三峡库尾小南海急滩整治数值模拟研究

Study on Xiaonanhai Beach Regulation in Three Gorges Reservoir by Numerical Simulation

小南海滩段受三峡水库库区回水影响,在水库低水位运行时出现急滩碍航。航槽内水流流态较差,水流较急,多回流和乱水。为改善水流条件,提升航道等级,笔者利用平面二维水流数学模型对该滩段进行整治研究。根据河段近期地形测图和实测水文资料建立模型并对沿程水位、流速、流向及分流比进行相似性验证。在验证合理的基础上采用数学模型进行方案试验,对比分析后确定最终方案。结果表明方案2:在生板堆下游筑2道潜坝(潜坝坝顶高程分别为设计水位以下6.0、6.5 m),降低车亭碛锁坝高程为171.2 m并对右岸碗石、车亭碛右汊及车亭碛上段航槽进行疏浚,疏浚底高程为168 m。实施后,该滩段碍航滩险消除,通航水流条件明显改善,航槽基本稳定。达到II级航道要求。

The Xiaonanhai beach is affected by the backwater of the Three Gorges Reservoir region, and appears rapids when the reservoir runs at low water level. In the channel,the flow regime is poor, urgent, refluent and chaotic. In order to improve the flow condition and channel grade, this paper studied the Xiaonanhai beach by using the mathematical model of two-dimensional water flow. According to the recent terrain mapping and measured hydrological data, this paper validated the similarity between water level, velocity,flow and divergence ratio. On the basis of verification, the mathematical model was used to carry out the program test, and the final scheme was determined after the analysis. The second program results showed that two dive dams(dive dam was crested below the design water level below 6. 0 m and 6. 5 m) was built under the Shengbangdui, and the height of the lock dam of Chetingqi was reduced by 171. 2 m. The right bank of Wangshi, the right branch of Chetingqi and the upper section of Chetingqi were dredged to the elevation of 168 m. After the implementation of the second program, the flow condition and the channel grade were improved. It met the requirements of Class II channel.