| The water intake of the hydropower station is located at the head of the diversion power generation system and is an important control building for water diversion and power generation.In the inlet section,there is generally a trash rack.The rigidity of the trash gate is small and the stability is poor.In the project,the stability and integrity of the trash gate and its ancillary structure are often increased by setting up the tie beam.The system of the trash rack pier-connected beam is prone to large deformation and large tensile stress under the action of earthquake.If the damage occurs,it will have an important impact on the normal operation of the whole hub.In this paper,ANSYS software is used to establish a three-dimensional finite element model of the intake tower(73.2m height)of the Xia Kaifu Gorge Hydropower Project in Zambia.The displacement and stress response of the structure under earthquake action are calculated by the vibration mode decomposition response spectrum method.The main research contents and results are as follows:(1)The dynamic response of the inlet tower under seismic action is calculated and analyzed by the formation decomposition reaction spectrum method.The results show that the system of the trash rack pier-connected beam generates large deformation and stress,analyzes the cause and finds out the influence of the trash rack.The relevant factors of stress and displacement of the trash rack pier-connected beam system are compared with related factors,and a reasonable design scheme is proposed to reduce the displacement and stress of the trash rack pier-connected beam system.(2)By establishing the inlet tower model of 10 cross beams of different cross-section dimensions,the influence of the cross-section dimension of the beam on the trash rack pier-connected beam system is studied.It is concluded that the beam of larger cross-section can effectively limit the barrier pier.Deformation,improve the stress of the system.(3)By establishing the inlet tower model of 10 longitudinal beams of different cross-section dimensions,the influence of the cross-section dimension of the beam on the trash rack pier-connected beam system is studied.It is concluded that increasing the section size of the longitudinal beam does not significantly affect the deformation of the trash gate,which is not conducive to the safety and stability of the system and increases the engineering cost.(4)By establishing 15 kinds of chamfering models,the influence of different cross-section dimensions and slope angles on the trash rack pier-connected beam system is studied.It is concluded that a chamfer can be added at the end of the beam.While reducing the amount of concrete,it can achieve the same effect as increasing the cross-section size of the beam;Adding a chamfer at the end of the longitudinal beam can slightly reduce the vertical displacement of the trash gate and slightly improve the stress of the system;In the case of the same amount of concrete,the slope with the added chamfer is optimal when 3:1 is selected.(5)Through the establishment of four different thickness trapping pier inlet tower models,the influence of the thickness of the trash gate on the trash rack pier-connected beam system is studied.It is concluded that the thicker trash gate can effectively reduce its horizontal displacement,but the vertical displacement increases slightly,and the system stress is obviously improved.For the trash rack pier-connected beam system of the hydropower station shore tower inlet,the inlet tower can be reduced by increasing the cross beam size,reducing the longitudinal beam size,adding the chamfer to the connected beam and increasing the thickness of the trash gate.The stress and displacement of the connected beam system of the trash gate ensure the safety and stability of the trash rack pier-connected beam system of the inlet tower.This conclusion can provide a reference for the design of towering water towers of similar structure. |
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