盾构隧道斜螺栓-凹凸榫新型环间接头抗剪性能分析

Analysis on Shear Resistance of New-style Inter-Ring Joint with Bolt and Tenon in Shield Tunnel

以苏通GIL工程为背景,建立三维精细化有限元模型,对盾构隧道斜螺栓-凹凸榫式新型环间接头承受压剪作用时的受力和变形过程进行仿真分析,并通过数值模拟说明其必要性。模型采用实体单元,对盾构隧道环间接头混凝土、螺栓、套筒、垫片等细部结构进行1∶1模拟,基于三维模型对环间接头错台、接头转动及凹凸榫作用等进行分析,并采用接头抗剪足尺试验进行对比验证。结果表明:(1)环间接头在顺剪和逆剪加载条件下,接头错台量曲线的变化规律相近,均呈抛物线+直线形状,但逆剪工况时接头刚度比顺剪低20%;(2)环间接头受剪时会产生转动,转动角随着剪切力增大,最大达0.11 rad,不同剪轴比下纵向力对转动角的影响不同;(3)凹凸榫对接头抗剪性能有10%幅度的强化作用,且不受剪切方向影响;(4)与接头抗剪足尺试验对比表明,三维精细化环间接头模型能反应接头的实际受力变形过程,刚度差在10%左右。

Based on the Sutong GIL project, a three dimensional refined finite element model is established to simulate the stress and formulation of new-style inter-ring joint with bolt and tenon in shield tunnel under axial and shearing forces, whose necessity is illustrated by numerical modeling. The concrete, bolts, sleeves, gaskets and other detailed structures of the joint are 1∶1 modeled with solid elements. The dislocation and rotation of the joint, and the effect of the tenon are analyzed based on the three-dimensional model. The results are testified by a full-scale test. The results show that:(1) The displacement curves of the inter-ring joint under different loading of positive and negative shearing are similar, and both show a line shape of parabola-and-straight. However, the shear stiffness under negative shearing is about 20% lower than that under positive shearing;(2) The inter-ring joint will rotate when it is sheared. The angle of rotation increases with the shearing force and reaches a maximum of 0.11 rad. And the effect of longitudinal force on the rotation angle is different under different shear axis ratios;(3) The tenon can strengthen the shear resistance of the joint by 10%, and this is not affected by the shearing direction;(4) Compared with the full-scale joint shear resistance test, it is shown that the three-dimensional and refined inter-ring joint model can reflect the actual force and deformation process of the joint, and the stiffness difference is about 10%.