In order to analyze the stress distribution law of the segmental assembly structure of a large-tonnage steel arch bridge,a finite element model of the steel truss flexible arch bridge was established with the Qijiang River Bridge as the background.The construction of multiple segmental assembly was simulated,and the influence of system transformation on the structural stress distribution characteristics was analyzed.The results are as follows.After assembling the truss and lower deck,the peak stress of a truss occurs in mid-span and decrease along both sides.After assembling the upper deck and arch ribs,the stress on the end side increased by 1times.After the tension of hangers,the stress at 1/4 span increa-ses by 1.4 times.In construction stage,the stress of the upper deck is higher than that after the bridge is formed.Its stress is bimodal along the longitudinal bridge,and the peak stress located on 1/4 span.The stress of the lower deck is lower during the construction phase,but its stress increases by 85%after removing the supports.Before the system con-version,the stress of the structural details including the arch feet and truss fulcrums at both ends is small.However,af-ter the beam-arch system conversion,the stress of these details increased by 0.7 and 2 times respectively.Subsequently,the mode analysis was carried out,and the frequency and rigidity in construction stage were investigated.According to a-nalysis results,the installation of truss and decks has a little impact on the structural rigidity.However,after the instal-lation of the arch ribs,the structural rigidity will be reduced significantly.In addition,removing the supports from both sides of the bridge to the middle of the span can ensure a smooth transition of stress and linear shape.
关键词
钢桁梁柔性拱桥/体系转换/拼装施工/应力分布/数值模拟
Key words
steel arch bridge with truss/system transformation/assembly construction/stress distribution law/numerical simulation
维普
万方数据