悬索桥主塔纵向受力的估算方法

基于悬索桥的传力特点,提出主塔纵向受力简化分析模型,对中、边跨主缆的内力及线形进行分析,根据主缆无应力长度相等的原则推导出塔顶位移、塔底弯矩和轴力的计算公式.分别以主跨为1000米的单跨及三跨悬索桥为例,利用简化计算方法对主塔的纵向受力进行了计算,并与有限元计算结果进行对比分析.结果表明,简化公式具有良好的计算精度,且可同时适用于单跨及三跨悬索桥,满足了概念设计的要求.

Simplified analytical method for longitudinal mechanical properties of suspension bridge towers

Based on the path of force conduction of suspension bridge towers, a simplified analytical model for their longitudinal mechanical properties is proposed. The internal force and line shape of main cable are analyzed, Explicit formulations about the displacement, bending moment and axial force of the towers are obtained based on the constant unstressed length. Both single-span and three-span suspension bridges with length of 1 000 m are took as examples. The mechanical indexes of the towers are calculated by the proposed formulations. A comparison between the simplified results and numerical results shows a good accuracy of the simplified analytical method. All the proposed formulations are proved applicable to both single-span and three-span suspension bridges.