隧道喷射混凝土回弹量的降低方法及应用实践

Reduction Method and Application Practice of Springback Amount of Shotcrete in Tunnel

隧道喷射混凝土法是常用的隧道围岩支护方式之一,但是在施工过程中需要注意控制好喷射混凝土的回弹量问题,否则会影响施工质量和增加施工成本。文章结合笔者工作经验,探讨了隧道喷射混凝土在初喷阶段和粘性喷射时的回弹产生机理,并提出了合理选择材料、控制输料管距离、调整工作风压、控制混凝土配合比、喷射工艺等降低回弹量的措施。

Shotcrete method is one of the common support methods of tunnel surrounding rock,but in the process of construction,it is necessary to control the springback of shotcrete,otherwise it will affect the construction quality and increase the construction cost.Based on the author's working experience,this paper discusses the springback mechanism of tunnel shotcrete in the initial spraying stage and viscous spraying,and puts forward some measures to reduce the springback,such as reasonable selection of materials,control of the distance of the conveying pipe,adjustment of the working wind pressure,control of the mix proportion of concrete and spraying technology.