On Water Burst Patterns in Underwater Tunnels

Water bursts, the result of the combined effects of regional geological conditions, hydrological conditions and construction disturbances, are the main risk during construction of underwater tunnels. Their occurrence is based on the source and channel of the water and is affected significantly by unfavorable geology. In this paper, typical water-burst cases both at home and abroad are analyzed, and four patterns for water burst are concluded: a hydraulic fracture pattern, a seepage failure pattern, an interface opening pattern and a rock failure pattern. Corresponding geological and hydrological conditions are presented as well. Using the Nanjing Weisan Road river-crossing tunnel as an example and utilizing the acquired geological and hydrological information, a water burst prediction is carried out and relevant measures are taken accordingly, thus preventing a water-burst disaster during tunnel construction.