基于纤维增强的隧道喷射混凝土回弹控制研究

Study on Springback Control of Shotcrete in Tunnel Based on Fiber Reinforcement

喷射混凝土是一种广泛使用的隧道支护方式,但其与泥质砂岩界面黏附性较差,施工回弹量大,浪费严重。针对该问题,通过在喷射混凝土中添加纤维并开展室内试验与现场试验,探究纤维类型及不同纤维掺量对混凝土回弹率的影响。试验结果表明:玄武岩纤维在喷射混凝土回弹控制中有显著作用,添加玄武岩纤维的混凝土的抗压强度明显提高;相比普通混凝土,添加玄武岩纤维后的喷射混凝土的回弹率减少约17%;从节约施工成本和控制混凝土回弹出发,隧道施工中建议玄武岩纤维掺量为2.35 kg/m^(3),此时的喷射混凝土回弹率为13.9%。该研究结果可应用于指导实际施工,能很大程度上节约施工成本,减少资源浪费。

Shotcrete is a widely used tunnel support method, but its interface adhesion with argillaceous sandstone is poor, the construction springback is large, and the waste is serious. In view of this problem, the influence of fiber type and fiber content on concrete springback rate is explored by adding fibers to shotcrete and carrying out indoor and field tests. The test results show that basalt fiber plays a significant role in the springback control of shotcrete, and the compressive strength of concrete with basalt fiber is significantly improved. Compared with ordinary concrete, the springback rate of shotcrete after adding basalt fiber is reduced by about 17%. In order to save the construction cost and control the concrete springback, it is recommended to add 2.35 kg/m^(3) basalt fiber in the tunnel construction, and the springback rate of shotcrete is13.9%. The research results can be applied to guide the actual construction, which can save the construction cost and reduce the waste of resources to a great extent.