采用盾构法施工不可避免会引起地表及建筑物的变形沉降。为了研究盾构侧穿桥梁时对桥梁沉降变形的影响，以北京昌平二期工程盾构侧穿桥梁为例，采集桥桩和地表沉降变化数据，结合盾构推进土压和注浆量，分析桥桩及桥梁周边地表在不同阶段的沉降变形情况。得出： 1）当盾构低土压侧穿桥梁时，会引起桥梁横向的差异沉降； 2）低注浆率穿越浅覆土层及不良填土层时，隧道正上方范围内的地表仍会发生隆起变形。因此，盾构侧穿时，必须保证合理土压和注浆率，防止桥梁发生断裂裂缝及穿越不良土层时出现地表冒浆。

Deformation and settlement will occur to the ground surface and surrounding buildings in shield tunneling. In the paper, the settlement of the bridge and ground surface in different phases of the construction of the shieldbored tunnel of phase 2 of Changping Line of Beijing Metro are analyzed, so as to minimize the influence of the shield tunneling on the bridge and ground surface. Conclusions drawn are as follows: 1) Differential settlement will occur to the bridge when the shield side crosses the bridge with low earth pressure; 2) Heaving deformation will still occur to the ground surface above the tunnel when the shield passes through the poor backfill layers under shallow cover with low grouting rate. As a result, rational earth pressure and appropriate grouting rate are very important for the safety of the bridge and the ground surface.