改扩建桥梁基础围堰及桥墩冲刷分析研究

Analysis and Study on Scour of Cofferdams and Abutments of Reconstructed and Expanded Bridges

摘要:

为探究采用老桥保留、上游分离增建方案的改扩建桥梁工程中冲刷在不同阶段对老桥基础的影响，依托具体工程实例，采用水文分析确定改扩建桥梁河道的洪水特性，得到相应的行洪参数，接着采用FLUENT数值仿真分析改扩建桥梁围堰施工时对既有桥梁的冲刷影响。分析结果表明：位于上游的新桥围堰对老桥桩基而言充当着类似冲刷防护中牺牲桩的作用，能在极大程度上减小老桥的冲刷。该研究的分析结果可为类似改扩建工程项目的建设方案制定提供依据。

Abstract:

In order to explore the impact of scour on the old bridge foundation at different stages of the reconstruction and expansion bridge project by using the old bridge retention and upstream separation and addition scheme, relying on the specific engineering examples, the hydrological analysis is used to determine the flood characteristics of the reconstructed bridge channel and obtain the corresponding flooding parameters, and then FLUENT numerical simulation is used to analyze the impact of the reconstructed bridge cofferdams on the scour of the existing bridges. The analysis result shows that the new bridge cofferdam located upstream acts as a sacrificial pile for the old bridge pile foundation in scoring protection, which can decrease the scour of old bridge to a great extent, which can be referenced for the similar reconstruction and expansion projects.