ISSN 1000-3665 CN 11-2202/P

    考虑颗粒形态的滑坡体运移特征研究

    Migration characteristics of landslide considering particle morphology

    • 摘要: 考虑岩土材料的颗粒形态,对评估边坡稳定情况和滑坡运移范围的准确性至关重要,但目前颗粒形态对大尺度边坡相关问题的影响研究尚不明确。为探究颗粒形态与边坡稳定性及滑坡体运移特征的关系,基于实际工程滑坡,采用颗粒离散单元法,构建了不同颗粒形态构成的二维边坡。使用球形度和棱角度两个颗粒形态参数来分别反映颗粒的整体轮廓特征和棱角数目,研究了粒径缩放和颗粒形态对边坡稳定系数的影响。通过强度折减法使边坡破坏,进一步分析了滑坡体的运移特征。研究结果表明:对于工程尺度滑坡,粒径缩放对边坡稳定系数预测有一定的影响阈值;颗粒球形度与边坡稳定系数呈反比,棱角度与边坡稳定系数呈正比,且颗粒球形度与滑坡体的平均滑动速度呈正比;滑坡体运移范围受颗粒形态影响,颗粒球形度越高,运移范围越大。研究结果进一步揭示了,颗粒形态导致的能量耗散特征差异是滑坡体运移距离与堆积状态变化的主要内因。该研究可为滑坡致灾范围预测和防灾减灾工程提供参考。

       

      Abstract: Considering the particle morphology of geotechnical materials is essential for accurately assessing slope stability and predicting landslide migration. However, the influence of particle morphology on large-scale slope stability and landslide dynamics remains unclear. To reveal the impact of particle morphology on slope stability and landslide migration characteristics, a two-dimensional slopes of varied particle morphology were constructed using the particle discrete unit method, based on real-world engineering landslide. Two particle morphology parameters, sphericity and angularity, were used to characterize the overall contour characteristics and number of edges of the particles, respectively, and the effects of particle size scaling and particle morphology on the slope stability coefficient were investigated. With the slope damaged by intensity reduction, the migration characteristics of the landslide body were further analyzed. The results show that, in respect of engineering scale landslide, particle size scaling presents a threshold of impact on slope safety factor prediction. Particle sphericity is inversely proportional to slope safety factor, whereas angularity is proportional to slope safety factor, and particle spherical degree is proportional to the average sliding velocity of landslide. The migration area of landslide is affected by the morphology of particles, with a higher sphericity of particles leading to a larger migration area. The difference in energy dissipation characteristics caused by particle morphology is the main internal cause of the change of landslide migration scope and accumulation state. This study can provide basic information for landslide disaster scope prediction and disaster prevention and mitigation engineering.

       

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