| 摘要: |
| 针对新干航电枢纽工程引起的库区江心洲浸没问题，通过建立江心洲浸没评价的地下水三维非稳定流有限元渗流模型，在多年平均水文条件下，按堤外抬田防渗和堤内多种浸没控制措施（防渗墙与减压井联合布设工况方案）进行浸没评价和控制预测。结果表明：①在无防渗措施工况下，江心洲迅速发生顶托型浸没，而防渗墙可延缓江心洲堤内浸没发生的时间，同时在堤外抬田，可有效控制浸没程度；②对比预测不同的减压井（井径及其与防渗墙的垂直距离）布设方案的运行效果，结果显示在大井径且井列线位于居民建筑物临界处时，能够有效控制江心洲堤内的浸没范围；③防渗墙与减压井联合布设时，在达到浸没控制要求的条件下，防渗墙可大大减小减压井排水量。不同工况的对比研究可为新干航电枢纽工程库区江心洲浸没控制及方案设计提供科学依据。 |
| 关键词: 航电工程 库区浸没 地下水 减压井 防渗墙 数值模拟 |
| DOI： |
| 分类号:P641 |
| 基金项目:国家重点研发计划资助项目（2016YFC0402803）；国家自然科学基金资助项目（41572209） |
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| Prediction and control of groundwater immersion of the mid-channel bar |
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LIU Yanan, ZHOU Zhifang, YANG Yun, LI Mingyuan
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School of Earth Science and Engineering, Hohai University, Nanjing
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| Abstract: |
| In order to mitigate the groundwater inundation in the mid-channel bar as a consequence of water storage of Xingan Navigation and Power Junction, a three-dimensional transient flow simulation model is established by finite element method to evaluate and control hazards. Under long-term average hydrological conditions, groundwater immersion assessment and control prediction are performed with a variety of mitigation measures (farmland-raised engineering outside the Juzhou Embankment and combination of impervious wall and relief wells inside the embankment) based on the simulation model. The prediction results indicate that: (1) Without immersion control measures, the backwater immersion quickly occurs at the mid-channel bar. However, the impervious wall can greatly delay the process time of groundwater immersion in the mid-channel bar. Meanwhile, the farmland-raised engineering outside the embankment effectively controls the degree of groundwater immersion. (2) The comparison results based on the operational effects of different relief wells (borehole diameter, vertical distance from the cutoff wall) show that relief wells with a large well diameter located at the line along the residential building can effectively control the immersion area in the embankment. (3) The combined usage of impervious wall and the relief well can greatly reduce the discharge of the relief well under the immersed control requirements. To sum up, the comparative study with different control measures can provide a scientific basis for the immersion control and scheme design of the mid-channel bar in the Xingan Navigation Power Junction. |
| Key words: navigation and power project reservoir immersion groundwater relief well impervious wall numerical simulation |
