考虑纵向轴力的矩形盾构隧道纵向抗弯刚度有效率研究  

Study on the Effective Rate of Longitudinal Bending Stiffness of Rectangular Shield Tunnels Considering Longitudinal Axial Force

作　　者：周晓舟 李志刚 林秀桂 Zhou Xiaozhou;Li Zhigang;Lin Xiugui(Shanghai,Municipal Engineering Design Institute(Group)Co.,Ltd.,200092,China)

机构地区：[1]上海市政工程设计研究总院(集团)有限公司,200092

出　　处：《特种结构》2025年第1期10-15,共6页Special Structures

基　　金：江苏省重点研发计划资助项目(BE2018675)。

摘　　要：纵向抗弯刚度有效率是分析矩形隧道纵向性能的关键参数,其定义为当受到相同荷载时,均质梁与非均质梁相应位置的位移比。对于矩形盾构隧道,由施工期压力及螺栓预紧力产生的纵向轴力也是隧道纵向结构分析中不可或缺的因素。本文提出一种考虑纵向轴力的矩形盾构隧道纵向抗弯刚度有效率的理论计算方法,并对影响纵向抗弯刚度有效率的相关因素如弯矩轴力之比、截面形状、螺栓分布等进行了分析。研究表明,弯矩轴力之比λ是影响纵向抗弯刚度有效率的决定性因素,其表征着衬砌受拉边缘由弯矩和轴力分别引起的拉压应力之比,当λ=0时,隧道模型退化为无轴力的志波模型,当λ≥1时,纵向抗弯刚度有效率为1,隧道可等效为均质梁。此外,截面形状与螺栓分布对纵向抗弯刚度有效率也有较大的影响,截面形状越扁平,螺栓线刚度越小,纵向抗弯刚度有效率越低。The effective rate of longitudinal bending siffness is a key parameter for analyzing the longitudinal performance of rectangular tunnels.It is defined as the ratio of displacements at corresponding posi tions between a homogeneous beam and a non-homogeneous beam when subjected to the same load.For rectangular shield tunnels,the longitudinal axial force generated by construction period pressure and bolt pretension is also an in-dispensable factor in the longitudinal structural analysis of the tunnel.This paper proposed a theoretical calcula-tion method for the effective rate of longitudinal bending stiffness of rectangular shield tunnels considering longi-tudinal axial force,and analyzed the factors affecting the effective rate of longitudinal bending stiffness,such as the ratio of bending moment to axial force,cross-sectional shape,and bolt distribution.The research indicated that the ratio of bending moment to axial forceλis a decisive factor affecting the effective rate of longitudinal bending stiffnessη.It characterizes the ratio of tensile and compressive stresses at the tension edge of the lining caused by bending moment and axial force,respectively.Whenλ=0,the tunnel model degenerates into Shiba-model without axial force.Whenλ≥1,the effective rate of longitudinal bending sifnessηis 1,and the tunnel can be equated to a homogeneous beam.Additionally,the cross-sectional shape and bolt distribution significant-ly affect the effective rate of longitudinal bending sifess.The flatter the cross-sectional shape and the smaller the bolt line siffness,the lower the effective rate of longitudinal bendi ng sifness.

关 键 词：纵向轴力 矩形盾构 纵向抗弯刚度有效率 

分 类 号：TU91[建筑科学—建筑理论]