The spectre of a major earthquake looms over Bangladesh, and Dhaka is the most at risk.
Experts have described the density of high-rise buildings in the capital as “a thorn in the neck", urging the government to properly maintain building clearance guidelines to protect the city.
They added that a major earthquake usually occurs in the region every century. The last major earthquake on the Madhupur fault was in 1918, and the one before that in 1822.
Dr Mehedi Ahmed Ansary, a professor at the department of civil engineering of Buet who specializes in geotechnical and earthquake engineering, told Dhaka Tribune: “Most of the constructions in Dhaka city do not comply with the building code. As a result, the whole of Dhaka city will be at risk if there is a major earthquake.”
The government should issue earthquake guidance measures and ensure that buildings are not constructed without proper clearances, while building owners should take responsibility to check the results of building tests and permission from Rajdhani Unnayan Kartripakkha (Rajuk) to strengthen weak structures, he said.
According to the expert, up to 300,000 people may die if a magnitude 7 earthquake strikes Dhaka right now.
“An earthquake with a magnitude of 7, smaller than the one in Turkey, would not only have buildings collapse in Dhaka but also turn the city into a fire pit due to the unplanned electricity transmission and gas lines,” Dr Ansary added.
“Earthquakes have increased in frequency in the country in the last two to three years, and we have not had a big earthquake here in 100 years. This is a matter of worry. That means these small vibrations are signs of energy building up. As a result, there is a fear of a major earthquake ahead,” he further said.
A dire situation
A joint survey by the Integrated Comprehensive Disaster Management Programme (CDMP) and Jica in 2009 revealed that if an earthquake of magnitude 7 or more is felt in Bangladesh, 72,000 buildings in such major cities as Dhaka, Chittagong and Sylhet would collapse and 135,000 buildings would be damaged.
Sources at Fire Service and Civil Defence said 76% of Dhaka city's roads are narrow, which would make it difficult to carry out rescue operations in case of an earthquake.
Besides, 60% of the buildings have been constructed after changes in the original design, leading to fears that these unplanned buildings may collapse immediately during a major earthquake. Explosions in gas, electricity, and water lines would make matters worse.
Prof ASM Maksud Kamal, pro-vice chancellor and professor of the Department of Disaster Science and Climate Resilience of Dhaka University, said soft soil in parts of the capital makes buildings there particularly vulnerable to earthquakes.
He said: “Some 35% of Dhaka city's soil is red. In case of an earthquake, the damage to the buildings built on this soil will be less. The remaining 65% of the soil is soft. In case of an earthquake, the seismic stability will be higher on soft soil and the damage will also be higher. Also, if the city of Dhaka is hit by a major earthquake, the number of people who will die under the rubble, by fire and electrocution is quite large.”
High rise buildings can cause bottlenecks
There are two fault lines in Dhaka: one passing east through the middle of Progoti Soroni, and another in the area surrounding Turag and some new areas towards Mohammadpur Bosila, Rajuk Planner and DAP Project Director Md Ashraful Islam told Dhaka Tribune.
“This is a sand area. Buildings in such areas are being constructed on weak pilings, which raises earthquake risks,” he added.
“A magnitude 7 or 7.5 earthquake could have been dealt with had all builders maintained the building code. Soil liquefaction can occur if foundation piling is not done properly,” he said.
Collapsed high-rise buildings may block off the narrow roads of the capital, making emergency response activities extremely difficult, the official added.
“We have already identified 229 commercial buildings, including various school college buildings, markets, and hospitals, as vulnerable and risk prone. Modification notices are issued periodically. It is time consuming to strengthen structures,” he further said, stressing that Rajuk has been trying to ensure that all buildings are built according to the code.
