高烈度地震区跨断层隧道不同厚度减震层减震效果分析*

为进一步提高高烈度地震区跨断层隧道抗震性能，基于达万高速天坪寨隧道F1断层段，利用有限差分数值软件FLAC3D对跨断层隧道施设不同减震层厚度减震效果进行研究。结果表明:当天坪寨隧道F1断层段施设减震层厚度为150 mm时，减震效果最优，其次为200，100，50 mm；当施设150 mm减震层时，横向与竖向位移分别减小5.88%与8.50%，最大主应力减小36.02%，最小主应力减小12.21%，最大剪应力减小51.61%，最小安全系数提高52.45%～65.32%。研究结果可为高烈度地震区跨断层隧道抗震设计提供参考。

Analysis on shock absorption effect of shock-absorbing layer with different thicknesses for fault-crossing tunnels in high seismic intensity zone

In order to further improve the seismic performance of the fault-crossing tunnels in high seismic intensity zone,relying on the F1 fault section in Tianpingzhai tunnel of Dazhou-Wanzhou Expressway,the finite difference numerical software FLAC3D was used to study the shock absorption effect of shock-absorbing layer with different thicknesses installed in the fault-crossing tunnel.The results showed that the 150 mm shock-absorbing layer had the best shock absorption effect for the F1 fault section in Tianpingzhai tunnel,followed by the 200 mm and 100 mm shock-absorbing layers,and the shock absorption effect of 50 mm shock-absorbing layer was the worst.When installing the 150 mm shock-absorbing layer,the lateral and vertical displacement reduced by 5.88% and 8.50% respectively,the maximum principal stress reduced by 36.02%,the minimum principal stress reduced by 12.21%,the maximum shear stress reduced by 51.61%,and the minimum safety factor increased by 52.45%~65.32%.The research results can provide reference for seismic design of fault-crossing tunnels in the high seismic intensity zones.