基于特征因子的排水管网地下水入渗分析方法

采用基于水质特征因子的雨污水管网化学质量平衡方程,建立了污水管网和混接污水管网的地下水入渗量定量分析方法,并据此建立了管道破损程度的评价方法.针对上海市中心城区的3个排水系统,采用总氮和硬度分别作为表征生活污水和地下水的水质特征指标,并采用不确定性分析理论,对该区域雨污水管网系统的地下水入渗量进行了解析.计算结果表明,管道破损不严重,地下水入渗量符合设计要求,管网破损程度评估结果符合预期管道状态;表明提出的基于水质特征因子的地下水入渗量的分析计算方法可行,可用于管网破损和维护判断.与德国和美国标准相比,我国排水管道地下水入渗基准值较高,表明我国管道施工和养护技术有待进一步提高.

Quantification of Groundwater Infiltration into Urban Drainage Networks Based on Marker Species Approach

A methodology was proposed to estimate its quantity and the corresponding pipe defect grade. This method was applied to estimating the groundwater infiltration into three separate sewer and storm systems of the City of Shanghai, China. Here, hardness and total nitrogen were used as markers to indicate groundwater and domestic wastewater into sewer pipes and storm pipes with inappropriate sewage entry. Absolute flows of groundwater were estimated in conjunction with Monte Carlo entry exit mass balance simulation. The apportioned groundwater flows fell within the allowable designing requirements, and the assessed pipe defect grades fit the anticipated pipe conditions, proving the proposed method feasible and applicable to pipe maintenance assessment. Information also showed that actual allowable groundwater inflow was larger for the study site in comparison with German and US standards, and hence pipe construction and maintenance technologies in China need improving.