李东,杜俊,刘磊,等.泥质粉砂岩粒度分形特征及其与抗剪强度参数的关系[J].河南理工大学学报（自然科学版）,2025,44(1):37-45.

LI D, DU J, LIU L, et al. Granulometric fractal characteristics of argillaceous siltstone and their relationship with shear strength parameters[J]. Journal of Henan Polytechnic University(Natural Science) , 2025, 44(1): 37-45.

泥质粉砂岩粒度分形特征及其与抗剪强度参数的关系

李东1,2,杜俊2,刘磊1, 熊治茗2,3

1.昆明理工大学 国土资源工程学院，云南 昆明  650093;2.昆明学院 建筑工程学院，云南 昆明  650214;3.昆明理工大学 公共安全与应急管理学院，云南 昆明  650093

摘要:泥质粉砂岩堆石料剪切力学特性与分形特征的相关性研究对排土场边坡稳定性具有重要意义。 目的 为探究不同粗粒含量下泥质粉砂岩堆石料力学响应特性，并探讨其与分形维数的相关性， 方法 以不同粗粒含量堆石料为研究对象，开展室内直剪试验，分析土体在不同粗粒含量下抗剪强度参数与分形维数之间的相关性并揭示其力学响应机理。 结果 结果表明：泥质粉砂岩堆石料抗剪强度受粗粒含量影响显著，相同垂直压力下堆石料抗剪强度随粗粒含量增加而增大，以垂直压力2 000 kPa为例，粗粒含量由20%增加到80%，其抗剪强度增幅19.66%。抗剪强度参数与粗粒含量密切相关，随着粗粒含量增加，黏聚力减小，内摩擦角增大，内摩擦角受粗粒含量影响更显著。分形维数随着粗粒含量增大呈减小趋势，它可表征堆石料颗粒级配组成及不均匀特征，当分形维数为1.887~2.631时，表明堆石料为级配良好的土体。分形维数与粗粒含量和抗剪强度参数之间存在相关性，分形维数与黏聚力呈正相关，与粗粒含量和内摩擦角均呈负相关。 结论 粗粒含量对泥质粉砂岩堆石料的力学性质影响显著，同时分形维数可作为评价堆石料级配和不均匀特征的重要参数。

关键词:泥质粉砂岩;粗粒含量;直剪试验;剪切特性;粒度分形

doi: 10.16186/j.cnki.1673-9787.2023100006

基金项目:国家自然科学基金资助项目（11862010）；云南省地方本科高校基础研究联合专项重点项目（202101BA070001-137）

收稿日期:2023/10/05

修回日期:2024/03/08

出版日期:2025/01/02

Granulometric fractal characteristics of argillaceous siltstone and their relationship with shear strength parameters

LI Dong1,2,DU Jun2,LIU Lei1, XIONG Zhiming2,3

1. Faculty of Land Resources Engineering， Kunming University of Science and Technology， Kunming  65009, Yunnan， China; 2. College of Architecture and Civil Engineering， Kunming University， Kunming  650214， Yunnan， China; 3. Faculty of Public Safety and Emergency Management， Kunming University of Science and Technology， Kunming  65009, Yunnan， China

Abstract: The correlation between the shear mechanical properties and fractal characteristics of argillaceous siltstone rockfill is critical for understanding dump slope stability. Objectives This study aims to investigate the mechanical response characteristics of argillaceous siltstone rockfill under varying coarse grain contents and to analyze their correlation with fractal dimensions. Methods Large-scale direct shear tests were conducted on rockfill with different coarse grain contents. The relationship between shear strength parameters and fractal dimensions was examined， and the underlying mechanical response mechanisms were explored. Results The results indicate that the shear strength of argillaceous siltstone rockfill is significantly influenced by coarse grain content. Under the same vertical pressure， shear strength increases with higher coarse grain content. For instance， at a vertical pressure of 2 000 kPa， increasing the coarse grain content from 20 % to 80 % led to a 19.66 % increase in shear strength. Shear strength parameters were closely related to coarse grain content： as coarse grain content increased， cohesion c decreased， whie the internal friction angle φ increased. The internal friction angle was more sensitive to changes in coarse grain content. The fractal dimension D  decreased with increasing coarse grain content， reflecting particle gradation and heterogeneity. When D ranged from1.887 to 2.6, the rockfill exhibited well-graded characteristics. A co-rrelation was identified between fractal dimension D， coarse grain content， and shear strength parameters：D was positively correlated with cohesion c， but negatively correlated with coarse grain content P₅ and internal friction angle φ. Conclusions Coarse grain content significantly affects the mechanical properties of argillaceous siltstone rockfill. Additionally， the fractal dimension serves as a critical parameter for evaluating gradation and heterogeneity in rockfill materials.

Key words: argillaceous siltstone; coarse grain content; direct shear test; shear properties; particle fractal