Evaluating Liquefaction Resistance of Soil & Improvements
In this paper, assessment of liquefaction of soils by various approaches have been reviewed and presented in chronological order. The study focuses on comparative procedural assessment of simplified conventional and empirical methods and deriving the best method to ascertain MSF defining liquefaction index point wr.t. CRR & CSR. Simplified method given by Seed, Tokimatsu-Yoshimi (T-Y) and Idriss & Boulanger methods of liquefaction assessment have been analysed from SPT results. A comparative study is made among the existing three SPT based statistical methods and then developed method for prediction of liquefied and non-liquefied cases in terms CSR & CRR with respect to the field observations. Case histories of soil liquefaction are analysed using empirical methods, further the arithmetic analysis to predict the liquefaction potential of soil. The results are compared with the currently used statistical methods in terms of CRR & CSR. Based on the results, comparison has been done to derive optimistic method to analyse the CRR for soil liquefaction point of view. Comparison chart is illustrative to Magnitude scaling factor by different methods which tends to draw curve giving most safe and valid reading of MSF w.r.t. earthquake magnitude. Close rate of successful prediction for liquefactions shows good generalization capabilities of statistical approach. The developed method is found to be more efficient compared to the empirical methods in identifying the point of liquefaction. However, it needs more study with new data sets of different liquefaction case histories to confirm or disprove the present findings.