摘要
桥墩会改变桥址河段的流场,产生壅水和涡旋,阻碍河道行洪,所以大型桥梁在建设前必须论证其对河道的影响程度.使用Delft3D建立了赣江河道平面二维非恒定流数学模型,并使用原形观测数据对模型进行了参数率定和验证.开展了拟建朝阳大桥对赣江河道综合影响的研究,对大桥建设前后赣江河段的水位、流速和赣江东西两汊分流比的变化进行了数值模拟分析.计算结果表明:建桥后上游水位最大壅高0.07m,影响范围在桥上游约640m范围内;桥位上游流速略有减小,最大减小值为0.08m/s,桥位下游流速有增有减,变化幅度在±0.06m/s之内,流速影响范围为桥位上游1 000m至桥位下游1 600m;建桥对东西河分流比影响不明显.模型计算与物模试验成果基本吻合,结果表明,大桥的建设对河道水流的影响较小.
Bridge piers in the river can change the flow field, cause backwater and eddies, and block the flood passage. Comprehensive influence of proposed large-scale bridges on the river should be studied before con- straction. This paper uses Delft3D to build a two-dimension unsteady flow numerical model of Ganjiang Riv- er. This model is calibrated and verified by the measured data in the field, and used to study the influence of the proposed Chaoyang Bridge on the Ganjiang River The changes of water level, velocity field and the divi- sion ratio of east and west branches are analyzed through the numerical modeling before and after the con- struction of the bridge. The results show that there is a maximum back-up water level of 0.07m about 640m upstream this bridge. The flow velocity decreased slightly about 1000m upstream this bridge with a largest decreased value of 0.08m/s. The flow velocity changed in a range of （-0.06±0.06） m/s about 1600m downstream the bridge. The influence of river division is not obvious. Calculated results and physical model test results are basically consistent. In general, the construction of Chaoyang Bridge has little direct effect on the river water flow.
出处
《三峡大学学报（自然科学版）》
CAS
2014年第6期1-5,共5页
Journal of China Three Gorges University：Natural Sciences
基金
国家自然科学基金委员会面上项目(51279046)
关键词
赣江
朝阳大桥
数值模拟
水位
流速
Ganjiang River
Chaoyang Bridge
numerical modeling
water level
flow velocity
