The Effect Of Shear-wave Velocity On The Structure And The Liquefaction Resistance Of Saturated Loose Sands (Silts)

It is an important problem to research the effect of shear-wave velocity on liquefaction resistance and structure of saturated sands (silts) for evaluating saturated sands liquefaction resistance. Therefore, following researches has been done in this paper.1. The effect of the shear wave velocity on the cyclic liquefaction resistance of saturated loose sands (silts) has been studied using a new cyclic triaxial system with measurements of shear wave velocity. The cyclic strain with the number of cycles is analyzed for the saturated loose undisturbed and remolded silt samples. The correlation between their cyclic liquefaction resistances is further studied. Results show that cyclic strains of saturated loose undisturbed and remolded silts are consistant and their cyclic liquefaction resistances are same if their shear wave velocities are same. The consistency does not depend on the cyclic strain criterion determining the number of cycles to liquefaction.2. The correlation between the shear-wave velocity and the structure of the saturated loose silt (sand) has also been researched. The dry unit weight and the shear-wave velocity were used to remold silt samples respectively. If samples were remolded according to the dry unit weight of undisturbed samples, the liquefaction resistance of remolded samples is lower than that of undisturbed samples. If the shear wave velocity of remolded samples was regulated to that of undisturbed samples, the liquefaction resistance of remolded samples is close to that of undisturbed samples. If shear wave velocities of loose sand samples with different structures were regulated to the same, their cyclic liquefaction resistances were the same. Therefore, the shear wave velocity of loose soils is an important controlling parameter describing the difference of structures.3. The orthogonal analysis method was used to optimize the relation predicting the liquefaction resistance of in situ strata, which was developed based on cyclic triaxial experimental results with measurements of shear wave velocity. The result shows that the predictive accuracy of the revised relation reachs to 81.6% and increases 11.5 % comparing with the unrevised relation.