Department of Civil Engineering, Yaşar University, Izmir, Turkey.
Faculty of Civil Engineering, Urmia University of Technology, Urmia, Iran.
Water Environ Res. 2019 May;91(5):407-416. doi: 10.1002/wer.1037. Epub 2019 Feb 7.
Sediment deposits may influence the performance of the sewer systems. Sediments are the main store of pollutants which causes sewer systems overflows. In order to prevent the deposition of sediment in sewer systems, self-cleansing design criteria are used. Among various criteria, "self-cleansing with deposited bed" criterion is found appropriate for designing of large sewers. Allowing small thickness of deposited bed in large sewers decreases the required channel bed slope and construction costs. This study presents a bed load self-cleansing model established on wide ranges of experimental data. Comparison of developed model with the existing models in the literature shows its higher performance on variety of data sources. Examples for the application of the model are presented, and design graphs and charts for different pipe sizes are proposed. As a result, the optimum deposited bed thickness is found 1%-5% of the pipe diameter; however, 1% is recommended for sewer pipes design. PRACTITIONER POINTS: Nondeposition sediment transport condition with a bed deposit criterion is found appropriate for large sewer pipe design. The precision of a model is linked to the ranges of experimental data and parameters used for the models development. The optimum range of deposited bed thickness can be adopted in the range of 1% to 5% of the pipe diameter.
沉积物的沉积可能会影响下水道系统的性能。沉积物是污染物的主要储存库，会导致下水道系统溢出。为了防止下水道系统中沉积物的沉积，可以使用自清洁设计标准。在各种标准中，“带沉积床的自清洁”标准被认为适合于大型下水道的设计。在大型下水道中允许较小的沉积床厚度可以降低所需的渠道床坡度和建设成本。本研究提出了一个基于广泛实验数据的床载自清洁模型。将开发的模型与文献中的现有模型进行比较，表明其在各种数据源上具有更高的性能。还展示了模型的应用示例，并提出了不同管道尺寸的设计图表。结果表明，最佳沉积床厚度为管道直径的 1%-5%；然而，建议将 1%用于下水道管道设计。从业者要点：带沉积床标准的非沉积泥沙输送条件适合于大型下水道管道设计。模型的精度与用于模型开发的实验数据和参数的范围有关。最佳沉积床厚度范围可以在管道直径的 1%到 5%之间采用。
