堰塞体冲刷参数统计分析及快速预测方法

Statistical Analysis and Rapid Prediction Method of Erodibility Parameters of Barrier Dam

堰塞体冲刷模型参数是堰塞湖应急处置中溃决洪水评估的重要依据。目前,通常使用过剪应力模型和Wilson模型预测土体的冲刷速率,但对模型参数的取值范围尚没有统一认识。为研究两种模型冲刷参数与常规土性参数的关系和各类土体冲刷参数的范围,快速确定堰塞体冲刷模型参数,本文共收集279组冲刷试验数据,并根据土的统一分类标准将数据分为粗、细颗粒土两类;通过相关分析和回归分析得出了冲刷参数与常规土性参数的关系式,并根据关系式的拟合优度、可信度和泛化能力进行筛选,得出了粗、细颗粒土冲刷参数关于常规土性参数的回归方程,并对比试验数据得到的冲刷参数与回归方程预测得到的冲刷参数,得出不同土料的冲刷参数范围;最后,以白格堰塞体为例,依据本文建立的冲刷参数数据库及统计关系,对其冲刷参数和冲刷速率进行了分析。研究成果可以用来快速确定堰塞体的冲刷参数,为应急处置条件下快速评估溃决洪水风险提供理论和数据支撑。

The erodibility parameters of barrier dam were an important basis for the evaluation of the outburst flood in the emergency treatment of the dammed lake.The erosion rate was typically modeled with excess shear stress model and Wilson model.However,there is no unified understanding of the range of erodibility parameters.In order to study the range of erodibility parameters of various types of soils and the relationship between the erodibility parameters of two models and soil properties,quickly determine the erodibility parameters of the dam,a database of 279 test results were collected from the literature review as well as by contacting researchers and organizations working on erosion around the world.The samples were classified into coarse-grained and fine-grained soils according to the unified soil classification system.Correlation analysis and regression analysis of the data were used to obtain the relationship between the erodibility parameters and soil properties.Four measures were used to evaluate the statistical significance of the relationship between erodibility parameters and soil parameters for coarse-grained and finegrained soils:R2、MSE、Fvalue/Fstatistic and cross-validation.The erodibility parameters obtained from the experimental data were compared with the erodibility parameters predicted by the regression equation,the range of erodibility parameters of different soil and correlation between erosion parameters and soil parameters were obtained.According to the erodibility parameters database,the regression equation of erodibility parameters were obtained through statistical analysis of limited soil parameters and erodibility parameters to quickly predict the erosion rate of the soil.Finally,taking Baige weir plug as an example,according to the erodibility parameter database and statistical relationship established in this study,the erodibility parameters and erosion rate were analyzed rapidly.The research findings can be used to quickly determine the erosion parameters of the dam plug body, and provide help for rapid assessment of the risk of burst flood under emergency conditions.