摘要
作为常见的岩土工程材料,对土石混合体的数值模拟能为工程建设提供直接依据。土石混合体的数值模拟包含建模和仿真阶段。在建模阶段,提出了基于石氏接触理论的背景网格-EAB块石投放算法,新的算法避免了块石的反复投放与块石间重叠判定,提高了块石投放建模的效率。在数值仿真阶段,将数值流形法(NMM)应用到二维土石混合体的模拟中,对二维土石混合体的计算模型进行了适应性的简化,通过对每个块石生成单独的数学覆盖,为土体建立统一的数学覆盖,建立了适用于土石混合体的计算模型,该模型可用于模拟填石等散体系统和连续介质共同作用。最后,通过对二维土石混合体试件进行压缩试验的算例,展现了围压对于土石混合体峰值抗压强度的影响,以及土石错动对于土石混合体抗压强度演化的影响,验证了该计算模型在模拟散体系统与连续介质共同作用时的有效性和适用性。
Soil-rock mixture deserves special attentions from engineers as one type of general geotectmlcai material, i ne 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.
作者
陈立
张朋
郑宏
CHEN Li ZHANG Peng ZHENG Hong(State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, Hubei 430071, China College of Civil Engineering and Architecture, Henan University of Technology, Zhengzhou, Henan 450001, China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2017年第8期2402-2410,2433,共10页
Rock and Soil Mechanics
基金
"973"项目资助(No.2014CB047100)
国家自然科学基金项目资助(No.11572009
No.51538001
No.51609240)~~
