Formation Mechanism and Stability Assessment of the Colluvial Deposit Slope in Zuoyituo

The basic features of the colluvial deposit slope in Zuoyituo such as geological conditions, dimensions, slip surfaces and groundwater conditions are described concisely in this paper. The formation mechanism of the slope is discussed. It is considered that the formation of the colluvial deposit slope in Zuoyituo has undergone accumulation, slip, load, deformation and failure. The effects of rainfall on slope stability are categorized systematically based on existing methodology, and ways to determine the effects quantitatively are presented. The remained slip force method is improved by the addition of quantitative relations to the existing formulae and programs. The parameters of the colluvial deposit slope are determined through experimentation and the method of back-analysis. The safety factors of the slope are calculated with the improved remained slip force method and the Sarma method. The results show that rainfall and water level in the Yangtze River have a significant effect on the stability of the colluvial deposit slope in Zuoyituo. The hazards caused by the instability of the slope are assessed, and prevention methods are put forward.

作揖沱崩滑堆积体稳定性评价及防治对策

本文首先从地质背景、形态特征、滑面特征及水文地质等方面,对作揖沱崩滑堆积体的特征进行了概括。在总结已有研究成果的基础上,将降雨对斜坡稳定性的影响进行了定量确定,并在剩余推力法公式和程序中加入这些量化关系,对剩余推力法进行了改进。然后用试验、参数反演及综合经验等方法确定了作揖沱崩滑堆积体稳定性计算的参数,采用改进的剩余推力法与Sarma法对其进行稳定性计算,结果表明:降雨与库水位的提升对作揖沱崩滑堆积体稳定性的影响较大。最后,根据作揖沱崩滑堆积体失稳可能产生的危害,提出了相应的防治对策。