纳米硅溶胶改良辽宁台安砂土的抗液化性能研究OACSTPCD

As a type of liquefiable sand,the sand in Taian,Liaoning Province,has liquefaction re-sistance,which is of great engineering importance.To explore the improvement effect of nano colloidal silica(CS)on the liquefaction resistance of Taian sand,a series of undrained dynamic triaxial tests was conducted to compare the liquefaction characteristics of pure and treated sand samples.The effects of CS concentration and curing time on the dynamic characteristics of the sand samples were analyzed.The research results indicate that(1)CS improves the liquefaction resistance of Taian sand.Under the action of a dynamic load,no liquefaction damage occurs in the treated sand samples.(2)The dynamic pore pressure and dynamic strain of the samples rapidly decrease at first and then stabilize with increasing the CS concentration and curing time.When the CS concentration increases to 4％and the curing time reaches three weeks,the improvement effect of the sample's liquefaction resistance is not obvious.(3)The hysteresis curve of CS-treated sand samples becomes more stable than that of the pure sand samples.With increasing CS con-centration,the damping decreases first and then tends to be stable,and the dynamic elastic mod-ulus gradually increases and then tends to be gentle,with a certain fluctuation.With increasing curing time,the damping decreases and the dynamic elastic modulus increases.The research results provide a reference for sand liquefaction treatment in the Taian region of Liaoning Prov-ince.