盾构隧道新型纵缝抗弯性能数值模拟研究

Numerical Study on Bending Resistance of New Type Longitudinal Joint in Shield Tunnel

随着盾构隧道向大直径、大埋深方向发展,对隧道纵缝的抗弯性能要求日益提升,因此出现了许多新型接缝形式。研究分析了一种包含新型无手孔连接结构的新型接缝,较传统纵缝改变了接缝细部构造,并调整了螺栓位置。通过建立新型接缝和传统接缝的三维精细化有限元模型,对比分析了新型纵缝在正负弯矩下的受弯行为,并探讨了轴力的影响。结果表明:不同工况中两种纵缝的受弯过程均可以分为线性段和非线性段,轴力的增加会增加受压区的损伤,降低连接件(螺栓及新连接结构)的作用;由于螺栓到受压区距离的变化,正弯矩下新型纵缝抗弯性能较传统纵缝有明显提升;负弯矩小轴力工况中新连接结构提升了接缝的抗弯性能,而大轴力工况中新型纵缝抗弯性能提升不明显。

With the development of shield tunnels in the direction of large diameter and large buried depth,the bending performance requirements of tunnel longitudinal joints are increasing day by day.Therefore,many new types of joints have appeared.A new type of joint,including a new type of no-handhole connection structure,is studied and analyzed.Compared with the traditional longitudinal joint,the detail structure of the joint is changed,and the bolt position is adjusted.By establishing a three-dimensional refined finite element model of the new joint and the traditional joint,the bending behavior of the new longitudinal joint under positive and negative bending moments was compared and analyzed,and the influence of axial force was discussed.The results show that the bending process of the two longitudinal joints in different working conditions can be divided into linear sections and nonlinear sections.The increase in axial force will increase the damage to the compression zone and reduce the effect of connectors(bolts and new connection structures).Due to the change in distance from the bolt to the compression zone,the bending resistance of the new longitudinal joint under a positive bending moment is significantly improved compared with the traditional longitudinal joint.The bending resistance of the joint of the new connection structure is improved under the conditions of negative bending moment and small axial force,while the bending resistance of the new longitudinal joint is not obviously improved under the condition of large axial force.