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在混凝土弹塑性损伤本构模型的基础上,考虑盾构管片拼装块与连接螺栓的非连续性和拼装块之间的接触关系,建立三维非连续接触计算模型。以苏州某地铁盾构隧道工程为例,对盾构管片的受力状况进行模拟计算,并与惯用法模型和修正惯用法模型的计算结果进行对比分析。结果表明:盾构管片内拱顶K拼装块部分区域的损伤因子超过了损伤临界值,这些部位将产生明显可见的裂缝;盾构管片拱顶与拱底内侧的受拉区域均产生了塑性变形,拱顶K拼装块的塑性区深度达到截面宽度的55%;盾构管片最大内力组合在两侧拱腰管片的接头处;三维非连续接触计算模型可以更好地反应管片接头对内力的影响和管片混凝土材料的受力及变形特性;模型中盾构管片接头处接触单元的设置消除了其他模型中接头刚度差异对计算结果的影响,对盾构管片抗压刚度及抗弯刚度均会产生影响。
Based on the elasto-plastic damage constitutive model of concrete, considering the contact between the shield pipe segment and the connecting bolt and the assembly block, a 3D non-continuous contact calculation model is established. Taking a subway shield tunnel project in Suzhou as an example, the force condition of the shield segment is simulated and compared with that of the conventional method and the modified common law model. The results show that the damage factors in the partial area of the dome K in the shield segment exceed the critical value and the fractures will be obviously visible in these segments. Both the dome of the shield segment and the tension zone inside the dome Plastic deformation, the plastic zone of the dome K assembling block reaches a depth of 55% of the cross-sectional width; the maximum internal force of the shield segments is combined at the joint of the two sides of the arch ribs; the 3D discontinuous contact calculation model can better reflect the segment The influence of joint on the internal force and the force and deformation characteristics of the concrete; the setting of the contact unit at the joint of the shield segment in the model eliminates the influence of the difference of joint stiffness in other models on the calculation results, Stiffness and bending stiffness will have an impact.