王杰, 庄建琦, 孔嘉旭, 等. 2023. 基于DEM模拟的破碎对黄土滑坡动力学特征影响研究[J]. 工程地质学报, 31(2): 502-513. doi: 10.13544/j.cnki.jeg.2022-0716.
    引用本文: 王杰, 庄建琦, 孔嘉旭, 等. 2023. 基于DEM模拟的破碎对黄土滑坡动力学特征影响研究[J]. 工程地质学报, 31(2): 502-513. doi: 10.13544/j.cnki.jeg.2022-0716.
    Wang Jie, Zhuang Jianqi, Kong Jiaxu, et al. 2023. Influence of fragmentation on dynamic characteristics of loess landslide based on DEM simulation[J]. Journal of Engineering Geology, 31(2): 502-513. doi: 10.13544/j.cnki.jeg.2022-0716.
    Citation: Wang Jie, Zhuang Jianqi, Kong Jiaxu, et al. 2023. Influence of fragmentation on dynamic characteristics of loess landslide based on DEM simulation[J]. Journal of Engineering Geology, 31(2): 502-513. doi: 10.13544/j.cnki.jeg.2022-0716.

    基于DEM模拟的破碎对黄土滑坡动力学特征影响研究

    NFLUENCE OF FRAGMENTATION ON DYNAMIC CHARACTERISTICS OF LOESS LANDSLIDE BASED ON DEM SIMULATION

    • 摘要: 为研究滑体破碎对黄土滑坡动力学过程的影响,基于PFC2D建立了一种考虑到黄土特殊结构的可破碎离散元滑坡模型,通过改变细观强度参数生成不同强度滑体,模拟不同破碎率下的滑坡发生过程,分析了破碎对滑坡速度、流动性和堆积特征等方面的影响,再现了党川8#滑坡从启动到停止全过程。结果表明:(1)滑体峰值速度与破碎率呈负相关,具体表现为:滑体最大运动速度随破碎率的增大呈幂函数减小。(2)破碎对滑坡流动性的促进作用可能存在某阈值点,使得当破碎率小于该值时,有效摩擦系数随破碎率的增大不显著降低,反之则迅速减小。(3)随着破碎程度的增加,滑坡堆积厚度减小,水平分布范围越广,分选降低,孔隙的分布趋于均一化,且最大堆积厚度的位置多位于地形低洼处。(4)党川8#滑坡从失稳到停止运动总历时28 s,局部最大速度约17 m·s-1,最远滑动距离约195 m,破碎率达到19%。揭示了破碎对黄土滑坡动力学过程的影响,对黄土滑坡动力学研究具有一定参考价值。

       

      Abstract: A fragmentable discrete element landslide model takes into account the unique structure of loess and is built on the basis of PFC2D in order to investigate the impact of slide fragmentation on the dynamics of loess landslides. The landslide occurrence process under various fragmentation rates is simulated. The impact of fragmentation on the landslide velocity,mobility,and accumulation features is examined in order to replicate the whole process of the Dangchuan 8-meter landslide from beginning to end. The results show the follows. (1)The peak velocity of the slide is inversely related to the fragmentation rate,as evidenced by the fact that the maximum velocity of the slide movement falls as a power function with an increase in fragmentation rate. (2)There could be a cutoff point for the fragmentation-based encouragement of landslide mobility,below which the effective friction coefficient rapidly declines and does not change appreciably when the fragmentation rate rises above it. (3)As the degree of fragmentation increases,the landslide accumulation thickness decreases,sorting decreases,the horizontal dispersion broadens,the distribution of pores becomes more homogeneous,and the highest accumulation thickness is frequently found in low-lying terrain. (4)The Dangchuan 8-meter landslide had a fragmentation rate of 19%,a maximum local velocity of around 17 m·s-1,a maximum sliding distance of roughly 195 m,and a total duration from destabilization to cease movement of 28 s. It demonstrates how fragmentation affects a landslide's dynamic process,providing some useful context for those looking into the subject.

       

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