Study On The Resistance And Bearing Capacity Of Precast Concrete Filled Steel Tubular Pier Column In Mountainous Area

In recent years,the construction industry of transportation infrastructure and supporting facilities in China has entered a new period of development.The emergence of the assembled type has well solved the limitations of environment,traffic and construction time,which can greatly improve the construction efficiency,speed completion and enhance the energy consumption capacity of bridge piers.The concretefilled steel tube bridge,due to the restriction of the steel tube on the concrete,greatly improves the bearing capacity of the pier column,which makes it possible to complete the construction of the bridge pier column quickly,efficiently,durably and safely in the traffic construction in the mountainous area.Because segmented concrete-filled steel tubular piers are seldom used in practical engineering,it is necessary to do a lot of research on them in order to be widely used in practical engineering.Considering the above situation,in order to establish safe and reliable bridge piers in the harsh environment of mountainous areas,this paper studies the theoretical results and the antipush bearing capacity of concrete-filled steel tubular bridge piers with different reinforcement forms and bolted connection modes,and determines the main research contents and draws the following conclusions:(1)Through a large number of domestic and foreign research data on prefabricated concrete-filled steel tubular bridge piers,the numerical simulation methods and forms of concrete-filled steel tubular bridge piers are summarized.Through the segment assembling steel pipe axis of the arrangement of prestressed concrete bridge pier test of bolt connection bridge component simulation model of ABAQUS,will be the model of the numerical simulation results with the field data collected in the experiments data,determine the segmental precast steel pipe concrete piers of the feasibility of the numerical simulation method.(2)The segment-assembled concrete-filled steel tubular piers with prestressing on all sides are proposed,and the finite element simulation modeling method is used to analyze the pseudo-static results of the finite element method between the segmentassembled concrete-filled steel tubular piers with prestressing on the axial axis and unprestressed concrete-filled steel tubular piers,and to compare the differences of the anti-thrust performance of the three.The results show that the horizontal bearing capacity,energy dissipation and self-reset ability of the prestressed bridge piers arranged in the surrounding area are better,the prestressed bridge piers arranged in the axial area are the next,and the unprestressed bridge piers are the worst.(3)For the segmental concrete-filled steel tubular piers with prestressing on all sides,the influences of several parameters on the piers are considered,such as the pre-tightening force of bolts,the degree of prestress and the thickness of connecting steel tubes,etc.on the horizontal bearing capacity of the piers.The analysis results show that the peak value of horizontal resistance can be increased by increasing the degree of prestress and the thickness of connecting steel pipe,and the corresponding displacement load of peak value is larger,and the energy consumption capacity is increased.However,the bolt preloading force has little influence on the whole pier reciprocating loading process and can improve the strength before the yield stage slightly.The increase of steel tube thickness can prevent the bottom segment of CFST from entering the yielding state in advance.