HDPE供水管漏损对外管壁的冲蚀影响研究

Study on the Erosion of External Pipe Wall Due to HDPE Pipe Leakage

管道漏损是供水管网面临的一个重要问题,而管道漏损导致的管-土-水相互作用,会进一步加剧管材性能的劣化。为研究冲蚀对管道外壁的影响,本文开展了恒定压力冲蚀实验研究,揭示管道从微小的漏损发展至水流击穿土层产生爆管的整个过程,并记录漏损口、砂床表面的特征形貌以及漏损量的变化。同时利用数值模拟手段模拟了流场分布,以解释外管壁的冲蚀过程机理。研究结果表明,流化砂土对外管壁的冲蚀作用较为明显,能使漏孔外管壁凹陷变形,能够在较短时间内蚀穿管壁,扩大漏孔。

Pipe leakage is an important problem for water supply systems,and the degradation of pipe performance is further exacerbated by pipe-soil-water interactions caused by pipe leakage.To study the effect of erosion on the outer wall of the pipe,an experimental study of constant pressure erosion was carried out in this paper to reveal the whole process of a small leak developing into pipe burst.The characteristic morphology of the leak opening,the surface of the sand bed and the change of the leak volume were recorded.The flow field distribution was also simulated by means of numerical simulation to explain the mechanism of the erosion on the outer pipe wall.The research results show that the erosion effect of fluidized sandy soil on the outer pipe wall is more obvious,which can make the outer pipe wall of the leakage hole depressed and deformed;it can erode through the pipe wall and enlarge the leakage hole in a relatively short time.