地铁盾构隧道回填层的应力传导性能

盾构法施工隧道中，管片衬砌与围岩间的空隙采用回填层来填充，以达到稳定衬砌、传递压力和防渗等多重效果。基于均匀化理论和摄动技术，推导了水泥浆液和豆砾石两种材料混合而成的回填层的等效弹性模量解析表达式，进而应用弹性力学原理推导了衬砌和回填层的应力应变公式。算例分析结果表明：该方法求得的回填层的等效弹性模量小于根据体积比例计算的数值；提高回填层中水泥浆的弹性模量和体积分数，可以提高回填层的等效弹性模量，使回填层承担较多的应力，从而减小管片内的应力和应变；考虑回填层与否，衬砌的应力和应变值会有较大差异，说明回填层有利于衬砌的稳定性。该研究为TBM盾构施工隧道的衬砌设计提供了理论依据。

Stress conductivity of backfill in subway TBM construction tunnel

This paper is an attempt to improve lining stabilization, pressure transmission, and leak- age prevention, such as are necessary for filling up the space between segment lining and surrounding rock using the backfill associated with TBM construction tunnel. The improvement solution draws on hom- ogenization theory and perturbation technology and stems from deriving the analytical solutions for equiva- lent elastic modulus of backfill, a mixture of the cement slurry and pea gravel and thus deducing solutions for stress and strain of segment lining and backfill using elastic mechanics theory. The calculation exam- ples suggest that the method gives a smaller value of equivalent elastic modulus than does the currently used calculation method working on volume percentage; an increase in the values of elastic modulus and volume content triggers an increase in the equivalent elastic modulus, allowing backfill to survive more stress, with the consequent reduction in stress and strain in segment ; whether backfill is considered or not means a great difference between stress and strain values of segment lining, thus indicating that backfill assists lining stability. The research may provide the theoretic foundation for lining design of TBM con- struction tunnel.