Three-dimensional Static And Dynamic Finite Element Calculation Of The Inlet Water Tower Of Pumped Storage Power Station

With the rapid development of the society and economy,the country's demand for power resources has gradually increased,and adjusting the peak capacity of the power grid has become an inevitable and critical issue in the national economy.The development and construction of pumped storage power stations can not only solve the problem of power distribution in the power grid when the load is large,but also play the role of energy conservation and environmental protection,and realize the promotion of renewable energy conservation resources.Therefore,it is an effective scheme to build pumped storage power stations in suitable geological environment to relieve the pressure of power grid.Although the pumped storage power stations in China started late,its development speed is rapid,and it has played an important role in international development.There are many types of pumped storage power stations and they play a wide role.As an important part of pumped storage power stations,the inlet tower plays an important role in the safe operation of the whole power station.Because the inlet tower is built in the water and is limited by the terrain,the impact of the earthquake has become a very important factor affecting the safety of pumped storage power stations.In this paper,a pumped storage power station is taken as an example to establish a three-dimensional finite element model for the structure of the lower reservoir inlet tower.The static analysis and dynamic analysis are carried out under four working conditions,namely,normal storage working condition,freezing working condition,construction completion working condition,maintenance working condition and earthquake working condition.The main conclusions are as follows:(1)According to the established three-dimensional numerical model,the stress distribution calculated by static analysis can be obtained.Under the four working conditions,the external side of the water inlet tower and the upper side of the intersection line of the surrounding rock slope,the tensile and compressive stress are large,while the tensile and compressive stress of other parts are small.The column axial force of the frame is dominated by pressure,while the beam axial force is dominated by tension.Under the inspection condition,the Y-direction tensile stress on the side of the inspection door groove is the largest,reaching 2.2 MPa.In the remaining working conditions,the stress in all three parts of the tower body is small.(2)The dynamic analysis of seismic working conditions is calculated by the response spectrum method and the quasi-static analysis method.It can be seen that there is a certain stress concentration at the connection between the top surface of the inlet tower and the upper shelf structure.It is shown that the tensile and compressive stresses are increased in the X,Y and Z directions,especially the maximum tensile stress in the X direction can be increased by 8.6 times,the maximum tensile stress in the Y direction can be increased by 7.2 times,and the maximum pulling along the Z direction.The stress can be increased by 13 times and so on.(3)It can be seen that the anti-sliding stability and anti-overturning stability of the inlet tower meet the requirements for the anti-sliding stability and anti-overturning stability check of all working conditions.The compressive strength of the ground basal plane is much smaller than the compressive strength of the bedrock,and the bearing capacity of the foundation meets the requirements.(4)Reinforce the inlet tower and the shelf part according to the size of the tensioned steel bar.When repairing the working conditions,the left and right sides of the door trough are inspected at the water inlet of the tower body,and the structural reinforcement is carried out along the river direction.At the inlet of the tower body,the side of the upstream of the doorway is inspected,and the direction of the reinforcement is along the left and right bank.The area of the reinforcement is 1318.7 mm~2/m.When the frame is reinforced,the maximum reinforcement area is 10441 mm~2 at the second layer of the longitudinal ring beam along the left and right bank.