| Urban complex rail transit node which is a kind of station-bridge integrated structure makes comprehensive use of urban space to maximize the role of urban space and improve the efficiency of traffic operation.The structure with station and bridge connected is one of the most popular in multiple station-bridge integrated structures,but the bridges and subway stations in this kind of structure affect each other the design is difficult.In this paper,based on an urban complex rail transit node with station and bridge connected,the spatial finite element model is established by using finite element software Midas/civil,and the static characteristics,the dynamic characteristics are analyzed.Use finite element software Ansys to analyse and compare the mechanical performance of the two kinds of beam-column joints used in subway stations.Some main conclusions are obtained as follows:(1)The maximum stress of the continuous steel box girder bridge in the normal operation stage is 83.0 MPA,and the maximum vertical deflection of the main girder is 84.8 mm.The strength and stiffness of the main girder meet the requirements;(2)Under different load combinations,the maximum internal force and stress of the top floor beam system in the main body of the station(long-span atrium and its distribution span)appear in the B1-type steel box girder,the maximum tensile stress is234 MPa,the maximum compressive stress is-283 MPa,and the material strength of each steel box girder section meets the requirements;(3)In the reinforced concrete rectangular beams of negative 1st layer and negative 2nd layer,the positive section flexural bearing capacity of 1400×1400-type beam in negative 1st layer and 1500×1250-type with negative 2nd layer does not meet the requirements.After adding longitudinal steel bars to the beams which do not meet the design requirements,the flexural bearing capacity,shear bearing capacity and maximum crack width of all the reinforced concrete rectangular beams meet the design requirements;(4)The vibration frequency of the first 5 vibration of the whole station model is small,and the vibration fundamental frequency is 1.298 HZ,which indicates that the edge span stiffness of the structure is small.The vibration fundamental frequency of the main body of the station(long-span atrium and its distribution span)is 3.681 HZ,which indicates that the main body of the station has a large structural stiffness;(5)By comparing different local models of "beam-column joint",the concrete section of the "column-through" beam-column joint located between the top and bottom slab of the steel box is easy to crack and destroy,and the maximum equivalent force of the steel part of the modified "column-through" beam-column joint reaches378.9MPa.By comprehensive comparison,the “beam-through” beam-column joint is dominant in terms of stress and fabrication process.The maximum equivalent stress of its steel part is 277.5MPa,and most of the concrete part is under compression.Therefore,it is advisable to select the "beam-through" beam-column joint in this project. |
