Construction Organization Design Of Tunnel Renovation Project For Chang Dian Hydropower Station

The tunnel reconstruction project of the Changdian Hydropower Station is located on the right bank of Yalu river,the china-north Korea border of The Lagu Post Village of Dandong,Liaoning province.Changdian extension electromechanical station adopts a form of two mechines in one hole,designed the installed capacity of 200 MW,alleviate the problem of insufficient peak load regulation capacity of northeast grid,improved the situation of the primary Changdian Hydropower Station was unable to generate electricity when the water level was too low.the Shuifeng Dam can be operated normally under the condition through the construction organization of Tunnel Reconstruction Project of Changdian Hydropower Station.The project uses the method of backdam diversion for power generation.To ensure the power generation efficiency of the power station,the intake is below the dead water level of the reservoir..Comparing and selecting the optimal construction scheme according to the construction emphases and difficulties of the project.Firstly,arrange the site construction according to the construction site conditions.Then,calculate the quantity of air pressure,supply water,domestic water,total construction electricity,ventilation for underground works,annex area for construction according to the method adopted in the construction,to ensure the construction site.After compariing plans,the optimal construction scheme for each part is full section drainage hole is adopted in the construction of pilot tunnel,guaranteed inlet molding in one blast,profile forming intactly,the diameter of the ballast after blasting is moderate,less effect on surrounding structures.Crushed stones pit chooses to excavate layer by layer lining the way finally,it means concrete lining shall be carried out immediately after the completion of the first layer of side top arch excavation,continue to dig down after lining,circular construction,According to the analysis of the construction site,the diversion tunnel adopts different lining methods,upriver uses the side roof arch,firstly uses the loop wheel machine lining,the lower part lags behind uses of sample frame lining,downriver uses full section needle beam table car lining,molding in one time.both the gate shaft and surge shaft will excavated by reverse shaft excavation,excavate the pilot shaft first.then extended guide hole by artificial blast,concrete placing shaft gate use three hole vertical shaft sliding form for continuous concreting,three holes are hoisted and molding simultaneously,the diameter of the surge shaft is too large,construction of main shaft after the combined form concreting impedance hole.Main shaft concreting uses vertical shaft sliding form with multiple construction platforms,lift the ring to the concrete and molding integral.The conclusion is drawn through construction organization design is:through the construction of the project mastered a series of construction scheme technology,completed the construction without affecting the normal using of existing buildings.Summarized the scheme of construction and technical methods used in this project,will provide guiding suggestions for similar projects in the future.