大跨度连续刚构桥跨中下挠问题研究及对策分析

发布时间：2018-01-03 15:38

本文关键词：大跨度连续刚构桥跨中下挠问题研究及对策分析　出处：《云南大学》2016年硕士论文　论文类型：学位论文

【摘要】：近年来预应力混凝土连续刚构桥以其施工操作简便、受力合理、造价经济等优势得到了广泛的应用。但是由于连续刚构桥在我国起步较晚,设计理论不完善,施工技术水平不够先进,近年来对该类桥梁运营情况进行检查发现存在大量缺陷。大跨度预应力钢筋混凝土连续刚构桥存在的主要病害是主跨跨中长期下挠和箱梁梁体开裂,这些病害对行车的舒适度造成严重影响,威胁桥梁的正常使用,所以研究如何控制连续刚构桥主跨跨中长期下挠,具有十分重要的现实意义。首先,通过查阅资料和调查研究有关连续刚构桥设计、施工、运营情况,分别从纵向预应力损失、主梁混凝土收缩徐变、活载超载以及箱梁开裂造成的刚度损失这四方面讨论大跨度预应力混凝土连续刚构桥发生跨中下挠原因。其次,选取了主跨为104m、130m、150m的三座连续刚构桥,用Midas/civil建立有限元模型,计算分析了连续刚构桥预应力损失、混凝土收缩徐变计算模型、箱梁开裂造成的刚度损失以及活载超载这些因素对对不同跨径连续刚构桥跨中下挠的敏感性。调查发现云南省一座主跨为102.25m的连续刚构桥(龙腾大桥)采用了创新的设计方案,目前已经运营3年,桥梁跨中不仅没有下挠反而提高了15mmm左右。研究分析龙腾大桥的设计方案,用Midas/civil建立有限元模型,与跨径相同并采用传统设计方案设计的连续刚构桥进行有限元模型对比,分析龙腾大桥的设计方案与传统连续刚构桥的设计方案对控制连续刚构桥跨中长期下挠的差异。最后,选取云南省在建的主跨为130m和150m连续刚构桥,用Midas/civil软件建立全桥有限元模型。将主跨为.1.30m和150m的连续刚构桥采用龙腾大桥的设计方案进行设计变更,比较这两座连续刚构桥在设计变更前后桥梁结构的差异,从理论上研究龙腾大桥设计方案对其他跨径连续刚构桥可否起到有效控制跨中长期下挠的作用。
[Abstract]:In recent years, prestressed concrete continuous rigid frame bridge has been widely used because of its advantages of simple operation, reasonable force and economical cost. However, the design theory of continuous rigid frame bridge is not perfect because of its late start in our country. The level of construction technology is not advanced enough. In recent years, a large number of defects have been found in the operation of this kind of bridges. The main diseases of long-span prestressed concrete continuous rigid frame bridges are the mid- and long-term deflection of the main span and the cracking of the box girder. These diseases have a serious impact on the comfort of driving and threaten the normal use of bridges. So it is very important to study how to control the mid- and long-term deflection of the main span of continuous rigid frame bridge. First of all. Through consulting the data and investigating the continuous rigid frame bridge design, construction, operation, respectively from the longitudinal prestressing loss, the main beam concrete shrinkage and creep. The causes of mid-span deflection of long-span prestressed concrete continuous rigid frame bridge are discussed from the four aspects of live overload and stiffness loss caused by box girder cracking. Secondly, the main span is 104m / 130m. The finite element model of 150m continuous rigid frame bridge is established by Midas/civil, and the calculation model of prestress loss and concrete shrinkage and creep of continuous rigid frame bridge is calculated and analyzed. The stiffness loss caused by box girder cracking and the sensitivity of live overload to the deflection of continuous rigid frame bridge with different spans were investigated. It was found that a continuous rigid frame bridge with a main span of 102.25m was found in Yunnan Province. Longteng Bridge) has adopted the innovative design scheme. At present, the bridge has been in operation for 3 years, and the bridge has not only no deflection, but also increases about 15mm. The design scheme of Longteng Bridge is studied and analyzed, and the finite element model is established with Midas/civil. The finite element model of the continuous rigid frame bridge is compared with that of the continuous rigid frame bridge with the same span and the traditional design scheme. This paper analyzes the difference between the design scheme of Longteng Bridge and that of traditional continuous rigid frame bridge to control the mid-long term deflection of continuous rigid frame bridge span. Finally. The main spans under construction in Yunnan Province are 130m and 150m continuous rigid frame bridges. The finite element model of the whole bridge is established by using Midas/civil software. The continuous rigid frame bridge whose main span is .1.30m and 150m is changed by the design scheme of Longteng Bridge. By comparing the difference of bridge structure between the two continuous rigid frame bridges before and after the design change, this paper theoretically studies whether the design scheme of Longteng Bridge can effectively control the mid- and long-term deflection of other continuous rigid frame bridges.
【学位授予单位】：云南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U445.71

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