围岩弹性抗力对隧道结构受力的影响分析

运用荷载结构模型及有限元分析手段，以新建200km时速城际铁路隧道衬砌为研究对象，分析了围岩弹性抗力对二衬结构受力的影响。随着围岩弹性抗力的增大，拱顶弯矩及拱肩弯矩绝对值、拱顶竖向位移变小，而拱顶轴力及安全系数变大。说明，围岩越坚硬，衬砌结构受力越有利。随着二衬厚度的增大，拱顶弯矩及拱肩弯矩绝对值变大，而拱顶轴力、拱顶竖向位移及安全系数变小。随着混凝土强度等级的提高，拱顶弯矩、拱肩弯矩及安全系数变大，拱顶轴力和拱顶竖向位移变小，但这些量值的变化幅度较小，说明混凝土弹性模量对二衬受力影响很小。

Influence of elastic resistance of wall rock on tunnel lining internal forces

Using load structure model and FEM, influence of elastic resistance of wall rock on second lining internal forces is analyzed on the basis of tunnel lining of new intercity railway. With the increasing wall rock elastic resistance, vault bending moment, spandrel bending moment and vault vertical displacement decrease gradually, and vault axial force and safety factor increase. The results show that the harder the rock, the better the tunnel lining mechanics state. With the lining becoming thicker, vault bending moment, spandrel bending moment increase, and vault axial force, vault vertical displacement and safety factor decrease. When the strength grade of concrete increases, vault bending moment, spandrel bending moment and safety factor increase, and vault axial force, vault vertical displacement decrease. However, changes of these values are very smaller. The results show that elastic modulus of concrete has small influence on second lining.