拱脚变位对覆土波纹钢板拱桥受力性能的影响

结合内蒙某实际桥梁参数,利用有限元软件建立了考虑土与波纹钢板相互作用的二维平面应变模型,通过对模型施加强制位移,计算分析了10种不同拱脚变位工况下结构的受力和变形的变化规律.拱脚发生水平位移时对结构受力性能的影响比拱脚发生竖向沉降时大,拱脚水平位移造成结构位移增大,拱圈应力由受压转为受拉;拱脚不均匀沉降对结构的影响较均匀沉降大;特别是拱脚同时发生不对称的竖向和水平位移使结构位移显著增加,拱圈两侧拉压应力数值都明显增大.拱脚变位还会造成拱脚反力变化,特别是不均匀拱脚变位时会出现反力方向变号.尽管覆土波纹钢板拱桥变形适应能力较强,但在设计和施工中也应采取措施,避免和减小基础的变位.

Effect of Springing Displacement on Mechanical Performance of the Buried Corrugated Steel Arch Bridge

The simplified two-dimension plane strain finite element model considering the soil-structure interaction is established according to parameters of a real bridge in Inner Mongolia.The variation law of the force and deformation of the bridge with ten different springing displacement conditions are calculated by imposing coercive displacements of the model.The analysis results show that horizontal displacement of the arch springing has much more impact on the bridge than vertical displacement and the deformation increased obviously and the stress of the arch ring turned to tension from compression.The uneven settlement of the springing has more negative impact than the uniform settlement.Especially,the deformation and the stress,both tension and compression,increased notably when the uneven horizontal and the vertical displacement occurred simultaneously.The support reactions are also varying with the springing displacement.The uneven springing displacement even resulted in a significant change of the direction of the reaction force.So,although the corrugated steel plate arch bridge has strong ability to adapt the deformations,it is necessary to take some control methods to avoid the springing displacement.