New code effective immediately for buildings under construction and new ones
Dubai civic authorities on Wednesday issued new rules asking all new projects to raise the threshold of buildings to withstand earthquake tremors up to 5.9 on the Richter scale.
A senior official at Dubai Municipality was reported in local media as saying that the standard was raised as part of the authority’s aim to ensure the public’s safety and the quality of buildings in the emirate, as a result of the increasing number of earthquakes recorded in Iran.
Yousuf Abdullah Al Marzouqi, Acting Director of Buildings Department at Dubai Municipality, explained that the new code is effective immediately and will be carried out in buildings under construction and those that do not have a building permit from the department.
“The modifications will affect the requirements of the structural design and sector loads related to earthquakes, while those related to wind speed have not been changed and remains the same,” said Al Marzouqi.
The wind code that is now in use by the municipality states that structures should withstand a basic wind speed of 45 metres per second for a three-second gust, which is equivalent to 160km/h.
The seismic code was modified following a number of meetings with specialists, which resulted in modifying the code so that buildings are divided into two categories: zones 2A and 2B. Under the previous seismic code, there was only zone 2A.
According to the new regulations, zone 2A covers buildings that have between five to 10 floors, and should withstand tremors up to 5.5 on the Richter scale. Zone 2B covers buildings that have more than 10 floors and are now required to withstand tremors up to 5.9 on the Richter scale.
The seismic and wind code has been under review since 2009 and its last draft was based upon “basic wind speed for design in conjunction with wind tunnel testing”.
In 2003, representatives from RWDI, a Canadian firm of consulting engineers and scientists, carried out a wind climate analysis. They collected data from Abu Dhabi, Dubai, Ras Al Khaimah, Sharjah and Qatar.
RWDI’s findings recommended that high-rise structures should withstand a wind speed of 36.4 metres per second, but the municipality is also taking a conservative approach to the recommendation and will use a slightly higher number of 38 metres per second.