Seismic Induced Landslide Vulnerability in the Chittagong City, Bangladesh

Md Shofiqul Islam

doi:10.3759/joge.v2i1.3751

Abstract

Chittagong is the second largest city of Bangladesh and evidences of hundreds of earthquakes that jolted this city and its surrounding areas. In this paper, we show the cause of slope failure in Chittagong city with the response of earthquake (seismic) activity. We have collected four in-situ samples from each of the upper and lower layers, i.e., eight samples from each of the seven different locations (Motijharna, Tankir Pahar, Batali Hill, Khulshi, Kushumbag, Akbar Shah, Lebu Bagan (Andhar Manik)) for laboratory analysis. Furthermore, mathematical modeling by using Limit Equilibrium Method showed that most of the dry slopes may fail at medium to big earthquake. Motijhartna, Tankir pahar and Batali hill area with discontinuities or joints are most vulnerable during an earthquake. The area with massive formations without any natural discontinuity is less risky to respond to medium earthquake of magnitude 6.5.