Are Dubai’s towers earthquake-proof?
Buildings to be constructed in the near future in Dubai will be built under a new set of rules to ensure they are able to withstand earthquakes within the region. However the current towers are safe enough but more precautionary steps will be implemented to ensure the safety of residents, a senior Municipality official said.
“We adopted the International Building Code in the 1990s, and the code divided world regions into seismic zones according to their seismicity. Dubai and Abu Dhabi were classified in that code as zone 0, which means they are not seismic zones,” Moawya Abdul Rahman, head of structural engineering unit at Dubai Municipality, told Gulf News.
But recent studies showed the previous assumptions were not valid and indicated a slight increase in the real seismicity values of the Gulf area. Therefore, there was a need to change the seismic design requirements for buildings.
“The municipality regularly collaborates with experts from a number of local and foreign research bodies, including the Earthquake Engineering Research Institute in Istanbul, and we are always updated with any new research outcomes in this field even if they are minimal ones,” he said.
As part of Dubai Municipality’s stand in ensuring public safety, it issued circular 191 that modified the seismic design requirements for buildings, which included changing the seismic zone for Dubai from zone 2A to zone 2B.
“The extra cost of construction due to these changes is not much, and hardly exceeds 10 per cent, which includes the extra amount of steel and concrete used,” explained Abdul Rahman.
In mid-May, Dubai Municipality revised its earthquake building code with immediate effect to increase the threshold of building construction to withstand earthquakes of up to 6 on the Richter scale.
The former threshold was 5.5 on the Richter scale.
No buildings suffered major damage and no injuries were reported from the most recent aftershocks of up to 4.3 on the Richter scale from an Iranian quake but the new revisions should provide even more protection against natural disasters, said officials.
Bharat Bhatia, CEO of Conares Steel based in Dubai, said he is keen to work with Dubai Municipality to help plan more stringent measures for building materials that will help build better quake-proof high-rise structures in the emirate.
“Earthquake factors depend on the foundation of the buildings,” he said, noting that much of the 250,000 metric tonnes consumed every month in Dubai is imported from other countries. “They use the standard guides that are allowed.”
Bhatia said he wasn’t aware of new upgrades in the revised earthquake code but encouraged municipal officials to examine ways of using higher-tensile strength steel, adding that local steel mills can help supply new made-in-UAE steel streams that meet higher standards.
Like efforts in Kuwait and Qatar, the UAE could create its own steel patents with stronger tensile properties that would set the bar higher in the region.
Bhatia said he had no problems with municipal inspectors doing regular inspections of any new and improved earthquake-proof batches of steel called for by Dubai Municipality.
Improved steel could easily be produced at Conares Steel’s facilities in Jebel Ali, he said, given that the company can revise its steel recipes to suit more tailored orders for specific requests by contractors erecting new buildings, he said.
Wind codes now in use by the municipality state that structures should withstand a basic wind speed of 45 metres per second for a three-second gust, which is equivalent to 160km/h.