Evaluation of the Equivalent Number of Cycles in Liquefaction Potential Study Using Energy Approach

The equivalent number of cycles concept is used essentially for evaluating soil liquefaction potential. N is used to convert irregular cycles in a time history of vibration in soil layers resulted from site response analysis into regular motions with uniform cycles required for assessment of soil liquefaction potential. Several methods have been proposed to estimate the equivalent number of cycles. In this study, these methods and their efficiency as well as interrelations are discussed. Then, the number of equivalent cycles is assessed from energybased method, using the calculated dissipated energy in each layer of soil deposit and from hysteresis loops. This is achieved through a nonlinear site response analysis. It will be described how to evaluate N from energy-based concepts. It is shown that despite of the other concepts, energy-based method’s results are more precisely and can be used to evaluate soil liquefaction potential.

Keywords:

equivalent number of cycles , soil liquefaction potential , dissipated energy , energybasedmethod