Huang Zhichao, Su Qian, Liu Ting, Huang Junjie, Wang Xun, Kaewunruen Sakdirat
School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, China.
Department of Civil Engineering, School of Engineering, University of Birmingham, Birmingham B15 2TT, UK.
Polymers (Basel). 2024 Jan 31;16(3):404. doi: 10.3390/polym16030404.
Excessive settlement of the subgrade seriously reduces the service quality of slab tracks and threatens trains' running safety. While the utilization of foamed polyurethane is recognized as an effective solution, previous research on its expansion mechanism and its impact on track lifting requires further refinement. Accordingly, a series of full-scale tests, including expansion force tests on foamed polyurethane with diverse qualities and lifting tests of polyurethane grouting with varied qualities on the track structure, have been conducted. The expansion development process of foamed polyurethane is meticulously elucidated, and key expansion parameters are analyzed. Simultaneously, this research explores the lifting behavior of foamed polyurethane grouting under the slab tracks, yielding new insights into essential lifting parameters for track formation repair and maintenance. Based on the experimental data, this study proposes new empirical formulas to comprehensively describe both the expansion mechanism of foam polyurethane and its lifting behavior under the slab tracks. The outcomes of this research offer a new breakthrough for the design of lifting mechanism for maintaining slab track structures through the utilization of foam polyurethane slurry grouting, such as determining the optimal grouting quantity. In addition, these results are instrumental to the evaluation of lifting effects and service life, enhancing the circular economy of railway track systems.
路基过度沉降严重降低了板式轨道的服务质量，并威胁列车运行安全。虽然使用泡沫聚氨酯被认为是一种有效的解决方案，但以往关于其膨胀机制及其对轨道抬升影响的研究仍需进一步完善。因此，进行了一系列全尺寸试验，包括对不同质量的泡沫聚氨酯进行膨胀力试验，以及对轨道结构进行不同质量的聚氨酯灌浆抬升试验。详细阐述了泡沫聚氨酯的膨胀发展过程，并分析了关键膨胀参数。同时，本研究探讨了板式轨道下泡沫聚氨酯灌浆的抬升行为，为轨道成型修复和维护的关键抬升参数提供了新的见解。基于实验数据，本研究提出了新的经验公式，以全面描述泡沫聚氨酯的膨胀机制及其在板式轨道下的抬升行为。本研究成果为利用泡沫聚氨酯浆液灌浆维护板式轨道结构的抬升机制设计提供了新的突破，例如确定最佳灌浆量。此外，这些结果有助于评估抬升效果和使用寿命，提高铁路轨道系统的循环经济。
