强震区跨断层隧道纤维混凝土衬砌抗震效果分析*

为进一步提高高烈度地震区跨断层隧道在地震时的安全性和稳定性，依托天坪寨隧道F1断层段，通过有限元数值计算软件ABAQUS对纤维混凝土隧道衬砌的抗震效果进行研究。分析素混凝土二衬结构、钢-玄武岩混杂纤维混凝土（SBHFRC）二衬结构及钢纤维混凝土（SFRC）二衬结构的位移、应力及安全系数的变化情况。结果表明:SFRC衬砌结构最大横向、纵向位移分别增大12.57%，1.43%，竖向位移减小33.83%，SBHFRC衬砌结构的最大横向、纵向、竖向位移分别增大6.69%，22.35%，25.32%；SFRC二衬最大、最小主应力分别增加26.09%，19.69%，SBHFRG二衬最大、最小主应力分别增加3.16%，2.16%；SFRC二衬与SBHFRC二衬的最大剪应力分别增加20.82%，2.23%；衬砌结构采用SFRC和SBHFRC时的安全系数分别提高59.72%，54.74%；二衬结构采用SBHFRC时抗震效果优于采用SFRC时的抗震效果。研究结果可为强震区跨断层隧道抗震设计提供依据。

Analysis on seismic effect of fiber concrete lining in cross-fault tunnel at strong earthquake area

In order to further improve the safety and stability of the cross-fault tunnels in the high-intensity earthquake area during the earthquake,relying on the F1 fault section of Tianpingzhai tunnel,the seismic effect of fiber concrete tunnel lining was studied through the finite element numerical calculation software ABAQUS.The displacement,stress and safety factor of plain concrete second lining structure,steel-basalt hybrid fiber concrete (SBHFRC) second lining structure and steel fiber concrete (SFRC) second lining structure were analyzed.The result showed that the maximum lateral and longitudinal displacements of SFRC lining structure increased by 12.57% and 1.43%,respectively,and the vertical displacement decreased by 33.83%.The maximum lateral,longitudinal and vertical displacements of SBHFRC lining structure increased by 6.69%,22.35% and 25.32%,respectively.The maximum and minimum principal stresses of the SFRC second lining increased by 26.09% and 19.69%,respectively,and the maximum and minimum principal stresses of the SBHFRG second lining increased by 3.16% and 2.16%,respectively.The maximum shear stress of the SFRC second lining and the SBHFRC second lining increased by 20.82% and 2.23%,respectively.When the lining structure adopted SFRC and SBHFRC,the safety factors increased by 59.72% and 54.74%,respectively.When the second lining structure adopted SBHFRC,the seismic effect was better than that of SFRC.The research results can provide a basis for the seismic design of cross-fault tunnels at the strong earthquake area.