堰塞坝溃决参数模型评估与优化分析

Evaluation and optimization analysis of barrier dam breach parameter models

地震、强降雨等引起滑坡堵塞河道形成堰塞坝,一旦堰塞坝发生溃决将产生重大灾害。由于多数堰塞坝自形成到溃决时间较短,处置时间往往有限,因此在应急处置中对堰塞坝溃决关键参数进行快速预测十分重要。采用国内外最新的堰塞坝案例和3个模型性能定量评价指标,对现有的土石坝和堰塞坝参数模型的预测能力进行了评估,针对现有堰塞坝溃决参数模型的局限性,通过回归分析建立了新的相对客观的峰值流量、溃口几何形态、溃决历时等参数的预测模型,并在实际堰塞坝溃决案例中与现有较优模型进行了对比分析。结果表明:现有土石坝模型不适用于堰塞坝的溃决参数预测;在各参数较全面且准确的情况下,现有的若干模型皆有较高的准确性;本文建立的新模型具有相对简单、客观的优点,拥有较好的溃决参数预测能力,预测结果可为堰塞坝应急处置提供参考。

Earthquakes,heavy rainfall,etc.,cause landslides to block rivers and form barrier dams.Once a barrier dam breaks,tremendous disasters will occur.Due to the short time from formation to breach of most barrier dams,the disposal time is often limited.It is very important to predict the key parameters of barrier dam breach in emergency disposal.In this paper,the prediction abilities of existing parameter models for earth-rock dams and barrier dams were evaluated by using the latest barrier dam cases in China and abroad and three quantitative evaluation indexes of model performance.In view of the limitations of the existing barrier dam failure parameter models,a new relatively objective prediction model for predicting peak flow,breach geometry,breach duration and other parameters was established by regression analysis,and it was compared with the existing popular models by actual dam break case.The results show that the existing earth-rock dam models are not suitable for predicting the breach parameters of barrier dams.Under the condition that the parameters are comprehensive and accurate,several existing models have high accuracy.The new model established has better prediction ability on dam break parameters and it has advantages of relatively simple and objective acquisition of parameters.The prediction results can provide reference for emergency treatment of barrier dams.