对新建异型桥梁承台桩基托换受力的分析

Analysis on Stress Transformation of Pile Foundation Underpinning of Existing Bridges in Shield Construction of Urban Subway

为解决城市地铁施工中盾构区间线路与既有桥梁桩基的冲突,在不中断交通的情况下保证盾构掘进时既有桥梁的稳定,以厦门地铁6号线集华区间盾构为例,采用桩基托换技术处理周边复杂情况和工程的难点,运用MIDAS/FEA与MIDAS/CIVIL软件建立模型,通过对比分析桩基托换时新建桩基与原有桩基的受力转换。结果表明桩基托换技术在安全、工艺及工期进度等方面优于原有拆桥方案。通过辨识在施工过程中存在的风险因素,采取具体的管控措施,保证城市交通主动脉平稳运行。

In order to solve the conflict between the shield section line and the existing bridge pile foundation in urban subway construction and ensure the stability of the existing bridge during shield tunneling without interrupting the traffic,taking the shield in Jihua section of Xiamen Metro Line 6 as an example,the pile foundation underpinning technology is used to deal with the surrounding complex situations and engineering difficulties,and the three-dimensional model is established by MIDAS/FEA and MIDAS/CIVIL software to analyze the stress conversion between the new pile foundation and the original pile foundation during pile foundation underpinning.The results show that the pile foundation underpinning technology is superior to the original bridge demolition scheme in terms of safety,technology and construction schedule.By identifying the risk factors existing in the construction process,specific control measures shall be taken to ensure the smooth operation of urban traffic.