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| 土石坝漫顶破坏溃口发展数值模型研究 |
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陈生水,钟启明,任强
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南京水利科学研究院,江苏,南京,210029;水文水资源与水利工程国家重点实验室,江苏,南京,210029
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| 摘要: |
| 我国已溃决土石坝中由于漫顶破坏而造成的比例高达50%以上,因此,开展土石坝漫顶溃决机理和溃口发展过程研究,正确预测溃口流量过程线及溃坝致灾后果很有必要.本文首先根据现场溃坝调查资料和大型溃坝试验结果,研究分析了土石坝的溃决机理和溃决过程,在此基础上提出了一个描述土石坝漫顶破坏溃口发展过程的数值模型.该模型采用高速水流泥沙输移公式来计算溃坝水流对溃口纵横向的连续冲蚀;采用溃口边坡稳定性分析来模拟边坡失稳坍塌所引起的间歇性横向扩展;通过楔块体力的平衡计算来模拟坝体突发性崩塌所引起的溃口增大现象;通过下游坝体冲槽和坝顶溃口流量平衡来建立两者发展过程的相互影响.最后利用该模型计算分析了板桥水库土石坝发生漫顶溃决的溃口发展过程及溃口流量过程线,模拟结果与实测资料基本一致,从而证实了该模型的合理性. |
| 关键词: 土石坝 漫顶破坏 数值模型 |
| DOI： |
| 分类号:TV641 TV13 |
| 基金项目:国家重点基础研究发展规划项目，国家自然科学基金重点项目，南京水利科学研究院基金项目 |
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| Numerical model study on break development due to overtopping failure for earth-rock dam |
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CHEN Sheng-shui,ZHONG Qi-ming,REN Qiang
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| Abstract: |
| Overtopping failure leads to more than 50% of the broken earth-rock dams in China, so it is necessary to study the mechanism of overtopping failure and the process of break development in order to forecast the discharge hydrograph of break and the consequence due to dam-break. In this paper, based on the field survey data and model test results, the overtopping failure mechanism and process of break development of earth-rock dams are analyzed, and a numerical model which describes the process of break development of earth-rock dams is put forward. The model has the following characteristics:the sediment transport formula of high-velocity flow considering the physical and mechanical properties of the dam material is used to calculate the break-induced flow impact on the longitudinal and transversal expansion of the break;the break slope stability analysis is made to simulate the later intermittent expansion of break caused by sudden dam collapse;the balance between the flow discharge through downstream notching and that through dam top break is comsidered to establish their mutual relationships. Finally, the model is used to calculate the process of break development and the discharge hydrograph of an earth-rock dam due to overtopping failure. The result is in good agreement with the observed data. |
| Key words: earth-rock dam overtopping failure numerical model |
