Comparison of Three Procedures for Evaluating Earthquake-Induced Soil Liquefaction (original) (raw)

Using a reliability-based analysis for evaluating soil liquefaction potential

2011

Simplified methods based on in-situ tests such as the standard penetration test (SPT) and the cone penetration test (CPT), are widely used by geotechnical engineers for assessing the liquefaction potential of soils. The four studied methods are those recommended by the NCEER and those proposed by Boulanger and Idriss. In our study, a reliability analysis, based on conventional probability theory, is used to calculate the relationship between the liquefaction probability and reliability index on one hand, and the traditional factor of safety on the other hand. The case study is in Qatar in the Persian Gulf. Hundreds of CPT and SPT tests have been carried out at this site. Uncertainty in the evaluation of peak horizontal earthquake induced ground acceleration is considered. It is observed that the probability of liquefaction drastically changes for a small change in the factor safety. RÉSUMÉ Des méthodes simplifiées basées sur les essais in-situ comme l’essai de pénétration standard (...

EVALUATION OF LIQUEFACTION POTENTIAL OF SOILS -A REVIEW

Journal of Emerging Technologies and Innovative Research, 2018

Liquefaction of soil during earthquakes results in catastrophic damages to life and property. The deformations of soil during earthquakes pose a serious risk to the stability of structures. Niigata earthquake in Japan and the Bhuj earthquake in India incurred large scale damage to the buildings and dams. It is essential to evaluate the resistance of soils to liquefaction. This paper deals with understanding the process of liquefaction and estimating the liquefaction potential of soils by various laboratory tests and empirical approaches. The undrained behaviour of soils in cyclic shearing is explained with the help of cyclic triaxial testing and cyclic direct simple shear test. The results of the cyclic direct simple shear test conducted on loose Fraser river sand in Vancouver, Canada are discussed in this paper. The empirical approach developed in 1996 NCEER and 1998 NCEER/NSF workshops to determine the liquefaction potential of soils is presented. This empirical approach is a simplified procedure based on field tests which can be used in practice to evaluate the liquefaction potential of soils.