Shweli(?) Hydropower Station Branch Pipe Joint Hydraulic Test

In the construction of the pressure steel pipe of hydropower station,the manufacturing process of the bifurcated pipe is complex,the construction period is long,the welding stress of the reinforcing rib of the bifurcated pipe and the two sides of the shell and tube is high,and the laminar tear is easy to cause the structural instability.Therefore,made after bifurcated pipe pressure test,to test the rationality and correctness of the design of pressure pipe and pressure pipe manufacturing and installation quality,ensure safe operation and reliability of welding joint performance verification of steel bifurcated pipe,the peak level of residual stress,and eliminate the pipe welding stress;at the same time on the main pipe and the stress concentration of the diversion pipe section stress strain test.Burma Ruili River hydropower station is a diversion type power station,arranged in two parallel pressure steel pipes,each steel pipe end are respectively provided with a main pipe and a diversion pipe type are crescent ribbed Y-pipe,design head stand is 4.12 MPa.Pressure pipe installation is the key line,line construction,installation progress of fork pipe is the key;in addition,the V class surrounding rock is the main part of the branch,branch pipe,after a period of excavation,the rock stress release,bifurcated pipe must be in the assembly,the need for two dig the tunnel can meet the welding and installation and test work space requirements,but also increased the risk of deformation of surrounding rock.In view of the above research,to determine the pressure of pipeline diversion pipe and main branch pipe joint pressure test,which is the main branch pipe,diversion pipe and branch pipe combination test system combined with the one-time pressure test.In this paper,the whole process of joint pressure test pipe were studied,including test purpose,process design and test process,through the analysis of the collected data,proved that the structure stress condition of normal branch pipe,each measuring point in the large safety reserve within the range of elastic deformation,reduce the residual stress of the weld,describes the process joint bifurcated pipe hydraulic test is feasible and can effectively reduce the pressure pipe installation period and reduce the construction cost,improve project quality,reduce the safety risk of adverse geological conditions of surrounding rock pipe installation.The conclusions can be used as reference for similar projects.