可靠性分析方法和面流消能工的优化设计

Reliability analysis and optimum hydraulic design of surface flow regime to downstream river bed

本文根据可靠性理论,分析了在一定鼻坎型式和坝高条件下,影响面流流态的主要随机最(总泄量Q和单宽泄量q)的主观和客观不确定性,论证了其概率分布特性.在此基础上,根据流态过渡的临界状态条件,确定了两个极限状态方程,采用国际安全度联合委员会建议的JC方法计算了面流流态的可靠指标β和失效概率P_f.计算成果表明,通过改变工程设计参数和运行方式,可以大大增加面流流态发生的可靠度,减少不利流态发生的机率,从而达到优化水力设计和运行的目的.

In this paper, according to the reliability theory the uncertainties of the main random variables (the discharge Q and the discharge per unit width q) which effect the surface flow regime to the downstream river bed are analyzed, the characteristics of their probability distributions are disscused, two critical state equations are derived from the critical conditions of the transition of flow regime, the reliability index β and failure probability Pf are calculated by JC method.These calculated results show that the reliability of forming surface regime can be increased, the probability of forming unfavourable flow regime can be decreased by adjusting the design values and operation modes in order to achieve the aim of optimum design and operation.