Study On Effects Of Different Steel Corrosion Position And Dynamic Water Pressure On Seismic Performance Of RC Bridge Pier Reinforcement

With the continuous expansion of infrastructure construction in China,Bridges have become an indispensable part of the transportation network connecting various cities and villages.Especially in recent years,the construction of cross-sea bridge in China has shortened the distance between cities and saved time for people's travel.For example,the completion of the hong kong-zhuhai-macao bridge has greatly reduced the time and space distance between Hong Kong,zhuhai and Macao.The bridge adjacent to the seaside is corroded by chlorine ions in the natural environment,which leads to the corrosion of steel reinforcement and bears the action of wave load at the same time.Therefore,the anti-seismic performance of bridge pier will become the key to the safe operation of the bridge.To some extent,the single study on the impact of steel corrosion on the seismic performance of bridge and the single study on the impact of hydrodynamic force on the seismic performance of bridge pier cannot fully reflect the seismic performance of bridge pier.Based on this,this paper conducts the following research:(1)In this paper,based on the characteristics of bridge piers and pillars,the pier model of a simply-supported girder bridge in yantai city is established by using the finite element software ABAQUS,and the self-vibration model of the pier is calculated to determine the pier Rayleigh damping coefficient.Seismic wave processing software SeismoSignal is used for baseline correction and band pass filtering of Chi-Chi seismic data.(2)The steel bar at the bottom of the pier rusts,leading to the increase of the main compressive stress of concrete,and the concrete damage will be aggravated with the increase of the corrosion of steel bar at the bottom.Corrosion in other parts has little effect on compressive stress.(3)It is found that the z-direction displacement of the pier is most affected by the corrosion of steel reinforcement at the bottom of the pier.It has little effect on X and Y displacement.With the increase of steel corrosion at the bottom of bridge pier,the z-direction displacement of concrete increases by 8.7%.(4)Under the action of hydrodynamic pressure,the corrosion of steel reinforcement at the bottom of the pier has the greatest influence on the seismic resistance of the pier.With the increase of steel corrosion at the bottom of the pier,the concrete z-direction displacement gradually increases,and the lower the seismic performance of the pier is,when the steelcorrosion at the bottom increases to 20%,the concrete displacement increases by 9.9%.When the steel reinforcement of the bridge pier is intact and there is hydrodynamic pressure,the maximum bending moment of the concrete is 1012 kN? m,and the maximum bearing capacity of the bridge pier is 823 kN ? m when the steel corrosion amount at the bottom of the bridge pier is20% under the hydrodynamic pressure.(5)This paper revises the checking formula of bridge pier bearing capacity,puts forward the correction coefficient ? and determines its value range.A correction factor of ? is proposed for the length formula of plastic hinge region of the finite element improved model of bridge pier.