Dynamics of dilative slope failure
Dynamics of dilative slope failure
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DOI：
10.1130/g32855.1
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发表时间：
2012-07
期刊：
影响因子：
5.8
通讯作者：
Y. You;P. Flemings;D. Mohrig
中科院分区：
文献类型：
--
作者：
Y. You;P. Flemings;D. Mohrig
破裂是一种后退性水下斜坡破坏，受膨胀和随之而来的孔隙压力下降控制；它有可能产生浊流，形成厚厚的浊积岩序列。我们提出了在破裂破坏期间进行的孔隙压力测量，以及一个物理模型，该模型显示了破坏沉积物内的孔隙压力场如何与破坏表面相关的侵蚀速率相关联。我们证明任何膨胀颗粒材料都可能发生破裂。大陆架破裂的情况可能很常见，这使其成为将沉积物转移到深海的重要机制。破坏过程中边坡破坏与孔隙压力耗散之间存在动态平衡。这种平衡导致了一种使用简单的材料特性（固结系数）来估计破裂造成的沉积物释放速率的方法。与以前的工作相反，我们发现由于侵蚀和孔隙压力耗散之间的耦合，侵蚀速率与沉积物的膨胀无关。侵蚀和孔隙压力耗散之间的平衡使稳态孔隙压力场与沉积物的渗透率脱钩；这是第一次在沉积物破坏中发现这种行为。
Breaching is a style of retrogressive subaqueous slope failure controlled by dilation and consequent pore pressure drop; it has the potential to generate turbidity currents that build thick successions of turbidites. we present pore pressure measurements made during breaching failure, as well as a physical model that shows how the pore pressure field within the failing deposit is connected to the erosion rate associated with the failure surface. we show that breaching can occur in any dilative granular material. conditions for breaching could be common on the continental shelf, making it an important mechanism in transferring sediment into the deep ocean. a dynamic equilibrium exists between the slope failure and the pore pressure dissipation during breaching. this equilibrium leads to a way to estimate the rate of sediment release from breaching using a simple material property, the coefficient of consolidation. contrary to previous work, we find that the erosion rate is independent of the dilation of the deposit due to the coupling between erosion and pore pressure dissipation. the equilibrium between the erosion and pore pressure dissipation decouples the steady-state pore pressure field from the permeability of the deposit; this is the first time this behavior has been recognized in sediment failures.