基于塑性损伤的盾构隧道双层衬砌三维实体非连续接触模型研究

发布时间：2018-07-26 19:23

【摘要】：在分析基于梁弹簧模式和壳弹簧模式盾构隧道双层衬砌数值模型的基础上,分别建立依据接合面接触状态不同划分的盾构隧道双层衬砌三维实体复合结构和叠合结构计算模型。该模型通过混凝土塑性损伤模型表征混凝土的非线性特性,考虑管片内置钢筋对结构力学性能的影响,采用已有模型模拟钢筋屈服、硬化和软化现象,建立三维螺栓实体代替弹簧单元模拟管片接头,真实反映盾构管片之间、管片与连接螺栓及管片与二次衬砌接合面的接触情况。以广深港狮子洋隧道双层衬砌为工程实例,建立2种计算模型进行研究,通过与依托同样工程背景下的相似模型试验管片和二次衬砌内力和位移结果进行对比分析,两者具有较好的一致性,验证了该模型模拟盾构隧道双层衬砌结构力学行为的准确性和适用性。研究结果表明:(1)双层衬砌在受力过程中管片与二次衬砌在局部存在非协调变形,接合面发生分离现象,出现零压区。(2)由于封顶块构造的原因,封顶块对应位置二次衬砌易出现应力集中现象,该位置轴力和弯矩变化不均匀,管片与二次衬砌接合面接触压应力较其他位置偏大。研究成果对盾构隧道双层衬砌的设计分析具有一定的参考价值。
[Abstract]:Based on the analysis of double-layer lining numerical model of shield tunnel based on beam spring mode and shell spring mode, The three dimensional composite structure and superimposed structure of shield tunnel double-layer lining were established according to the contact state of the joint. In this model, the nonlinear behavior of concrete is characterized by plastic damage model of concrete. Considering the influence of the steel bar on the mechanical properties of the structure, the existing model is used to simulate the yield, hardening and softening of the steel bar. Three-dimensional bolt entity instead of spring element is established to simulate segment joint, which truly reflects the contact between shield segment and connecting bolt, and between segment and secondary lining. Taking the double-layer lining of Lion Yang Tunnel in Guangzhou-Shenzhen Port as an engineering example, two kinds of calculation models are established and studied. The results of internal force and displacement of the similar model test segment and secondary lining are compared with those of the similar model under the same engineering background. It is proved that the model is accurate and applicable to simulate the mechanical behavior of double-layer lining structure of shield tunnel. The results show that: (1) in the course of loading, there is a non-conforming deformation between the segment and the secondary lining, the joint surface is separated, and the zero pressure zone appears. (2) because of the construction of the roof block, The stress concentration of the secondary lining is easy to appear in the corresponding position of the roof block, the axial force and bending moment of this position are not uniform, and the contact compressive stress of the joint face between the segment and the secondary lining is larger than that of the other positions. The research results have certain reference value for the design and analysis of shield tunnel double-layer lining.
【作者单位】：西南交通大学交通隧道工程教育部重点实验室;四川公路桥梁建设集团有限公司勘察设计分公司;
【基金】：国家自然科学基金面上项目(51278424) 中央高校基本科研业务费专项资金资助项目(2682014CX070) 国家高技术研究发展计划(863)项目(2014AA110401)~~
【分类号】：U455.91;U451

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