为研究嘉绍大桥对钱塘江涌潮形态及水动力的影响,在分析现场涌潮观测资料的基础上,建立基于KFVS格式的平面二维涌潮数学模型,计算比较了建桥前后涌潮及潮流场的变化。结果表明:受嘉绍大桥阻隔影响,涌潮经过桥位时其形态的整体性被破坏,过桥后约500m涌潮形态基本恢复,桥位下游涌潮高度增加,桥位上游涌潮高度降低;建桥对涨、落潮流的影响主要在桥位近区,对上下游的潮位和流向影响较小,桥位上下游涨、落潮流速减小0~5%,桥轴线断面桥跨中间流速增加2%-10%;建桥对涌潮的影响是局部的,桥位上下游近区的潮动力有所减弱。
According to the observed data of the tidal bore shape, a 2-D mathematical model based on the KFVS ( kinetic flux-vector splitting) scheme was employed to study the impact of Jiashao Bridge on the current field of the Qiantang River. The results show that the integral morphologic of the tidal bore is destroyed due to the bridge piers, when the bore passing, the tidal bore shape recovers about 500 m upstream of the bridge site. The bore height downstream of the bridge site rises, and that of upstream of the bridge site lowers. The maximum impact of the bridge construction occurs at the adjacent area of the bridge axis, and little impact on the variation of the tidal level, and the tidal volume of upstream and downstream reach. The flood and ebb flow velocity of upstream and downstream reach decreased about 0-5%, and that between bridge piers at the bridge axis cross-section increased amount 2%-10%. The impact of Jiashao Bridge on the tidal bore is local; hydrodynamics power at upstream and downstream of bridge site will be weakened.