大跨度预应力混凝土梁桥挠度控制研究市政工程专业论文.docxVIP

Study Study on Deflection Control of Large—span Prestressed Concrete Girder Bridges ABSTRACT This paper mainly surrounded the excessive midspan lag which was a main problem of large-span prestressed concrete girder bridges at present，make a brief summary of the survey of development，characteristics and common diseases of large—span prestressed concrete girder bridges at first；this was followed by the comparisons of structure characteristics，internal forces and vertical displacement of different long-span prestressed concrete girder bridges and the analyses of inherent laws among those factors，which aimed at three different long-span continuous beam and continuous rigid frame bridges；then prestress，selfweight of structure，box girder rigidity,concrete creep and shrinkage，first time loading age of box girder segments and combined effect of multiple factors were studied to compare their influences on deflection，and then summarized various possible causes of excessive vertical displacement especially long-term excessive vertical displacement of large-span prestressed concrete girder bridges；finally focused on the study of deflection control programs which using top slab tendons，bottom slab tendons，reducing selfweight of the upper structure or using cables，as well as combining programs based on the above—mentioned deflection control programs， with a hope to offer reasonable proposals for the design and construction of those bridges． KEY WORDS： large—span girder bridge，deflection control，top slab tendons， bottom slab tendons，dead 10ads， cables II 插图清单图1．1 插图清单 图1．1 悬臂浇筑施工法 ．．2 图1．2 悬臂拼装施工法 2 图1．3 广西柳州大桥 3 图1．4 重庆长江大桥(T形刚构公路桥) ．3 图1．5 虎门大桥辅航道桥主跨跨中桥面挠度变化速率图 8 图1．6 汾江大桥、潭州大桥的下挠时间曲线 8 图1．7 科罗·巴岛桥倒塌后 一9 图1．8 底板分层劈裂事故