Research conclusions：Affected by the under-passing of the pipelines, the roadbed of the existing track experienced the process of apparent settlement during construction, apparent post-construction settlement, settlement becoming slow and settlement becoming stable. As the roadbed settlement was large and the rail settlement increased relatively, the rail was uplifted necessarily. The track geometric deformation and rail displacement were small and didn't exceed the control values. Affected by soil disturbances and the seasonal change of the groundwater level, the structure of Shangdi Bridge near the engineering site floated and the differential settlement between the Bridge and the roadbed increased. The attention would be paid to the influence of the back fill soil and ground water on the bridge.