自锚式悬索桥静力特性模型试验研究

Experimental Study on Static Characteristics Model of Self-anchored Suspension Bridge

为研究自锚式悬索桥在运营阶段的静载响应规律,以应变相等为原则,按静力相似理论对哈尔滨市三环西线跨松花江大桥主桥进行1∶50缩尺模型试验研究。以轴向刚度、弯曲刚度相似为主进行模型设计,重点关注桥梁的受力与变形性能。根据有限位移理论的仿真分析,结合相关规范的规定,制订桥梁静力试验工况及试验方法。基于最不利加载工况下的试验数据,对该桥的主缆、吊索、主梁的受力及变形特征进行分析。结果表明:双塔对称体系自锚式悬索桥的边主跨挠度分布情况与三跨连续梁类似,但由于竖向索力的弹性支撑作用,结构挠度减小,证明结构在静力作用下能承担的荷载更大;各关键构件荷载安全系数均在规范限值以内,大桥结构受力偏于安全;各测试工况试验值与理论计算值总体吻合较好,模型能较好反映实桥的受力特性,同时也印证了缩尺模型设计的合理性。

To study the static load response regularity of self-anchored suspension bridge in operational stage, based on the principle of equal strain and the static similaity theory, we conducted the 1 ： 50 scale model test study of the main bridge of Songhuajiang Bridge on the West Third Ring Road in Harbin. The model design gave priority to the similarity of axial stiffness and flexural rigidity, mainly focused on the force and deformation properties of the bridge. We made the scheme for the static test conditions and test methods of the bridge according to the simulation analysis by the finite displacement theory, and combined with the relevant specifications. Based on the test data under the most unfavorable loading conditions, we analysed the force and deformation eharaeterties of the main cables, the slings and the girders. The results show that （ 1 ） the distributions of the main span and side span deflections of 2-pylon symmetrical system self-anchored suspension bridge are similar to that of 3-span continuous beam, however, the structure deflection decreases due to the elastic supporting effect of the vertical cable tension, which proved that the structure can bear more load affected by the static force; （2） the load safety factors of every key component are within the specification limits, the bridge structure stresses are relatively safe; （3） every test value under the test conditions is in consistent with the theoretical calculated value, the model can better reflect the real force characteristics of the bridge, it also verified the rationality of the scale model design.