Mi Yun Reservoir Spillway Radial Steel Gate-security State Analysis And Countermeasure

The Miyun reservoir is located in the northeast of Beijing,70 km away from downtown Beijing.The large hydro engineering not only supply water for the large city but also protect the people in the region from floods.As the most important surface water source of drinking water and flood protection project of the capital,the Miyun reservoir plays a very important role in ensuring the security of the capital,production,living water supply and environmental protection of the city.In order to ensure the safety of the reservoir,when the water level exceeds limit level,we will vent out the water through thedischarge structures.The main of Miyun reservoir are the first spillway,the second spillway and the third spillway.And there are 16 radial gates on the spillways,which can discharge as more as 15530 m~3/s flow when the water at the maximum level.But the spillway radial gate and hoist the longest running period of more than 50 years in a dry and wet environment.As a result,corrosion,wear and aging of metal structural parts to varying degrees which has a serious impact on the safe operation of the Engineering.To make matters worse,the water level of the Miyun reservoir will rise rapidly when it receives the water from the middle route of the south to North Water Transfer project.The water level of the Miyun reservoir will rise from low to high,which will seriously threaten the safety of the reservoir.Therefore,it is very important to study the safety state of spillway radial gates.Basing on the years of operation and maintenance of the metal structure of Miyun Reservoir in recent years,the paper consists of the appearance inspection,the corrosion quantity examination,the welding seam ultrasonic flaw detection,the gate material examination,the hoist operation management,the gate opening and closing force examination and the computation and the typical gate structure finite element computation and so on.Finally,the safety status of the radial gate and its hoist of the three spillway are systematically analyzed and evaluated in the paper.The main research contents are as follows:(1)Investigating the construction of the arc gates project,we summarized the engineering types and technical features of the arc gates.The appearance and corrosion status of the gate were analyzed by means of visual inspection of the arc gates.Nondestructive inspection of gate welds is carried out by means of ultrasonic inspection.Hardness and mark are determined by gate material testing.The detection of the hoist machine parts and electrical parameters detection were carried out in the paper,.(2)The force of gate opening at the designed water level is calculated through the safety testing.Compared with the rated opening force of the hoist,the safety factor of the hoist is obtained,which can determine the reliability of the hoist gate of hoist.The operation and management analysis of the radial gate hoist is carried out,at the angle of the gate management system,safety inspection,identification and reinforcement measures.(3)According to the engineering characteristics of gate panels,load-bearing components and connectors,the strength evaluation criteria are determined.The finite element numerical model of third spillway spillway arch steel gate is established.The strength,stiffness and stability of the main members are analyzed.The deformation and stability of the support arm are analyzed under two conditions,including the action of the bending moment,the in-plane and the moment acting on the plane.