STUDY OF TBM CONSTRUCTION OF DIVERSION TUNNEL FOR JINPING II HYDROPOWER STATION

The diversion tunnel for Jinping II Hydropower Station is currently the largest group of hydropower tunnels in China.The surrounding rock masses of the tunnel are of long length,deep embedded depth and technical difficulties of construction,which is a variety of geological hazards such as water bursting,rockburst,collapse and so on.It is necessary to choose the safe and rapid excavation technology for ensuring construction safety and power generation schedule,so a large number of studies and analysis of the technology of TBM construction is conducted;and the results are as follows:TBM construction method is feasible not only in the view of rock drillability and cutter wear but also from rock deformation and fracture;but it is some advantage for the traditional drill and blast method to deal with issues such as groundwater,rockburst,large deformation and so on,and which has a better protective effect in the personnel safety.It can do better in solving a series of engineering problems on the construction process if using the continuous improvement of construction technology and supporting tools which come from between geological prediction and construction.