断层破碎带区隧道的开挖变形分析

Analysis of Tunnel Excavation Deformation in Fault Broken Zone

断层破碎带是隧道施工中常见的不良地质体,在含有断层破碎带的隧道中进行施工建设极易诱发岩块掉落、突水突泥等地质灾害,研究断层破碎带区隧道的开挖变形可以有效预判工程风险,提高工程质量。本文采用数值模拟方法,结合枫树下隧道穿越断层破碎带工程背景,在考虑断层破碎带这个关键因素的基础上,对断层破碎带的数值本构模型进行了选取,并对开挖模拟后的隧道进行了受力变形分析。结果表明:无论在Ⅰ区开挖还是Ⅱ区开挖,模拟过程中63个开挖位移控制点,都会遭遇到较大的形变问题且均发生在断层破碎带的区域,尤其是Ⅱ区,隧道底部隆起值较大。

Fault fracture zone is a common adverse geological body in tunnel construction,and the fault fracture zone of the tunnel construction is easily induced rock fall,water bursting mud and other geological disasters.And the project risk could be predicted effectively by studying the fault fracture zone area of tunnel excavation deformation.In this paper,combined with the maple tunnel crossing the fault fracture zone,the numerical simulation method which considering the fault fracture zone was adopted on the basis of the key factors of fault fracture zone,and the forced deformation of the tunnel after excavation was simulated analyzed.The results showed that,no matter in zone Ⅰ or Ⅱ,the 63 excavation displacement monitoring points in the simulation process will encounter a large deformation problem,and all of them occur in the fault fracture zone,especially in zone Ⅱ,where the tunnel bottom heave value is large.