既有预应力混凝土T形刚构桥加固设计方法研究

发布时间：2018-03-07 23:35

本文选题：T形刚构桥　切入点：承载力　出处：《长安大学》2015年硕士论文　论文类型：学位论文

【摘要】：T形刚构桥由于具有受力明确、施工快捷、墩梁之间不需要设置支座等优点,上世纪七八十年代,我国修建了大量这种结构体系的桥梁。经过十几年或几十年的通车运营,这些早期建造的T形刚构桥由于设计荷载等级较低、车辆严重超载、养护不当等原因,目前发现存在大量的病害和破损,多数的T形刚构桥无法满足日益增多的车流量承载需求。本文结合我国T形刚构桥的应用经验与实际运营状况,在总结前人研究成果的基础上,对既有预应力混凝土T形刚构桥的加固设计方法进行研究。首先介绍了国内外T形刚构桥的发展概况,分析该种桥型自身的受力特点和在使用过程中存在的各类问题,总结了T形刚构桥加固技术的研究现状和工程实践中常用加固方法。以马兰大桥为依托工程,介绍了该桥的上部结构、下部结构、桥面系及附属结构的病害检查结果,对桥梁技术状况给予了评定。在此基础上,对荷载试验结果进行了分析,得到实桥目前的基本状况,对实桥的实际承载能力进行了评定。采用以增加体外预应力钢筋为主的综合加固方法对马兰大桥进行加固,分析了体外预应力单独作用下主梁的受力性能,对加固后主梁的承载力、应力、挠度等进行了验算,并与加固前的主梁受力状态进行了对比分析,探讨加固效果。本文最后根据旧桥的实际工作状况评估结果,从改变结构体系的角度提出一种新的加固T形刚构桥的设计方法,将原结构的挂梁拆除,替换为钢箱梁,钢箱梁与T构主梁固结,原桥由T形刚构桥转变为连续刚构桥。对改变结构体系加固后的主梁进行了受力分析,并与原桥的受力状态进行了对比,分析该种方法理论上的可行性。
[Abstract]:Because T-shaped rigid frame bridge has the advantages of clear force, quick construction and no need to set supports between piers and beams, in 0th century, a large number of bridges of this kind of structure system were built in our country. Due to the low design load grade, serious overloading of vehicles and improper maintenance of these early T-shaped rigid frame bridges, a large number of diseases and breakages have been found at present. Most T-shaped rigid frame bridges can not meet the increasing demand for traffic flow. This paper, based on the application experience and practical operation of T-shaped rigid frame bridges in China, summarizes the previous research results. The reinforcement design method of existing prestressed concrete T-shaped rigid frame bridge is studied. Firstly, the development of T-shaped rigid frame bridge at home and abroad is introduced. This paper summarizes the present situation of strengthening technology of T-shaped rigid frame bridge and the commonly used reinforcement methods in engineering practice. Based on Ma Lan Bridge, it introduces the inspection results of the superstructure, substructure, deck system and subsidiary structure of the bridge. The technical condition of the bridge is evaluated. On this basis, the load test results are analyzed, and the present basic condition of the bridge is obtained. The actual bearing capacity of the real bridge is evaluated. The comprehensive reinforcement method, which mainly increases the external prestressing bar, is adopted to reinforce Ma Lan Bridge, and the mechanical behavior of the main beam under the action of external prestressing alone is analyzed. The bearing capacity, stress, deflection and so on of the strengthened main beam are checked and calculated, and the stress state of the main beam before strengthening is compared and analyzed, and the effect of reinforcement is discussed. Finally, according to the actual working condition of the old bridge, the paper evaluates the results. From the point of view of changing the structure system, a new design method of strengthening T-shaped rigid frame bridge is put forward. The hanging beam of the original structure is removed and replaced with the steel box girder, and the steel box girder is consolidated with the T-structure main beam. The original bridge is transformed from T-shaped rigid frame bridge to continuous rigid frame bridge. The stress of the main beam strengthened by the changed structure system is analyzed and compared with that of the original bridge, and the feasibility of this method is analyzed theoretically.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.72;U448.231

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