FAULT-DOMINATED WATER MODEL AND MULTIFACTOR METHOD FOR PREDICTING WATER INFLOW AND INRUSH OF DEEP LONG TUNNEL IN FRACTURED ROCK MASSES

The prediction of water inflow and inrush in deep tunnels is relatively difficult due to the mechanical and hydro-mechanical characteristics remarkably different from those in shallow tunnels,and the difficulty in geological exploration as well.In respect to deep and complex geological environments,such as high initial geostress,high hydraulic gradient and high rock temperature,etc.,a multifactor prediction method based on the fault-dominated water model has been proposed,in terms of the research work on West Route of South-to-North Water Transfer Project.Firstly,a macro geological model is adopted to preliminarily assess water inflow and inrush,mainly regarding large-scale faults as groundwater channels.Based on the effect laws of deep geological environment factors which have influence on water inflow and inrush,a series of coefficients are determined and utilized for the final modification of water inflow and inrush estimated by the macro geological model.The presented method can be employed for assessment of water inflow and inrush from deep long tunnels during tunnel construction and supporting.