The purpose of this study was to investigate the efficiency of organic matter such as rice husk and palm-leaf stalk as envelopes in drainage pipes. For this purpose, to simulate field conditions in vitro, we used a physical model consisting of a plexiglass cylinder with a height of 200 mm and diameter of 100 mm, with five holes attached to the manometers and an inlet at the bottommost part and an outlet at the topmost part with a water tank which provided a fixed head. Experiments were carried out with five types of organic matter (i.e. rice husk, three types of powder and palm-leaf fibres) on Ramshir agricultural soil which required envelopes according to existing standards. The results showed that among the envelopes utilized, the highest outflow (discharge) rate was related to powder No. 3 (the most coarse-grained powder) in a gradient of 0.5. By increasing the gradient to 2, envelope hydraulic fracturing was observed, which means that it was unable to retain soil particles with finally an inadequate filtering function for this organic material. In gradient 2, the highest output discharge was related to palm stalk and leaf fibres, which is reflected in the proper hydraulic performance of this envelope and its high filtering properties. Finally, comparing the value of the gradient ratio in the higher gradients confirmed the results.

中文翻译：

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有机围护结构对地下排水性能的定性评估*

本研究的目的是调查稻壳和棕榈叶秆等有机物作为排水管封套的效率。为此，在体外模拟现场条件，我们使用了一个物理模型，它由一个高度为 200 毫米、直径为 100 毫米的有机玻璃圆柱体组成，压力计上有五个孔，最底部有一个入口，顶部有一个出口，水箱提供一个固定的头。使用五种类型的有机物质（即稻壳、三种粉末和棕榈叶纤维）在 Ramshir 农业土壤上进行了实验，根据现有标准需要封套。结果表明，在使用的信封中，最高的流出（排出）率与 3 号粉末（最粗粒度的粉末）有关，梯度为 0.5。通过将梯度增加到 2，观察到包络水力压裂，这意味着它无法保留土壤颗粒，最终对这种有机材料的过滤功能不足。在梯度 2 中，最高输出流量与棕榈茎和叶纤维有关，这反映在该外壳的适当水力性能及其高过滤性能上。最后，比较较高梯度中的梯度比值证实了结果。