行洪断面补偿疏浚设计方案分析

Analysis on the compensation dredging design scheme of flood crossing section

拟建浦仪公路过江通道工程中桥梁工程实施后会减小八卦洲左汊分流比,必须采取行洪断面补偿疏浚措施。通过采取物理模型试验对防洪评价中2种补偿方案进行比较分析,初步推荐以在上坝段桥轴线断面上、下游共500 m范围内对-3～-15 m等高线区域进行开挖,开挖深度3 m,以补偿桥轴线河床断面的过水面积的方案二为行洪断面补偿方案。以方案二为基础进一步优化,从而确定最终行洪断面补偿疏浚设计方案。

After the implementation of the bridge project in the proposed Puyi Highway Crossing River Passage Project,the left-turn split ratio of the Baguazhou would be reduced,and the dredging measures for the flood crossing section must be taken.Through the comparison and analysis of 2 compensation schemes in flood control evaluation by the physical model test,it was preliminarily recommended to excavate the-3 to-15 m contour line area within 500 m of the upstream and downstream sections of the bridge section of the upper dam section.The excavation depth of 3 m to compensate for the over-water area of the riverbed section of the bridge axis was the compensation plan for the flood section.Therefore,further optimization was carried out based on the second scheme to determine the dredging design scheme for the final flood section compensation.