Study On Seismic Performance Of Assembled Prestressed Concrete Pier With Corroded Steel Bars

With the development of bridge construction,many bridges need to be built in coastal areas.As an important part of bridge structure,the importance of piers is self-evident.Compared with other forms of piers,prefabricated piers are widely used in sea crossing bridges,with the advantages of less labor consumption,short construction period,easy quality assurance,little impact on the environment,and strong self reset ability.The reinforced concrete structure in the marine environment will be affected by the chloride ion in the environment for a long time.The existence of chloride ion will destroy the passive film of the reinforcement and eventually lead to the corrosion of the reinforcement.At the same time,our country is also a country with frequent earthquakes.In the marine environment,the fabricated bridge piers have to face the double tests of steel corrosion and earthquake.Therefore,it is necessary to carry out the research on the seismic performance of the fabricated bridge piers with steel corrosion.In this paper,the aseismic performance of the assembled prestressed concrete bridge pier is studied,the main research work is as follows:(1)By referring to a large number of relevant literature,this paper summarizes the research status of seismic performance of prefabricated piers at home and abroad and the research status of seismic performance of corroded reinforced piers.(2)In order to obtain more accurate mechanical property parameters of corroded steel bars,electrolytic corrosion of steel bars and prestressed steel bars are carried out,and tensile tests of different loading modes are carried out by using electro-hydraulic servo electronic universal testing machine.(3)By using Pushover Method,the seismic performance of assembled piers with different corrosion rate under monotonic horizontal load is studied.The sensitivity analysis of the factors affecting the ultimate bearing capacity and displacement ductility coefficient of assembled piers is carried out,and the influence law of key factors on the seismic performance of assembled piers with steel corrosion is explored.(4)This paper studies the aseismic performance of the assembled bridge pier with steel corrosion under the action of low cycle reciprocating load.The research is divided into five working conditions: only longitudinal steel corrosion,only energy consuming steel corrosion,only prestressed steel corrosion,only stirrup corrosion,and all corrosion.The influence of different steel corrosion on the aseismic performance of the assembled bridge pier is explored.At the same time,the sensitivity analysis of the factors that affect the energy dissipation capacity of the assembled bridge pier is carried out,and the influence degree of the key factors on the seismic performance of the assembled bridge pier with steel corrosion is explored.