U形槽基坑施工对邻近高速铁路桥墩的影响分析

Analysis of the Impact of U-shaped Groove Foundation Pit Construction on the Adjacent High-speed Railway Bridge Piers

以U形槽结构近距离、斜交下穿杭绍台城际铁路线的某特大桥工程为依托,采用三维有限元软件模拟U形槽结构从基坑开挖到主体完工及荷载施加的全过程,分析相邻铁路桥墩对各施工阶段的影响。在模拟分析过程中设置观测控制点,着重分析在近距离斜交状态下,桥梁墩顶的垂直位移、水平位移与施工阶段的关系,并研究墩身产生的不均匀应力对结构安全及后期运营的影响。研究发现,在斜交状态下,墩顶的不均匀位移差达到0.758 mm,主应力值增大10%。工程中应严格控制斜交角度与邻近距离,研究成果可为类似工程设计提供参考。

Based on the U-shaped groove structure for close range and oblique underpass of a certain super large bridge project on the Hangzhou-Shaoxing-Taizhou Inter-city Railway line,the research uses three-dimensional finite element software to simulate the whole process of U-shaped groove structure from foundation pit excavation to main body completion and load application,and analyzes the influence of adjacent railway bridge piers in each construction stage.Set the observation control points in the process of simulation analysis,the research analyzed at close range oblique condition,vertical and horizontal displacement of the bridge pier top with the relationship of the construction stage,and shafts of the non-uniform stress influence on structure security and the late operation.It was found that in the condition of oblique state,the uneven displacement difference at the top of the pier reached 0.758 mm,and the principal stress value increased by 10%.The skew angle and proximity distance should be strictly controlled in the engineering,and the research results can provide reference for similar engineering designs.