高堆石坝施工度汛挡水风险动态控制模型研究

在高堆石坝施工度汛不允许过水的条件下,通过调整坝体施工进度可实现挡水风险控制。针对挡水风险的不确定性,将自适应控制理论引入高堆石坝施工度汛过程,构建挡水风险动态控制模型。采用实测洪水序列的一阶自回归模型模拟洪水过程,计算施工度汛实时挡水风险率;考虑决策者风险偏好,以度汛决策阶段可接受风险率作为期望轨迹对实时风险率进行跟踪,以实体轨迹逼近期望轨迹为目标,动态调整高堆石坝挡水高程,控制度汛挡水风险至可接受范围内。工程实例分析表明:施工度汛挡水风险动态控制模型能有效控制风险至预期,并较好地解释了决策者意愿付出最大成本在度汛后期趋于稳定的原因,为高堆石坝施工进度控制和度汛决策提供了依据。

Water retaining risk dynamic control model for high rock-fill dams under construction in flood season

Risk control of high rock-fill dam construction in flood season can be achieved by appropriate dam filling schedule. This study has introduced an adaptive control theory to the development of a water retaining risk dynamic control model and the design of control schemes on high rock-fill dam construction. The flood hydrograph is simulated by a first-order autoregressive time series model using measured flood series, and real-time risk can be calculated. Then, the rock-fill dam filling progress is adjusted dynamically by limiting the real-time risk to the accepted risk range, which can be taken as a desired trajectory on account of the risk preference of decision-maker. By such a dynamic adjustment, the real-time risk as entire trajectory will aim to track this desired trajectory to maximum coincidence. Application to a practical case shows that this dynamic control model can effectively control the risk to the expected target and explain why the maximum cost that the decision-maker is willing to pay tends to be stable in late flood season. This study provides support for the progress control and flood protection decision making.