沪通长江大桥施工期对桥区河床演变影响分析

为研究大型跨江桥梁工程建设后对桥区河床响应的影响,以沪通长江大桥为例,进行大桥建设期间桥区河床地形、汊道分流比监测,对比分析工程建设前后桥区汊道分流比、桥区河床平面、断面、冲淤变化特征,掌握大桥工程建设后的桥区水动力、大型沉井基础局部冲刷、桥区深槽响应的影响特点,并与前期模型研究成果进行对比分析,为大桥工程顺利建设和工程河段跨江桥梁建设提供科学依据.分析结果表明,大桥施工期间天生港水道桥墩基础局部冲刷及深槽冲刷幅度2~3 m;浏海沙水道28#、29#主墩基础及深槽冲刷幅度较大,深槽断面普遍冲刷4~5 m,主墩28#、29#基础局部冲深28.1 m、19.1 m.大桥施工期间对桥轴线断面流速分布影响较小,桥区汊道分流比基本稳定,对桥区河势稳定影响较小.

Analysis of the Influence of the Construction of the Hutong Yangtze River Bridge on the Response of the river Bed in the Bridge Area

In order to study the influence of large-scale bridge construction on the response of river bed in the bridge area,taking the Hutong Yangtze River Bridge as an example,the monitoring of river bed topography and branch diversion ratio in the bridge area was carried out during the construction of the bridge,and the characteristics of branch diversion ratio,river bed plane,section and erosion and deposition changes in the bridge area before and after the construction of the project were compared and analyzed,so as to master the hydrodynamic force and large-scale sunk well foundation Bureau in the bridge area after the construction of the bridge project The influence characteristics of scour and deep channel response in the bridge area are compared with the previous model research results,which provides scientific basis for the smooth construction of the bridge project and the construction of the river crossing bridge in the project reach.The results show that during the construction of the bridge,the local scour and deep channel scour of the pier foundation of Tianshenggang waterway are 2~3 m;the scour of the main pier foundation and deep channel of the 28#and 29#Liuhaisha waterway are relatively large,the section of the deep channel is generally 4~5 m,and the local scour of the 28#and 29#main pier foundations are 28.1 m and 19.1 m.During the construction of the bridge,the influence on the velocity distribution of the bridge axis section is small,the diversion ratio of the branches in the bridge area is basically stable,and the influence on the stability of the river regime in the bridge area is small.