盾构隧道管片接头三维精细化数值模拟研究

Three-dimensional Refined Numerical Simulation of Segmental Joint of Shield Tunnel

针对现有盾构隧道管片接头构造数值模拟难以准确反映接头实际受力和变形过程的问题,以苏通GIL工程管片接头为研究对象,建立三维精细化接头数值模型,模型采用实体单元模拟接头混凝土、螺栓、套筒、垫片等构造并在螺栓上施加预紧力,采用梁单元模拟钢筋。通过接头抗弯足尺试验验证数值模型计算结果的准确性,进而分析螺栓连接状态对于接头抗弯性能的影响。结果表明:1)所建立的接头三维精细化模型能较好地反映接头在压弯荷载作用下的变形规律,与接头抗弯足尺试验结果的对比表明其具有较好的计算准确度;2)正负弯矩作用下,无螺栓时接头总体上更易发生张开和竖向变形,正弯矩下有无螺栓对于接头张开、竖向变形的影响较大且与轴力和弯矩有关,负弯矩下两者之间的差距较小且基本不变;3)接头采用斜螺栓连接时,正弯矩下有无螺栓对于接头抗弯刚度的影响较负弯矩下更大。

The numerical results of segmental joint of shield tunnel often cannot accurately reflect the actual force and deformation process of the joints.Hence,a three-dimensional refined numerical model of segmental joint of Sutong GIL project is established,in which solid elements are used to simulate the concrete,bolts,sleeve,gaskets,etc.,beam elements are used to simulate the reinforcements,and preload are applied on the bolt.Based on the numerical model,the calculation is carried out and compared with the full-scale compression-bending test to verify its accuracy.The numerical model is used to analyze the influence of bolt connection state on the bending performance of the joint.The results show that:(1)The three-dimensional refined model of the joint can reflect the deformation law under compressive bending loads,and it has good calculation accuracy.(2)Under positive and negative bending moments,the joint is prone to opening and vertical deformation when there is no bolt;the joints with/without bolt has a greater impact on the joint opening and vertical deformation,and the influences are related to the magnitude of axial force and bending moment under positive bending,while the difference between influence of joint with bolt and that of joint without bolt is small and basically unchanged under negative bending.(3)When the joint is connected by oblique bolts,the influence of the joint with/without bolt on the bending stiffness of the joint under positive bending is greater than that under negative bending.