基于灵敏度分析的斜拉桥拉索更换顺序研究

Study on Sequence of Cable Replacement for Cable-stayed Bridge Based on Sensitivity Analysis

通过对部分换索桥梁换索顺序的调研,按照拉索不同的布置形式,总结了目前拉索更换所采用的主要顺序,并利用有限元分析方法对某双塔双索面斜拉桥进行了模拟换索,分析得到了偏于安全的换索顺序。通过拆单根索的弯曲应变能的变化,分析了斜拉桥换索的整体顺序。通过分析不同换索工况下的索力增量变化规律,包括单塔拆1根、双塔同侧索面对称拆4根、双塔不同侧索面反对称拆4根等3种工况,对拉索更换顺序进行了研究,并对其中的同侧索面和不同侧索面拆除4根拉索的工况进行了主梁线形的分析,建立了有限元模型。分析认为,斜拉桥拉索的更换宜从短索向长索反对称进行。

By analyzing the cable replacement sequence survey of some bridges,the major sequence of cable replacement was summarized according to the different arrangement forms of the cable,and the safety cable replacement sequence was obtained from simulating the cable replacement of a cable-stayed bridge with double towers and double cable planes using the finite element model.The sequence of cable replacement of cable-stayed bridge was analyzed according to the variation of bending strain energy when only one cable was replaced.The variation of cable force in different cable replacing conditions were compared,including replacing one cable of single tower,replacing four cables symmetrically on the same side of double towers and replacing four cables antisymmetrically on the different sides of double towers,and the sequence of cable replacement was studied.The alignment control of bridge girder was analyzed under the conditions of replaceing four cables on the same side of double towers and replacing four cables on the different sides of double towers,and established a finite element model.By summarizing and analysis,the cable replacement of cable-stayed bridge should proceed antisymmetrically from the short cable to the long cable.