Effective Stress Analysis of an Earth Dam on Deep Sandy Alluviums During Strong Earthquakes

Using the finite element liquefaction program based on Biot’s dynamic theory for fluid-saturatedporous media and a multimechanism constitutive model for sandy soils,dynamic effective stress analysis of an earth dam on deep sandy alluviums during an M6.8earthquake is conducted.A comparison of calculated and measured values shows some differences in acceleration and permanent deformation.Because the calculated values essentially reflect actual distribution,the accuracies of the numerical and constitutive models are validated.On the basis of the numerical analysis results,it can be concluded that a reinforcement measure for the dam and its underlying foundation is unnecessary because liquefaction in only a small area may occur in these zones.However,an anti-liquefaction reinforcement measure should be taken because liquefaction in large areas may occur in the shallow layers of sandy alluviums near the dam toe.