营业线桥梁改建工程中,为了保证既有线的行车安全,桥梁基础工程采用沉井施工是较为普遍的一种方法。沉井施工中,为了使桥墩基底受力处于最安全的状态,使墩身基底完全置于沉井顶上,并在容许偏心范围内。为此,沉井在下沉过程中,必须随时观测并纠正它的中线位置,使其保持正确与垂直。 Business line bridge reconstruction project, in order to ensure the traffic safety of existing lines, bridge foundation engineering using sunk well construction is a more common method. In the construction of caisson, in order to make the pier foundation in the most secure state of stress, so that the base of the pier body completely placed on top of the caisson, and allow the eccentric range. Therefore, during the sinkhole sinking process, the centerline position of the sinkhole must be observed and corrected at any time so as to maintain its correctness and verticality.