In view of the deficiency that the existing calculation method for longitudinal stiffness of shield tunnel was lack of experimental verification and did not consider the influence of factors such as bolt tensile stiffness,the analytical calculation method for longitudinal stiffness of shield tunnel was deduced theoretically at first.Then,taking the shield tunnel of Shanghai Metro as the background,a scale model test was designed and carried out,and the analytical calculation method was verified by the measured results.Finally,the longitudinal stiffness of this type of shield tunnel was calculated based on the project background of the shield tunnel in the Pearl River Delta region.The results show that due to the existence of bolt preload,the longitudinal stiffness of the measured tunnel is larger when the mid-span loading is small,but with the increase of the mid-span loading,the measured results tend to be close to the theoretical calculation results,which verifies the rationality of the analytical calculation method.The tensile stiffness of longitudinal bolts of shield tunnels in the Pearl River Delta region in the elastic stage,plastic stage and plastic deformation stage is 2.125 5 × 10 6,0.985 9 × 10 6and 3.185 6 × 10 6 N·m-1,respectively,while the longitudinal stiffness is 3.306 8 ×10 8,1.534 5×10 8 and 4.954 3×10 8 N·m2,respectively.Considering that there are differences in the deformation stages of the longitudinal bolts in a certain range when the longitudinal deformation of the metro shield tunnel occurs,the actual value of longitudinal stiffness should be determined according to the longitudinal bolt tension amount caused by the maximum deformation of the tunnel.
关键词
地铁/盾构隧道/纵向刚度/螺栓拉伸刚度/纵向螺栓/模型试验
Key words
Metro/Shield tunnel/Longitudinal stiffness/Bolt tensile stiffness/Longitudinal bolts/Model test
维普
万方数据