变跨变幅钢栈桥结构设计及受力性能分析

Analysis of Structural Design and Mechanical Performance in Steel Trestle with Variable Amplitude and Span

【目的】为了研究变跨变幅钢栈桥在多荷载工况下的承载性能。【方法】以向莆联络线向莆左线特大桥施工中的一座钢栈桥为研究对象,通过桥梁有限元软件Midas civil建立数值模型,分析其在5种不同工况下各个构件的受力状态。【结果】研究结果表明:钢栈桥贝雷梁在各种工况作用下,结构强度及刚度均有较大安全富余;桩顶分配梁在工况1及工况2作用下,其折算应力的安全富余系数较小,仅为1.23和1.20,工况5作用下其刚度的安全富余系数为1.20,施工过程中需要避免过重的临时荷载堆放;钢管立柱在工况5作用下的正应力安全富余系数仅为1.50,施工过程中应采取措施确保施工的安全性;转角处三角区设计符合结构性能要求。【结论】研究成果可为同类栈桥设计提供借鉴。

【Objective】To study the load-bearing capacity of variable span and amplitude steel trestle bridges un-der multiple loading conditions.【Method】A steel trestle bridge in the construction of the Xiangtang-Putian left line special bridge on the Xiangtang-Putian connection railway line is taken as the research object.A numerical model was established by using the bridge limited element software Midas civil to carefully study the stress state of each component under five different conditions.【Result】The results show that the bailey beam has a large safety margin under different conditions;the safety margin factor of the pile top distribution beam is small under condition 1 and 2,reaching only 1.23 and 1.20,and the safety margin factor of its stiffness is 1.20 under condi-tion 5.It is necessary to avoid excessive temporary loads during construction;the positive stress safety margin factor of the steel tube column under condition 5 is only 1.50,and measures should be taken to ensure safety dur-ing construction;the design of the triangular area at the corner meets the structural performance requirements.【Conclusion】The results may provide some reference for the design of similar trestle bridges.