Toward a Complete Kinematic Description of Hydraulic Plucking of Fractured Rock
Toward a Complete Kinematic Description of Hydraulic Plucking of Fractured Rock
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DOI：
10.1061/jhend8.hyeng-13193
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发表时间：
2023-07
影响因子：
2.4
通讯作者：
Michael Gardner
中科院分区：
文献类型：
--
作者：
Michael Gardner
水力采摘冲刷是景观演变中的一个基本过程，在这个过程中，大型的优质岩块被流动的水流从裂隙岩体中侵蚀而成。这一过程还会影响与水相互作用的工程结构，如大坝和桥梁，并经常导致操作和安全问题，因为大量材料的侵蚀可能会损害结构基础和适用性。为了评估场地的潜在冲刷，目前的方法要么是经验推导的，要么假设特定的破坏模式，要么显著简化了潜在侵蚀岩石颗粒的几何形状。这限制了这些方法更广泛的适用性，以及它们对冲刷风险提供可操作的洞察的能力。为此，将离散单元法与格子Boltzmann法相结合，应用于裂隙岩石水力拉拔的评价。在该方法中，显式地考虑了岩石颗粒的三维形状，包括每个颗粒如何与流体动态地相互作用。此外，还采用大涡模拟方法对经常发生拔毛的强湍流流动条件进行了模拟。结果表明，该建模方法能够在不限制潜在失效机理的情况下，在两个实例场景中捕捉到正确的解块运动学失效模式，并自然地捕捉到支配响应。这一能力使这种冲刷评估技术得到了广泛的应用，因为特定地点的特征可以直接输入到冲刷风险评估中，以了解当地特征对拔毛过程的影响。
Scour by hydraulic plucking is a fundamental process in landscape evolution in which large, competent rock blocks are eroded from a fractured rock mass by flowing water. This process also affects engineered structures interacting with water, such as dams and bridges, and often leads to operational and safety concerns because erosion of large volumes of material can compromise structure foundations and serviceability. To assess potential scour at a site, present methods either are empirically derived, assume a specific failure mode, or significantly simplify the geometry of potentially eroding rock particles. This limits the broader applicability of these methods and their ability to offer actionable insight into scour risk. Therefore, the discrete-element method coupled with the lattice Boltzmann method was applied to assess hydraulic plucking of fractured rock. In this approach, the three-dimensional shape of rock particles was considered explicitly, including how each particle interacts dynamically with fluid. Additionally, the highly turbulent flow conditions at which plucking often occurs were modeled using large-eddy simulation. The results show that this modeling methodology was able to capture the correct kinematic failure mode in block removal in two example scenarios without restricting the potential failure mechanism, and naturally captures the governing response. This capability makes this scour assessment technique broadly applicable since site-specific characteristics can be input directly into scour risk assessments to understand the influence of local features on the plucking process.