EVALUATION OF LIQUEFACTION POTENTIAL OF RIVER ALLUVIUM AT DIAMER BASHA DAM SITE

Abstract

Liquefaction is rapid loss of shear strength in loose, saturated granular soils during
an earthquake. This phenomenon is one of the most common causes of failure of civil engineering
structures including dams and other water retaining structures. Keeping in view its devastating effects,
the liquefaction potential of Diamer Basha dam site has been evaluated based on site geology and
seismicity of the area. Different in-situ as well as laboratory testing data like standard penetration test
(SPT), Atterberg’s limits and Grain size analysis is collected and analyzed with their application to
geotechnical earthquake engineering. The latest and evolving methods i.e. Seed and Idriss, Tsuchida΄s
liquefaction susceptibility method and Wang (1979) method have been employed to evaluate the
liquefaction potential of granular and clayey silt deposits. The study revealed that the granular deposits
of the river alluvium are prone to liquefaction as evaluated both by Seed & Idriss and Tsuchida΄s
liquefaction susceptibility method. However, the clayey silt river deposits according to Wang (1979)
and Tsuchida methods are not susceptible to liquefaction.