Research On The Theorical Analysis And Application Of The Metro Shield Tunnel Segment Joint

As the shield tunneling method is more and more widely used in the ground engineering in recent years, especially played a great role in urban subway engineering. The segment play a significant role as the long-term carrier of the shield tunnel, the mechanical properties of it is especially important, as the joint is an important part of shield tunnel segment, which properties have large effects on the mechanical properties of the whole tunnel structure. while the non-continuous properties of the segment joints and the construction loads cause the properties of shield tunnel in the construction stage have a large difference with normal use stage, therefore, based on the shield tunnel of SuZhou Metro, this paper aims at the mechanical properties of the segment joint to do the research works as follow several aspects:1. Analyzed the whole mechanical process of the segment joint, established a mechanical model of segment joint, got the analytical expression of joint rotation angle and joint stiffness under positive and negative bending;2. Established the finite element model based on the therotical analysis of the segment joint, and the factors related to the joint stiffness sensitivity was analyzed by the finite element model, compared the results of two segment joint models, and gave a calculate model of the bending stiffness of shield tunnel segment joints and some related recommendations for the design of Suzhou Metro;3. Based on the study of mechanical properties of joint, compared three categories segment model which widely used in design of segment, summed up the differences between non-continuous model and the continuum model, optimized the design process for the segment, used the non-continuous model and the joint stiffness calculated by this paper to take sensitive analysis on some key design parameters;4. Based on the mechanical properties of segment joint, extended the non-continuous joints model to whole tunnel, built three-dimensional discrete joint finite element model of shield tunnel, analyzed the effect of non-continuous joints on the segent properties of the shield construction stage, and analyzed the grouting pressure, jack thrust, assembly methods, and the special construction conditions of shield tunnel.