TITLE:
The Hidden Earthquake Induced Liquefaction Risks in the Rohingya Refugee Camp Hills & Surrounding Areas of Ukhiya, Cox’s Bazar, Bangladesh—A Geotechnical Engineering Approach
AUTHORS:
Abu Taher Mohammad Shakhawat Hossain, Md. Shakil Mahabub, Tanmoy Dutta, Mahmuda Khatun, Toru Terao, Md. Hasan Imam, Hossain Md Sayem, Md. Emdadul Haque, Purba Anindita Khan, Sheikh Jafia Jafrin
KEYWORDS:
Earthquake, Magnitude, Factor of Safety (Fs), Liquefaction Potential Index (LPI) & Risk
JOURNAL NAME:
Open Journal of Earthquake Research,
Vol.12 No.3,
August
16,
2023
ABSTRACT: Liquefaction is one of the
major catastrophic geohazards which usually occurs in saturated or partially
saturated sandy or silty soils during a seismic event. Evaluating the potential
liquefaction risks of a seismically prone area can significantly reduce the
loss of lives and damage to civil infrastructures. This research is mainly
focused on the earthquake-induced liquefaction risk assessment based on
Liquefaction Potential Index (LPI) values at different earthquake magnitudes (M
= 5.0, 7.0 and 8.0) with a peak ground acceleration (amax) of 0.28 g in the Rohingya Refugee camp
and surrounding areas of Ukhiya, Cox’s Bazar, Bangladesh. Standard Penetration
Test (SPT) results have been evaluated for potential liquefaction assessment.
The soils are mainly composed of very loose to loose sands with some silts and
clays. Geotechnical properties of these very loose sandy
soils are very much consistent with the criteria of liquefiable soil. It is
established from the grain size analysis results; the soil of the study area is
mainly sand dominated (SP) with some silty clay (SC) which consists of 93.68%
to 99.48% sand, 0.06% to 4.71% gravel and 0% to 6.26% silt and clay. Some
Clayey Sand (SC) is also present. The silty clay can be characterized as medium
(CI) to high plasticity (CH) inorganic clay soil. LPI values have been
calculated to identify risk zones and to prepare risk maps of the investigated
area. Based on these obtained LPI values, four (4) susceptible liquefaction
risk zones are identified as low, medium, high and very high. The established
“Risk Maps” can be used for future geological engineering works as well as for
sustainable planning, design and construction purposes relating to adaptation
and mitigation of seismic hazards in the investigated area.