地铁隧道盾构穿越高架桥桩基托换工程计算分析

为有效计算地铁隧道盾构穿越高架桥桩基托换施工前后桥梁承台及桩基受力的变化情况，保证桩基托换工程的顺利进行，本文依托厦门市轨道交通6号线隧道盾构下穿跨杏林湾路高架桩基托换工程，结合桩基托换工程特点和工程现场的实际情况，利用MIDAS/fea与MIDAS/civil建立桥梁桩基托换三维数值模型和梁单元模型，并通过该模型对施工现场的桥梁桩基托换工程进行数值计算，重点分析桩基托换施工中新建承台及桩基承载力的变化情况，据此提出桩基托换施工质量的控制措施，保障桩基托换工程质量，为类似工程的顺利建设提供理论指导与参考。

Calculation and Analysis of Pile Foundation Underpinning Engineering for Subway Tunnel Shield Crossing Viaduct

In order to effectively calculate the stress changes of base slab and pile foundation of the bridge before and after the pile foundation underpinning construction of subway tunnel shield crossing viaduct, and ensure the smooth progress of the pile foundation underpinning project, relying on the pile foundation underpinning project of the tunnel shield of Xiamen Metro Line 6 crossing Xinglinwan Road Viaduct, combined with the characteristics of the pile foundation underpinning project and the actual situation of the engineering field, Midas/fea and MIDAS/civil are used to establish the three-dimensional numerical model and beam element model of pile foundation underpinning of the bridge to numerically calculate the pile foundation underpinning project of the bridge in the construction field. The changes in the bearing capacities of the new base slab and pile foundation during the pile foundation underpinning construction are specially analyzed. Based on this, the control measures for the construction quality of pile foundation underpinning are put forward to ensure the quality of pile foundation underpinning project, which provides the theoretical guidance and reference for the smooth construction of similar projects.