Wang Qiyun, Zeng Jiajun, Shen Qingqing, Lin Huaming, Long Yao
College of Civil and Construction Engineering, Hunan Institute of Technology, Hengyang, 421002, China.
College of Civil Engineering, Fujian University of Technology, Fuzhou, 350118, China.
Sci Rep. 2025 Jan 2;15(1):35. doi: 10.1038/s41598-024-83472-7.
Research on the evolutionary behavior of the particle breakage processes in coarse-grained soil under the action of train load is of practical significance for subgrade construction and maintenance. However, existing studies have not addressed the prediction of particle size distribution evolution. In this paper, the MTS loading system is used to simulate the dynamic train load effect on coarse-grained soil fillers. The study analyzes the influence of dynamic stress amplitude, loading frequency, and vibration times on both the macro-characteristics and micro-characteristics of particle breakage. The characteristics of particle fragmentation in coarse soil filler under high-speed train load are elucidated. Furthermore, a predictive model for the evolution of particle size distribution curves in relation to particle content and relative particle size is established using the ZHU continuous grading curve equation. This model captures the evolution process of particle breakage characteristics in coarse-grained soil fillers subjected to high-speed train loads. The applicability of this model has been verified. Based on the grading prediction model, an integral expression for the breakage rate index is derived, and the evolution characteristics of particle breakage in coarse-grained soil fillers under the action of train load are analyzed. The results indicate that during filling, the particle breakage mode of coarse-grained soil fillers during filling is primarily characterized by fracture and fragmentation; conversely, under dynamic cyclic loading conditions, it is predominantly characterized by fracture and grinding. The breakage rate aligns with the measured results, suggesting that the breakage rate index established in this study can effectively describe the evolution process of particle breakage in railway subgrade coarse-grained soil. After the reaching one million loading cycles, both deformation and particle breakage degree in coarse-grained soil fillers tend to stabilize. Under the action of dynamic stress amplitudes ranging from 10 to 200 kPa and loading frequencies between 2 and 12 Hz, the particle breakage index stabilizes below 1.1%. These research findings contribute to a deeper understanding of the evolutionary processes affecting engineering characteristics of railway subgrade coarse-grained soils and provide a theoretical as well as experimental foundation for railway subgrade construction and maintenance.
研究列车荷载作用下粗粒土颗粒破碎过程的演化行为对路基施工和维护具有实际意义。然而，现有研究尚未涉及粒径分布演化的预测。本文利用MTS加载系统模拟列车动荷载对粗粒土填料的作用。研究分析了动应力幅值、加载频率和振动次数对颗粒破碎宏观特性和微观特性的影响。阐明了高速列车荷载作用下粗粒土填料中颗粒破碎的特性。此外，利用朱连续级配曲线方程建立了与颗粒含量和相对粒径相关的粒径分布曲线演化预测模型。该模型捕捉了高速列车荷载作用下粗粒土填料颗粒破碎特性的演化过程。验证了该模型的适用性。基于级配预测模型，推导了破碎率指标的积分表达式，并分析了列车荷载作用下粗粒土填料颗粒破碎的演化特性。结果表明，在填筑过程中，粗粒土填料的颗粒破碎模式主要表现为断裂和破碎；相反，在动循环加载条件下，主要表现为断裂和研磨。破碎率与实测结果吻合，表明本研究建立的破碎率指标能够有效描述铁路路基粗粒土颗粒破碎的演化过程。在达到100万次加载循环后，粗粒土填料的变形和颗粒破碎程度趋于稳定。在10至200kPa的动应力幅值和2至12Hz的加载频率作用下，颗粒破碎指数稳定在1.1%以下。这些研究结果有助于更深入地了解影响铁路路基粗粒土工程特性的演化过程，为铁路路基施工和维护提供理论和试验基础。
