盾构隧道掘进引起上方已建隧道的纵向变形研究

发布时间：2018-02-24 15:45

  本文关键词： 盾构掘进 Kerr地基模型 纵向变形 剪切刚度　出处：《岩土力学》2014年09期 　论文类型：期刊论文

【摘要】：城市地铁隧道施工中经常遇到新建隧道下穿上方已建隧道的例子,如何提前预测已建隧道的纵向变形是目前工程界普遍关心的问题。基于能够考虑土体变形连续性的Kerr地基梁理论,分别将已建隧道简化为欧拉伯努利梁和铁木辛柯梁,将新建隧道对已建隧道的作用简化为高斯分布荷载,建立了新建隧道施工对上方已建隧道影响的解析分析方法;并利用离心机试验结果进行了验证。分析了地层损失率、荷载形状参数和隧道与土体相对抗弯刚度对已建隧道纵向变形的影响。探讨了隧道剪切刚度对隧道纵向变形的影响。研究发现,当隧道剪切刚度趋于无穷大时,Kerr地基上的铁木辛柯梁退化为欧拉伯努利梁;对于抗弯刚度较大的隧道(如抗弯刚度大于7.54×106kN·m2),Kerr地基梁具有较好的适用性;已建隧道的剪切刚度对其纵向变形何纵向曲率产生显著影响;当隧道等效剪切刚度有效系数≤1/4时,必须考虑隧道剪切刚度对隧道纵向变形的影响。将所提分析方法应用于上海盾构隧道穿越工程中,并与现场实测结果进行对比,验证了方法的合理性。
[Abstract]:In the construction of urban subway tunnels, there are often examples of newly built tunnels passing through the built tunnels above them. How to predict the longitudinal deformation of the tunnel in advance is a problem of general concern in the engineering field at present. Based on the theory of Kerr foundation beam which can consider the continuity of soil deformation, the existing tunnel is simplified into Euler Bernoulli beam and Temuxinco beam, respectively. The effect of newly built tunnel on built tunnel is simplified as Gao Si distributed load, the analytical analysis method of the influence of newly built tunnel construction on the upper tunnel is established, and the result of centrifuge test is used to verify, and the formation loss rate is analyzed. The effects of load shape parameters and the relative bending stiffness of tunnel and soil on the longitudinal deformation of the tunnel are discussed. The effects of shear stiffness on the longitudinal deformation of the tunnel are discussed. When the shear stiffness of the tunnel tends to infinity, the Temuxinko beam on the Kerr foundation degenerates into an Eulerian Bernoulli beam, which is suitable for the tunnel with higher flexural stiffness (such as the bending stiffness greater than 7.54 脳 10 ~ 6 KN 路m ~ 2 路m ~ (2)). The shear stiffness of the tunnel has a significant effect on the longitudinal curvature of the tunnel, and when the effective coefficient of the equivalent shear stiffness of the tunnel is 鈮，

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