某富水断层隧道涌水治理方案优化分析及工程应用

Optimization and Application of the Treatment Schemes for Water Inrush in a Water-rich Tunnel in Fault Zones

以武九高速高楼山公路隧道为例,针对以断层破碎带为主控因素的隧道突水治理问题展开数值分析研究。基于FLAC 3D有限差分法及流固耦合分析原理,研究了导水洞排水、注浆堵水和排堵结合等不同治理方式对隧道涌水量及围岩稳定性的影响。结果表明:对于富水断层隧道发生A、B级别的大量涌水时,建议同时采取导水洞排水、注浆堵水的排堵结合措施,导水洞设置在近断层处,且与隧道相对距离为0.75(D+l),注浆圈厚度控制在7 m以内,注浆圈相对渗透系数比不超过10,既能降低涌水量,又能保证围岩的稳定性;对于C级涌水隧道,可采取注浆措施,注浆厚度不低于3 m,相对渗透系数不低于20;对于D级及以下涌水隧道,采取常规抽排水措施即可。

Based on the Gaoloushan Highway Tunnel on Wudu-Jiuzhaigou Expressway as an example,this paper carries out a numerical analysis to investigate the treatment issues of water inrush in the tunnel governed by fault fracture zones.Based on the FLAC 3D finite difference method and the principle of fluid-solid coupling analysis,this paper investigates the influence of different treatment methods on tunnel water inrush and stability of surround⁃ing rocks,such as drainage,grouting,and combination of drainage and grouting.The results show that:(1)when a se⁃rious water inrush of Grade A or B occurs in a water-rich tunnel passing through fault zones,it should take the treat⁃ment measures combining the drainage through drainage tunnels with stopping water by grouting.Specifically,the drainage tunnels should be set near the fault,with a relative distance of 0.75(D+l)to the tunnel,while the thickness and relative permeability coefficient of the grouting ring should be controlled within 7 m and 10 respectively.This can not only reduce the amount of water inrush but also ensure the stability of surrounding rocks;(2)for a tunnel with a Grade C water inrush,it could adopt the grouting measure with the grouting thickness no less than 3 m and the relative permeability coefficient no less than 20;(3)for a tunnel with a water inrush of Grade D or below,it could take conventional measures such as pumping and discharge.