【作者】 高策；

【导师】 卢文良；

【作者基本信息】 北京交通大学 ， 桥梁与隧道工程， 2010， 硕士

【摘要】 预应力连续箱梁桥具有整体性能好、结构刚度大、变形小、抗震性能好等优点,在现代公路、铁路建设中得到越来越广泛的应用。支架现浇施工法是最古老、最成熟、应用最广泛的桥梁施工方法之一,目前贝雷梁,大直径钢管柱配合碗扣钢管支架组成的组合支架在施工中得到了广泛的应用。目前对组合支架现浇连续箱梁施工过程的研究还不够深入,经常发生诸如梁体开裂、支架倒塌等工程质量问题和安全事故。为了安全施工,确保组合支架的安全和稳定,对组合支架现浇施工中各构件的受力和稳定性进行研究很有必要。本文论述了组合支架的组成构件和在施工中的应用情况,并分析了国内外发生的支架倒塌事故的原因。论文介绍了结构稳定的相关理论,并结合京沪高速铁路濉河特大桥跨104国道(40+56+40m)连续箱梁桥的实例,介绍了现浇连续箱梁的施工工艺。论文完成了对跨104国道连续梁施工阶段的梁体和支架应力的监测和数据分析,并采用大型有限元软件MIDAS/Civil建立全桥模型进行施工模拟,并将计算结果和监测值对比,规律基本一致。论文还用MIDAS/Civil软件分别建立了贝雷梁,大直径钢管柱和碗扣支架的有限元模型,把不同施工阶段现浇箱梁恒载反力施加到组合支架上,分析了组合支架各部分在施工阶段的受力情况。并对大直径钢管柱和碗扣支架进行屈曲分析,分析高度、位置分布及支撑对大直径钢管柱稳定性的影响,同时分析了立杆纵横距、水平剪刀撑、竖向剪刀撑等因素对碗扣支架屈曲荷载的影响。论文的研究成果对组合支架施工设计及其在连续箱梁现浇施工中的应用,保证施工质量,保障施工安全有积极的参考价值。更多还原

【Abstract】 Prestressed continuous box girder bridge has many advantages, such as good overall performance, great structural rigidity, small distortion and good seismic performance. It is widely used in the modern road and railway construction. Cast-in-site construction with falsework is one of the oldest, most mature and most widely used bridge construction methods. Currently composite falsework composed of bailey beams, large diameter steel tube column and cuplock scaffolding is widely used in construction.Due to the search of continuous cast-in-site box girder used composite falsework construction is a not deep enough, quality problems such as cracking of beams, security incidents such as scaffolding collapse occur frequently. Therefore, for security, construction and the security and stability of the composite falsework, it is necessary to search the force and stability of the falsework, components in continuous cast-in-site box girder construction.This paper discusses the combination of composite falsework and the application in construction firstly, and then analysis the cause of scaffolding collapse accident occurred at home and abroad. Secondly introduced the theory of structural stability, and combines the Sui river bridge across State Road 104 (40+56+40m) continuous box girder bridge of Beijing-Shanghai high speed railway, introduced cast-in-site construction technology. Stress monitoring and data analysis of the continuous beam across State Road 104 in different construction stages are completed in this paper.In the paper, the whole finite bridge model established for construction simulation by large finite element software MIDAS/Civil. After comparing the results and monitoring data, they have the similar law.Finite models of bailey beams, large diameter steel tube column and cuplock scaffolding are established by MIDAS/Civil software. Dead load of the continuous box girder in different construction phases is applied to the composite support, and then analysis the components force of composite falsework in different construction stages.Finite element model of large diameter steel tube column and cuplock scaffolding were established. The influence of some important factors on buckling loads of falsework is analysed. These factors include vertical and horizontal distance, horizontal strut, vertical strut and step distance.The results in the paper are valuable for design and force research in the construction by composite falsework. It gives valuable reference for the application of composite falsework in cast-in-site construction, to ensure bridge quality and safe construction.更多还原