斜拉桥拉索单元模型及其计算模拟

斜拉索的模拟有许多种方法,而应用最为普遍的则属等效弹性模量法,运用Ernst公式进行弹性模量的修正。然而,对于跨度日渐增大的斜拉桥的拉索,此方法是否还能保证其模拟的精确性还需要进一步的探讨。为此,讨论了斜拉索的非线性特征,建立斜拉索的状态方程,并介绍了几种常见的索模型及其特点,其中详细介绍了等效弹性模量法的原理。算例中运用Ernst公式对苏通大桥6根长短索进行修正,计算主梁竖向位移,并与悬链线模型算出的结果进行精度比较,分析得出等效弹性模量法的适用范围。

CABLE MODEL AND COMPUTING SIMULATION OF CABLE-STAYED BRIDGES

Many methods are available to simulate bracing cables,of which the equivalent elastic modulus method is the most common one.The elastic modulus can also be corrected by Ernst formula.The nonlinear characteristics of the bracing cables are discussed and the state equation for the bracing cables is also established.Several common cable models and their features are presented,of which the principle of the equivalent elastic modulus method is described in detail.Taking Suzhou-Nantong Bridge for example,whose six long and short cables are corrected by Ernst formula;the calculated vertical displacement of the main girder is compared with the result by the catenary model,and the applicable scope of the equivalent elastic modulus method is also got by the analysis.