地铁盾构隧道下穿既有构筑物沉降分析及对策

以国内某盾构隧道下穿既有构筑物为工程依托，运用有限元分析软件Plaxis模拟盾构隧道开挖的全过程．对施工所引起的沉降进行数值模拟分析。研究结果表明：隧道下穿住宅楼时，桩基础会产生较大的不均匀沉降；隧道下穿锅炉房时，左右线开挖后引起的基础沉降都超出了可控范围；隧道在先后下穿住宅楼和锅炉房的施工过程中都存在较大风险。通过研究提出了盾构施工期间技术措施，有效地控制构筑物沉降，以达到相关安全性要求。

Subsidence and Countermeasures of Metro Shield Tunneling Underneath Existing Buildings

Based on a domestic engineering of metro shield tunneling underneath existing buildings, the article uses finite element analysis software Plaxis to simulate the whole process of shield tunnel excavation, analyzes the subsidence problems caused by the construction. The research result shows that： when tunneling underneath residential buildings, pile foundation will produce larger uneven settlement; when tunneling underneath boiler room, foundation settlement is beyond the control; there are significant risks in the process of tunneling construction successively under residential buildings and boiler room. Techni- cal measures during shield tunneling are put forward to control structure settlement effectively and achieve related safety requirements.