中文摘要：

黄土开挖边坡在降雨作用下坡面破坏可分为片蚀破坏、沟状侵蚀、坍塌破坏3个阶段。通过野外现场地质调查,建立调查区域露天煤矿某段运煤大道处黄土开挖边坡三维数值分析模型,采用V-G模型设定渗流边界函数,并以此根据室内外实验设定初始负孔隙水压力;在有限差分软件中运用fish语言将野外现场测得的稳定渗透系数与边坡开挖高度关系编入渗流计算命令流中,模拟了不同降雨强度下孔隙水压力、开挖边坡位移、坡面冲刷程度、最大主应力变化情况,提出黄土区开挖边坡在降雨作用下沟状侵蚀在第三级台阶（坡高60m）左右破坏严重,坡高高于此高度应注意沟状侵蚀的剧烈扩展并加以防治;应在开挖边坡顶部以及台阶坡顶、坡肩处加强监测与防护治理工作。

英文摘要：

The failure of excavated loess slope under rainfall has three stages, inclding sheet erosion, gully erosion and collapse failure. A three-dimensional numerical analysis model was established for the excava- ted loess slope at a section of the coal transporting road on the open pit coal mine in the surveyed area. The V-G model was set the seepage boundary function, and on this basis, the initial negative pore water pres- sure was set based on indoor and outdoor experiments. In the finite difference software fish language was used to incorporate the correlatoin hetween stable permeability coefficient and height of excavated slope and the changes in pore water pressure, displacement of excavated slope, degree of slope erosion and maxi- mum principal stress were simulated under different rainfall intensities. It is suggested that the excavated loess slope is subjected to severe gully erosion at the third bench （slope height： 60 m） under rainfall. Therefore, attention should be paid to violent extension of gully erosion of the slope section above this height, and proper prevention and control measures should be taken for this section. Besides the top of ex- cavated slope, the top of bench and the slope shoulder should monito.