基于堰前最高水位最大熵分布的施工导流风险模拟方法

Construction diversion risk simulation method based on maximum entropy distribution of the highest water level in weir

为直观描述围堰运行期导流风险率函数,准确进行施工导流风险评估,利用洪峰和洪量联合分布,以熵最大为原则推求最高水位分布密度函数,结合导流建筑物泄流不确定性,随机模拟堰前最高水位序列,提出了基于堰前最高水位最大熵分布的施工导流风险模拟方法,并计算导流风险率。实例分析表明,该方法模拟的施工洪水能较好地反映实测洪水系列,所推求的堰前最高水位分布密度函数合理,能弥补传统施工导流风险模拟难以反映围堰使用近期实测洪水过程真实情况的不足,在保证准确性的前提下提高了风险计算效率与普适性,可为施工导流风险分析与方案决策提供依据。

Based on maximum entropy distribution of the highest water level in weir, in this paper we present a simulation method of construction diversion risk that intuitively describes the diversion risk rate function of operational cofferdam and accurately assess construction diversion risk. In our method, the highest water level distribution density function is derived by using the distribution of flood peak and flood volume with the maximum entropy principle. Meanwhile, combining the discharge uncertainty of diversion buildings, the method stochastically simulates the highest water level sequence in weir. Then the method is employed to calculate diversion risk rate. The analysis shows that the simulated construction flood can well reflect the measured flood series. Moreover, the derived distribution density function of the highest water level in weir is reasonable, which can fully reflect true situation of recent measured flood in weir compared with traditional methods. On the premise of accuracy, this method improves risk calculation efficiency and applicability. Therefore, the method provides support for risk analysis and program decisions of construction diversion.