大跨度预应力连续刚构桥长期挠度研究

发布时间：2018-01-30 14:35

本文关键词： 大跨径连续刚构桥长期挠度健康监测恒载零弯矩　出处：《广州大学》2014年硕士论文　论文类型：学位论文

【摘要】：自进入19世纪以来，随着预应力体系的发展，大跨径预应力连续刚构桥以其施工简便、造价经济、受力合理、行车舒适等独特的优势得到了快速发展。但是，国内外大跨径预应力连续刚构桥普遍存在一个问题—跨中过度下挠,且普遍没有建立相应的健康监测系统实时对桥梁的运营状态进行监测评估，导致一些此类桥型出现严重病害甚至突然垮塌，，造成了严重的经济损失甚至危机人们的生命财产安全，因此对大桥运营状态实时监测与长期挠度控制的研究有重大意义。本文首先以某大桥为工程背景，运用桥梁设计分析软件midas civil模拟计算其长期挠度，分析对比预应力损失、混凝土收缩徐变计算模式等因素对大跨径预应力连续刚构桥跨中长期挠度的影响，分析影响大跨度预应力连续刚构桥跨中长期挠度各种因素的敏感性。其次，本文系统介绍了某大桥的健康监测系统，包括其工作方式、硬件配置、监测系统的安装等，并通过对该大桥从成桥至今3年的跨中挠度实时监测数据的收集，把监测长期挠度与理论计算值做了比较，分析预应力混凝土连续刚构桥长期挠度的变化规律，列举了该大桥在行车荷载下跨中挠度的跳动规律，为大桥的安全性评价提供基本依据，最终为此类桥型的施工、设计、养护等提供依据。最后，为主动控制大跨度预应力连续刚构桥跨中长期下挠病害，本文基于恒载零弯矩理论，采用顶板预应力控制跨中长期下挠方式，使桥体自重产生的正弯矩与预应力产生的负弯矩平衡，达到控制跨中长期下挠的目的，并将重配预应力束后的跨中位移与原设计作比较分析，验证恒载零弯矩法在控制大跨径预应力混凝土连续刚构桥跨中长期挠度的可行性。
[Abstract]:Since 19th century, with the development of prestressed system, long-span prestressed continuous rigid frame bridge has been developed rapidly with its unique advantages such as simple construction, economical cost, reasonable force, comfortable driving and so on. There is a common problem of long-span prestressed continuous rigid frame bridges at home and abroad-excessive deflection in the span, and there is no corresponding health monitoring system to monitor and evaluate the operation status of the bridge in real time. As a result, some of these bridges appear serious diseases or even suddenly collapse, resulting in serious economic losses or even a threat to the safety of people's lives and property. Therefore, it is of great significance to study the real-time monitoring and long-term deflection control of the bridge. In this paper, the bridge design and analysis software midas civil is used to simulate and calculate the long-term deflection of a bridge, and the loss of prestressing force is analyzed and compared. The influence of concrete shrinkage and creep calculation model on the long-span prestressed continuous rigid frame bridge span deflection is analyzed. The sensitivity of various factors affecting the long-span prestressed continuous rigid frame bridge span deflection is analyzed. Secondly, this paper systematically introduces the health monitoring system of a bridge, including its working mode, hardware configuration, monitoring system installation and so on. Through the collection of the real-time monitoring data of the mid-span deflection of the bridge from the completion of the bridge to three years, the long-term deflection of the bridge is compared with the theoretical calculation value, and the variation law of the long-term deflection of the prestressed concrete continuous rigid frame bridge is analyzed. This paper enumerates the runout rule of the midspan deflection of the bridge under the traffic load, which provides the basic basis for the safety evaluation of the bridge, and finally provides the basis for the construction, design and maintenance of this kind of bridge. Finally, in order to actively control the long-span prestressed continuous rigid frame bridge span mid- and long-term deflection disease, based on the theory of zero moment of dead load, the roof prestressed control method of mid-long term deflection is adopted in this paper. The balance of the positive moment caused by the weight of the bridge body and the negative moment produced by the prestressing force can achieve the purpose of controlling the mid-span deflection in the long term, and the mid-span displacement after the rearrangement of the prestressing beam is compared with the original design. The feasibility of zero-moment dead load method in controlling long-span prestressed concrete continuous rigid frame bridge span deflection is verified.
【学位授予单位】：广州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441;U448.23

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