中文摘要：

目的对地基黄土液化前后的微结构变化进行研究，更好地认识黄土的动力性质及液化机理。方法以新建郑（州）-西（安）高速铁路为例，选择典型路段（华阴、潼关、灵宝和偃师等），采集大量原状黄土样品，进行动三轴液化试验。基于GIS软件对黄土液化试验前后的扫描电镜照片进行定量化数据提取和处理并进行分形研究。结果结果表明液化试验后黄土孔隙微结构具有分形特征，揭示了黄土分形分维同孔隙比之间有近似的直线关系。结论液化前黄土孔隙的分形维数明显大于液化后分形维数；区域上自西向东，孔隙分维都减少。

英文摘要：

Aim By studying loess microstructure pre and post liquefaction of high-speed railway foundation to better recognize the dynamic properties and liquefaction mechanism of loess. Methods Taking four typical sections （ Huayin, Tongguan, Lingbao, Yanshi） of Zhengzhou-Xi＇an high speed railway as object, collecting sufficient loess samples, dynamic triaxial liquefaction tests have been carried out. Based on the fractal theory and image-processing techniques such as Photoshop, ArcView and ArcMap, loess SEM photos pre and post liquefaction have been processed and quantitative data were achieved. Results The result shows that the pore microstructure of loess has the character of fractal, and then the approximate line relationship between the fractal dimension and the void ratio is discussed. Conclusion Loess microstructure fraetal dimension of pre-liquefaction is obviously higher than that of post-liquefaction, and zonely, the microstructure fractal dimension reduces from west to east.