Deformation control construction method for shield tunneling machine underneath passing existing bridge

The invention discloses a deformation control construction method for shield tunneling underneath passing of an existing bridge. The method comprises the following steps of S1, preparation before construction, S2, underneath passing process control of a shield tunneling machine, S3, control after underneath passing of the shield tunneling machine and S4, setting of continuous monitoring. Compared with an existing technical method, the method has the advantages that by designing a standardized scheme of under-bridge construction of the shield tunneling machine and formulating parameters, the overall step flow of the scheme is reduced, a preposed risk section test is designed, meanwhile, timely secondary processing is achieved in an actually-excavated section, and under the condition that the overall step flow is reduced, the risk of the shield tunneling machine is reduced. And the step of synchronous construction in the tunnel is greatly reduced. 本发明公开了一种盾构下穿既有桥梁变形控制施工方法，包括以下步骤：S1.施工前准备，S2.对盾构机下穿流程控制，S3.对盾构机下穿