Poor engineering and the use of floodplains for building construction could contribute to the economic and human costs of a strong earthquake hitting Dhaka city, a leading expert has warned.
Bangladesh University of Engineering and Technology (BUET) Professor Mehedi Hasan Ansari told the Dhaka Tribune that Bangladesh is “waiting for a strong earthquake like in 1897”, which had an estimated magnitude of 8 on the Richter scale.
“In addition to faulty building construction practices, the rapid use of the city’s floodplain will play a role in possible building collapse and subsequent human causalities, if an earthquake of 7.5 magnitude hits Dhaka,” the professor said.
According to the ‘Dhaka Profile and Earthquake Risk Atlas’ study conducted in 2014, around 50,000 deaths and up to $5.7 billion in damages could result from an earthquake of magnitude 7.5 striking the capital.
The study was based on a probable model of a 7.5-magnitude tremor along the Madhupur Fault line and was conducted by the Bangladesh Urban Earthquake Resilience Project with assistance from the World Bank and Earthquakes and Mega-cities Initiatives (EMI).The research data estimated that around 88,000 buildings - over one quarter of the total in Dhaka - will be extensively damaged. DNCC could suffer the collapse of up to 54,000 buildings, while DSCC could face the collapse of 34,000 buildings.
The study further showed that Dhaka North City Corporation (DNCC) could face an estimated bill of around $3.4billion, while the Dhaka South City Corporation (DSCC) might suffer damages of around $2.2 billion.
The study identified several aspects of construction which could compromise the structural integrity of buildings during a quake.
These include soft-story, flat slab, heavy overhang, torsional irregularity, slender and short column, non-parallel system, poor concrete, insufficient gap, non-structural vulnerability, soil liquefaction, narrow access and absence of fire protection.
In addition to a projected 50,000 deaths, the 2014 study estimated around 200,000 injuries resulting from a large quake..