Earthquakes and other disasters can lead to the formation of a large number of inverse grading landslide deposits, which can cause secondary disasters such as landslides and debris flows under rainfall conditions. It is of great value to study the accumulation and permeability characteristics of the landslide deposits in order to reduce the risk of piping and slumping. This paper classifies and statistically analyzes the accumulation characteristics of typical high-speed and long-distance landslides inverse grading deposits around the world, and obtains their layered accumulation characteristics. On this basis, an experiment was conducted to investigate the permeability characteristics of inverse grading stacking structures, considering the factors of seepage time, fine particle content, and discontinuous gradation. The results indicate that the inverse grading deposits can be classified into three distinct layers, i.e., carapace, body facies, and basal facies. The cumulative distribution curve of particles is shifted from the left to the right, with the content of coarse particles rising in a sequential manner, with no crossover between the curves. The slope of each layer is distinct, and the phenomenon of particle size reduction occurs. It was found that the permeability coefficient varied with seepage time and was negative exponential correlation and closely related to fine particle content. When the content of fine particles in the basal facies is less than 40%, the permeability coefficient of the body facies and the carapace increases by up to 21.4 % with time. Conversely, they all begin to decline over time, with decreases of up to 50% or more. In the context of discontinuous gradation, the sensitivity of the permeability coefficient to the time factor is positively correlated with the fine particle content, exhibiting a discontinuous range of up to 7.01 times. Regression analysis indicates that the permeability coefficient of the inverse grading deposits is highly linearly correlated with the mean particle size and exhibits a negative exponential correlation with the uniformity coefficient.

中文翻译：

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高速长距离滑坡中逆级配沉积物的堆积及渗透特征


地震和其他灾害会导致形成大量逆级滑坡沉积物，在降雨条件下会导致山体滑坡和泥石流等次生灾害。研究滑坡沉积物的堆积和渗透特性，以降低管道和坍塌的风险，具有重要价值。本文对全球典型的高速、长距离滑坡逆级沉积物的堆积特征进行了分类统计分析，得到了它们的层状堆积特征。在此基础上，进行了试验，研究了逆级配堆积结构的渗透特性，考虑了渗流时间、细颗粒含量和不连续级配等因素。结果表明，逆级配矿床可分为甲壳、体相和基底相 3 个不同的层。颗粒的累积分布曲线由左向右移动，粗颗粒的含量按顺序上升，曲线之间没有交叉。每层的斜率不同，出现粒径减小的现象。结果表明，渗透系数随渗流时间的变化呈负指数相关，与细颗粒含量密切相关。当基底相中细颗粒的含量小于 40% 时，体相和甲壳的渗透系数随时间增加高达 21.4 %。相反，它们都随着时间的推移开始下降，下降幅度高达 50% 或更多。 在不连续级配的情况下，渗透系数对时间因子的敏感性与细颗粒含量呈正相关，表现出高达 7.01 倍的不连续范围。回归分析表明，逆级配矿床的渗透系数与平均粒径呈高度线性相关，与均匀性系数呈负指数相关。