Abstract: The construction of the water rich and fractured zone in the water conveyance tunnel can easily lead to excessive deformation of the tunnel surrounding rock, mud and water inrush, and instability of the working face, seriously affecting the safety of the water conveyance tunnel construction. Therefore, this article relies on the Yinchuo Jiliao Water Diversion Tunnel crossing the rich water fractured zone project, and uses the TSP advanced geological prediction method to understand the characteristics of the surrounding rock in front of Zhangzi, which is relatively fractured, with poor integrity and strong water richness. In response to the unfavorable geological situation, a three-dimensional water conveyance tunnel model was established using finite element software. The vertical displacement of the tunnel arch crown, horizontal displacement of the arch waist, and uplift displacement of the arch bottom were compared under three working conditions: non grouting reinforcement, half section curtain grouting, and full section curtain grouting. The suitable reinforcement scheme and technical indicators of full section curtain grouting for this project were determined. Further combining the drilling inspection method, P-Q-t curve method, and excavation sampling method, the reinforcement effect of the full section advanced curtain grouting scheme adopted was evaluated. The research methods and conclusions of this article can provide reference for similar projects.

Key words: rich water fractured zone, water conveyance tunnel, advance curtain pre grouting, finite element analysis, reinforcement effect

摘要： 输水隧洞穿越富水破碎带施工易导致隧洞围岩变形过大、突泥突水、掌子面失稳等现象,严重影响输水隧洞施工安全。为此,文中依托引绰济辽输水隧洞穿越富水破碎带工程,采用TSP超前地质预报手段了解了掌子面前方围岩较破碎、完整性较差、富水性强的特点。针对该不良地质情况,通过有限元软件建立三维输水隧洞模型,对比了未注浆加固、半断面帷幕注浆、全断面帷幕注浆这3工况下隧洞拱顶竖向位移、拱腰水平位移以及拱底隆起位移结果,确定适合该工程的加固方案以及全断面帷幕注浆技术指标。进一步结合钻孔检查法、P-Q-t曲线法、开挖取样法,评估了所采用的全断面超前帷幕注浆方案的加固效果。文中研究方法和结论可为类似工程提供一定借鉴。

关键词: 富水破碎带, 输水隧洞, 超前帷幕预注浆, 有限元分析, 加固效果