铁路高墩大跨预应力混凝土连续刚构桥的施工控制

【作者】 廖文华；

【导师】 王星华；

【作者基本信息】 中南大学 ， 建筑与土木工程， 2008， 硕士

【摘要】 预应力混凝土连续刚构桥以其施工简便、造价经济、受力合理、行车舒适等独特优势在近年来得到迅速广泛应用,在主跨100～300m范围内几乎成为首选桥型。而在预应力混凝土连续刚构桥悬臂施工过程中,已建成梁段的线型在后期施工中是不可调节的,因此为了保证大桥的顺利合龙及成桥线型满足设计要求,同时成桥内力控制在设计容许范围内,必须在桥梁施工过程中进行施工控制工作。本文通过采用有限元软件对渡口河特大桥工程进行施工状态模拟,计算主梁在各施工阶段的预拱度,然后在施工过程中由实测数据对模型进行实时修正,最后使主梁线形、受力状态满足设计要求。通过施工监控,主梁线型、应力均符合控制目标,满足设计和相关规范要求;由于铁路高桥桥墩刚度大,通过监测在主梁施工过程中,128m高墩只下沉了2mm,对连续刚构成桥没有产生次生应力,表明连续刚构成桥结构安全可靠。研究表明高墩沉降和位移对大桥的连续刚构梁的内力有较大的影响,高空风力的大小对大桥的合龙精度也有着不小的影响。总结渡口河特大桥的施工监控工作,我们认为在预应力混凝土连续刚构箱梁桥的施工监控工作中,如果要进一步提高监控精度,需要建立自动数据采集系统,包括位移、温度、应变等。但是,建立这样一个系统,投入很大,目前国内同类桥梁中很少采用。同时需要在自动数据采集系统的基础上建立一套自动的控制调整系统。更多还原

【Abstract】 Because of convenient construction, economy cost, reasonable force, driving comfort for prestressed concrete continuous rigid frame bridge, it was widly used in China, and bridge with 100～300m main span was almost the first choice.But in cantilever construction process of prestressed concrete Continuous rigid frame bridge, built beam block could not be regulation in the late construction, for guarantee linear and internal force of bridge in design control range in close up of cantilever, construction control work must be done in bridge construction. In this paper,FEA methods was used in simulating constrution behavior of Dukouhe Great Bridge, and pre-camber in main beam construction, then FEA model was real-time amendment according to contrasting data collected in construction , finally made linear of main beam and force behavior to meet the design requirements.According to made constrution monitoring, main beam linear and stress meet control target, and meet design and codes requirements; because ridge of pier of railway bridge is big, 128m pier’s settlement was 2mm in main beam construction according to monitoring, so there was no secondary stress in continuous rigid frame bridge construction, which show bridge structure is safe and reliable.Research shows that high pier settlement and displacement of the continuous rigid frame bridge beams internal forces have a greater impact, high-altitude winds on the size of the bridge closure also has a non-precision small.On the whole,in construction monitoring process of Dukouhe Great Bridge,if improve the accuracy of monitoring, a monitoring system with monitoring function on displacement, temperatur and strain and so on was needed. But a system like that would need more expensive, so it was rarely used in bridge monitoring in China. At the same time, an auto-control system must be set up based on Automatic Data Acquisition System.更多还原