Study On Static Characteristics And Transverse Seismic Performance Of Integral Bridge With Different Pier Beam Connection Forms

Integral abutment seamless bridge is also known as integral bridge.The bridge type cancels the traditional bridge deck expansion joint and abutment support,improves the integrity of the bridge,and solves the problems of traditional bridge bearing damage,expansion joint damage,bridge head jump and and excessive bridge maintenance costs.The integral abutment seamless bridge pours the main beam together with the abutment,cancels the abutment support and increases the stiffness of the abutment,which leads to the stiffness of both ends of the bridge greater than that of the pier.This situation easily leads to the adverse situation of the pier of the integral bridge under the earthquake action.The abutment bearing is cancelled in the integral bridge,but the pier bearing still exists,which leads to the replacement and maintenance of pier bearing still need to spend a lot of money.At present,some integral bridges have cancelled the pier support,It is very important to study the static characteristics of this kind of integral bridge,especially the transverse seismic performance,but there is a lack of research in this aspect.In view of this,this paper takes Yongchun SHANGBAN bridge in Fujian Province as the actual engineering background,considering the structure soil interaction,establishes the FEM models of pier beam hinged integral bridge(conventional integral bridge)and pier beam rigid integral bridge(full integral bridge)respectively,and analyzes their static characteristics and transverse seismic performance.The main contents and achievements of this paper are as follows:(1)This paper introduces the development process of seamless bridge,summarizes the current situation of seismic research of integral bridge,analyzes the factors influencing the seismic performance of integral bridge,and briefly discusses the theoretical analysis method of bridge seismic.(2)The finite element model of SHANGBAN bridge is verified to prove the reliability of the FEM model.In order to highlight the uniqueness of integral bridge,the static characteristics of ordinary continuous beam bridge,pier beam hinged integral bridge and pier beam rigid joint integral bridge under constant load,temperature load and vehicle load are compared and analyzed.The comparison results show that: the constant load and temperature load have the least influence on the deflection of the main beam of the pier beam rigid joint integral bridge.Under the action of temperature load,the bending moment of the main beam section of the pier beam rigid joint integral bridge at the pier support has a sudden change.Under the action of vehicle load,the bending moment of the main beam section at the middle of the side span of different bridges is in the order of ordinary continuous beam bridge,pier beam hinged integral bridge and pier beam rigid joint integral bridge Body bridge.(3)The response spectrum method and time history analysis method are used to analyze the seismic response of pier beam hinged integral bridge,pier beam rigid integral bridge and continuous beam bridge,and the seismic response of abutment,abutment pile foundation,main beam and pier of different types of bridges under seismic action is explored.The analysis results show that the transverse displacement,shear force and bending moment of piers from small to large are pier beam hinged integral bridge,pier beam rigid connected integral bridge and ordinary continuous beam bridge;the transverse displacement of main girder from small to large are pier beam rigid connected integral bridge,pier beam hinged integral bridge and continuous beam bridge;the transverse displacement of piers and main girder at piers of two types of integral bridges are higher than that of abutment and main girder at abutment The longitudinal displacement is larger,and the main beam displacement is larger than the pier displacement,which means that the overall bridge pier is prone to the problems of transverse seismic stop damage,bearing deformation or excessive displacement under seismic action;the structural response along the bridge direction of the three types of bridges is similar to that of the transverse bridge;the common continuous beam bridge is prone to the problems of main beam collision,falling beam and bearing damage.(4)According to the static analysis and lateral seismic response analysis of the bridge,the rigid joint integral bridge with pier and beam can reduce the maintenance cost of the bridge support and the displacement of the main beam under the earthquake,but the stress of the pier of the rigid joint integral bridge with pier and beam is larger,and the shear failure of the pier is easier than that of the hinged integral bridge with pier and beam.Based on the pier beam hinged integral bridge,the bearing stiffness,pier diameter,abutment pile section,soil type around the pile and abutment pile length are selected as parameters to compare the lateral seismic response of abutment and pier under seismic action of integral bridge with different parameters.It is suggested that in the design of bridge parameters,the diameter of abutment pile can be increased to reduce the lateral displacement of abutment,the soil around pile with larger m value can be selected to reduce the lateral displacement of abutment and pier,and the diameter of pier can be selected to improve the lateral seismic performance of bridge.