强震区跨断层隧道局部接触注浆抗震效果研究

为进一步提高高烈度地震区跨断层隧道的抗震性能,文章依托中义隧道冲江河断层段,利用有限差分数值计算软件对跨断层隧道强震动力响应特性和围岩局部接触注浆抗震效果进行了研究。研究结果表明:(1)中义隧道冲江河断层段强震影响范围约为20 m;(2)采取局部间隔注浆抗震措施后,二衬竖向最大位移抗震效果为1.74%,横向最大位移抗震效果为1.62%,最大主应力极值抗震效果为15.09%,最小主应力极值抗震效果为0.1%,可通过施设抗震缝或减震层予以解决;(3)采取局部间隔注浆抗震措施后,断层破碎带段最小安全系数明显提高,监测断面5最小安全系数为3.120,抗震效果达60.91%,监测断面6最小安全系数为2.807,抗震效果达50.27%。

Study on the Effect of Local Contact Grouting in Cross-fault Tunnel in Strong Earthquake Area

In order to further improve the seismic performance of cross-fault tunnels in seismic zones of intensity,the dynamic response characteristics of cross-fault tunnels under strong earthquakes and the seismic effect of local contact grouting in surrounding rocks are studied by using finite difference numerical calculation software based on the middle fault section of Zhongyi tunnel.The results show that:(1)the influence range of strong earthquakes in the middle fault section of Zhongyi tunnel is about 20 m.(2)After adopting local interval grouting seismic measures,the seismic effect of the vertical maximum displacement of the secondary lining is 1.74%,the seismic effect of the lateral maximum displacement is 1.62%,the seismic effect of the maximum principal stress extreme value is 15.09%,and the seismic effect of the minimum principal stress extreme value is 0.1%.(3)After adopting the seismic measures of local interval grouting,the minimum safety coefficient of the section of fault fracture zone is significantly increased.The minimum safety coefficient of the measured section 5 is 3.120,the seismic effect is 60.91%,the minimum safety coefficient of the monitored section 6 is 2.807,and the seismic effect is 50.27%.