强潮山溪性河口围垦后桥墩最大冲刷深度研究

Study on the maximum scour depth of piers of a bridge after reclamation in a hilly,fluvial and macro-tidal estuary

山溪性强潮河口围垦工程的实施束窄了河口的行洪通道,由此可能降低河口固有涉水建筑物的安全稳定性.为此,在就河口围垦对桥墩冲刷影响进行初步分析的基础上,利用平面二维嵌套潮流数学模型以及一般冲刷和局部冲刷的半经验半理论公式,就霍童溪河口围垦工程实施之后下游云淡大桥桥墩的可能最大冲刷深度进行计算,结果表明,围垦工程实施后,洪水期间云淡大桥的桥墩冲刷还是相当严重的,有必要对桥墩采取相应的防护措施.此外,通过对桥墩最大冲刷深度的影响因素进行探讨,指出实际桥墩冲刷深度一般还是难以达到计算所得到的可能最大冲刷深度.

Reclamations in a hilly, fluvial and macro-tidal estuary will narrow flood channels. Consequently, it may reduce the safety and stability of hydraulic structures downstream. For this, the paper calculated the maximum scour depth of piers of Yundan Bridge in Fujian province through a 2D numerical model, the semi-empire and semi-theory formulae about general scour and localized scour. The results indicate that, during flooding period, the scour depth of piers of Yudang Bridge is comparatively serious; so it is necessary to take protecting measures for piers. In addition, influence factors about the maximum scour depth of bridge piers are discussed, and then the conclusion is put forward that actual scour depth of piers hardly reach the calculated amount.