Study On The Seismic Behavior Of The Connected Beam Structure Of The Grid-gate Pier Of The High-rise Watwe Intake Tower Based On The Time-history Analysise Method

Tower inlet shape structure is complex and most of the building structure built in the water,its stress distribution is very complex,under seismic load is easy to produce large deformation and damage,especially the connection of trash rack pier beam and connected to the tower body and trash rack pier girder due to the low stiffness,is the weak part of tower body,easy to produce too much tension and compression stress,structure,their destruction,leading to trash rack pier damage.Once the barrage pier is damaged,the water diversion system will not be able to operate normally and the safe operation of the hydropower station will be affected.In this paper,the finite element analysis software is used to establish the three-dimensional finite element model of the water intake tower,and the time-history analysis method is used to analyze the stress and displacement distribution of the high-rise water intake tower under static and dynamic loads,so as to find out the key parts affecting the safety of the water intake tower.Through the systematic comparison and selection of the cross-section dimensions of key parts(beam,longitudinal beam and side pier),the expected purpose can be achieved.The main research contents and results are as follows:(1)By studying the influence of the cross section width and height of the beam on the key parts of the water intake tower,it is found that increasing the cross section width or height of the beam can effectively reduce the maximum tensile stress of the beam and the maximum main tensile stress of the barrage pier,but at the same time will slightly increase the maximum tensile stress of the longeron.(2)Through the study of cross section of longitudinal beam width and height change on the influence of the intake tower key parts,found that increasing girder cross section width or height,are able to increase its maximum tensile stress and longitudinal beams and the maximum principal tensile stress of the breast wall connection,and the maximum principal tensile stress of trash rack pier and beam of the maximum tensile stress.(3)By studying the influence of the cross section form of the end of the beam and the longitudinal beam on the key parts of the water intake tower,it is found that increasing the cross section height of the end of the beam can reduce the maximum tensile stress of the beam itself and limit the displacement of the vertical flow direction of the gripper pier,and slightly increase the maximum tensile stress of the longitudinal beam;The maximum tensile stress of the longitudinal beam itself and the maximum tensile stress of the connection part between the longitudinal beam and the breast wall can be reduced by increasing the height of the section at the end of the longitudinal beam.Therefore,it is beneficial to reduce the tensile stress of the connecting beam system to increase the cross section height of the beam and longeron.(4)By studying the trash rack side piers thickening position in beam,the longitudinal beam and the influence of the trash rack pier,found in the first half of the trash rack side piers lateral segment(from trash rack side piers along the front in the direction of flow delay 14 m)thickening and trash rack side piers lateral all upset(mound the front along the flow direction at the edge of the trash rack postponed 29 m)thickening can make beams,longitudinal beam and the maximum tensile stress reduces trash rack pier.(5)Through the analysis of the influence of changing the thickness of the barrage pier on the key parts of the water intake tower structure,it is found that increasing the thickness of the barrage pier can effectively reduce the maximum tensile stress of the beam and the maximum main tensile stress of the barrage pier,as well as reduce the displacement of the barrage pier in the X and Z directions.