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Optimization and Application of the Treatment Schemes for Water Inrush in a Water-rich Tunnel in Fault Zones
(1. Gansu Changda Highway Co., Ltd., Lanzhou 730000; 2. Gansu Provincial Transportation Research Institute Group Co., Ltd.,Lanzhou 730000; 3. Key Laboratory of Bridge and Tunnel Health Monitoring and Safety Assessment Technology of Gansu, Lanzhou 730000; 4. Institute of Geotechnical Engineering, Xi′an University of Technology, Xi′an 710048)
Abstract 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 racture 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 surrounding rocks, such as drainage, grouting, and combination of drainage and grouting. The results show that: (1) when a serious water inrush of Grade A or B occurs in a water-rich tunnel passing through fault zones, it should take the treatment 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
Abstract：
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 racture 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 surrounding rocks, such as drainage, grouting, and combination of drainage and grouting. The results show that: (1) when a serious water inrush of Grade A or B occurs in a water-rich tunnel passing through fault zones, it should take the treatment 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
ZHANG Fujun1 HU Jun2,
3 DUAN Yu4 ZHU Caihui4
.Optimization and Application of the Treatment Schemes for Water Inrush in a Water-rich Tunnel in Fault Zones[J] MODERN TUNNELLING TECHNOLOGY, 2022,V59(2): 122-131
2022, Vol. 59 