大渡河某水电站围堰工程中悬挂式防渗墙深度的确定

Determination of depth of suspended cut-off walls in cofferdam of a hydraulic power station in Dadu River

以稳定渗流有限元分析方法为基础,结合优化设计中的参数敏感性分析方法和目标函数分析方法,将施工工期作为目标函数,将堰体下游出溢处水力坡降和围堰施工时间作为约束条件,进行大渡河某水电站围堰工程中悬挂式防渗墙深度的优化研究。分析了悬挂式防渗墙不同深度计算条件下的施工工期、下游出溢处水力坡降和堰体流量等敏感性因素,进而通过归一化思想得到它们分别与防渗墙深度的关系,再根据约束条件求取悬挂式防渗墙的最优化深度,并给出了优化深度的计算结果图。对悬挂式防渗墙深度的研究,不仅对于工程建设的时效性和安全性是必要的,而且为全面、合理的评价悬挂式防渗墙的功效提供了理论依据。

Based on the FEM for steady seepage, and combining with the analyse of parametric sensitivity and the objective function in optimal design, the construction schedule was taken as the objective function and the overflow hydraulic gradient and the construction time as the restrictive conditions, the optimization of depth of suspended anti-seepage wall in the cofferdam of a hydraulic power station in the Dadu River was performed. Variation of some sensitive parameters including the hydraulic gradient and the schedule with depth of suspended anti-seepage wall was analyzed, and the relationship among them was obtained through the normalization of thinking. The anti-seepage depth was obtained through the restraint condition, and the optimized depth was then yielded. The results were not only necessary for the economy and safety of the engineering construction, but also reasonable for the theorietical basis of the evaluation to suspended cut-off walls.