基于Copula函数的混凝土特高拱坝变形风险量化模型

对混凝土坝运行状态的风险量化分析是大坝风险管理中的重要环节,通常使用单个变形监测点数据进行混凝土坝变形风险分析,但对于混凝土特高拱坝,同时还应考虑坝基和坝体的变形状态。因此,提出了一种基于变形监测数据和Copula函数计算混凝土特高拱坝变形风险率的方法。以四川锦屏一级混凝土特高拱坝为例,先通过构造反映变形监测量残差与风险率关系的风险概率函数,分别得到坝体和坝基变形监测量风险,再结合Copula函数考虑坝体变形和坝基变形风险的相关关系,得到锦屏一级混凝土特高拱坝的多变量变形风险率,取2014年7月2~26日变形风险进行分析,对比仅考虑坝体变形变量和同时考虑坝体、坝基变形变量的结果,多变量变形风险率考虑大坝两重要部位的风险,结果更加安全可靠。

Quantitative Risk Model for Deformation of Concrete Ultra high Arch Dam Based on Copula Function

Risk quantification of concrete dam operation plays an important role in dam risk management. The data of single deformation monitoring point is commonly used to conduct risk analysis of concrete dams. For the concrete ultra high arch dam, the deformation of both the dam foundation and the dam body should be taken into consideration. Therefore, this paper proposed a method to calculate the deformation risk ratio of concrete ultra high concrete arch dams on the basis of deformation monitoring data and Copula function. Taking the Jinping I concrete ultra high arch dam in Sichuan as an example, first of all, a risk probability function which reflects the relationship between the deformation monitoring residual and the risk ratio was constructed, the risk ratio of the dam body and the dam foundation deformation were obtained separately. Then, combined with Copula functions, the correlation between dam foundation deformation and dam body deformation was considered and the multi variable deformation risk ratio of Jinping I concrete ultra high arch dam was obtained. Taking the deformation from July 2 to 26, 2014 for risk analysis, compared to merely considering the deformation of dam body or the deformation of dam foundation, the results exhibit that the multi variable deformation risk ratio is safer and more reliable with the consideration of the deformation of both two important regions of the dam.