Search Articles

Home / Articles

Seismic Liquefaction Susceptibility and Ground Deformation Evaluation using Geotechnical Characterization

. Syeda Saria Bukhary & Syed Muhammad Abbas Abdi


Abstract

Earthquake shaking can trigger the complex phenomenon of seismic liquefaction. The purpose of this study is to assess the Liquefaction Potential Index (LPI) and liquefaction-induced ground deformations (LGD) during earthquakes in Karachi, Pakistan. Karachi, home to over 20 million inhabitants, is located in one of the most tectonically active regions in the world. To date, no comprehensive studies have evaluated LPI and LGD for this city or produced detailed maps for various earthquake scenarios, leaving a significant research gap that this study aims to fill. The Standard Penetration Test (SPT) is a commonly used geotechnical field method to evaluate the penetration resistance of the subsurface strata and can be used for assessing LPI and LGD. For this study, SPT bore data was collected from 100 sites across Karachi. Analyses were conducted for earthquake magnitudes of 6.5 and 7.5, using peak ground accelerations (amax) of 0.16g, 0.2g, and 0.24g. Results revealed that coastal areas of Karachi are particularly susceptible to LGD, with settlements exceeding 30 cm and lateral displacement indices greater than 100 cm at most of these locations. Specifically, the greatest LGD is expected in the coastal regions of Clifton Cantonment, Korangi Creek Cantonment, Jamsheed Town, and Korangi Town for earthquake magnitudes of 6.5 and 7.5 at amax=0.2g.

 

Keywords- Liquefaction potential index, Soil Settlement, Lateral Displacement Index, Standard Penetration Test, Liquefaction-induced deformation

Download :