Abstract

Seepage-induced failures in granular soils pose a potential hazard for geotechnical engineering, but the types and mechanisms of seepage failures have not been fully clarified. In this paper, the mass fractal dimensions of testing soils were used to describe the cumulative mass distribution of particles, which was closely related to the uniformity coefficient, fine content, porosity, dry density and permeability coefficient. A series of hydraulic tests were performed to show seepage failure behaviors of sandy gravels, coarse sands and fine sands. By linking the mass fractal dimension to the critical hydraulic gradient, a zone segmentation approach for seepage failure types was proposed to distinguish seepage failures, including piping, suffosion and heave. Piping failure originates from internal instabilities in inhomogeneous soils and has been observed in sandy gravel samples. Suffosion occurs in coarse sand samples due to external and internal erosion of loose particles. Heave failure is dominated by fine content and has been observed in fine sand samples. By comparing the changes in the mass fractal dimension before and after seepage failure, it is feasible to predict piping failure in sandy gravels and suffosion in loose coarse sands, while it is almost impossible to predict heave failure in fine sands.

中文翻译：

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粒状土渗流破坏分形特征试验研究

摘要

粒状土渗流破坏对岩土工程构成潜在危害，但渗流破坏的类型和机制尚未完全阐明。本文采用试验土的质量分形维数来描述颗粒的累积质量分布，其与均匀性系数、细粒含量、孔隙度、干密度和渗透系数密切相关。进行了一系列水力试验，以显示砂砾石、粗砂和细砂的渗流破坏行为。通过将质量分形维数与临界水力梯度联系起来，提出了一种渗流破坏类型的区域分割方法，以区分渗流破坏，包括管道、膨胀和隆起。管道故障源于不均匀土壤的内部不稳定性，并且已在砂砾石样品中观察到。由于松散颗粒的外部和内部侵蚀，粗砂样品中发生了膨胀。升沉破坏主要由细粒成分组成，并且已在细砂样品中观察到。通过比较渗流破坏前后质量分形维数的变化，可以预测砂砾石中的管涌破坏和松散粗砂中的膨胀破坏，而预测细砂中的隆起破坏几乎不可能。