关键词: 南京饱和细砂, 液化流动特大变形, 剪切模量衰减, 循环加载幅值, 初始剪应力比

Abstract: To study the post-liquefaction stress-strain relationship of saturated Nanjing sand, shear moduli reduction in the liquefaction state, the dilation state and the unloading state were investigated under different loading conditions. As results, the effective confining pressure, the initial shear loading, and the amplitude of cyclic loading have less effect on shear moduli reduction of saturated Nanjing sand in the liquefaction state and the dilation state. However, these factors have great effect on shear moduli reduction of saturated Nanjing sand in the unloading state. As the effective confining pressure and the cyclic loading amplitude increasing, the post-liquefaction shear moduli of saturated Nanjing sand in unloading stage are all stronger and the shear moduli soften faster under the subsequent cyclic loadings. Meanwhile, as the initial shear stress increasing, the post-liquefaction shear moduli of saturated Nanjing sand are also stronger, but it softens slower under the subsequent cyclic loadings. Based on the test results, the decay function of the shear moduli of saturated Nanjing sand in different loading stages are also given.

Key words: saturated Nanjing sand, liquefaction-induced extreme flow large deformation, shear moduli decay, cyclic loading amplitude, initial shear stress ratio