Evaluation Of The Application Of Pressure Rain Draining System In Large-scale Sports Stadium

With the development of national physical education, sports facilities are become an important aspect of construction engineering. Sports stadium is due to its huge roof, collection and discharging of the roof rainwater has always been one of the problems concerned in the field of building water and wastewater engineering for buildings.On the basis of the futures of sports stadium itself, the structure system of the sports stadium roof is introduced in this paper. A comprehensive discussion on the basic principle and features of rain draining system is made as well. It gives a comprehensive analysis of the application of pressure rain draining system in large-scale sports stadium by comparing its working principles and features with traditional gravity draining system. Based on the author’s personal working experience, it analyses and expounds the design, system layout and construction of recent typical engineering examples in which this system has been applied.Evaluation shows that pressure rain draining system has a lot advantages in the application of large-scale sports stadium roof compared with traditional gravity draining system. Diameter of the pipe and space of its installation required is much smaller. It provides a great convenience for the construction and installation of the pipeline without setting slope for hanger tube, saving a lot of sports building interior. Pressure rain with a high velocity can provide better self-cleaning function for the system. Pressure rain draining system reduced the sewer connection pipe and buried pipe, as well as the workload of underground. If the same brand and the same series of drainage pipe are used, pressure rain draining system will save more money than gravity draining system.Gravity draining system with a longer design return period can improve the drainage capacity and security, and it is favorable in economic allowed range. It is found that increasing the design return period of pressure rain drainage system, a corresponding increase will be in the design dimension of rainwater hopper, drainage pipe and gutter,therefore the depth of water before siphon rainwater head decreasing. Instead, the formation of siphon will be affected.It is not the longer return period the better in the pressure rain drainage system will be. Based on the critical depth of water before rainwater hopper, a critical return period can be calculated and it is suggested that the drainage of rainwater is graded according to the critical return period so that the pressure rain draining system can be fully utilized.When determining siphon rainwater head according to the design flow, without considering other factors, the total flood discharge is larger before the formation of siphon when using smaller diameter rainwater head. It also needs comprehensive consideration according to design specifications when selecting rainwater head.