车道荷载作用下的矮塔斜拉桥的索梁活载比

Under the Action of the Lane Load for Cable/Girder Ratio of the Extradosed Cable-stayed Bridges

针对矮塔斜拉桥的受力特点,现有的界定矮塔斜拉桥与斜拉桥索梁活载比简化公式存在缺陷。采用比拟梁法,推导出车道荷载作用下的索梁活载比计算公式。比较了该公式与已有简化公式和有限元计算结果,结果表明,该公式与有限元解更为逼近。研究表明,在计算矮塔斜拉桥的索梁活载比时要计入车道荷载中的集中荷载的影响,并提出权矩阵可界定矮塔斜拉桥、斜拉桥及连续体系梁桥。

On the basis of the loading features of extradosed cable-stayed bridges, there are some defects existed in the simplified cable/girder live load ratio formulation between extradosed cable-stayed bridges and cable-stayed bridges. Using the analogy girder method, cable/girder live load ratio formulation under the action of lane load was deduced. Compared with the results of present simplified formulation and finite element method （FEM）, it shows that the above formulation is closer to the finite element method （FEM）. The experimental results shows that calculating of the cable/girder live-load ratio of the extradosed cable-stayed bridges should consider the influence of concentrated load of the lane load. The concept of the weight matrix was introduced to separate the extradosed cable-stayed bridges from the cable-stayed bridges and the continuous girder bridge.