PILE RESPONSE DUE TO EARTHQUAKE INDUCED LATERAL SPREADING

Tanwar.H K, Biswas.S, Manna.B

Abstract: Liquefaction assessment is a key aspect when the pile foundations are designed under seismic loading. The liquefaction associated with lateral spreading and flow failures that can affect the overall stability of the pile foundations. This study is emphasized to investigate the extent of the liquefaction zone and the effect of the liquefaction on the pile is also monitored by the means of estimating the maximum bending moment developed due to lateral ground displacement. The investigation site is located at I.I.T. Kharagpur Extension Centre, Block No. HC, Plot. 7, Sector-III, Salt Lake City, Kolkata, India. The diameter and pile shaft length are 0.45 m and 22 m, respectively. The soil samples are collected from three boreholes located at the site of investigation and it is explored to a depth up to 30.45 m below the ground level. The boreholes reveal that the subsoil generally consists of six types of soil layers and the water table is at a depth of 1.25 m below the ground surface. A finite element model is simulated as per the field conditions using QUAKE/W (GeoStudio, 2007) to determine the depth of the liquefaction zone. The soil layers are idealized as 14 nodded rectangular elements. Initial static and dynamic analyses is performed by considering the linear elastic and equivalent linear models of soil using the earthquake history of peak acceleration of 0.16g. It is observed that the layer 1 susceptible to liquefaction due to high excess pore water pressure in that layer. Analytical study is carried out for the estimation of the maximum bending moment induced in the pile subjected to lateral ground displacement. The maximum deflection of the pile is also estimated due to the lateral ground displacement caused by the liquefaction

Keywords: Earthquake, Ground displacement, Lateral spreading, Liquefaction, Pile

DOI: https://doi.org/10.15623/ijret.2012.0102002