Study On Seismic Performance Of Double Column Mixed System Piers

With the acceleration of urban modernization,urban roads are becoming more and more crowded.In order to slow down the growth of urban traffic volume and develop the diversification of urban traffic space,the construction of urban viaduct has become particularly necessary.Due to the strict requirements of urban viaduct construction,prefabricated piers,which have the advantages of fast construction speed,convenient casting of components and less interference to surrounding traffic,have been used more and more widely.Compared with the whole cast-in-place bridge pier,the mechanical properties of the prefabricated bridge pier need to be further optimized,so it is necessary to carry out experimental and theoretical research on it.For this,this article is based on ABAQUS finite element software to study the double column type prefabricated bridge pier computing simulation method,and put forward a kind of construction speed and connection technology a new type of structure is simple,safe and reliable bridge pier,the pier abutment adopts reinforced concrete segment connection,pier column and pile caps section at the bottom of the common casting,the upper is using reinforced concrete segment pier prestressed steel strand,through grouting holes reserved connection,namely "prefabricated-half cast-in-place connection".In view of this kind of hybrid system double column piers,by comparing with integral cast-in-place double column piers and prestressed prefabricated double column piers in terms of mechanical properties and parametric analysis,the seismic performance of this kind of piers is studied,and theoretical basis is provided for the practical engineering application of this kind of piers.The specific research contents are as follows:(1)based on the finite element analysis software ABAQUS,in order to determine correct and reasonable pier simulation method,finite element software were introduced in detail in the modeling process and key technical points of processing method,and through the existing test results and data,build and test specimens of the same size overall cast-in-place and precast bridge pier assembled piers,comparing two piers of test results and simulation results to verify the correctness of the simulation method,the analysis results show that the finite element model calculation results of abutment stress nephogram of concrete damage and the experiment of concrete pier damage are basically the same,the hysteresis curve of both highly fit at the same time,It is shown that the finite element modeling method can well reflect the mechanical properties of bridge piers in practice,thus verifying the accuracy of the simulation method.(2)The finite element model of the mixed system two-column bridge pier and the finite element model of the integral cast-in-place two-column bridge pier and the prestressed twocolumn bridge pier with the same structural parameters are established,and the differences of the mechanical properties of the three are compared and analyzed comprehensively.Research results show that the overall cast-in-place double column pier system of ultimate bearing capacity and ductility capacity are better than mixed double column pier and prestressed assembly double column pier,but the rest of the two kinds of pier since the reset ability is stronger than the overall cast-in-place double column pier,for bridge structures in areas prone to earthquakes,the reset ability is superior,to help the earthquake restoration of bridge piers.(3)Parameterized analysis was carried out for the mixed system double-column piers.Five groups of piers with different structural parameters were designed.The corresponding finite element model was established and the mechanical behavior of the piers under cyclic loading was analyzed.The effects of stirrup ratio,axial compression ratio,concrete strength,prestress degree of prestressed strand and strength of energy dissipating reinforcement on the mechanical properties of piers are studied.The results show that with the increase of concrete strength and axial compression ratio of piers,the energy dissipation capacity and ultimate bearing capacity of piers also increase,but at the same time,the ductility capacity of some piers is sacrificed.The ductility of piers can be improved by increasing the reinforcement ratio of stirrups in piers.As an important part of bridge pier,prestressed strand and energy-dissipating steel bar have a great influence on the seismic performance of bridge pier.With the increase of prestress and energy-dissipating steel bar strength,the hysteretic performance and energy-dissipating capacity of bridge pier are obviously enhanced.Figure: [56] table:[18] reference:[64]...