| 摘要: |
| 针对堰塞坝坝体土石料的宽级配特性，引入与水流方向垂直的附加作用力来考虑粗颗粒对细颗粒的阻拦、遮蔽作用以及细颗粒对粗颗粒的包围、填实作用，提出了一个可模拟堰塞坝漫顶溃决过程溃口发展规律与流量过程的数值模型和相应的计算方法，利用该模型对唐家山堰塞坝泄流过程进行了模拟，得出的泄流槽发展规律与洪水流量过程与实测资料接近，验证了该模型和计算方法的合理性。进一步，利用笔者建议的数学模型及数值计算方法，比较分析了唐家山堰塞坝除险过程中泄流槽断面型式对堰塞坝泄流过程的影响，发现堰塞湖在采用泄流槽引流除险时，泄流槽深度与断面型式对其泄流过程具有重要影响，增加泄流槽深度，可明显提高泄流效率，但堰塞湖下游将承受更大的风险。对于同样深度的梯形泄流槽，如果将槽底部断面减小，形成复合梯形泄流槽，不仅可减少开挖工作量，而且没有明显降低泄流效率，同时后者的泄流过程更为平缓，最大洪峰流量减小，出现的时间滞后，堰塞湖下游承受的风险也将降低。 |
| 关键词: 堰塞坝 溃坝 数学模型 泄流槽 唐家山 |
| DOI： |
| 分类号:TV122+.4 |
| 基金项目:国家自然科学基金资助项目（51109141，51379129，91215301，51209140） |
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| Dam-break numerical model for a barrier dam and its application |
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CHEN Sheng-shui, ZHAO Tian-long, ZHONG Qi-ming
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Key Laboratory of Failure Mechanism and Safety Control Techniques of Earth-Rock Dam, Ministry of Water Resources, Nanjing Hydraulic Research Institute
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| Abstract: |
| Considering the wide gradation characteristics of barrier dam materials, an additional force perpendicular to the water flow direction is introduced into the model to consider the block function and bridging effect of coarse particles on fine particles, and the way in which fine particles surround and fill coarse particles. A numerical model with a calculation method describing the discharge process and breach development due to overtopping failure of a barrier dam is proposed. The model and the calculation method have been used to calculate and analyze the discharge process of Tangjiashan barrier dam. The calculated results are close to the observed data, which indicates that the model and the calculation method are reasonable. A comparative analysis on the influences of the discharge process of the Tangjiashan barrier dam with different cross sections of a drainage channel is carried out, and it is found that the depth and the cross section of the drainage channel have a major impact on the discharge process. With the increase in drainage channel depth, the discharge efficiency is improved significantly, but the risk of the downstream would be higher. For the trapezoid drainage channels with the same depth, if the cross section is changed to compound section by decreasing the bottom width, the excavation work decreases without causing a considerable decrease in the discharge efficiency. In addition, the discharge curve is flatter, indicating a lower peak discharge and a longer time to reach peak discharge, and therefore it will diminish a risk for the downstream of the dammed lake. |
| Key words: barrier dam dam-break numerical model drainage channel Tangjiashan |
