武汉长江隧道盾构段结构型式研究

武汉长江隧道是我国在高水压、强透水地层中修建的第一条大直径盾构隧道,且左侧河床历年冲淤变化幅度较大,如何选择合理的隧道结构型式是工程设计必须考虑的关键问题.为此,在国内外现有单层管片衬砌和全环双层衬砌的基础上,研究提出了一种新型的“管片衬砌+非封闭内衬”的双层衬砌结构该结构在不增加隧道开挖直径的前提下,允分利用圆形隧道底部和两侧的富余空间现浇钢筋混凝土,并与车道板结构共同组成非封闭二次衬砌结构,可以大幅度地减少河床冲淤变化时的结构横向变形,并确保隧道底部与两侧这些重点部位的防水性能及结构长期稳定性,是一种值得推荐的创新结构方案.

A Study of the Structure Type of the Shield-Driven Section of the Yangtze River Tunnel

The Yangtze River Tunnel is the first large-diameter tunnel located in the stratum of high water pressure and high water permeability,and the variation amplitude of channel scouring and silting on the left side has been very high over the years.Thus a reasonable structure type is one of the key considerations in the engineering design.Based on the single-layer segment lining and the full-ring double-layer lining,this paper proposes a new composite lining consisting of "segment and non-enclosed inner linings." Assuming no increase of the excavation diameter,construction of this structure can make full use of the space at the bottom of the circular tunnel and the two sides to cast reinforced concrete on site.The structure will form a non-enclosed secondary lining with the traffic lane slab,substantially reducing the lateral deformation of the structure and ensuring the water resistance of the key areas as well as the long-term stability of the structure.