| 摘要: |
| 河床下切导致的闸坝下游水位降低，上下游水位差增大，造成原有消能工不能满足消能要求，甚至大洪水时发生严重破坏。小埠东橡胶坝工程采用一、二级消力池联合消能工设计，由于下游河道连续多年采砂超量，河床急剧下切，导致消能工多次毁坏，严重危及闸坝安全且带来巨大损失。通过水力学模型模拟了小埠东枢纽消能工消能效果，分析了破坏原因。结合多个消能工优化方案的消能试验，提出的推荐方案一、二级消力池均能产生稳定的水跃，满足校核洪水消能要求。通过变动枢纽下游水位的消能试验，研究了消能工推荐方案下游河道允许下切极限。工程实际应用表明，推荐的消能工结构遭遇大洪水时未发生破坏，研究提出的因河床下切造成的消能破坏加固理念和对策可为类似工程借鉴参考。 |
| 关键词: 河床下切 消能工 二级消能 消能试验 允许河床下切极限 |
| DOI： |
| 分类号:TV653 |
| 基金项目: |
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| Riverbed incision damagable to hydraulic structure and its countermeasures |
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LI Yan-fu, HAN Chang-hai, YANG Yu
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State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering， Nanjing Hydraulic Research Institute
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| Abstract: |
| Riverbed incision at the downstream of the dam would induce fall in water level and water level fluctuation. As a result， the original energy dissipater of the dam can not be able to dissipate water power completely. Rising water power will destroy the energy dissipation structure. An energy dissipation structure having two steps is used in the Xiaobudong rubber dam. Due to excessive sand mining， the riverbed was sharply incised for successive years， the energy dissipation structure was thus destructed. The structure was reinforced many times， but during a heavy flood the energy dissipation structure between the first stilling pool and the second still pool was destroyed around the whole dam line, which brought huge economic losses and threat to the Xiaobudong rubber dam. In this study， based on hydraulic experiments, the failure of the energy dissipator of the Xiaobudong dam is analyzed. The connection section between the first and second energy dissipaters has been re-designed， and as a result, in the first and second stilling basins, stable hydraulic jump, is formed, and the energy dissipator is found in good condition. Besides， the limit depth of riverbed incision is also studied. After reinforcement measures are actually implemented， the energy dissipator of the dam is able to dissipate the water power completely， and the energy dissipation structure suffers no damage again. The ideas and measures of the reinforcement in this study can provide a reference for other energy dissipators facing the similar threat caused by riverbed incision. |
| Key words: riverbed incision energy dissipation structure energy dissipater having two steps hydraulic experiment for energy dissipation limit riverbed incision depth |
