145 Dynamics of Natural and Built Environments (Posters)

Our communities, economies and infrastructure depend on interactions between the natural and built environments. Engineered systems (e.g. earthworks, structures, utilities) must be resilient to evolving natural forcings, and similarly engineered systems must also minimize negative effects on the natural environment.

Monday, 20 October 2025
8:00 AM - 5:30 PM
HBGCC, Hall 1

Soil Liquefaction Risk in Dhaka, Bangladesh During Large Earthquakes

Paper number: 145-4
Program: Technical Sessions
Time: 8:00 AM – 8:00 AM

Authors

Abstract

Bangladesh has experienced several strong earthquakes in the past, highlighting the importance of studying the risk of soil liquefaction, especially in the capital city, Dhaka. This study assesses the likelihood of liquefaction during two potential earthquake scenarios (Mw 7.0 and 7.5) under both dry and wet seasonal conditions. The analysis focuses on three geological zones in Dhaka: (1) Madhupur Terrace, (2) Marsh and Artificial Fill, and (3) Holocene Floodplains.

We used Standard Penetration Test (SPT) data from 26 boreholes to estimate liquefaction probabilities. For an Mw 7.0 earthquake during the dry season, the likelihood of liquefaction is 68% in Zone 1, 80% in Zone 2, and 88% in Zone 3. These probabilities increase during the wet season to 90%, 100%, and 100%, respectively. For an Mw 7.5 earthquake, the risk rises to 79%, 98%, and 90% in the dry season, and to 99% and 100% in the wet season. This demonstrates that both stronger earthquakes and higher groundwater levels significantly increase the chance of liquefaction.

X-ray diffraction analysis also revealed that Illite, Kaolinite, and Chlorite are common clay minerals at different depths, with Smectite found in Banani, which could influence liquefaction behavior. A spatial analysis using Inverse Distance Weighting (IDW) indicates that several areas, such as Uttara, Turag, Pallabi, Darus Salam, Kafrul, Tejgaon, Rampura, Motijheel, and Demra, are at higher risk. The number of people potentially affected ranges from 3.6 million (Mw 7.0, dry season) to nearly 14 million (Mw 7.5, wet season). These findings emphasize the importance of careful urban planning and disaster preparedness in Dhaka.

Geological Society of America Abstracts with Programs. Vol. 57, No. 6

doi: 10.1130/abs/2025AM-414772

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