TBM施工隧道仰拱预制块的力学特性研究

针对TBM施工隧道仰拱预制块的特殊结构,采用围岩-结构模式，进行了模拟施工动态的受力影响计算分析。计算结果表明,围岩初始应力场对仰拱受力有明显影响, 随着竖向压力的增大，仰拱中心的内、外侧应力均增大；随着水平压力的增大，仰拱中心内侧应力减小、外侧应力基本不变；减小复合衬砌结构中初期支护厚度以及变刚性接头为柔性接头均会改善仰拱受力。最后，用试验数据验证计算的正确性，其结论可供TBM施工隧道仰拱预制块的优化设计参考。

Study on mechanical characteristics of precast block of inverted arch for TBM construction tunnel

According to the special structure of precast block of inverted arch for TBM construction tunnel , the dynamic construction state is modeled by FEM with surrounding rock- structure calculating model. The calculating results indicate that surrounding rock initial stress has an obvious influence on interior force of invert center, interior force increases with the vertical force increasing in both side of invert center, and decrease with horizontal force increasing in interior side , unchangeable in outer side. Reduce the first-lining size in composite lining or change rigid connection to flexible one can improve the interior force of precast block of inverted arch. And the calculation result is verified with the experimental data. So the conclusions can be for reference for the similar TBM construction tunnel engineering.