【作者】 李哲；

【导师】 刘忠玉；

【作者基本信息】 郑州大学 ， 工程力学， 2010， 硕士

【摘要】 近几年随着我国铁路事业的飞速发展,特别是随着掀起的新一轮建设客运专线的高潮到来,预应力混凝土结构在我国铁路工程中的应用越来越广泛,研究预应力混凝土结构施工对推动我国预应力技术的发展,具有十分重要的意义。本文针对郑武客运专线跨机场高速公路特大桥京广连续梁桥中单箱单室、斜腹板、变高度、变截面结构的工程实例,系统研究了三向预应力体系现浇连续梁桥的施工技术。文中首先介绍了悬灌施工在国内外的发展现状及其发展趋势,然后结合跨京广连续梁桥的工程概况,对整个工程施工方案进行了精心设计,设计了轻型三角形挂篮,引入了挂篮纵移自锚的构想,并对挂蓝的组成结构进行了介绍,通过试压的方法,对挂蓝的承载及受力性能进行了检验,为下一步各阶段混凝土施工时立模标高的设定提供了参照依椐；然后在预应力张拉方面,从张拉前的准备工作、钢束的制作、张拉的顺序、张拉应力及伸长值的计算、张拉的流程及张拉的注意事项等方面进行了细致的研究,同时在张拉过程中对应力孔道摩阻损失情况进行了试验测定,该试验结果为应力张拉达到设计要求提供了可靠的保证。文中还对合拢段的施工技术做了大量的技术研究,依据合拢段“低温浇筑、又拉又撑”的设置原则,确定了合拢段的施工顺序,在施工中通过采取优化配合比设计、提前建立准确的温度场、加强施工过程各项技术指标监控等一系列措施为合拢段的顺利实施提供了保证,本工程实例采用预埋地脚螺栓和用钢劲性工字钢骨架焊接的工艺,有效地解决了在锁定中出现的一系列问题,通过该项工程的具体实践证明在合拢中采取的各项措施是切实可行的,操作起来也比较方便,在今后的类似的工程施工项目中很有推广应用价值。更多还原

【Abstract】 With the rapid development of China railway in recent years, especially the construction summit of a new round of passenger dedicated line coming, the application of pre-stressed concrete structure in China railway project has become more and more widespread, hence the research of construction for pre-stressed concrete structure is of great importance in promoting Chinese pre-stressed technology。This paper will take over-crossing airport expressway of Zhengzhou-Wuhan passenger dedicated line and Beijing-Guangzhou continuous girder with single box and cabinet, inclined web plate, changing height and cross-sections as an example, in order to systematically research the construction technology of cast-in-situ continuous girders in terms of three pre-stress systems。This thesis starts by introducing the development status and tendency of cantilever construction at home and abroad, and then combines the project general situation of Beijing-Guangzhou continuous girders, and then elaborately designs the construction method statement of this project by adopting light-triangle hanging basket and proposing the concept of anchor longitudinally moving with hanging basket, in addition, the comprising structure of hanging basket is introduced by the method of trial pressing, and then the bearing capacity as well as stress performance are tested, which provides reference basis for the setting of formwork and elevation during concrete construction in further stages; in the aspect of pre-stress tensioning, the preparatory work before tensioning, the manufacture of steel strands, the tensioning sequence, the tensioning stress and calculation of extension length, the tensioning procedure as well as items to be paid attention to during tensioning are researched in detail. At the same time, the stress channel frication loss during tensioning is tested and determined, and this testing result provides reliable assurance for stress tensioning reaching designing requirements.Furthermore, the construction technology in closing segment is massively researched, based on the setting principle of’concreting under low temperature, pulling and staying’, the construction sequence in closing segment is determined. During construction, a series of measures are adopted to provide assurance for the smooth construction in closing segment, such as optimizing the design of mix proportion, establishing accurate temperature field in advance, strengthening the monitoring of all technical indexes during construction course. In the example adopted in this thesis, the pre-reserved foundation bolt and the technology of ’工’-type steel skeleton welding with steel stiffness are used to effectively handle a series of problems during locking. The specific practice in this project demonstrates that all measures used during closing construction are practical and feasible, as well as easily operated, so these measures are of great popularizing and applying value for the construction of similar projects.更多还原