隧道土体刚度比对开挖引起隧道变形影响

Effect of Tunnel-Soil Stiffness Ratio on Tunnel Deformation Caused By Basement Excavation

基坑开挖卸荷不可避免地会引起周围地铁隧道的变形。目前,很多学者对此进行了研究。涉及的因素也从几何尺寸到物理参数。然而,纵观研究发现,尚没有针对隧道-土体刚度比的研究,而该指标涉及到土与结构的相互作用问题中两个最重要的参数,必然会对隧道的变形产生影响。因此,本文在离心模型试验的基础上,开展有限元数值模拟分析,研究隧道-土体刚度比对隧道纵向隆起和横向衬砌变形的影响,分析隧道变形规律,并构建隧道-土体刚度比与隧道变形的关系。研究结果表明,隧道-土体刚度比对隧道变形影响显著,隧道变形与隧道-土体刚度比的对数呈线性关系。此外,给出了预测隧道纵向和横向变形的统一简化公式,便于工程应用。

Stress relief due to basement excavation may inevitably cause deformation on nearby metro tunnel.Nowadays,many researchers have studied this issue. The factors involved are also from the geometric dimension to the physical parameters. However,throughout the previous study,it is found that there is no research on tunnel- soil stiffness ratio（ RTS）. This index is related to the two most important parameters of the interaction between soil and structure,and it is bound to have an impact on the deformation of the tunnel. Based on the centrifugal model test,finite element analysis is hence conducted to study the effect of RTS on tunnel deformation both in longitudinal and transverse direction. Deformation law of tunnel lining is analyzed,and the relationship between RTS and the deformation of the tunnel is constructed. It is shown that RTS has significant influence on tunnel deformation. The relationship between tunnel deformation and the logarithm of RTS is linear. Moreover,a unified simplified formula for predicting tunnel deformation both in the longitudinal and transverse deformation is given,which is convenient for engineering application.