穿越岩溶地区隧洞施工开挖防渗措施研究  

Study on Anti-seepage Measures of Tunnel Construction Excavation Through Karst Area

作　　者：苏凯[1,2,3] 杨逢杰 龚睿 朱洪泽[1] SU Kai;YANG Feng-jie;GONG Rui;ZHU Hong-ze(State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan 430072,China;Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering(Ministry of Education),Wuhan University,Wuhan 430072,China;Hubei Provincial Key Laboratory of Water System Science for Sponge City Construction,Wuhan University,Wuhan 430072,China)

机构地区：[1]武汉大学水资源工程与调度全国重点实验室,湖北武汉430072 [2]武汉大学水工岩石力学教育部重点实验室,湖北武汉430072 [3]武汉大学海绵城市建设水系统科学湖北省重点实验室,湖北武汉430072

出　　处：《中国农村水利水电》2024年第5期215-220,225,共7页China Rural Water and Hydropower

摘　　要：穿越岩溶地区隧洞在施工开挖期极易遭遇涌水突泥现象,如何选择合适的防渗措施减少隧洞渗流量一直是热点问题。依托某引调水工程,建立岩溶地区复杂地层三维有限元模型,重点考虑洞顶回填混凝土、洞周注浆圈、混凝土防渗墙3种防渗措施,研究了隧洞开挖过程中孔隙水压力及隧洞渗流量的变化规律,分析了防渗墙和注浆圈渗透系数对渗流特征的影响。结果表明:在本工程中,混凝土防渗墙对隧洞孔隙水压力分布的影响非常大,防渗墙之间水位降低程度明显,而洞周注浆圈对隧洞渗流量的影响最大,施工时要保证注浆圈的质量;孔隙水压力随着与隧洞中心水平距离增加而增加,随着与隧洞中心竖直距离增加呈现先增大后减小的变化趋势;随着注浆圈或防渗墙渗透系数增加,注浆圈或防渗墙区域内的孔压增长速率逐渐降低,隧洞渗流量不断增大。It is very easy to encounter the phenomenon of water and mud gushing during construction and excavation of tunnel through karst area.How to choose appropriate anti-seepage measures to reduce the seepage flow of tunnel has always been a hot issue.In this paper,a three-dimensional finite element model of complex strata in karst area is established based on a water diversion project.Three anti-seepage measures,namely back-filling concrete on the roof of the tunnel,grouting ring around the tunnel and concrete cutoff wall,are mainly considered.The change law of pore water pressure and seepage flow of the tunnel during tunnel excavation is studied,and the influence of permeability coefficient of the cutoff wall and grouting ring on seepage characteristics is analyzed.The results show that the concrete cutoff wall has a great influence on the distribution of pore water pressure in the tunnel,the water level between the cutoff walls decreases obviously,and the grouting ring around the tunnel has the greatest influence on the seepage flow of the tunnel,and the quality of the grouting ring should be ensured during construction.The pore water pressure increases with the increase of the horizontal distance from the tunnel center,and increases first and then decreases with the increase of the vertical distance from the tunnel center.With the increase of the permeability coefficient of the grouting ring or the cutoff wall,the pore pressure growth rate in the area of the grouting ring or the wall decreases gradually,and the seepage flow of the tunnel increases continuously.

关 键 词：岩溶地区 水工隧洞 施工开挖 混凝土防渗墙 注浆圈 

分 类 号：TV672[水利工程—水利水电工程]