中文摘要：

2010年10月21—22日,陕西延炼厂区储油罐下方的斜坡发生缓慢滑移,造成了巨大的经济损失。滑坡发生前当地没有降雨或地震,为探究其形成过程,在边坡上取代表性土样进行土水特征曲线测试、配制不同含水率土样,进行常规三轴试验和直剪试验,以确定土体的非饱和渗透曲线和强度参数。建立边坡滑动前的有限元模型,进行非饱和渗透与非饱和强度的耦合分析,得到凝结水入渗过程中边坡的应力场,据此可得不同时间段的边坡稳定系数,揭示其破坏过程。结果表明,水蒸气凝结水在斜坡内长期滴渗,使得坡体地下水位缓慢上升,地下水位浸润潜在滑面前,稳定系数基本不变,待地下水位开始浸润边坡潜在滑面时,稳定系数开始迅速降低,最终导致斜坡破坏。

英文摘要：

The Yanlian landslide occurred on October 21-22, 2010. The slide mass cut off 24 oil transfer pipelines and the road from the factory to an oil tank, and buried part of the coal storehouse. The 34 oil tanks hanged over the top of the head scarp because of this. The landslide led to a suspending of the refinery work for a week and caused economic losses of approximately 700 million RMB. There was no rainfall or earthquake occurring before the slope failed, so the cause of the landslide is deeply concerned by the refinery managers and researchers. Site exploration shows that the sliding mass is the unsaturated-saturated loess material and groundwater is rich in the landslide and poor in the surrounding slopes. Further investigation shows that the water drops released from the vapor heating furnaces on top of the slope are the only source of groundwater. A pre-failure slope model is used to simulate the water infiltration process and the stress field. The slope stability is calculated with the shear stress and the strength along the potential sliding surface. The results suggest that rising of the groundwater level led by penetration of the water drops is the key factor imitating the landslide. A long term accumulation of the very little water drops infiltrating into the slope resulted in the rise of groundwater level and caused the slope failure.