{"title":"分形粒度分布的颗粒雪崩流动性增强:离散元素分析的启示","authors":"A.N. Shi , G.C. Yang , C.Y. Kwok , M.J. Jiang","doi":"10.1016/j.epsl.2024.118835","DOIUrl":null,"url":null,"abstract":"<div><p>Granular avalanches are a form of hazardous landslide that rapidly travels long distances, with the grain-size distribution of their fragmented deposits developing fractal characteristics. In this study, we perform three-dimensional discrete element simulations of granular avalanches in a rotating drum to evaluate the effect of fractal particle size distributions on the flow mobility. The mobility of granular avalanches, measured as the inverse of the surface inclination angle, increases with the fractal dimension following a bilinear relationship with an abrupt slope change at a critical fractal dimension of 3.25, which delimits a roller-developing regime from a roller-active regime. The flow enters the roller-active regime when the fractal dimension is greater than 3.25, during which a complete basal layer of small particles separating the drum base and the flowing particles above is formed. Micro-mechanical evidence suggests that small particles at the drum base act as rotating bearings to reduce the effective basal friction, attenuate energy dissipation, and thereby enhance flow mobility.</p></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":null,"pages":null},"PeriodicalIF":4.8000,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Enhanced mobility of granular avalanches with fractal particle size distributions: Insights from discrete element analyses\",\"authors\":\"A.N. Shi , G.C. Yang , C.Y. Kwok , M.J. Jiang\",\"doi\":\"10.1016/j.epsl.2024.118835\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Granular avalanches are a form of hazardous landslide that rapidly travels long distances, with the grain-size distribution of their fragmented deposits developing fractal characteristics. In this study, we perform three-dimensional discrete element simulations of granular avalanches in a rotating drum to evaluate the effect of fractal particle size distributions on the flow mobility. The mobility of granular avalanches, measured as the inverse of the surface inclination angle, increases with the fractal dimension following a bilinear relationship with an abrupt slope change at a critical fractal dimension of 3.25, which delimits a roller-developing regime from a roller-active regime. The flow enters the roller-active regime when the fractal dimension is greater than 3.25, during which a complete basal layer of small particles separating the drum base and the flowing particles above is formed. Micro-mechanical evidence suggests that small particles at the drum base act as rotating bearings to reduce the effective basal friction, attenuate energy dissipation, and thereby enhance flow mobility.</p></div>\",\"PeriodicalId\":11481,\"journal\":{\"name\":\"Earth and Planetary Science Letters\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":4.8000,\"publicationDate\":\"2024-07-04\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Earth and Planetary Science Letters\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0012821X2400267X\",\"RegionNum\":1,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"GEOCHEMISTRY & GEOPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Earth and Planetary Science Letters","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0012821X2400267X","RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
Enhanced mobility of granular avalanches with fractal particle size distributions: Insights from discrete element analyses
Granular avalanches are a form of hazardous landslide that rapidly travels long distances, with the grain-size distribution of their fragmented deposits developing fractal characteristics. In this study, we perform three-dimensional discrete element simulations of granular avalanches in a rotating drum to evaluate the effect of fractal particle size distributions on the flow mobility. The mobility of granular avalanches, measured as the inverse of the surface inclination angle, increases with the fractal dimension following a bilinear relationship with an abrupt slope change at a critical fractal dimension of 3.25, which delimits a roller-developing regime from a roller-active regime. The flow enters the roller-active regime when the fractal dimension is greater than 3.25, during which a complete basal layer of small particles separating the drum base and the flowing particles above is formed. Micro-mechanical evidence suggests that small particles at the drum base act as rotating bearings to reduce the effective basal friction, attenuate energy dissipation, and thereby enhance flow mobility.
期刊介绍:
Earth and Planetary Science Letters (EPSL) is a leading journal for researchers across the entire Earth and planetary sciences community. It publishes concise, exciting, high-impact articles ("Letters") of broad interest. Its focus is on physical and chemical processes, the evolution and general properties of the Earth and planets - from their deep interiors to their atmospheres. EPSL also includes a Frontiers section, featuring invited high-profile synthesis articles by leading experts on timely topics to bring cutting-edge research to the wider community.