南方滨海城市排水管网典型缺陷类型普查及成因机制分析

Typical defect types and cause mechanism of sewer pipelines in southern coastal city

对典型南方滨海城市排水管网开展全面清淤疏通和多手段检测评估,结果表明区域内共存在缺陷7889处,平均88.52处/km。针对5种主要缺陷类型的数据统计与研究分析表明:破裂缺陷占比33.84%,一般发生在交通干道处的小管径HDPE管,主要是上部交通循环荷载与柔性管长期老化破损共同作用的结果;树根缺陷占比23.73%,通常位于城市高植被覆盖度区域的管道破裂或接口错动位置,一般与台风暴雨诱发的地表水土流失密切相关;变形缺陷占比16.39%,分布规律及成因与破裂缺陷类似,但内外因素的影响程度较轻,在不利条件下可转化为破裂缺陷;腐蚀缺陷占比8.08%,均为钢筋混凝土管,是管内腐蚀性废水与倒灌的海水直接作用的结果;障碍物缺陷占比7.9%,大多是侵占管道截面的废弃建筑垃圾,一般位于管道倒坡或变径异常的排泄不顺畅位置。研究成果总结了南方滨海城市排水管网典型缺陷类型的特征规律、形成原因与演化机制,可以为该地区或类似城市排水管网的评估与修复提供技术指导。

This paper carries out comprehensive dredging and multi-means detection and evaluation of the drainage network of typical southern coastal cities.The results show that there are 7889 defects,with an average of 88.52 km.The data statistics and research analysis of five main defect types reveal that the rupture defect accounts for 33.84%,which mainly occurs in the small-diameter HDPE pipe at the main traffic road,which is the result of the combined action of the upper traffic cyclic load and the long-term aging and damage of the flexible pipe.Root defects account for 23.73%,which are usually located at the location of pipeline rupture or interface dislocation in urban areas with high vegetation coverage,which is generally closely related to surface water and soil loss induced by typhoon and rainstorm.Deformation defects account for 16.39%,and their distribution law and causes are similar to those of fracture defects,but the influence of internal and external factors is light,which can be transformed into fracture defects under adverse conditions.Corrosion defects account for 8.08%,which are all reinforced concrete pipes,which is the result of the direct action of corrosive wastewater in the pipe and poured seawater.Barrier defects account for 7.9%.Most of them are construction waste occupying the pipeline section,which is generally located at the position where the drainage is not smooth due to abnormal slope or diameter change of the pipeline.The research results summarize the characteristics,causes and evolution mechanism of typical defect types of coastal urban drainage network,which can provide technical guidance for the evaluation and repair of drainage network in this area or similar cities.