Research On Bearing Characteristics And Damage Resistance Of Continuous Rigid Frame Bridges

As a transportation hub between highways and highways,bridges have been widely used in mountainous highways in recent years.The continuous rigid frame bridge is a structural system commonly used in the construction of large span bridges,and its common span is between 100 and 300 meters.It forms the whole body of the pier body and the girder body during construction,therefore,the main girder and the pier body form a rigid frame structure.On the one hand,this kind of construction method will be relatively reasonable in terms of bearing capacity of the main girder,on the other hand,the structure makes the pier body have great potential in the structure.However,its disadvantages are the large bending moments in the mid-span,stress concentration,and large strains,the existence of these defects will make our troops unable to get reinforcements in time in the war,and may even affect the prosperity and decline of a country.The crash barrier of the bridge is mainly used to protect the safety of vehicles and surrounding people and buildings,and also to reduce the damage to the bridge.In this paper,based on the Bai-Sui-Xi Bridge and the 110 national De-Sheng-Kou Bridge,the finite element model of the continuous rigid frame bridge is established,and its bearing characteristics,kinetic energy damage to the collapsed segments at different positions,and the collision buffer structure on both sides of the bridge are provided.Were studied.The APDL parametrization programming commands in ANSYS software are used to realize continuous rigid frame bridge entity modeling and finite element mesh division.The loadbearing characteristics of the continuous rigid frame bridge were analyzed using the software Workbench.A dynamic analysis was performed using Truegrid and LS-DYNA,it was found that the damage resistance of the web was stronger than that of the combination of the top plate and the bottom plate,the reinforcement arrangement at the impact point was not themore dense the damage resistance of the web was strong.Finally,the optimization design of the expansion ring and the expansion ring/foam aluminum buffer energy-absorbing device are proposed for the problem of the low buffering and energy-absorbing efficiency of the crash barrier,and a novel buffered energy-absorbing structure is designed for it.The research results are as follows:(1)The bending moment and strain at the mid-span section of the continuous rigid frame bridge are the greatest,and the stress concentration phenomenon easily occurs.(2)Through the modal analysis of the continuous rigid frame bridge,it is easy to cause greater deflection and deformation in the cross-section.(3)Because the cross section is small and the bending moments,stresses,and strains are large,the cross section of the continuous rigid frame bridge is easily damaged.(4)The penetration resistance of the continuous rigid frame bridge will decrease with the increase of the speed of the kinetic energy bomb,the anti-penetration ability of the web is stronger than that of the combination target of the top plate and the bottom plate.(5)The traditional buffer barriers on both sides of the bridge are poor in energy absorption,this paper presents two types of buffered energy-absorbing devices,through numerical simulations,good results have been achieved and the ability of the bridge to resist damage has been improved.