| 摘要: |
| 堆石料流变是堆石坝工后变形的重要成分，当前用以研究其特点的室内流变试验的成本很高，所得时间参数难以直接应用，而细观力学模拟因为成本低且理论上无尺寸约束，已成为研究堆石料流变的新途径，其底层逻辑是：自重及外荷载诱发内部颗粒随时间逐渐破裂，引起颗粒之间互相填充、滑移、重排，系统重新稳定，按此循环直到无新的破裂。可见，对颗粒与时间相关的力学特性进行测试是开展该模拟前的重要环节。本文进行了堆石料颗粒恒载压缩试验。结果表明：在应力水平大于0.85时出现颗粒延迟破裂，破裂用时与应力水平呈负相关指数函数关系；颗粒变形不大但时变特征显著，可用西原模型复现，且时变特征与应力水平相关。本文结果可为堆石料流变细观力学模拟的开展提供一些必要条件，有利于该领域的发展。 |
| 关键词: 堆石料颗粒 恒载压缩 颗粒延迟破裂 应力水平 流变模型 时间相关变形 |
| DOI： |
| 分类号: |
| 基金项目: |
|
| Study on delayed breakage and time-dependent deformation of rockfill particles |
|
Yang Yu-fei, Guo Yu, Chi Shi-chun, Wang Feng
|
|
School of Infrastructure Engineering,Dalian University of Technology
|
| Abstract: |
| The creep of rockfill material is an essential component of the deformation of rockfill dams after construction. Currently, indoor creep tests used to study such features are very costly and the resulting time parameters are difficult to apply directly. In contrast, microscopic mechanical simulations have emerged as a new approach to investigate creep in rockfill materials due to their low cost and theoretical lack of size constraints. The underlying logic is that self-weight and external loads induce gradual internal particle breakage over time, leading to mutual filling, sliding, and rearrangement of the particles, resulting in system stabilization, repeating this cycle until no new breakage occurs. Therefore, testing the time-dependent mechanical properties of the particles is an important step before performing such simulations. The constant load compression test was performed on rockfill particles in this study. It is shown that for stress levels above 0.85, delayed breakage of the particles occurs, with the time-to-breakage being negatively correlated with the stress level following an exponential function. The deformation of the particles is minimal, but the time-dependent features are significant and can be reproduced by the Nishihara model, where these features are related to the stress level. The findings presented in this paper provide the necessary conditions for microscopic mechanical simulations of rockfill creep, contributing to the development of this field. |
| Key words: Rockfill particles constant-load compression Delayed particle breakage Stress level Creep model Time-dependent deformation |
