邻近水库富水断层破碎带隧道注浆圈参数研究

Grouting Circle Parameters of Tunnel in Water Rich Fault Fracture Zone at Adjacent Reservoir Area

隧道穿越富水断层破碎带施工风险较大,常采取超前全断面预注浆进行处理。本文依托皖南一工点通过建立渗流数值模型分析了注浆圈不同厚度、渗透系数下隧道周边地下水渗流规律。结果表明:未支护条件下开挖,渗流达到稳定状态后地下水压力呈漏斗状分布;隧道涌水量随着注浆圈厚度增加而减小,注浆圈厚度宜控制在5~8 m;减小注浆圈的渗透系数可有效减小隧道涌水量,注浆圈渗透系数宜控制在2.00×10^(-7)~2.67×10^(-7) m/s;注浆圈厚度和相对渗透系数一定时隧道埋深与隧道周边涌水量近似成线性关系。经实施,隧道穿越断层破碎带区段涌水量为1.42 m^(3)/(d·m),注浆参数选取合理,加固效果良好。

The construction risk of tunnel crossing the fracture zone of water rich fault is large,and the advance full section pre-grouting is often adopted for treatment.Taking an engineering in south of Anhui Province as background the seepage laws of groundwater around the tunnel under different thickness and permeability coefficient of grouting circle were analyzed by establishing the seepage numerical model.The results show that the groundwater pressure distribution is funnel-shaped after the excavation seepage reaches a stable state without support.The water inflow of the tunnel decreases with the increase of the thickness of grouting circle,and the thickness of grouting circle should be controlled at 5~8 m.Reducing the permeability coefficient of grouting circle can effectively reduce the water inflow of the tunnel,and the permeability coefficient of grouting circle should be controlled at 2.00×10^(-7)~2.67×10^(-7) m/s.When the thickness and relative permeability coefficient of grouting circle are certain,the buried depth of the tunnel is approximately linear with the water inflow around the tunnel.After implementation,the water inflow of the tunnel crossing the fault fracture zone is 1.42m^(3)/(d·m),the selection of grouting parameters is reasonable and the reinforcement effect is good.