel trusses will be exposed to museum visitors, most of the building’s steel won’t be visible. Few steel elements are straight and few spans are repetitive, some spans are up to 40 metres long, posing vibration issues that must be resolved, adds Erakovic.

One of the most complicated steel segments, he says, is the museum’s “Plug” or great hall because it is specified as a column-free space so long spans have to be precisely engineered.

It is a “constant challenge” to produce a workable design within the tight budget, adds Erakovic.

From a steel standpoint, Erakovic, who headed the structural engineering team at Toronto’s Royal Ontario Museum when he was with Halsall Associates, says the Winnipeg museum commission is as complicated as the landmark Toronto building.

But for the lead engineer and his colleagues (including HY’s 3D software expert Crispin Howes) the museum (the first national museum to be built outside of Ottawa) is less daunting in a sense because of experience the team has gained on unusually difficult designs over the past few years.

“At the time of ROM, we were still working with something that was fairly new.”

Since then, the team has engineered equally complicated buildings, including the MGM City Center project featuring spectacular 40-storey twin Veer Towers in Las Vegas that rise with a lean.

The new Winnipeg museum, which will be about 100 metres tall, will contain 24,600 square metres. Caisson construction is slated for April, with steel erection to follow in 2010.

“It’s a very fast-track job, which adds to the challenge,” says Erakovic.

“So far it has been the most enjoyable difficult job I’ve ever done.”

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