某地铁盾构隧道破损机理分析及加固设计

地铁盾构隧道建设规模不断扩大,已建及在建盾构隧道破损事故时有所闻。盾构隧道加固技术研究成为地铁隧道施工及运营的重要课题。针对某地铁盾构隧道破损工程实例,在隧道破损机理分析的基础上开展加固设计工作。破损机理研究表明:该地铁盾构隧道病害产生的主要原因为商业项目基坑施工诱发地铁隧道侧方土压力卸载和隧道侧方地层抗力降低所致。盾构隧道加固设计应遵循"先急后缓,里外兼修"原则,执行刚度、耐久性修复标准,并满足后期运营结构安全性及耐久性要求。

Damage Mechanism Analysis and Strengthening Design for a Metro Shield Tunnel

With the sustained growth of construction scale of metro shield tunnel, some damage phenomena have frequently been seen among shield tunnels, as-built or still under construction.Therefore,study on shield tunnel strengthening technology has become an important topic in construction and operation of metro tunnel. This paper was based on a project case of damaged metro shield tunnel,and carried out strengthening design after analyzing the damage mechanism of this tunnel. The damage mechanism research showed that: the damage of this tunnel was mainly caused by a commercial project's foundation pit excavation,which induced the unloading of the lateral soil pressure around the metro tunnel and induced the decreasing of the lateral resistance force of the strata. Furthermore,this paper proposed that the strengthening design for shield tunnel should comply with the principle of "emergency treatment first then normal repairing; considering both the internal and external parts when repairing",should be according to the rigidity-based and durability-based repairing standards,and should meet safety and durability requirements of the structure after being repaired and put into operation.