Abstract: In order to ensure the construction safety of karst tunnel, the unfavorable geological body can be accurately predicted using integrated prediction method so as to significantly reduce the potential for disasters. Setting the Zijingshan Tunnel of the Da-Guang’nan Expressway as the project background, firstly, the developing characteristics of the karst of Zijingshan Tunnel is studied through geological analysis. And then, long-distance detection of unfavorable geology is done with the TSP (tunnel seismic prediction) method; so an accurate prediction of the ZK221+960 underground river’s location is obtained; and a short detection of the underground river's direction is done using geological penetrating radar. The detection result is consistent with actual disclosure direction. For the actual situation of Zijingshan Underground River, drainage tunnel program is eventually made after many analysis of various treatment program. Under the premise of ensuring the safety and duration of tunnel construction, the hole drainage program is optimized. The optimized processing program achieves good results in the Zijingshan Underground River’s governance, which has some reference significance for the similar engineering.

Key words: karst development features, underground river, TSP, ground penetrating radar, drain tunnel