Numerical Analysis for Granular Ground Using the Advanced DEM

使用高级 DEM 对粒状地面进行数值分析

• 批准号: 01550389
• 负责人: KIYAMA Hideo
• 金额: $ 1.34万
• 依托单位: Tottori University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1989
• 资助国家: 日本
• 起止时间: 1989 至 1990
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01550389/
• 关键词: DEM; Flow Element Method; Mechanics of Granular Material; Discontinuous Rock Mass; Pore water; Fractal; 個別要素法

The main purposes of this investigation are to demonstrate that DEM is a helpful method in examining geotechnical problems, moreover, to clear the behavior of ground as granular material.First, for the attainment of these purposes, elasto-plastic type DEM was developed, which expressed plastic energy dissipations caused by elements contact, and coupled with solid skeletons and pore water pressures and flow. However, it had be come clear that analytical results of the modified DEM were too much influenced by the values of plastic constants. So large and irreversible deformations of solid skeletons with random generations of pore were modeled by the reduction of element stiffness. Consolidation and liquefaction problems were analyzed with regular arrangements of uniform circle elements, and e-log p curves and changes of pore water pressure during cyclic loading were illustrated. Through these analyses, The applicability of DEM to sandy soil ground was certified.Second, fractal dimensiona … More l analysis was introduced, which was intended to evaluate the roughness of the jointing surfaces and to determine the analytical conditions of DEM in applying to discontinuous rock mass. Analyses for rock slopes composed of hundreds of uniform rectangular blocks were carried out where discontinuities were simplified as following two patterns ; 'intermittent' and 'cross-continuous'. The comparison between pseudo-static inclination analysis and dynamic shaking analysis gave effective data in discussing the stability of rock slopes. After these fundamental colculations, DEM analyses were performed on a rock slope failure which happened along Echizen coast road. Some Probable scenarios of the slope failure were obtained, which may give useful information to judge the true cause and failure behavior by comparison with field observations.All the results obtained from this study fulfilled the requirements as mentioned above. After the accomplishment of the main purposes, a new numerical method named FLEM was expressed utilizing the basic theory of DEM. FLEM is expected to be a powerful method in analyzing large deformation and flow problems. Less

本研究的主要目的是为了证明DEM是一种有效的分析岩土工程问题的方法，并且可以明确地基作为散体材料的特性。首先，为了达到这些目的，建立了弹塑性DEM，它表达了单元接触引起的塑性能量耗散，并与固体骨架和孔压和流动相耦合。然而，可以清楚地看到，修正后的DEM的分析结果受塑性常数的影响太大。因此，具有随机生成的孔洞的固体骨架的大而不可逆的变形可以通过单元刚度的降低来模拟。采用均匀圆形单元对固结和液化问题进行了分析，给出了循环荷载作用下的e-logp曲线和孔压变化曲线。通过这些分析，验证了DEM在砂土地基中的适用性。第二，分维…进一步介绍了L分析方法，用于评价节理面的粗糙度和确定DEM应用于不连续岩体的分析条件。对由数百个均匀矩形块体组成的岩石边坡进行了分析，其中不连续面简化为以下两种模式：间歇和交叉连续。拟静力倾角分析与动力振动分析的对比，为岩质边坡稳定性的探讨提供了有效的数据。在这些基本计算的基础上，对发生在Echizen海岸公路上的一个岩石边坡破坏进行了DEM分析。通过与现场观测结果的对比，得到了一些可能的边坡破坏情景，为判断边坡的真正原因和破坏行为提供了有用的信息，所有的研究结果都满足上述要求。在此基础上，利用数字高程模型的基本理论，提出了一种新的数值方法--FLEM方法。自由流体法有望成为分析大变形和大流动问题的有力方法。较少

项目成果

H., FUJIMURA: "Fractal Dimension Analysis for Evaluation of Granular Shear Properties." Reports of The Faculty of Engineering, Tottori University,. Vo1.20, No. 1. 199-126 (1989)

H.，FUJIMURA：“用于评估颗粒剪切性能的分形维数分析”。

H., KIYAMA: "A Proposal of FLEM for Large-deformation-to-Flow Problems." Proceedings of the 23rd Symposium on Rock Mechanics. 332-336 (1991)

H., KIYAMA：“针对大变形流动问题的 FLEM 提案。”

藤村 尚・西村 強・木山 英郎: "フラクタル次元解析による粒状体のせん断特性の評価" 鳥取大学工学部研究報告. 20. 119-126 (1989)

Takashi Fujimura、Tsuyoshi Nishimura 和 Hideo Kiyama：“通过分形维数分析评估颗粒材料的剪切性能”鸟取大学工学部研究报告。20. 119-126 (1989)。

西村 強・木山 英郎・藤村 尚: "間隙水連成型DEMの拡張と適用法" 岩の力学国内シンポジウム講演論文集. 8. 411-416 (1990)

Tsuyoshi Nishimura、Hideo Kiyama、Takashi Fujimura：“孔隙水耦合 DEM 的推广和应用方法”全国岩石力学研讨会论文集 8. 411-416 (1990)。

N., NISHIMURA: "An Analysis of a Rock slope Failure by DEM." Reports of The Faculty of Engineering, Tottori University. Vo1.21, No. 1. 187-193 (1990)

N.，NISHIMURA：“通过 DEM 分析岩石边坡破坏。”