风撑对半穿式应急钢桁梁面外稳定性的影响研究  

Study on Effect of Wind Brace on External Stability of Half-through Emergency Steel Truss Girder

作　　者：赵曼 陈士通[2,3,4] 孙志星[2,3,4] 许宏伟 黄晓明[5] ZHAO Man;CHEN Shitong;SUN Zhixing;XU Hongwei;HUANG Xiaoming(School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;Collaborative Innovation Center for Performance and Security of Large-scale Infrastructure,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;Hebei Engineering Innovation Center for Traffic Emergency and Guarantee,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;School of Transportation,Southeast University,Nanjing 210096,China)

机构地区：[1]石家庄铁道大学土木工程学院,河北石家庄050043 [2]石家庄铁道大学省部共建交通工程结构力学行为与系统安全国家重点实验室,河北石家庄050043 [3]石家庄铁道大学大型基础设施性能与安全省部共建协同创新中心,河北石家庄050043 [4]石家庄铁道大学河北省交通应急保障工程技术创新中心,河北石家庄050043 [5]东南大学交通学院,江苏南京210096

出　　处：《铁道学报》2023年第3期144-152,共9页Journal of the China Railway Society

基　　金：国家重点研发计划(2021YFB2600605,2021YFB2600600)。

摘　　要：为探析风撑对半穿式应急钢桁梁面外稳定性的影响,通过理论推导给出风撑轴力、半框架侧向位移计算公式,并以某56 m跨半穿式应急钢桁梁为研究对象,分别采用有限元法、本文方法和规范方法进行计算,对比验证理论推导的正确性和合理性,以及规范方法中忽略风撑影响的不合理性;开展面外稳定参数影响分析,探讨风撑的作用机理以及风撑面积、风撑夹角对半穿式应急钢桁梁稳定性的影响规律。研究表明,半穿式应急钢桁梁稳定分析中应充分考虑风撑的作用,忽略其影响不利于轻量化设计;参数影响分析表明,风撑轴力、半框架侧向位移、上弦杆侧向支撑刚度以及结构整体稳定性均随风撑面积和风撑夹角的不同而变化。对于本文算例,综合考虑各种因素,建议风撑面积取为腹杆面积的20%~50%,风撑竖向夹角取15°~35°,可显著提高上弦杆侧向支撑刚度,线弹性稳定系数提高18%~32%,风撑对半穿式应急钢桁梁面外稳定性的改善最优。In order to discuss and analyze the effect of wind brace on the external stability of half-through emergency truss girder,the calculation formulas of axial force of wind brace and lateral displacement of semi-frame were given through theoretical derivation.Based on the case study of a 56 m half-through emergency steel truss girder,the FEM,the method in the paper and the method in the code were respectively used to carry out calculations to prove by comparison of the calculation results the correctness and reasonability of theoretical derivation and the unreasonableness of the ignorance of the brace effect in the code.The parameter effect analysis of external stability was conducted along with the discussion of the action mechanism of wind brace and the effect of wind brace area and wind brace angle on the stability of the half-through truss girder.The results show that the effect of wind brace should be considered in the stability analysis of half-through emergency steel truss girder.Ignoring the brace effect is adverse to lightweight design.The parameter effect analysis shows that the axial force of the wind brace,the lateral displacement of the semi-frame,the lateral stiffness of the upper chord and the overall structural stability change with the brace area and the brace angle.In the proposed example,with comprehensive consideration of various factors,it is suggested that the brace area of about 20[WTB4]%~50[WTB4]%of the area of the web member,and the vertical brace angle of about 15°~35°can improve the lateral stiffness of upper chord significantly.With the improvement of linear elastic factor of stability by about 18[WTB4]%~32[WTB4]%,the wind brace can best improve the external stability of half-through girder.

关 键 词：半穿式钢桁梁 风撑 面外稳定性 风撑面积 风撑夹角 

分 类 号：U448.22[建筑科学—桥梁与隧道工程]