几种控制软弱围岩大变形应急方法的效果评价

以西汉高速酉水隧道大变形为背景，采用FLAC3D岩土数值模拟软件对围岩注浆加固、临时仰拱加固、系统锚杆加固等方法进行数值模拟分析，同时结合现场监控量测和施工经验教训作出以下效果评价：1）理论计算表明围岩注浆的加固效果显著，上台阶临时仰拱的效果整体优于围岩注浆；2）现场监控表明围岩注浆质量离散性大，钢拱架临时仰拱控制效果最佳但属临时措施；3）增加常规砂浆锚杆效果甚微应慎用。最后提出控制围岩大变形的相对合理的应急工程措施。

Evaluation on Effectiveness of Several Emergency Countermeasures to Control Large Deformation of Soft Surrounding Rock Mass

Youshui tunnel is located on Xi-Han expressway in Shaanxi province.Large deformation occurs at many places in this tunnel.The monitoring data shows that the deformation is rapid and lasts long duration.Against this background,evaluation is made on the effectiveness of several typical emergency countermeasures such as grouting,temporary invert and systematic rockbolts,by means of analyzing on the mechanisms,making numerical simulations by FLAC3D,monitoring and drawing lessons from the construction.The following conclusions are drawn： 1） the theoretical calculations show that the consolidation effect of grouting is significant and the effect of temporary inverts is better than that of grouting;2） the monitoring data shows that the effect of grouting is discrete,the effect of temporary inverts is the best and the conventional mortar-grouted rockbolts have almost no consolidation effect.In the end,relatively cost-effective emergency countermeasures to control the large deformation of the surrounding rock mass are recommended.