【作者】 曾有艺；

【导师】 颜东煌； 李学文；

【作者基本信息】 长沙理工大学 ， 桥梁与隧道工程， 2009， 硕士

【摘要】 随着我国高速公路建设的蓬勃发展,桥梁建设进入了前所未有的高潮时期,预应力连续刚构桥以其结构整体性能好、抗震能力强、抗扭刚度大、桥墩抗推刚度较小等特点,近年来发展较快,是大跨、高墩桥梁的首选桥型之一。预应力设计是预应力混凝土连续刚构桥上部结构设计的重要组成部分。目前,部分已建成并投入运营的预应力混凝土连续刚构桥出现了主梁跨中挠度过大的问题,其多数是因为预应力设计时对预应力束的应力损失估计不足造成的。本论文以湖南邵永高速公路湘江大桥为工程背景,通过现场试验对长束预应力损失的规律进行研究,将研究结果用于大桥的上部结构计算中,并结合应变的现场测试结果分析验证了不同工况下控制截面的应力情况。首先给出了识别引起结构预应力损失的孔道偏差系数k的两种方法(间接法和直接法)。通过对测得的预应力索沿程应力和混凝土箱梁截面应力数据的分析处理,得到合理的管道偏差系数k,找出预应力损失的变化规律。然后运用大跨度桥梁设计计算与控制分析软件(BDCMS)计算预应力混凝土连续刚构桥在不同工况下控制截面的应力情况,其中分别采用了规范规定的偏差系数和现场试验得到的偏差系数进行计算,并比较分析。最后,利用所得的计算结果,对箱梁关键截面的应力应变进行验证分析。这些结果对该桥的施工控制,提供了可靠的数据依据,保证了施工质量。同时,对预应力混凝土桥梁设计与施工具有指导意义。更多还原

【Abstract】 With the rapid development of highways in our country, bridge construction has come in the upsurge period hitherto unknown, PC continuous rigid frame bridge was developed fleetly by the advantage of its good wholeness、strong anti earthquake and large torsional stiffness in recent years, and it is the first choice in long span and tall pier bridges. Prestressed design is an important part in upper structure design. At present, oversized mid-span deflection always appears in long span prestressed concrete continuous rigid frame bridges used, the reason of which is that the structure prestressed loss is estimated lower.This article take the Shaoyong highway Xiangjiang bridge in Hunan Province as the project background , conduct the research of the rule of the prestressed loss in the long steeple through the field test, calculates the upper structure of the bridge with the research result, and combine the scence test result of stress to confirm stress of control section under the different operating condition.First, gave two methods (indirect method and direct method) to identify the prestress pipe deviation coefficient‘k’that cause the structure loss of prestress. Through analyze prestressed cable along the stress and stress concrete box girder cross-section data,we can obtains reasonable pipe deviation coefficient‘k’, and discovers the change rule of prestress loss.Second, the analysis software of long span design calculates and control analysis is used to calculate the deflection and the stress situation of control section under the different operating condition for prestressed concrete continual rigid frame bridge, the pipe fraction factor which separately used which the standard to have stipulated and the field test obtains to carry on the computation, and conducting a comparative analysis to the result.Finally, uses the obtained test result, carries on the confirmation analysis to stress strain of the box girder essential section.The conclusion may provide reliable datum for structure construction controlling and guarantee the quality of construction. At the same time, the conclusion has guide significance for designing and constructing long span prestressed concrete bridges.更多还原