斜拉桥锚拉板式索梁锚固结构传力机理及疲劳可靠性研究

针对锚拉板式索梁锚固结构部分区域应力集中严重,疲劳性能不明确等问题,对湛江海湾大桥锚拉板式索梁锚固结构分别进行了足尺比例静载和疲劳模型试验,研究了其结构特点、制造工艺、应力集中程度、塑性区大小和分布、关键构造细节的疲劳性能等。通过有限元计算,对影响结构性能的一些重要参数进行了分析。研究结果表明,该结构部分区域存在一定程度的应力集中,在1.7倍设计荷载作用下个别区域出现了屈服,经循环加载疲劳试验结构关键部位未发现疲劳裂纹,结构的静承载力和疲劳性能均能满足设计要求,并具有一定的安全储备。研究结果为类似结构的设计提供了可靠的参考数据,并对结构参数优化、改善结构受力性能等具有一定的指导意义。

Mechanical behavior and fatigue reliability of tensile anchor plate structure in the cable-beam anchorage zones of cable-stayed bridges

Stress concentrations and uncertain fatigue performance are the primary problems for tensile anchor plates at cable-beam anchorage zones in cable-stayed bridges.In order to investigate the mechanical behavior and fatigue reliability of the structures,a full-scale static-load model test and a fatigue model test of the tensile anchor plate structure of the Zhanjiang Gulf bridge(a cable-stayed bridge in Guangdong,China) were performed.Problems such as structural features,manufacture processes,stress concentrations,distributions of plastic zones and fatigue performance of some structural details,were studied.Based on 3-D FEA results,the important parameters influencing the structural performance were analyzed.The test results showed that the areas of stress concentrations were fairly localized,plastic yield occurred in few regions under 1.7 times the design load,and no fatigue cracks were found after cyclic loading.The structural performance satisfies the design requirement.