Microstructure evolution of granular soils in cyclic mobility and post-liquefaction process
Microstructure evolution of granular soils in cyclic mobility and post-liquefaction process
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DOI：
10.1007/s10035-016-0621-5
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发表时间：
2016-06
期刊：
影响因子：
2.4
通讯作者：
Gang Wang;Jiangtao Wei
中科院分区：
文献类型：
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作者：
Gang Wang;Jiangtao Wei
了解颗粒土的微观结构的演变可以提供重要的见解，土壤液化的本构模型。在这项研究中，使用离散元模拟研究了液化过程的微观力学观点。据观察，在不排水循环荷载的各个阶段，土壤表现出明确的变化，在承载结构，由坐标数和非仿射位移的演变。一个新的颗粒空隙织物，称为“质心距离”，还提出了量化的演变颗粒和空隙分布在颗粒填料。组构指数与散体土的循环动度和液化后变形有很强的相关性。织物指数的演变表明，液化前后颗粒和空隙会不可逆地重新分布。在液化后阶段，土体可形成高度各向异性的颗粒-孔隙结构和承载力。
Understanding the evolution of microstructure in granular soils can provide significant insights into constitutive modeling of soil liquefaction. In this study, micromechanical perspectives of the liquefaction process are investigated using the Discrete Element simulation. It is observed that during various stages of undrained cyclic loading, the soil exhibits definitive change in the load-bearing structure, indicated by evolution of the coordination number and non-affine displacements. A new particle-void fabric, termed as “centroid distance”, is also proposed to quantify the evolution of particles and voids distribution in the granular packing. The fabric index is found to have strong correlation with cyclic mobility and post-liquefaction deformation of granular soils. Evolution of the fabric index indicates that particles and voids redistribute irreversibly before and after liquefaction. A highly anisotropic particle-void structure and loading-bearing capacity can be formed in the post liquefaction stage.