February 26, 2021
The head of the Construction Engineering Organization says Tehran’s buildings even most modern ones are simply not built to withstand a major earthquake, which is long overdue in the capital and bound to be made worse since much of the city floats on sewage.
Ahmad Khorram told state broadcasting that the biggest threat is to the southern half of the city.
“Sub-surface layers of the city, to the south of Enqelab Street [in downtown Tehran], have become pliable as the groundwater level is high there,” Khorram said. “In fact, buildings are floating on a layer of sewage. In the event of a six-magnitude earthquake, these layers will collide and buildings will collapse,” he said.
Tehran is in the process of building a sewerage system, but until recent decades the city had only septic tanks. Tehran was the largest city in the world without a sewerage system.
As for the earthquake threat, the city is calculated to be due a major quake on average every 150 years. The last major earthquake to hit Tehran struck in 1830, when Tehran was Iran’s capital but actually little more than a big village.
Khorram said, “In the year ending March 2004, the Japan International Cooperation Agency conducted a study in Tehran and reached the conclusion that hundreds of thousands of residential units would be ruined and millions of people killed if a six-magnitude earthquake were to strike Tehran.”
An earthquake of magnitude 6.0 or greater on the Richter scale strikes somewhere in Iran on average of once every year and a half.
Khorram said people need to know that it is better to spend 8 percent of the total cost of construction on seismic strengthening of a building instead of seeing an earthquake ruin their properties.
“The lifespan of buildings in Iran was an average of 30 years in the 1970s; now it has been reduced to 23-24 years, whereas in Europe and America their buildings’ lifespan was 30 years and now exceeds 120 years. There’s a long path ahead of us to improve the lifespan of buildings to 50 years. That won’t be possible using traditional construction methods; less than 5 percent of constructions in Iran follow modern industrial techniques and methods.”
Rouzbeh Zahiri-Hashemi, managing director of the Maskan Investment Group, the parent company of Bank Maskan, said, “Iran’s construction sector has been facing the inflow of inefficient and unprofessional investors for years now. The absence of even a single rule regarding people who are both investors and builders has led to a decline in construction quality and rapid deterioration of residential properties.”
Asked why the average lifespan of residential buildings in Iran is much shorter than the global average, he said, “That is chiefly because of the work being done by unprofessional hands, rather than by efficient, certified builders.”
“Is it possible for ordinary people to manufacture vehicles? Can they secure permits easily? Certainly not! But what happens when the same people decide to build a house? No legal hurdles face them. The fact is that there isn’t a unified and integrated system in place to supervise housing construction like the one in place for manufacturing cars.”