基于土体细观结构重构技术的渗流场数值模拟

发布时间：2018-05-15 04:18

本文选题：四参数随机生长法 + 土体细观结构　；参考：《岩土力学》2015年11期

【摘要】：真实土体的细观结构由许多个大小不一的土颗粒团组成,传统四参数随机生长法(QSGS)构建的土体结构土颗粒团比较均匀,与实际情况存在较大的差异。为弥补这一缺陷,考虑土体孔隙率及自相关函数的影响,对传统的四参数随机生长法进行改进,实现了更接近于真实土体的细观结构重构。在此基础上基于格子Boltzmann方法,采用D2Q9模型,通过设置模型入口、出口边界为非平衡态外推格式,左右边界及土颗粒边界为标准反弹格式的边界条件,建立了模拟重构土体细观渗流场的二维模型。同时,针对一算例编制了相应的计算程序,研究了恒定流速入渗情况下重构土体的细观渗流场。研究表明:土体的渗流方向优先选择连通性较好孔隙所形成的通道,流速受控于通道整体连通性的优劣。整体贯通型的通道流动速度较快,部分连通的孔隙中其流动速度相对较慢。即使局部孔隙空间较大,其渗流速度仍取决于是否位于贯通型通道上。
[Abstract]:The meso-structure of real soil consists of many soil particle clusters of different sizes. The traditional four-parameter random growth method (QSGSs) is relatively uniform, which is quite different from the actual situation. In order to remedy this defect, considering the influence of soil porosity and autocorrelation function, the traditional four-parameter random growth method is improved to realize the meso-structure reconstruction which is closer to the real soil mass. On this basis, based on the lattice Boltzmann method, D2Q9 model is adopted. By setting the entry of the model, the exit boundary is a non-equilibrium extrapolation scheme, and the left and right boundary and the soil particle boundary are the boundary conditions of the standard rebound scheme. A two-dimensional model is established to simulate and reconstruct the mesoscopic seepage field of soil. At the same time, the corresponding calculation program is compiled for a numerical example to study the reconstruction of the mesoscopic seepage field of soil under the condition of constant velocity infiltration. The results show that the flow direction of soil is preferential to the channel formed by the better porosity, and the velocity of flow is controlled by the overall connectivity of the channel. The flow velocity of the whole through channel is faster than that of the partially connected pore. Even if the local pore space is large, the percolation velocity still depends on whether or not it is located on the transfixion channel.
【作者单位】：昆明理工大学建筑工程学院;中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室;
【基金】：国家自然科学基金资助(No.51179187) 昆明理工大学人才培养基金资助(No.KKSY201306023)~~
【分类号】：TU43

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