考虑内部预制结构的盾构隧道抗震性能分析

Seismic Analysis of Shield Tunnel Considering Internal Prefabricated Structure

近年来,预制结构逐渐应用于隧道内部结构,如上海复兴东路隧道、南京纬三路隧道等。与现浇结构相比,预制结构具有生产效率高、产品质量好、工人劳动强度低、保护环境等优点。但是,其连接部位薄弱,抗震性能相对较差。以某盾构隧道为背景,基于目前盾构隧道抗震设计不考虑内部结构的现状,采用动力时程方法对比分析了预制和现浇两种内部结构形式对盾构隧道管片抗震性能的影响,从而系统评价了考虑内部预制结构的盾构隧道抗震性能。结果表明:设计地震作用下,考虑内部结构能明显改善盾构隧道管片的抗震性能,且内部现浇结构优于内部预制结构;罕遇地震作用下,内部现浇结构会先于盾构隧道管片破坏,且内部现浇结构相比内部预制结构更为不利。

In recent years,prefabricated structure has been gradually applied,such as Fuxing Road Tunnel in Shanghai,Weisan Road Tunnel in Nangjing. Compared with the cast-in-situ structure,prefabricated structure has many advantages,such as high production efficiency,products of good quality,low labor intensity of workers,environmental protection and so on. However,its seismic performance is relatively poor because of weak joints. In the background of the currently status that seismic designing of a shield tunnel without considering the internal structure,dynamic time history method was used to analyze the effect of prefabricated and cast-in-situ concrete structure on the seismic performance of the shield tunnel segment. Thus the seismic performance of shield tunnel with internal prefabricated structure was systematically evaluated. The results show that: in the design earthquake,considering internal structure can obviously improve the seismic performance of the shield tunnel segment,and cast-in-situ concrete structure outperforms the prefabricated structure. For the condition of rare earthquake,the destruction of the internal structure is earlier than that of the shield tunnel segment,and the cast-in-situ concrete structure is more disadvantage than the prefabricated structure.