(1. Geotechnical and Structural Engineering Research Center,Shandong University,Jinan,Shandong 250061,China;
2. China Construction Fifth Engineering Division Co.,Ltd.,Changsha,Hunan 410004,China)
Abstract:Water gushing in limestone breccia fracture zone is a complex geological disaster often encountered in tunnel construction. Compared with the general water gushing in fracture rock mass,due to the poor stability of surrounding rock and rock heterogeneity,gushing treatment in limestone breccias fracture zone is very difficult. For controlling the water gushing in breccias fracture zone with high water pressure and quantity in Zhongliangshan tunnel,water analysis and transient electromagnetic detection were conducted;and groundwater source and channel were analyzed. Based on this,drainage was done first to reduce the water pressure in surrounding rock,then grouting was carried out to strengthen shallow layer. The shallow layer grouting was divided into two parts,i.e. upper part and lower part. Curtain in deep rock was done to plug water. Plugging and drainage were combined in water gushing control. Those four measures formed a comprehensive treatment method. A good control effect was achieved through choosing adaptive grouting materials and matched technology. Surrounding rock deformation and water quantity were measured and analyzed to avoid rock instability induced by grouting pressure. The comprehensive water gushing treatment method well solved the problems during grouting process in breccia fracture zone and realized informatization construction.