土工基础

土工基础 ›› 2025, Vol. 39 ›› Issue (4): 679-682.

• 测试技术 • 上一篇    

煤矸石做路基填料分形级配效应的三轴剪切试验研究

胡曾强1，罗 浩2   

  1. （1.四川省交通建设集团有限责任公司,成都 610041；2.西华大学建筑与土木工程学院，成都 610039）
  • 收稿日期:2025-07-06 修回日期:2025-08-04 出版日期:2025-08-31 发布日期:2025-08-27
  • 作者简介:胡曾强（1990-），男，工程师，研究方向为土木工程、岩土工程。

Triaxial Shear Testing of Coal Gangue Subgrade Fillers: Fractal Gradation Effects on Mechanical Performance

HU Zengqiang1, LUO Hao2   

  1. (1.Sichuan Transportation Construction Group Co., Ltd., Chengdu 610041;
    2.School of Architecture and Civil Engineering, Xihua University, Chengdu 610039)
  • Received:2025-07-06 Revised:2025-08-04 Online:2025-08-31 Published:2025-08-27

摘要： 为推动煤矸石作为路基填料的资源化利用，通过静三轴剪切试验探究了分形维数与围压对煤矸石填料力学性能的耦合影响机制。以贵州纳雍县煤矸石为对象，设计了5种分形维数级配（D=2.1-2.45）和4种围压（50～300 kPa）。结果表明：煤矸石以SiO2-Al2O3-Fe2O3体系为主（总量>85%），具备良好的工程应用基础。各级配试样均呈鼓胀塑性破坏模式。强度参数分析显示，黏聚力c随分形维数增大从76.87 kPa增至101.81 kPa（增幅32.47%），而内摩擦角φ变化甚微（<12%），并将其嵌入莫尔-库仑理论，构建了一个能够量化预测级配煤矸石强度的半经验模型。该模型揭示了分形级配通过颗粒填充与咬合调控强度的内在机制，为煤矸石路基填料的优化设计提供了理论依据。

关键词: 煤矸石, 分形维数, 三轴剪切试验, 级配效应, 路基填料, 力学性能

Abstract: To advance the resource utilization of coal gangue as subgrade fill, this study systematically investigates the coupled effects of fractal dimension and confining pressure on the mechanical behavior of gangue through static triaxial shear tests. Using gangue from Nayong County, Guizhou, five gradations with fractal dimensions (D=2.1~2.45) and four confining pressures (50~300 kPa) were designed. Results show that the gangue is dominated by the SiO2-Al2O3-Fe2O3 system (>85%), indicating good engineering applicability. All specimens exhibited dilatant plastic failure. Strength parameters reveal that cohesion c increases from 76.87 kPa to 101.81 kPa (32.47% growth) with rising fractal dimension, whereas the internal friction angle φ varies negligibly (<12%). Embedded within the Mohr-Coulomb framework, a semi-empirical model is developed to quantitatively predict the strength of graded gangue. The model clarifies the underlying mechanism by which fractal grading governs strength through particle filling and interlocking, providing a theoretical basis for the optimal design of coal-gangue subgrade fills.

Key words: Coal gangue, Fractal dimension, Triaxial shear test, Gradation effect, Subgrade filler, Mechanical properties

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