ABSTRACT
Liquefaction potential assessment is of particular significance to geotechnical engineers in order to evaluate the risks for construction of high rise buildings, railway embankments, canal, road embankments, earth dams etc. in areas susceptible to liquefaction. Investigations were made at Rajarhat area of Kolkata, India by means of CPT, DMT, SPT and SDMT measurements. The main purpose of carrying out these tests is to grab a relatively rare opportunity to compare the results of all these methods for arriving at a conclusive evidence in predicting liquefaction. It was found that the results of all the in-situ techniques were relatively consistent in predicting liquefaction within a depth range of 0 to 17.0 m below the ground surface. CPT, DMT, SPT and SDMT are basically field-based in-situ tests for measurements of important geotechnical parameters and also provide reliable data for assessment of liquefaction potential of a site. In recent times Finite Element Method based (FEM), a powerful viable alternative tool is available to the geotechnical engineers for application in various fields. In the present investigation, an attempt has been made to study the assessment of liquefaction based on the numerical simulation using Finite element software in addition to all the field techniques mentioned before. The main objective of the present study is to evaluate the correlation between factor of safety against liquefaction using different in-situ test approaches as well as the FEM tool. Finally, the paper presents the correlation between the depth and factor of safety for this particular Rajarhat area of Kolkata for understanding the vulnerability of this area to liquefaction.
