Abstract The Junchang tunnel is a part of a major project in the Censhui highway in Guangxi province, China. The weathered granite part of the tunnel is approximately 180 m long with two lines and four lanes. Numerous water and mud inrush disasters frequently occurred in the weathered granite area, leading to serious economic loss and challenge to the constructors. Therefore, continuous grouting was carried out for the entire weathered part of the tunnel. This paper describes its curtain grouting for disasters prevention. Detailed discussion is presented on the safety thickness after grouting and the challenges encountered under different hydraulic-geological conditions. Specifically, a water and mud inrush model for the nonlinear flow and mass transfer behavior of weathered granite was used to evaluate the safety thickness in this project. Then, field studies with twenty-five grouting cycles and excavations were conducted to investigate the effective safety thickness. Negative correlation was observed between the safety thickness and the rock classification index [BQ]. Numerical simulation and field tests demonstrated that the thickness l should be larger than 3 m, and, in most cases, 5 m was sufficient when [BQ]

中文翻译：

---

君昌隧道地下水泥控制及帷幕注浆安全厚度案例研究

摘要 君昌隧道是广西岑水高速公路重大工程的一部分。隧道风化花岗岩部分长约180 m，分两线四车道。风化花岗岩区经常发生多起突水突泥灾害，给施工单位造成了严重的经济损失和挑战。因此，对隧道的整个风化部分进行了连续灌浆。本文介绍了其用于防灾的帷幕灌浆。详细讨论了注浆后的安全厚度和不同水力地质条件下遇到的挑战。具体而言，风化花岗岩非线性流动和传质行为的突水突泥模型用于评估该项目的安全厚度。然后，进行了 25 次灌浆循环和挖掘的现场研究，以调查有效安全厚度。在安全厚度和岩石分类指数[BQ]之间观察到负相关。数值模拟和现场试验表明，厚度 l 应大于 3 m，在大多数情况下，[BQ] 时 5 m 就足够了