Study On The Route Of Diverting Water From Nujiang River To Xinjiang And The Construction Technology Of Its Super-Long Tunnel(Inclined Shaft)

In order to alleviate the current situation of water shortage in Xinjiang,firstly this study put forward the project diverting water 60×10~8m~3 from the Nujiang river to Xinjiang through the analysis and discussion of the project diverting water from the Tongtian river to the west and the project diverting water from the south to the north,the construction of the super-long water-conveyance tunnel in the project of diverting water from the Nujiang river to Xinjiang is the control project of the whole water diversion project,Water-conveyance tunnel not only through the Zhaqu,the Tongtian River and Chumaer River and other large rivers,but also through the Tanggula and Kunlun Mountains and other larger mountains,the hydrogeological conditions are complex along the line,TBM is used in construction,it is necessary to solve the problem of advanced geological prediction and long distance ventilation of TBM under different complex geological conditions,In addition,the deep inclined shaft at the rear of the water conveyance tunnel is located above 3000m,and the construction and slag removal of the deep inclined shaft is one of the difficulties to be solved in the water diversion project.The main contents and conclusions are as follows:(1)plan the water diversion route and project scale,preliminary design the structure and size of the main building,estimate the project investment and study the feasibility of this scheme.The results showed that diverting water from the Nujiang river to Xinjiang is feasible in technology and economy.This scheme will not only avoids the contradiction of the project diverting water from the south to the north,but also reduce the difficulty and risk of water diversion project,It is a higher feasibility of diverting water schemes.(2)In order to speed up the excavation of the water-conveyance tunnel and ensure the quality of excavation,According to the engineering characteristics of long distance and deep buried of the water-conveyance tunnel,As TBM can not be drilled for 25km without overhaul,the total length of overhaul will reach 30km.Therefore,according to the service life of TBM and the slag requirement during construction,The water-conveyance tunnel is selected by double shield TBM,and 8 tunnels are excavated to divide the 492km water-tunnel into 9sections,The distance between the holes is 55km,the distance from 1# hole to the entrance of the water-conveyance tunnel is 56km,the distance from 8# hole to the exit of the water-conveyance tunnel is 51km.(3)In order to ensure the construction safety of the water-conveyance tunnel when crossing the complex geological conditions,it is necessary to carry out the advanced geological prediction of the hydrogeological condition of the strata within 120m before the TBM construction and take different forecasting methods according to different geological conditions,TBM encountered a large amount of water in the surrounding rock,Within the range of 120m ahead of TBM,Geological analysis method,TEM method and BEAM method were used to predict the geological prediction from the far to near.TBM encounters fault crushing zone,Within the range of 120m ahead of TBM,TSP method,Geological analysis method and Geological radar method were used to predict the geological prediction from the far to near.(4)According to the ventilation characteristics of the water conveyance tunnel,combined with the advantages and disadvantages of different ventilation modes,the water-conveyance tunnel employs pressure ventilation,the maximum ventilation length is designed as 12km,the full length 492km water-conveyance tunnel is divided into 23 sections by excavating the 22shafts,the maximum required airflow in the tunnel construction is 3168.9m~3/min.The total length of the deep inclined shaft in the tailrace of the tunnel is 522m,the dip angle is 50degrees,and the inclined shaft is divided into upper and lower sections for construction,the upper and lower sections are connected with a flat hole,the length of the upper and lower sections are 261m,the slag of the deep inclined shaft is carried out by the method of well-expanding of top-down.(5)The order of the influence of the dip angle of the inclined shaft,stone slag moisture content and the gravel gradation on the slag discharge rate is:the dip angle of the inclined shaft>stone slag moisture content>the gravel gradation.Under the condition of constant gravel gradation,the critical inclination of the inclined shaft decreases with the increase of the moisture content,under the condition of constant moisture content,The critical inclination of inclined the shaft decreases first and then increases with the increase of the slag diameter ratio.Under the condition that the moisture content of the slag is 1% and the gravel gradation is?,in the process of slag removal,the maximum critical inclination is 48 degrees.