空间交错隧道施工围岩应力影响范围及粘接锚杆作用机理的研究

Research on the influence range of space staggered tunnel construction interaction on surrounding rock stress and action mechanism of bonding bolt

研究空间交错隧道不同近接竖距施工对围岩应力变化的影响,以某市机场高速夏家岩隧道“上穿”贵昆铁路塔山脚隧道工程为依托,利用MIDAS/GTS有限元软件建立不同近接竖距下的空间交错隧道有限元模型,分析2隧道竖距分别为1、2、3、5、7、10、15和20 m此8种近接工况。研究结果表明:在交错中心附近2隧道围岩应力得到一定的释放,并且存在上部新建隧道对下部既有隧道的拱顶、拱肩位置的应力影响较大,下部既有隧道对上部新建隧道的仰拱底、拱脚位置的应力影响较大的变化规律;此外,还提出了基于该工程地质状况的围岩应力变化影响范围及长粘接型锚杆的作用机理。

In order to research the influence of different proximal vertical spacing construction of space staggered tunnel on surrounding rock stress change,based on the project of Xiajiayan Tunnel of the airport expressway of a city"upward crossing"the Tashanjiao Tunnel of Guiyan-Kunming Railway,MIDAS/GTS finite element software was used to establish the spatial staggered tunnel finite element model with different proximal vertical spacing,eight close working conditions with vertical spacing of 1,2,3,5,7,10,15 and 20 m are analyzed.The results show that the surrounding rock stress of the two tunnels near the staggered center is released to a certain extent,and the existing tunnel has a greater influence on the position stress of the vault and the shoulder of the existing tunnel,while the existing tunnel has a greater influence on the position stress of the inverted arch and the foot of the new tunnel.In addition,based on the engineering geological condition,the influence range of surrounding rock stress change and the action mechanism of long bonding bolt are also proposed.