第03节 导流设计流量(国外英文资料).docVIP

第03节 导流设计流量(国外英文资料) Section 3 flow design flow ???? Flow design flow is the main basis for selecting the guide flow scheme and designing the guide building. The flow design flow is usually determined by the analysis of the guide flow and the lead time. One, guide flow standard ????? Broadly, the diversion standard is that the choice of diversion design flow for the standard of construction diversion design, it includes the early diversion, dam detention of diversion standard, etc. ????? Early stage of construction diversion standards, according to the water conservancy and hydropower project construction organization design norms, should be first based on the following index of the diversion buildings, diversion buildings can be divided into Ⅲ ~ Ⅴ level. In accordance with the level and type of the diversion building, the corresponding flood recurrence period shall be selected as the initial standard of diversion during the specified period. ????? In fact, the selection of the guide criteria is influenced by many random factors. If the standard is too low, the construction safety is not guaranteed. On the other hand, makes the diversion engineering design size is too big, not only increase the cost of diversion, and probably because of its size is too big cant finish, the passive situation caused by engineering construction. Therefore, the determination of the standard of large engineering guide flow should be combined with the analysis of risk degree to make the selection criteria more economical and reasonable. Second, the period of diversion ???? In the process of construction, different construction diversion methods and water and drainage structures can be used in different stages. The order in which different flow patterns are combined is usually called a diversion program. Diversion period is according to the diversion procedure divided by the duration of each construction stage, meaningful diversion period, mainly is the cofferdam retaining water and guaran