考虑衬砌变形与接头特征的盾构隧道纵向刚度

针对盾构隧道纵向刚度计算未考虑衬砌差异变形、接头特征及错缝拼装增强效应，定义考虑错缝拼装作用的横向刚度有效率，提出衬砌差异变形系数与接头等效刚度修正系数.推导盾构隧道纵向等效刚度计算式并结合数值法开展算例分析，探讨纵向等效刚度对不同修正系数的敏感性.研究表明：衬砌结构承载时，水平变形较竖向变形小15%，假定两方向变形相同存在不足；利用实际接头和等效螺栓环计算管片环缝张开量相差17.6%，接头等效为螺栓环存在不容忽视的误差；衬砌错缝拼装使横向刚度提高了17.5%，对隧道纵向刚度影响显著；盾构隧道纵向刚度计算中，考虑衬砌差异变形、接头特征及横向刚度与否对应的等效刚度相差14.3%，对隧道纵向结构特性产生了明显的影响；隧道纵向刚度随着衬砌差异变形的增大近似线性减小，且随接头等效刚度修正值和横向刚度同向线性变化.
Abstract: The transverse rigidity ratio considering staggered installation effect, the differential deformation coefficient and joint rigidity correction coefficients were proposed aioring at the problem that the calculation of longitudinal equivalent rigidity has not considered differential deformation, longitudinal joint characteristics and enhancement caused by staggered installation. Then the calculation formula of longitudinal equivalent rigidity of shield tunnel was deduced combined with numerical method in order to conduct example analysis. The sensitivity of longitudinal rigidity to correction parameters was explored. Results show that the horizontal deformation of lining is 15% smaller than vertical deformation under the transverse action, so it is defective to assume the same deformation in two directions of segment ring. The difference of segment opening is 17.6% when calculation uses actual joint of segment rings or equivalent homogeneous bolt under the same load, and the indispensable error appears during the longitudinal bending calculation when equivalent homogeneous bolt represent the actual joints of shield tunnel. The transverse rigidity increases by 17.5% caused by staggered installation, which causes obvious influence on longitudinal rigidity. Equivalent rigidity difference is 14.3% when calculation considers differential deformation, joints characteristics and transverse rigidity or not, and the influence of rigidity difference on longitudinal structure characteristics is significant. The longitudinal equivalent rigidity linearly decreases with the increase of the differential deformation, and increases with the increase of the joint rigidity correction and transverse rigidity ratio in a linear relation.