初期支护参数对断层破碎带隧道围岩稳定性的影响研究

Study on the Influence of Initial Support Parameters on the Stability of Tunnel Surrounding Rock in Fault Fracture Zone

针对隧道初期支护的喷射混凝土厚度、锚杆长度、锚杆布设排距及锚杆布设环形间距对断层破碎带隧道围岩稳定性的影响问题,文中结合某铁路隧道工程,以断层破碎带隧道围岩为研究对象,利用数值模拟分析软件Midas•GTS NX,建立适合隧道开敞式TBM施工的数值模型并计算分析.结果表明:在一定范围内,增加锚杆的长度、减小锚杆的排距和间距能有效改善锚杆的受力,但对隧道围岩拱顶沉降影响较小;增加喷射混凝土的厚度可以有效控制围岩的变形,减小隧道围岩拱顶沉降,提高隧道围岩稳定性.

Aiming at the influence of shotcrete thickness,anchor length,anchor row spacing and anchor ring spacing on the stability of tunnel surrounding rock in fault fracture zone,combined with a railway tunnel project,this paper took the tunnel surrounding rock in fault fracture zone as the research object.Using the numerical simulation analysis software Midas•GTS NX,a numerical model suitable for tunnel open TBM construction was established and calculated.The results show that,within a certain range,increasing the length of the bolt and reducing the row spacing and spacing of the bolt can effectively improve the stress of the bolt,but has little effect on the vault settlement of the surrounding rock of the tunnel.By increasing the thickness of shotcrete,the deformation of surrounding rock can be effectively controlled,the vault settlement of tunnel surrounding rock can be reduced,and the stability of tunnel surrounding rock can be improved.