堰塞坝漫顶溃口流量变化过程的数值模拟

根据一般滑坡堰塞坝特点和实际观测到的堰塞坝溃口发展规律建立了一个溃口扩展模式,并将溃口扩展过程归纳为溃口垂直下切、横向扩展和坝坡溯源冲刷3种主要表现形式,采用通过试验资料建立的高强度泥沙冲刷计算公式将这3种表现方式联系在一起,建立了堰塞坝逐渐溃决数学模型,并利用实测溃坝资料验证了模型的可靠性.考虑到溃坝洪水计算的极大不确定性,本文对计算模型中的关键参数给定一定变幅范围进行计算,研究了其对计算结果的影响.研究结果表明,堰塞坝残留坝体高度和坝体物质抗冲性是影响溃坝流量的最重要因素,库容特性的影响相对较小.

Numerical modeling of flow through breach of landslide dams

Based on observation data, the development process of the breach of landslide dams due to over topping may divided into 3 modes: vertical erosion, breadthwise extension and regression erosion of dam slope. A mathematical model describing the gradual failure process of the landslide dams is established based on the formula expressing the high intensity erosion obtained from experimental data, which can integrate the 3 modes of breach development process together. The validity of the model is verified by observation data. The model is applied to sensitivity analysis on the effect of characteristic factors, including the residential dam height, erosion resistance of dam material and breach configuration on the flow discharge passing through the breach. The result shows that the residential dam height and erosion resistance of dam material are the important factors affecting the time for happening of maximum discharge.