钢桁梁螺栓滑移与空间扭曲变形映射机理研究

Study on Mapping Mechanism of Bolt Slippage and Spatial Distortion of Steel Truss Bridge

摘要:

对一座扭曲变形的80 m简支栓焊下承式钢桁梁桥进行了三维激光扫描精细测量和建模，并进行数值模拟，分析了节点螺栓预紧力变化对杆端抗弯刚度的影响、节点螺栓滑移与杆端抗弯性能映射关系，提出了用折减等效杆端抗弯刚度模拟螺栓滑移的简化模拟方法。当螺栓预紧力下降时，杆端抗弯刚度下降，且随着螺栓预紧力下降程度增大，杆端抗弯刚度下降速率变快。通过分析钢桁梁桥横向变形规律，在EE0～EE4、EE5～EE10和A7～A9处螺栓预紧力降低情况下，钢桁梁桥整体横向变形趋势与实际测量的横向变形趋势相同，且变形量相近。

Abstract:

The fine measurement and modeling of 3D laser scanning are carried out for a 80-m simple-supported bolt-welded through steel truss girder bridge with spatial distortion are carried out, and the numerical simulation is conducted to analyze the influence of pre-tightening force change of the node bolt on the bending stiffness of the rod end and the mapping relationship between the slippage of node bolt and the bending stiffness of rod end. A simplified method to simulate the bolt slippage by reducing the bending stiffness of equivalent rod end is presented. When the pre-tightening force of the bolt is reduced, the bending stiffness of the rod end decreases. With the increase of the reduction degree of bolt pre-tightening force, the bending stiffness of rod end decreases rapidly. By analyzing the transverse deformation rule of the steel truss girder bridge, under the condition of reducing the pre-tightening force of the bolts at EE0-EE4, EE5-EE10 and A7-A9, the overall transverse deformation trend of the steel truss girder bridge is the same as the actual measured transverse deformation trend of the bridge, and the deformation of the both is similar.