松散地层隧道预加固技术

Pre-reinforcement Technology of Tunnel in Loose Ground

为明确砂卵石隧道变形破坏特征,科学合理地提出松散地层公路隧道修建最佳预支护方案,基于数值计算,分析了目前常用的超前支护方式及加固效果,明确适用于砂卵石隧道的加固措施并重点分析合理的参数取值。结果表明:超前短管棚注浆对围岩变形控制效果最好,从初期支护内力和二衬应力来看,超前短管棚注浆超前支护方案固砂效果明显,虽工艺较复杂,会延滞工期,仍可作为松散地层超前支护推荐方案,确保支护效果与施工安全。

In order to clarify the deformation and failure characteristics of sand-gravel tunnel, the optimal pre-support scheme for highway tunnel construction in loose ground was put forward scientifically and reasonably.Based on numerical calculation, the commonly used pre-support methods and reinforcement effect were analyzed, and the reinforcement measures suitable for sand-gravel tunnel were defined and the reasonable parameters were analyzed.The results show that the advance short-pipe shed grouting has the best control effect on the surrounding rock deformation.For the internal force of initial support and the second lining stress, the support scheme of advance short-pipe shed grouting has obvious sand consolidation effect, although the process is more complicated.It will delay the construction period and can still be used as a recommended scheme for advance support of loose ground to ensure the support effect and construction safety.