列车振动负载对土壤结构和液压性能的影响
Kai Han1, Jiading Wang2, Tao Xiao1
1State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an, 710069, China.
Scientific reports
|March 29, 2024
概括
火车的振动显著改变了土壤的液压特性. 增加的振动频率通过改变孔隙结构来加速水分迁移并增强液压导电性,其效果在20Hz以上停滞不前.
科学领域:
- 地质技术工程 地质技术工程
- 土壤物理 土壤物理
- 环境科学 环境科学
背景情况:
- 列车引起的振动在基础设施建设中越来越令人担忧.
- 了解它们对土壤的影响对于预测土壤行为和确保结构稳定至关重要.
- 现有的研究往往忽略了细节的微观结构变化,影响着振动下的土壤液压系统.
研究的目的:
- 为了研究火车引起的振动负载对土壤液压性能的影响.
- 分析不同振动频率对土壤液压导电性和水分迁移的影响.
- 用扫描电子显微镜检查土壤孔中由于振动而发生的微观结构变化.
主要方法:
- 实验是在自行设计的室内土壤透平台上进行的,具有受控的振动负载.
- 扫描电子显微镜 (SEM) 的应用用于微观结构分析.
- 在不同振动频率 (0-80 Hz) 下测量土壤体积含水量,孔水压和液压导电性.
主要成果:
- 振动加速了土壤体积含水量稳定,最快的稳定时间下降被观察到高达20 Hz.
- 土壤孔中的水压随着振动频率的增加而显著增加,在80 Hz时,与没有振动相比,水压上升了105%.
- 土壤的液压导电率最初在20 Hz之前迅速增加 (40.1-47.4%),然后在更高的频率下显著放缓 (18.6-7.8%).
- SEM揭示了较小的土壤毛孔转化为较大的毛孔,毛孔复杂度下降,增强了液压导电.
结论:
- 火车引起的振动对土壤的液压性能有很大的影响,主要是通过改变孔隙结构.
- 更高的振动频率促进了土壤水分的迁移速度更快,并增加了孔水压.
- 该研究确立了土壤孔复杂性降低和在振动负载下增强的液压导电性之间的直接联系.
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