Evaluation of Hydraulic Performance of Sewage Pipe Networks

With the continuous increase in the urbanization rate, the amount of sewage received by the sewage pipe network has also been increasing annually. The phenomenon of high water level operation in sewage pipe networks has emerged in many cities, which seriously affects drainage efficiency. Therefore, constructing an effective evaluation method to assess the hydraulic performance of pipe networks operating at high water levels, as well as identifying high-risk pipelines, formulating cost-effective rehabilitation schemes, and evaluating the rehabilitation effects has become necessary to solve this problem. In this study, a sewage pipe network hydraulic performance evaluation method based on flow velocity, pipe fullness, and manhole fullness was established. This method comprehensively considers the instantaneous values and cumulative operation durations of each indicator in the pipeline and, thus, can accurately evaluate the hydraulic performance of the pipe network. This method was applied to the sewage pipe network in City H, and it was found that there existed problems such as low flow velocity, unreasonable pipe diameter, overloading, and high risk of overflow. After the renovation of specific pipeline sections according to the evaluation results, the comprehensive hydraulic performance of the pipe network was significantly improved, with the grade rising from “poor” to “medium +”. This research shows that this evaluation method can accurately assess the hydraulic performance of the current and the renovated sewage pipe network, providing scientific guidance for the renovation and optimization.