Analysis of slope fracturing under transient earthquake loading by random discrete element method
Analysis of slope fracturing under transient earthquake loading by random discrete element method
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DOI：
10.1016/j.ijrmms.2022.105171
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发表时间：
2022-09
影响因子：
7.2
通讯作者：
Tao Zhao;G. Crosta;Yong Liu
中科院分区：
文献类型：
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作者：
Tao Zhao;G. Crosta;Yong Liu
地震可能会在短期或长期内造成严重的岩石破裂。对断裂机制的综合分析对于评估地震易发区潜在的边坡失稳、滑坡和岩崩的风险至关重要。本文采用二维离散元法（DEM）研究了一个基长600 m、高300 m的完整岩质边坡的破裂过程，并通过随机场理论明确考虑了材料的非均匀性。共进行了5400次DEM模拟，并对边坡破裂特征进行了统计分析。地震动荷载引发了地震动的显着放大和坡顶的边坡破坏，导致裂缝密集且相互连接。这些裂隙将边坡劈裂成形状各异的岩石碎块，碎块大小服从威布尔累积分布。超过70%的生成的碎片是精细的0.1倍的初始斜坡的大小，而只有少数大的碎片存在于斜坡的基础。碎片粒度分布模式可以定量地与现场观测相一致。边坡最终破坏指数和累积破碎能的分布均符合正态分布规律。输入边坡的地震总能量主要耗散在结构面处，并随着边坡倾角的增大而减小。
Earthquake can cause significant rock fracturing in either the short or long terms. A comprehensive analysis of the fracturing mechanism is critical for assessing the risks of potential slope failures, landslides and rock avalanches in seismic prone areas. This study employed 2D discrete element method (DEM) to investigate the fracturing of an intact rock slope of 600 m in base length and 300 m in height, with explicit considerations of material heterogeneity by random field theory. A total of 5400 DEM simulations were performed, and the characteristics of slope fracturing were statistically analysed. The dynamic loading by earthquake has triggered significant amplifications of ground motion and slope damage at the slope crest, resulting in densely spaced and interconnect fractures. These fractures split the slope into a collection of rock fragments with varied shapes, and the fragment size followed the Weibull's cumulative distribution. More than 70% of generated fragments were finer than 0.1 times the initial slope size, while only few large fragments existed at the slope base. The fragment size distribution pattern could quantitatively agree with field observations. The distributions of final slope damage index and cumulated fragmentation energy all followed the normal distribution pattern. The overall bulk seismic energy input into the slope was dissipated mainly at discontinuities and decreased with the increase of slope inclination.