Abstract: In this study, the parameter characteristics of the database including 473 shear wave velocity test results from all over the world were analyzed. After that, the Logistic model was selected to build a new formula to evaluate the probability of liquefaction, considering four conventional parameters: PGA, shear wave velocity, water table and the depth of liquefiable layer. At last, the applicability of the formula under different probabilistic levels was studied and compared with the existing methods. This study shows that the ground vibration intensity is the primary parameter to influence liquefaction estimation. The shear wave velocity of liquefaction layer does not differentiate from the shear wave velocity of the non-liquefaction layer, so it is difficult to meet the basic requirements by using a semplice formula. The methods developed by Andrus and Shi Zhaoji misjudge many obvious non-liquefied points. Those misjudgments breach the existing knowledge and need improvements. The formula developed by this paper conforms to equal distribution of liquefaction points and non-liquefaction points when PL=50%, and the accuracy can reach about 70% in different intensity levels. In summary, this formula provides a reasonable and easy-to-use shear wave velocity liquefaction evaluation method.

Key words: liquefaction probability, probabilistic equation, conventional soils parameters, shear wave velocity