为研究盾构切削穿越高架桥桩基工况下的扩径再制造技术以及再制造后盾构对切桩工程的适应性，以北京地铁12号线盾构切削西坝河桥桩工程为背景，分析盾构刀盘系统、推进系统以及排渣系统切桩难点，并依据难点提出再制造要求，再对盾构各系统进行改造，最后研究再制造后各部分的切桩适应性。结果表明： 1）刀盘系统采用Q345B钢材、开口率达61%、配备切桩专用刀具以及搅拌棒，实现了刀盘系统耐磨性能、切削性能以及渣土改良性能的提升，基本适应切桩工况对刀盘系统的要求； 2）再制造后，对盾构转矩、推力进行校核，满足切桩要求，且留有较大的调整余度； 3）采用无轴式螺旋输送机出土器，降低了排出钢筋卡螺旋输送机的概率，螺旋输送机的输送能力、转矩、转速得到提升，可适应切桩对排渣系统的要求。

To investigate the adaptability of remanufactured shields (diameter enlargement) cutting through piles of a viaduct, the cutterhead, thrust, and mucking systems of a shield are analyzed and the remanufacturing requirements of the shield are established according to construction difficulties, thereby modifying the system. The remanufactured shield is applied to Beijing metro line 12 and cuts through piles of the Xiheba viaduct. The obtained results are as follows: (1) the cutterhead adopts steel material Q345B and has an opening rate of 61%, and with the help of pilecuttingdedicated cutters and stirring wing, the abrasion, cutting, and soilconditioning performances of the cutterhead are improved; (2) the torque and thrust of the remanufactured shield meet relevant requirements with adequate allowance; (3) the anaxialtype screw conveyer is adopted, which minimizes the possibility of a conveyer jamming induced by  reinforced bar and greatly improves the mucking efficiency.