Guidelines drawn up to safeguard tall buildings

Dubai: New guidelines to protect tall buildings from major earthquakes have been drawn up as current building codes are inappropriate, said a design expert.

Micheal Willford, the man behind the new rules and co-chair of the Council on Tall Buildings and Urban Habitat (CTBUH) working group on the Seismic Design of Tall Buildings, said buildings higher than 50m are introducing new challenges that must be met.

The International Building Code (IBC) and the Uniform Building Code are outdated, said Willford. "Old school rules unlike new school rules are not satisfactory for new buildings. They are only good for buildings that are 70m high."

New rules, put together by CTBUH, are performance-based and offer total design freedom, said Willford. Tall buildings were thought of as uneconomic and potentially did not meet the intended standards of IBC.

Outdated

Current codes, based on US codes, were developed to address the seismic design of low to moderate rise buildings.

CTBUH is recommending a performance-based approach to seismic design similar to what is being done in Japan and China, which requires that the design of a building is exposed to a series of computer simulated earthquakes to evaluate it.

Willford said the impact on design will be small.

David Scott, CTBUH chairman, said the council is committed to increasing awareness of the inadequacy of tall building codes.

Design codes historically only change after each big earthquake but with technology available today, designers can tell how a building will behave under extreme earthquakes with reasonable confidence, he said.