高烈度地震区隧道软硬围岩交接段刚柔并济抗减震技术研究*

为提高高烈度地震区隧道抗震性能，以某铁路隧道为研究背景，分析3种抗减震措施下隧道不同监测点隧道拱顶沉降、边墙收敛、衬砌结构PGA及最小安全系数，通过对比分析得到最优抗减震措施。结果表明:相比于工况1，工况2隧道拱顶沉降减小10.54%~81.10%，边墙收敛减小13.92%~78.77%，衬砌结构PGA减小31.42%~72.02%，最小安全系数增加18.04%~66.13%；相比于工况1，工况3结构拱顶沉降减小3.04%~18.02%，边墙收敛减小4.70%~32.00%，PGA增加13.95%~27.48%，最小安全系数增加7.49%~30.99%；工况4即“减震层+SFRC衬砌”刚柔并济法，相比于工况1，隧道拱顶沉降减小18.46%~83.98%，结构边墙收敛减小17.54%~85.47%，PGA减小30.00%~69.98%，最小安全系数增加47.95%~83.56%；4种工况抗减震性能由高到低依次为:工况4＞工况2＞工况3＞工况1。研究结果可为隧道软硬围岩交接段抗震设防提供理论参考。

Research on rigid-flexible combination anti-seismic technology on soft-hard surrounding rock intersection of tunnel in high intensity seismic area

To improve the anti-seismic response of the tunnel in high intensity seismic areas,taking an actual railway tunnel as the research background,the vault settlement,sidewall convergence,PGA of the lining structure and the minimum safety factor of the tunnel with three different seismic measures are compared and analyzed,so as to find the optimum seismic measure for the tunnel.The results show that compared with case 1,in case 2,the settlement of tunnel vault decreases by 10.54%~81.10%,the convergence of sidewall decreases by 13.92%~78.77,the PGA of lining structure decreases by 31.42%~72.02%,and the minimum safety factor increases by 18.04%~66.13%; in case 3,the settlement of tunnel vault decreases by 3.04%~18.02%,the convergence of sidewall decreases by 4.70%~32.00%,and the PGA increases by 13.95% 48%,the minimum safety factor increases by 7.49%～30.99%; in case 4,the settlement of tunnel vault decreases by 18.46%～83.98%,the convergence of structural sidewall decreases by 17.54%～85.47%,the PGA decreases by 30.00%～69.98%,and the minimum safety factor increases by 47.95%～83.56%.From high to low,the anti-seismic response of the four test cases is as follows: case 4>case 2>case 3>case 1.The research results provide a theoretical basis for the seismic fortification of the intersection of the soft and hard surrounding rock.