Han Kai, Wang Jiading, Xiao Tao, Li Shan, Zhang Dengfei, Dong Haoyu
State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an, 710069, China.
Sci Rep. 2024 Mar 28;14(1):7393. doi: 10.1038/s41598-024-57956-5.
Investigating the impact of train-induced vibration loads on soil hydraulic properties, this study conducted experiments using a self-designed indoor soil seepage platform that incorporates vibration loads. The experiments were complemented with scanning electron microscopy to analyze the influence of train-induced vibration loads on soil hydraulic conductivity and its evolutionary characteristics under different vibration frequencies. The experimental results indicated that as the vibration frequency increases from no vibration (0 Hz) to 20 Hz, the time required for the soil volumetric moisture content to reach its peak and stabilize decreases rapidly. However, after the vibration frequency exceeds 20 Hz, the rate at which the time required for the volumetric moisture content to reach its peak and stabilize decreases slows down. Furthermore, the soil pore water pressure increases with the increase in vibration frequency. At a vibration frequency of 80 Hz, the peak value of pore water pressure increases by 105% compared to the non-vibration state, suggesting that higher vibration frequencies promote the development and acceleration of soil pore moisture migration. Additionally, as the vibration frequency increases, the soil hydraulic conductivity initially experiences a rapid increase, with a growth rate ranging from 40.1 to 47.4%. However, after the frequency exceeds 20 Hz, this growth rate significantly decreases, settling to only 18.6% to 7.8%. When the soil was subjected to a vibration load, the scanning electron microscopy test revealed alterations in its pore structure. Micropores and small pores transformed into macropores and mesopores. Additionally, the microstructural parameters indicated that vibration load decreased the complexity of soil pores, thereby speeding up the hydraulic conduction process. This, in turn, affected the hydraulic properties of the soil and established a relationship between pore structure complexity and soil hydraulic properties.
为研究列车引起的振动荷载对土壤水力特性的影响，本研究利用自行设计的包含振动荷载的室内土壤渗流平台进行了实验。实验辅以扫描电子显微镜，以分析列车引起的振动荷载对不同振动频率下土壤水力传导率及其演化特征的影响。实验结果表明，随着振动频率从无振动（0Hz）增加到20Hz，土壤体积含水量达到峰值并稳定所需的时间迅速减少。然而，当振动频率超过20Hz后，体积含水量达到峰值并稳定所需时间的减少速率放缓。此外，土壤孔隙水压力随振动频率的增加而增加。在80Hz的振动频率下，孔隙水压力峰值比非振动状态增加了105%，这表明较高的振动频率促进了土壤孔隙水分迁移的发展和加速。此外，随着振动频率的增加，土壤水力传导率最初迅速增加，增长率在40.1%至47.4%之间。然而，当频率超过20Hz后，该增长率显著下降，仅降至18.6%至7.8%。当土壤受到振动荷载作用时，扫描电子显微镜测试显示其孔隙结构发生了变化。微孔和小孔转变为大孔和中孔。此外，微观结构参数表明振动荷载降低了土壤孔隙的复杂性，从而加速了水力传导过程。这反过来又影响了土壤的水力特性，并建立了孔隙结构复杂性与土壤水力特性之间的关系。
