陈村水道弯道河段建桥影响研究

Study on Impact of Bridge Construction in Chencun River

陈村水道是广州番禺和佛山南海两地的主要行洪通道,也是珠江的主要航道,担负着该地区的潮排、潮灌任务。陈村水道南番大道海怡大桥段为典型弯道河段,建桥前、后大桥所在河段的水位、流速、流态会发生变化。为评价拟建大桥对河道行洪和河势的影响,开展了河床演变分析和模型试验。分析和试验的主要结论为:(1)拟建大桥附近弯道河段相对稳定;(2)建桥后,桥位断面上游壅水最大值为5.7 cm,壅水影响范围在桥位上游600 m之内;(3)拟建桥墩未导致水流动力轴线明显偏移,左岸局部区域可能会发生局部冲刷、淘蚀现象;(4)拟建大桥对西海咀水闸及泵站的影响较小,当西海咀泵站及其扩建工程的泵站排涝时,泵站口门及护坦上落淤悬沙可顺利冲入主槽。

Chencun River which undertakes the task of tidal drainage and tidal irrigation,is the main flood passage in Panyu,Guangzhou,and Nanhai,Foshan,and also the main channel in the Pearl River. Haiyi Bridge section in Chencun River and in south of Panyu Road is a typical curve river. The water level,flow rate and flow state of the bridge section will change after the construction of the bridge. In order to evaluate the impact of bridge construction on flood flow and river regime,analysis and model test on river bed evolution are carried out. The main conclusions are as follows：（1）curve river section near the proposed bridge is relatively stable;（2）after construction of the bridge,the maximum of backwater in the upstream of the bridge section is 5. 7 cm,and the impact of backwater is within 600 meters in the upstream;（3） the proposed pier does not result in significant deviation of the hydrodynamic axis,and local scour and erosion may occur in the left bank;（4）the proposed bridge will have little effect on the water lock and pumping station in Xihaizui; when the pumping stations in Xihaizui and its expansion works are draining,the suspended sand on the entrance gate and the guard line of the pumping station can be washed into the main channel.