柔性系杆拱桥系杆力损失与系杆更换技术研究

发布时间：2018-08-20 10:22

【摘要】：本文以某跨径布置为46m+202m+46m的柔性系杆钢管混凝土拱桥为工程背景,以系杆拱桥可靠度理论及有限元分析理论为基础,针对不同系杆力损失情况下全桥力学性能变化、桥梁可靠度变化及系杆更换方法进行了深入研究。主要研究工作包括:①针对依托工程,采用一次二阶矩法及PNET法,研究了系杆力损失分别为0%、5%、10%、15%、20%及25%六种工况及不同使用年限下全桥力学性能及桥梁可靠度的变化规律。结果表明:各工况下,各构件可靠度表现为主拱肋边拱桩基;全桥最薄弱的部位出现在桩底截面。当系杆力损失为15%时,体系安全等级在任何使用年限内均小于三级,为保证桥梁的最低安全等级,当系杆力损失超过15%后应尽快实施系杆更换。②针对依托工程,以系杆力损失10%为初始状态,提出了4种系杆更换方案:单侧同时更换1根、2根、3根和4根,各方案下均实行上下游侧系杆同时更换,并对不同方案下的车辆进行间断放行,同时在施工间歇时对车辆进行限重放行。③对比分析了4种方案下桥梁力学行为变化及可靠度变化,结果表明:各方案下,控制截面应力、桥面挠度及系杆内力等均满足要求;但可靠度分析表明仅方案1、2可行,此外,方案2相比方案1的施工时间可缩短约一半,因此,建议采用方案2进行系杆更换。
[Abstract]:Based on the engineering background of a flexible concrete-filled steel tubular arch bridge with a span of 46m 202m and 46m, and based on the reliability theory and finite element analysis theory of the tied arch bridge, this paper aims at the change of mechanical properties of the whole bridge under the condition of different tie bar force loss. The variation of bridge reliability and the replacement method of tie rod are studied in depth. The main research work includes: 1, the first order second moment method and PNET method are used to study the variation of mechanical properties and bridge reliability of the whole bridge under six different working conditions and different service life respectively, the loss of tie rod force is 0, 5, 10, 15, 15, 20%, and 25%, respectively. The results show that the reliability of each component is the main arch rib arch pile foundation under each working condition, and the weakest part of the whole bridge appears in the pile bottom section. When the loss of tie bar force is 15, the safety grade of the system is less than three levels in any service life. In order to ensure the lowest safety grade of bridge, when the loss of tie bar force exceeds 15%, the replacement of tie rod should be carried out as soon as possible to support the project. Taking 10% loss of tie rod force as the initial state, four kinds of tie-bar replacement schemes are put forward: one side, two branches, three and four, all of which are replaced at the same time, and the vehicles under different schemes are released intermittently. At the same time, the change of mechanical behavior and reliability of the bridge under the four schemes are compared and analyzed during the intermittent construction. The results show that the control section stress, the deflection of bridge deck and the internal force of tie rod meet the requirements under each scheme; However, the reliability analysis shows that only option 1 / 2 is feasible, in addition, the construction time of scheme 2 can be shortened by about half compared with that of scheme 1. Therefore, it is suggested that option 2 be used to replace the tie bar.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.7;U448.225

【参考文献】