在天津市地铁一号线既有线改造工程中，必须解决将原有车站进行改造所面临的差异沉降控制问题。因车站地处交通要道下，附近交通拥挤，使得改造工作难度较大。从施工的环保和安全角度出发，对控制结构在开挖过程中、改造完成并回填土后的沉降以及减少新旧结构差异沉降方法进行了研究，给出了解决方案。

The control of the differential settlement subject to occur during the renovation of the existing stations of line 1 of Tianjin Metro must be guranteed. Due to the fact that these existing Metro stations are located right below the main streets with busy traffics, there exist great difficulties in the renovation of the Metro stations. From the viewpoint of construction environment protection and safety, the paper studies on the settlement of the controling structures of the Metro stations that occurs both during excavation and after renovation and backfilling and studies on the measures to minimize the differential settlement between the newlybulit structures and the existing structures. Finally, the paper recommends countermeasures for the control of the differential settlement.