Abstract Laboratory experiments and numerical simulation were conducted to study the residual liquefaction mechanism of two-layer seabed with upper crust layer under standing waves. In this study, the buildup process of pore pressure and onset of liquefaction were firstly analyzed. Furthermore, the residual liquefaction mechanism at the nodal section was discussed. In addition, a parametric study was conducted with the present model to investigate the effects of the soil and wave characteristics to residual liquefaction. The results indicate that the liquefaction occurred before the excess pore pressure reached the maximum, then the liquefaction advanced downwards to maximal depth. Different with nodal section, the horizontal transporting of pore pressure and the accumulating of plastic volumetric strain induced by cyclic normal stress contribute to the liquefaction at the antinodal section simultaneously. The former and latter contribute about 52.6% and 47.4% respectively at the depth of 0.15 m. The thinner upper crust layer, the smaller ks1/ks2 (ks2 = 1.2 × 10−6 m/s), the shorter wave period, the higher wave steepness result in a deeper liquefaction depth. Additionally, the wave period and wave steepness had a more significant effect for the upper crust layer than the lower layer at the nodal section, but the opposite trend appeared at antinodal section.

中文翻译：

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驻波作用下两层粉质海床孔隙压力响应与残余液化

摘要 通过室内试验和数值模拟，研究驻波作用下两层上地壳层海床残余液化机理。在这项研究中，首先分析了孔隙压力的建立过程和液化的开始。此外，还讨论了节点部分的残余液化机制。此外，还使用本模型进行了参数研究，以研究土壤和波浪特征对残余液化的影响。结果表明，液化发生在超孔隙压力达到最大值之前，然后液化向下推进到最大深度。与节点截面不同，孔隙压力的水平传递和循环正应力引起的塑性体积应变的积累同时促进了波腹截面的液化。前者和后者在 0.15 m 深度的贡献分别约为 52.6% 和 47.4%。上地壳层越薄，ks1/ks2越小（ks2=1.2×10−6 m/s），波周期越短，波陡度越高，液化深度越深。此外，波周期和波陡度对上地壳层的影响在节点截面比下地层更显着，但在波腹截面出现相反的趋势。ks1/ks2 越小（ks2 = 1.2 × 10−6 m/s），波周期越短，波陡度越高，液化深度越深。此外，波周期和波陡度对上地壳层的影响在节点截面比下地层更显着，但在波腹截面出现相反的趋势。ks1/ks2 越小（ks2 = 1.2 × 10−6 m/s），波周期越短，波陡度越高，液化深度越深。此外，波周期和波陡度对上地壳层的影响在节点截面比下地层更显着，但在波腹截面出现相反的趋势。