陡峭山区大跨度钢管拱桥悬臂拼装抗风性能及稳定性分析

Analysis on Wind Resistance and Stability of Long-span Steel Tubular Arch Bridge in Steep Mountainous area During Cantilever Assembly Construction

山区隘口风速大,对桥梁施工安全构成重大风险。文中结合某陡峭山区大跨度钢管混凝土拱桥施工项目,研究不同风速条件下静风荷载三分量对结构的影响程度和设置浪风索对提高结构稳定性的效果。针对浪风索初始拉应力较小、垂度大导致的浪风索刚度弱的问题,运用几何非线性数值分析方法,通过修正浪风索弹性模量,探讨不同风速条件下施工阶段钢管拱桥悬臂拼装受力性能和抗风稳定性。分析表明,初始索力较小的浪风索在较高风速下能有效提高结构抗风能力。

The high wind speed in mountain passes is a great risk to the safety of bridge construction.On the background of a construction project of long-span concrete-filled steel tube arch bridge in a steep mountainous area,the influence of three components of static wind load on the structure under different wind speed conditions and the improving effect of wave wind cable on the stability of the structure are studied in the paper.In order to solve the problem of weak stiffness caused by the small initial tensile stress and large sag of the cable,the mechanical performance and stability of cantilever assembly of steel tubular arch bridge under different wind speed conditions are studied by modifying the elastic modulus of the cable using geometric nonlinear numerical analysis method.The analysis shows that the wave-wind cable with small initial cable force can effectively improve the wind resistance of the structure under higher wind speed.