This paper presents results from a series of filtration tests to investigate geometrical and hydromechanical factors controlling the erosion of base particles and their subsequent capture into sand-gravel filters subjected to uniaxial static loading. The analysis revealed that the effectiveness of a filter, apart from its geometry (i.e. particles and constriction sizes), is also controlled by unique combinations of associated hydromechanical factors such as applied hydraulic gradients and the resulting effective stresses. Furthermore, it is observed that the base soil experiences a significant and continuous reduction in effective stress during internal flow (seepage), and the migration of base particles into the filter initiates after localised fluidisation in the base soil (i.e. at very low effective stress levels). Based on limit equilibrium considerations, a novel theoretical approach, different from all other existing methods, is proposed to estimate the critical hydraulic gradient for base soil erosion into granular filter and hence the retention capacity of filters. The current methodology is subsequently validated using experimental data from the published literature and promising results were obtained.

本文介绍了一系列过滤试验的结果，以研究控制基础颗粒侵蚀的几何和流体力学因素，以及它们随后被单轴静载荷捕获到砂砾过滤器中。分析表明，过滤器的有效性，除了其几何形状（即颗粒和收缩尺寸）外，还受相关流体力学因素的独特组合控制，例如施加的水力梯度和由此产生的有效应力。此外，据观察，在内部流动（渗流）期间，基础土壤的有效应力显着持续降低，基础颗粒在基础土壤中的局部流化后开始迁移到过滤器中（即在非常低的有效应力水平下） ）。基于极限平衡考虑，提出了一种不同于所有其他现有方法的新理论方法，用于估计基础土壤侵蚀进入颗粒过滤器的临界水力梯度，从而估计过滤器的保留能力。目前的方法随后使用已发表文献中的实验数据进行验证，并获得了有希望的结果。