关键词: 土石混合体, 二维细观结构模型, 将数值流形法, EAB

Abstract: Soil-rock mixture deserves special attentions from engineers as one type of general geotechnical material. The numerical simulation of soil-rock mixture provides direct consultation for engineering practices. The mesoscale model of soil-rock mixture was reconstructed first and appropriate numerical method was selected afterwards. Establishing mesoscale model in two-dimension can be summarized as filling the model area with randomly generated rock inclusions obeying known size distribution and meanwhile avoiding overlaps. In this paper, the background Mesh-EAB algorithm is proposed to replace the widely adopted random sequential addition algorithm. In the latter algorithm, a random position for the newly added rock inclusion needs to be repeatedly generated if overlap between this inclusion and previous added rock inclusions can be detected. Thus, it is based on trial-and-test. In the Background Mesh-EAB algorithm, a prior knowledge about overlap can be obtained and thus eliminate the necessity of trial-and-test and improve the efficiency. In the stage of numerical method, the numeric manifold method is adopted. Furthermore, the original numerical manifold method with uniform mathematical cover generator is modified adaptively. Due to the difference in the magnitude of deformations, individual mathematic cover is generated for each rock inclusions while uniform and denser mathematical cover is generated for soil. The revised numeric manifold method can reproduce the interaction between discrete blocks and continuous medium. Finally, the confined compression test of soil-rock mixture is simulated to unveil the influences of confining stress and dislocations between soil and rock on the compressive strength of soil-rock mixture.

Key words: soil-rock mixtures, 2D mesostructural model, numerical manifold method, EAB