Mechanical behavior of steel truss bridge stiffened with rigid cables in construction stage
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摘要: 采用空间有限元方法对刚性悬索加劲钢桁梁桥的施工全过程进行了仿真分析, 通过变化边界条件与施加节点强制位移分别模拟结构体系转换和内力调整, 采用释放纵梁一端的纵向刚度来模拟纵梁长圆孔的影响, 对比了6种主要工况下结构的内力和位移。分析结果表明: 通过体系转化和内力调整, 能有效地使刚性悬索与钢桁梁共同受力; 横、纵向内力调整能使结构的中边桁与中边跨的内力差异减小到5%以内; 在纵梁两端设置长圆孔能有效避免其过早参与纵向受力, 仅使整体结构的内力与挠度增加10%左右, 但使得纵梁与横梁的最大组合压应力分别从-271.1-、505.8 MPa降低到-63.0、-178.0 MPa, 小于材料的容许应力210 MPa。Abstract: 3D finite element numerical method was used to simulate the whole construction processes of steel truss bridge stiffened with rigid cables.Changing boundary conditions and imposing compulsory displacements on some nodes were applied to simulate system transformation and internal force adjustment respectively.Relaxing the longitudinal stiffness of an end of longitudinal girder was applied to simulate the effect of slotted holes.The internal forces and deflections were compared under six main conditions.Analysis result shows that rigid cables can participate in action with steel trusses more effectively through system transformation and internal force adjustment.Through internal force adjustment in longitudinal and lateral directions, the deviations of internal forces for the chords of middle truss and side truss, as well as that of midspan and sidespan, are less than 5%.Slotted holes set at both ends of longitudinal girder can avoid it taking part in longitudinal action prematurely, through which the internal force and deflection of main truss would increase by about 10%, while the maximum combined compressive stresses of longitudinal girder and floor beam would decline respectively from-271.1 MPa and-505.8 MPa to-63.0 MPa and-178.0 MPa, which are less than their allowable stress value 210 MPa.
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Key words:
- bridge engineering /
- rigid cable /
- steel truss /
- system transformation /
- internal force adjustment
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[1] GRIGGS J F E. Evolution of the continuous truss bridge[J]. Journal of Bridge Engineering, 2007, 12(1): 105-119. doi: 10.1061/(ASCE)1084-0702(2007)12:1(105) [2] WUZhen-wang. Research on suspended stiffening steel trussbridge[D]. Chengdu: Southwest Jiaotong University, 2006. (in Chinese) [3] GAO Zong-yu. Overall design of Wuhan TianxingzhouChangjiang River Rail-cum-road Bridge[J]. Bridge Construction, 2007(1): 5-9. (in Chinese) [4] WANG Jun. Study of construction technique of long spansteel truss structure[D]. Tianjin: Tianjin University, 2004. (in Chinese) [5] ZHOU Meng-bo. New techniques in construction of WuhuChangjiang River Bridge[J]. Bridge Construction, 2000(2): 12-19. (in Chinese) [6] XI N Bin, LI De-kung, LI Xiu-hua. Construction techniquesfor integral steel truss girder block of Caiyuanba ChangjiangRiver Bridge in Chongqing[J]. Bridge Construction, 2007(6): 56-60. (in Chinese) [7] LI U Yong-jian, LI U Jian, ZHU Ming. Static and dynamicmodel design of the total bridge of double-deck andthree maintrusses steel bridge with rigid cable[J]. Journal ofArchitecture and Civil Engineering, 2008, 25(1): 84-87. (in Chinese) [8] LI U Yong-jian, ZHANG Jun-guang, HUANG Jian-chao. Test model of whole bridge of double-deck and three maintrusses steel bridge with rigid cable[J]. Journal of Architectureand Civil Engineering, 2008, 25(3): 61-65. (in Chinese) [9] PENG Zheng-hua. Study on crucial technique of three maintrusses steel bridge with rigid cable[D]. Shanghai: TongjiUniversity, 2007. (in Chinese) [10] ZHAO Yu, HE Shuan-hai, SONG Yi-fan. Evaluation method-ology for existing truss-cable composite continuous steelbridge[J]. Journal of Chang an University: Natural ScienceEdition, 2005, 25(5): 47-50. (in Chinese) [11] ZHAO Yu, HE Shuan-hai. Evaluation for existing truss-cablecomposite continuous steel bridge based on stress releasemethod[J]. Journal of Chang an University: Natural ScienceEdition, 2006, 26(5): 40-42, 47. (in Chinese) [12] CHEN Wan-chun, ZHENG Xiao-yan, HAO Xian-wu, et al. Performance si mulation of existing continuous steeltruss bridges after beeing strengthened[J]. Journal ofChang an University: Natural Science Edition, 2006, 26(1): 43-48. (in Chinese) -
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