Assessment of soil liquefaction potential: a case study for Moulvibazar town, Sylhet, Bangladesh

Abstract

Liquefaction can intensify the destruction caused by an earthquake; thus, a region with high liquefaction potential could be more disastrous. Bangladesh is surrounded by the Indo-Burma Folded Belt in the east, the Dauki Fault and Himalayan Syntaxis in the north that are known to have occurred high magnitude earthquakes (e.g., M w > 7) in the past. Therefore, assessing seismic hazards in the regions that are economically growing fast is of great interest. Among many other hazard assessment parameters, soil liquefaction potential index (LPI) can be used to assess seismic hazards. In this study, we have assessed the seismic hazard potential for a small town (Moulvibazar) in the northeast Bangladesh documenting liquefaction potential indices for different surface geological units using an earthquake of moment magnitude M w 8 having a peak horizontal ground acceleration (PGA) of 0.36 g. Twenty-five standard penetration test (SPT) boreholes were completed within the study area to obtain SPT-N values for two surface geological units: (1) Holo-Pleistocene low elevated terrace deposits (Zone 1) and (2) Holocene flood plain deposits (Zone 2). Using the SPT-N values, the LPI values have been calculated for the soil profile of each borehole. The LPI values in the town vary from 0 to 42.33, whereas values from 1.42 to 7.52 are in Zone 1 and values from 0 to 42.34 are in Zone 2. It has been predicted that 42% and 78% areas of Zone 1 and Zone 2, respectively, might exhibit surface manifestation of liquefaction. The results of this study can be used for seismic risk management of Moulvibazar town.

Liquefaction potential analysis based on standard penetration test in coastal area (Case study: Loh Buaya, Rinca Island, Indonesia)

“…The third is to determine micro-zonation maps of LSI. micro-zonation map was created to determine the extent of liquefaction-prone areas [29][30][31][32]. Micro-zonation map created using Inverse Distance Weighted interpolation method based on LSI number in each borehole [33,34].…”

Liquefaction Potential Evaluation by Deterministic and Probabilistic Approaches

“…conducted a recent case study in which they used a standard penetration test data to estimate the liquefaction potential index for a small town (Moulvibazar) in northeast Bangladesh. The LPI values for each borehole's soil profile were derived using the 25 bore log SPT-N data with an earthquake magnitude of Mw=8 and a peak horizontal ground acceleration (PGA) of 0.36 g. The LPI values in town range from 0 to 42.33, with values ranging from 1.42 to 7.52 in the Holo-Pleistocene zone and 0 to 42.34 in the Holocene flood plain area [21].…”

“…Finally, maps of liquefaction hazard were created that corresponded to seismicity and had a yearly probability of exceedance values of 1%, 2%, and 10% in 50 years [26]. During the earthquakes in Bengal (1885), in Great India (1897), and in Srimangal (1918), significant liquefaction cases were seen in Bangladesh's alluvial deposits [21]. Pleistocene monoliths and alluvial deposits make up the town's subsurface soils (sand, silt, and clay).…”

Liquefaction Resistance Evaluation of Soils using Artificial Neural Network for Dhaka City, Bangladesh

“…During an earthquake, liquefaction can be devastating incurring widespread damage, which was revealed by Niigata Earthquake in 1964, Alaska Earthquake in 1964, Loma Prieta Earthquake in 1989, Chi-Chi Earthquake in 1999, and Sulawesi Earthquake in 2018 (Seed and Idriss 1967;Ku et al 2004;Lee et al 2007;Chao et al 2010;Sassa and Takagawa 2019;Hossain et al 2020). Therefore, in a seismic hazard-prone area, liquefaction resistance evaluation is an integral part of site characterization.…”

“…In Bangladesh, most of the subsurface lithology is characterized by unconsolidated, sandy and clayey floodplain sediments. In alluvial deposits of Bangladesh, following the Srimangal Earthquake in 1918, Great Indian Earthquake in 1897, and the Bengal Earthquake in 1885, the evidences of widespread liquefaction were documented (Middlemiss 1885;Oldham 1899;Stuart 1920;Hossain et al 2020). In the north and northeast areas of the country, the evidences of liquefaction were observed during paleoseismic studies, which are considered to be triggered by a series of earthquakes along the Dauki fault (Morino et al 2011(Morino et al , 2014a.…”