伴随着城镇化进程的提速，黄土地区由于工程切坡诱发了大量的工程滑坡。为了研究典型工程黄土滑坡的成因机制，以宝鸡市扶风县飞凤山滑坡为例，开展了野外地质灾害详细调查，同时进行原位渗水试验和原状黄土、古土壤试样土-水特征曲线测试。试验结果表明：当黄土存在小孔洞等结构性问题时，渗透系数可达10-4 cm/s量级，为中等渗透性等级；土-水特征曲线试验求得古土壤的进气值为11.5 kPa，大于黄土的9.0 kPa，同时曲线也显示了古土壤和黄土干湿交替过程中，强度和变形的演化出现分化。在试验结果分析基础上，指出工程切坡是滑坡发生的主要诱发因素，由此触发了土体一系列物理化学链锁反应，尤其是强化了土-水耦合作用的影响，催化了滑坡的发生。最后，提出了飞凤山滑坡的破坏模式为滑带双向发展、兼具滑塌灾害部分典型地质特征的渐进式破坏。

Along with the acceleration of urbanization process, a large number of engineering landslides are induced by artificial slope cutting in loess region. Feifengshan landslide has been selected as a typical case in order to study the mechanism of typical engineering landslide. Detailed field investigation has been done, meanwhile, in-situ water penetration test and soil water characteristic curve (SWCC) test on undisturbed loess and paleosol have been conducted in this study. The experimental results show that: The permeability coefficient of loess can reach medium grade about 10-4 cm/s, if loess has structural problems, such as small holes, cracks, and so on. The air entry value of paleosol is 11.5 kPa obtained by SWCC tests , which is higher than that of loess (9.0 kPa); at the same time, curve also indicates that the evolutions of strength and deformation of paleosol and loess will differentiate dry-wet cycle. With the increase of suction, the growth rate of shear strength of paleosol is lower than that of loess during drying phase, and the elastic volume shrinkage rate of paleosol, caused by compressing, is also lower than that of loess in the same process. Paleosol will have bigger expansion deformation than loess during wetting phase, because the clay content of paleosol is higher. On the basis of experimental results analysis and field investigation, it is founded that artificial slope cutting is the most important factor inducing Feifengshan landslide, which triggers a series of physical and chemical chain reactions, especially reinforces coupling effect between soil and water and accelerates the occurrence of landslide. Finally, we put forward the failure mode of Feifengshan landslide characterized by two-way development of sliding surface and typical progressive destruction, simultaneously having part of geological features of slumping.