Study On The Dynamic Character I St Ics And Seismic Response Of Yongning Water Conservancy Hub Steel Reinforced Concrete Pier

The gate pier of sluice structure is the main force supporting structure,its safety and reliability are directly influence the normal operation of the gate and the safety of the project.Therefore,this is the eternal proposition to ensure that the pier in a variety of work environment safe and reliable in water conservancy and hydropower engineering design and construction.Steel reinforced concrete pier is recently proposed,which has a strong bearing capacity reinforced by steel structure,high rigidity and good ductility.We take advantages of it to embed section steels in local tension zone of pier around corbel instead of traditional fan-shaped reinforced concrete structure.Results show that steel reinforced concrete gate piers especially suitable for high head and large discharge spillway under static loads.At present,the research on the steel gate of the discharge structure mainly concentrates on the static performance,and its dynamic performance has not yet begun.Based on the background of hydraulic engineering earthquake,using Guangxi Yongning Water Conservancy Project as enginee ring reference and the finite element numerical simulation analysis the dynamic characteristics and seismic response of steel seinforced soncrete sier.The conclusions are as follows:(1)The basic period of the concrete-filled concrete pier of the Yongning Water Control Project is 0.7 seconds.Compared with the characteristics of local ground motion,the period is 0.35 seconds,and the two are far apart and difficult to resonate.The basic period of the reinforced concrete pier is located in the ground Category of group IV,in addition to the fourth group,the steel-concrete concrete piers which are similar to the structure of the Yongning Water Control Project can be applied in many are as of our country.(2)The basic mode of the Yongning steel reinforced concrete pier is the right and left translation of the transverse flow direction,and the lateral stiffness of the pier is much smaller than that in the other two directions.In the earthquake,the upper pier body may occurred the lateral failure,its seismic calculation should based on lateral stiffness checking.(3)The hysteretic analysis of the piers and the two parts of the stee 1 sluice shows that the hysteresis of the piers is poor and the envelope area of the hysteresis curve is related to the development of the pier's plastic zone and the concrete cracked.The hysteresis curve of the bracket pedestal is more plentiful and its hysteresis performance is better because the ductility of the steel part of the bracket pedestal is playing a role.(4)The maximum seismic response shows that the seismic performance of the steel reinforced concrete pier on the Yongning water conservancy project is good,and most of the pier are in the elastic working state,but the deformations of the gate and the weir are dangerous and should be considered reinforcement measures to prevent the pier cracking.(5)The steel reinforced concrete piers on the Yongning water conser vancy project performed well under the earthquake of 5-7,and the response of the pier to the displacement and stress recorded by the seismic time history was always small and did not exceed the design value of the pier material.(6)According to the results obtained from the two methods of seismic analysis,the steel concrete pier of Yongning water conservancy project has a small deformation in the earthquake,which meets the design requirements of engineering seismic.As the earthquake intensity increases further,cracks may appear in the pier body.