大尺度缩窄水流桥墩非定常局部冲刷研究

RESEARCH OF UNSTEADY LOCALIZED SCOURING ON PIERS NARROWING CURRENT IN LARGE SCALE

通过动床试验,结合黄河下游细沙河床研究了大尺度缩窄河道时非恒定流桥墩的局部冲刷.研究结果表明,非恒定流洪水过程中的桥墩局部冲刷与恒定流的情况相比,两者之间存在差异而且有必然的联系.通过影响因素和试验数据的分析,建立了两者之间的关系和相应的非恒定流桥墩局部冲刷深度计算方法.经与原型非恒定流洪水实测资料对比,结果合理且比较符合实际情况.

Through dynamic river bed experiments and fine sand river bed in lower Yellow River, localized scouring on piers under unsteady flow when river channel is narrowed in large scale is researched. The result indicates that the localized scouring on piers under unsteady flood and scouring under steady flood are different and related necessarily. Through analysis of influencing factors and experiment data, their relation and relevant calculating methods of localized scouring depth on piers under unsteady flow are established. Compared with prototype observed data under unsteady flow flood, the result is reasonable and accords the practice well.