| 复杂滑坡三维离散建模方法及其在茂县滑坡中的应用 |
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| 引用本文： | 杨小龙, 王刚. 2023. 滑坡堆积体反粒序现象的离散元数值分析[J]. 工程地质学报, 31(6): 1941-1950. doi: 10.13544/j.cnki.jeg.2021-0276. |
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| 作者姓名： | 杨小龙 王刚 |
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| 作者单位： | ①.山地城镇建设与新技术教育部重点实验室，重庆 400045，中国;②.重庆大学，土木工程学院，重庆 400045，中国 |
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| 基金项目： | 国家自然科学基金项目(资助号：52079012，51679016) |
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| 摘 要： | 滑坡灾害调查发现，对于大型的高速远程滑坡，其堆积体中往往存在大粒径颗粒在上、小粒径颗粒在下的反粒序堆积现象。为了揭示大型滑坡反粒序堆积现象的机理和影响因素，借助离散元数值分析方法，研究分形维数、滑坡体积以及加速区长度对滑坡体内不同粒径颗粒移动过程的影响规律，并对鸡尾山滑坡进行模拟，分析其堆积体中反粒序堆积结构的形成原因。结果表明：滑坡体在滑动过程中因发生颗粒破碎而形成不同粒径大小的颗粒，在颗粒分选机制作用下，小粒径颗粒通过颗粒间的孔隙向滑坡体下方移动，大颗粒在剪切作用下越过小颗粒向滑坡体上方移动，最终在滑坡堆积体中形成反粒序堆积结构。颗粒分选过程主要通过动力筛分作用和剪切作用进行，其作用力大小与颗粒粒径大小和颗粒受到的上覆压力有关，分形维数越大、上覆压力越大，颗粒分选程度越小，反粒序堆积现象越不明显。
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| 关 键 词： | 颗粒破碎 颗粒分选 反粒序堆积现象 鸡尾山滑坡 |
| 收稿时间： | 2021-05-20 |
| 修稿时间： | 2021-08-31 |
Experiments on a gravity-free dispersion of large solid spheres in a newton fluid under shear |
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| Yang Xiaolong, Wang Gang. 2023. DEM study of inverse grading phenomenon in landslide deposits[J]. Journal of Engineering Geology, 31(6): 1941-1950. doi: 10.13544/j.cnki.jeg.2021-0276. |
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| Authors: | YANG Xiaolong WANG Gang |
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| Affiliation: | ①.Key Laboratory of New Technology for Construction of Cities in Mountain Area, Ministry of Education, Chongqing 400045, China;②.School of Civil Engineering, Chongqing University, Chongqing 400045, China |
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| Abstract: | The investigation of landslide disasters shows that for large high-speed long-distance landslides, there is the deposit phenomenon of inverse grading. This paper attempts to reveal the mechanism and influencing factors of deposit phenomenon of inverse grading in large landslide. It studies the influence of fractal dimension, landslide volume and slide length on the relative movement of particles with different sizes with the means of DEM. Furthermore, Jiweishan landslide is simulated and the inverse grading phenomenon is reproduced. The results show the follows. In the process of sliding, particles of different sizes are formed due to particle breakage. Under the effect of particle sorting mechanisms, smaller particles move to the lower part of the landslide through the pores among larger particles. Larger particles overpass the adjacent smaller ones under shear stress. Finally an inverse grading structure is formed in landslide deposits. The particle separation process is mainly controlled by the force of random fluctuating sieve and shear action and affected by the particle size and overburden pressure. The larger the fractal dimension is, and the larger the overburden pressure is, the smaller the degree of particle separation is, and the less obvious the deposit phenomenon of inverse grading is. |
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| Keywords: | Particle breakage Fractal dimension Deposit phenomenon of inverse grading Jiweishan landslide |
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