Abstract To build the expressway by the side of Three Gorge reservoir,tunnel construction was faced with the complex hydrogeological conditions,well developed karst and high risk of water inrush. A prevention system of high-risk karst tunnel was proposed in terms of the risk control of water inrush. Firstly,the regional karst features and water channels were revealed through the hydrogeological survey of karst and the analysis of the information such as lithology and topography. The characteristics of karst water were determined according to the long-term observation of rainfalls and water flows. Secondly,combined with the real-time information of construction,the water inrush risk was assessed by analyzing the risk surroundings and the risk factors. A geological prediction system for tunnels was presented based on the risk assessment. Finally,the curing programs of water inrush were optimized with the comprehensive geological prediction results. As such,both the region and the plan for water inrush curing were determined. The quality of excavation,support and grouting in the construction were ensured. The application of the approach provided the safety for the construction Jigongling Tunnel and avoided large-scale water inrush.
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Received: 04 July 2013
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