潮汐河口治导线放宽率计算公式的参数取值

受潮棱体蓄潮影响,潮汐河口整治工程往往需考虑一定的治导线放宽率。针对放宽率的计算目前已有诸多经验公式,其中潮差和治导工程蓄潮系数是公式中的两个重要参数,合理取值非常关键。从放宽率公式推导的基础公式出发,理论分析表明,公式中的潮差取为落潮流水位差更为合理;就治导工程蓄潮系数而言,现有文献提出的治导工程高、中潮位整治时分别取1.0和0.5过于简单。结合灌河口和长江口北槽航道整治工程案例分析表明,治导工程蓄潮系数不仅与整治建筑物高程有关,而且与整治工程平面布置形式密切相关,治导工程系数的取值部分情况下可采用经验公式计算取值,而复杂情况下建议结合数学模型或物理模型合理确定。

Parameter value of calculation formula for widening rate of regulation line at tidal estuary

Because of the influence of tide reserving,the widening rate of the tidal estuarine regulation line should be taken into consideration in the tidal estuary renovation project.There are many empirical formulae for calculating the widening rate,of which the tidal range and tide reserving coefficient are two key parameters,therefore the reasonable value of these parameters is critical.The theoretical analysis based on the basic formula derived from the widening rate formula shows that its more reasonable if the tide range value is set as the water-level difference during ebb process;as far as the renovation projects tide reserving coefficient is concerned,it is too simple to take 1.0 and 0.5 respectively in the high and moderate tidal levels proposed by the existing literature.We analyze the renovation project of the Guanhe Estuary and the north channel of the Yangtze Estuary,and the results show that the renovation projects tide reserving coefficient is not only related to the building altitude that is to be regulated,but also closely related to the layout of the renovation project.In some cases,the coefficient can be calculated by the empirical formula presented in this paper.Under complicated circumstances,the value of the coefficient is suggested to be determined in combination with the mathematical model or physical model.