盾构隧道受上方地下空间开挖荷载的影响分析

Shield Tunnel Excavation by the Top of the Underground Space of the Impact Analysis of Load

利用有限元软件MIDASGTS建立的三维有限元模型模拟下方盾构隧道的竖向和水平方向变形过程,以及在地下室和覆土荷载作用下的隧道变形增量、转换梁和连接板竖向变形、保护桩竖向和水平方向变形增量等,结果表明盾构隧道处于中风化岩层产生的变形增量约为其处于强风化岩层的13;增大转换梁刚度可在一定程度上减小盾构隧道和转换梁在上方荷载作用下的变形量;在基坑开挖和地下室施工全过程,盾构隧道的轴力和弯矩均处于较低受力水平,结构安全性未受影响。

Using MIDAS/GTS to establish three-dimensional finite element model simulation of shield tunnel under the direction of the vertical and horizontal deformation process and in the basement and the casing of the tunnel deformation under load increment,conversion beams and vertical connecting plate to the deformation,to protect vertical and horizontal deformation of pile increments. The results ob-tained from：increasing the stiffness of the beam transformation,be able to reduce the shield tunnel and the at the top of the load transfer beam under the action of deformation;in the basement excavation and construction of the whole process of shield tunnel axis force and moments at the lower level of force without endangering the safety of the tunnel structure.