【作者】 陈丽军；

【导师】 钱永久；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2012， 硕士

【摘要】 近年来,随着我国经济和交通事业的不断发展,大跨预应力混凝土连续刚构桥凭借其优越的结构性能,已经越来越广泛地应用于我国的工程建设中。但目前在用预应力混凝上箱形梁在施工和运营过程中出现相当数量裂缝病害,尤其是箱梁锚固区裂缝、腹板斜裂缝,有的甚至在未承受活载的自重阶段就出现裂缝,而混凝土的开裂也带来了严重的材料非线性问题。为探讨连续刚构桥锯齿块附近箱梁裂缝的开裂机理及有效的防治措施,本文以苍溪嘉陵江特大桥主桥为依托工程,采用有限元程序对预应力混凝土连续刚构桥齿板锚固处箱梁的受力状态和裂缝开展情况进行了计算分析。本论文主要的研究工作包括：(1)首先对国内外大跨预应力混凝土连续刚构桥的发展概况和目前箱梁裂缝的研究现状进行了介绍,在分析了混凝土裂缝成因的基础上重点分析了连续刚构桥锯齿块锚固处箱梁的开裂原因。(2)本文对混凝土箱梁的计算分析方法进行了介绍,并以苍溪嘉陵江特大桥主桥连续刚构为依托,通过建立整体有限元模型,进行整体结构分析,然后又建立局部有限元模型,对锯齿块附近箱梁的应力分布规律进行分析,并着重研究齿块锚面下底板纵向配筋对裂缝宽度的影响,最后提出几点预防锯齿块锚固处箱梁裂缝产生的建议。更多还原

【Abstract】 In recent years, with the continuous development of economy and traffic construction, Large-span PC Continuous Rigid Frame bridge with its fine structure performance has been widely applied in engineering construction in China. But quite amount of cracks are found during the construction and operation in the PC box girder bridges, especially cracks in the anchorage zone and the inclined cracks in the box girder webs of the bridges, and some cracks appear indeed in the deadweight phases. Moreover the craze of concrete brings severe nonlinear problem of the material. In order to probe into Large-span PC Continuous Rigid-frame Box Girder Bridge cracking mechanism of crack on the box girder near the prestressed anchorage and take effective prevention and control measures, this article relies on the Cangxi Jialingjiang River extra large bridge main bridge of Continuous Rigid-frame, using Finite Element procedure for PC Continuous Rigid-Frame bridge calculation of the stress and crack analysis. This paper mainly studies include:(1) Firstly, the development of large-span PC Continuous Rigid Frame Bridge and current research status of box beam crack are introduced in this article. And based on the analyses of the formation causes of concrete cracks, this research analyses the reason of cracks in the box girder near the tooth block anchored zone especially.(2) The article introduces the stress calculation and analysis method of box girder.And on the basis of Cangxi Jialingjiang River Bridge, the whole structure is analysed by the establishment of finite element model as a whole. Then through the establishment of local finite element model, the article analysis stress distribution in the box girder near the tooth block anchored zone, and focus on research effects on bottom the tooth block cracks by bottom longitudinal reinforcement. In the end, the research gives several advice of the prevention of crack in box girder near the tooth block anchored zone.更多还原