自锚式悬索桥主缆状态影响参数分析

摘要

This paper makes a thorough affecting parameter analysis on the initial construction state and completion state of the self-anchored suspension bridge.Make the main cable curve,the horizontal com-ponent force and the action point of the resultant force of the main cable to the main saddle as the con-trolling target,the rational completion state of the main cable is defined;take the Wusong’s bridge in the Jilin city as an example,the finite element mode of the main cable is created.Changing the model parame-ters,the initial construction state and the completion state of the main cable under different parameters are calculated,which are compared with the reference state,the affections of each parameter to the state of the cable are studied:main cable self-weight and the initial construction temperature have little effect on the state of the main cable;the length of the mid-span main cable mainly affects itself line-shape,while the length of the side-span main cable has big effect on each controlling target;make the initial construc-tion line-shape as the controlling condition,the location deviation of the main saddle and back anchorage face,happens before constructing the main cable,has little effect on the completion state,but which will have great effect on the completion state if happens on the completion stage.Engineering example analy-sis results show that,the tensile stiffness of the main cable and the tensile force of the rod will have some effect on the completion state of the main cable,proposed that the tensile stiffness of the main cable and the weight of the normal beam should be tested before constructing the main cable,and the deviation should be control within the rational limits;recommended that the initial construction line-shape of the main cable should have pre-elevation,which could cancelate the deformation of the main saddle and the back anchorage face on the completion stage,this conclusion has a strong guiding significance and refer-ence value on the work of constructing the main cable of the self-anchored suspension bridge.%对自锚式悬索桥主缆的空缆状态和成桥状态进行了影响参数分析。以主缆线形、主缆对主索鞍水平分力和合力作用点位置为控制目标，定义了主缆合理成桥状态；以吉林市雾凇大桥为例，建立了主缆有限元模型。改变模型参数，计算主缆在不同参数下的空缆状态和成桥状态，并将其与基准状态进行比较，具体研究各影响参数对主缆状态的影响情况。主缆自重和空缆架设温度均对主缆状态影响甚微，中跨主缆无应力索长主要影响其自身线形，而边跨无应力索长会对各控制目标均造成较大影响；以空缆架设线形为控制条件时，发生在空缆架设前的主索鞍和后锚面位置偏差对主缆成桥状态不构成影响，但其发生在成桥运营阶段的变形会严重影响主缆成桥状态。工程实例分析结果表明，主缆抗拉刚度和成桥吊杆力均会对主缆成桥状态造成一定影响，建议在空缆架设前实测主缆抗拉刚度和梁段标准节间重量，控制两者偏差在合理范围内；建议对空缆架设线形设置预抬高，以抵消主索鞍和后锚面在成桥阶段的变形，该结论对自锚式悬索桥的空缆架设工作具有较强的指导意义和参考价值。