鸭绿江界河公路大桥建设期桥区河段淤积原因分析

Cause of siltation in bridge navigable waters during construction of Yalu river highway bridge

基于多年实测地形资料,同时结合上游来水来沙情况,对鸭绿江界河公路大桥建设期桥区河段河床出现较大幅度冲淤变化的原因进行分析。研究表明:2010年3月—2010年9月,径流来流量较大,河段总体冲刷明显,河床呈现明显的右侧凸岸边滩冲刷,左侧凹岸深槽淤积的特点,大桥施工期淤积量较大的主要原因是前期冲刷量大、河床自动恢复平衡的结果。施工期内施工栈桥、运输栈桥等设施密集桩群对2010年大水后的回淤有明显的促进作用。

Based on the measured topographic data for many years,and combining with conditions of water and sediment upstream of the Yalu river,this paper analyzes the cause of large erosion and deposion on the riverbed of highway bridge waters in the period of bridge construction. The results show that from March 2010 to September2010,the runoff is larger and the riverbed erosion is obvious,which is featured with erosion at the right side of the protruding shore beach and deposition at the left side of the concave bank deep grooves. The main reason for the large erosion during construction of the bridge is the strong erosion at the early stage and automatic re-balance of the riverbed. During the bridge construction, the dense pile groups of the construction trestle and transport facilities promote greatly the backsiltation after the flood in 2010.