海底盾构隧道双层衬砌 柔性垫层研究

针对大连地铁5号线工程梭鱼湾南站单洞双线盾构区间隧道施工建设问题，探讨岩溶发育区海底隧地铁盾构隧道支护技术。考虑岩溶发育地区工程地质情况复杂及在特殊工况，如地震作用下，结构发生附加变形时的隧道安全，提出使用盾构隧道双层衬砌结构及柔性柔性垫层，通过理论分析、数值计算等方法，分析一定强制位移条件下，不同厚度及密度的柔性垫层对盾构隧道双层衬砌结构内力分布的影响。研究结果表明：随着材料密度的增加，隧道外衬所受最大弯矩先减少后增加，而内衬所受最大弯矩先增大后减小。相同密度情况下，随着材料厚度的增加，外衬最大弯矩逐渐增大，内衬最大弯矩逐渐减小。当柔性垫层材料性能适中能提供充分的协调变形空间时，隧道内外衬砌能合理分配结构附加变形产生的内力，从而大幅提高隧道支护的安全性能。

Research on Double-layer Lining and Flexible Damping Layer of Undersea Shield Tunnel under Earthquake Action

Aiming at the problem of construction of the single-hole and double-track shield tunnel in the section of the South Line of the Dalian Subway Line 5, the paper discusses the support technology for the subway shield tunnel in the karst development area. Considering the complex engineering geological conditions in karst development areas and the safety of tunnels under special working conditions, such as earthquakes, additional deformation occurs on the structure. Using double-layer lining shield tunnel and flexible layer, the influence of flexible layer with different thicknesses and densities on the internal force distribution of lining structure under certain forced displacement conditions is analyzed. Research indicates: With the increase of material density, the maximum bending moment of the external lining of the tunnel decreases first and then increases, while the maximum bending moment of the internal lining increases first and then decreases. At the same density, with the increase of material thickness, the maximum bending moment of the external lining gradually increases, and the maximum bending moment of the internal lining gradually decreases. When the material of the flexible cushion material is moderate enough to provide sufficient coordinated deformation space, the inner and outer lining of the tunnel can reasonably distribute the internal force generated by the additional deformation of the structure, thereby greatly improving the safety performance of the tunnel support.