双断层错动下隧道衬砌结构力学响应研究

Research on the Structural Response of Tunnel-LiningUnder Double-Fault Dislocation

从隧道穿越活化断层之间不同工况入手,建立穿越双断层隧道三维有限元模型,研究双断层错动(不同错动距离、不同间距)的隧道衬砌结构力学响应,对衬砌损伤定位。研究结果表明:随着双断层错动距离不断增加,隧道衬砌所受最大主应力逐渐增大,衬砌破坏范围不随错动距离增大而变化,破坏范围主要集中在断层面附近45~60 m范围内。在断层破碎带均为20 m的条件下,双断层间距大于或等于120 m以上时,隧道结构破坏仍存在过渡区域,可分区设置防护措施;当间距为90 m时,将会对隧道衬砌产生“叠加影响”,抗错断设防区域需将两断层包含在内。

Starting from different working conditions between the active faults of tunnel crossing,a three-dimensional finite element model through the double-fault tunnel is established to study the structural mechanical response of the tunnel lining under the double-fault layer(different migration distance,different spacing),and locate the lining damage.The results shows that as the double-fault misplacement distance continues to increase,the maximum principal stress of tunnel lining has gradually increased,the range of lining destruction does not change with the increase of dislocation distance,and the failure range is mainly concentrated in the range of 45~60 m near the fault plane.Under the condition that the fault fracture zones are all 20 m,when the double-fault spacing is greater than or equal to 120 m,the tunnel structure still has a transition zone where protection measures could be set up in different zones.When the spacing is 90 m,it will have a"superimposed impact"on the tunnel lining,the anti-fault defense area needs to include the two broken layers.