摘要
以西安建筑科技大学体育训练馆46.5米跨多弧形钢拱网格结构为工程背景,采用重力加载方式,对该大跨钢拱结构进行了现场原位试验。综合考虑结构的跨度、变截面形式、初始几何缺陷、荷载布置和多种荷载工况,采用有限元ANSYS软件建立了整体有限元模型,分别进行了该结构的特征值屈曲分析和几何非线性分析,找出了结构的屈曲模态,考察了不同初始缺陷对结构影响的敏感程度。根据试验数据与理论分析结果的比较,分析了该结构的受力机理,破坏形态和薄弱位置。结果表明,钢拱网格的结构形式均能很好满足结构跨度、负荷宽度、屋面荷载以及抗震性能等方面的要求,结构整体稳定性较好,初始几何缺陷对该类结构稳定承载力影响显著。研究成果为进一步评价该类结构可靠性及合理性提供有力的依据。
Prestressed concrete box girder bridges are widely used because of advantageous structural behavior and perfect shapes.However,in the past few years,excessive deflection at the midspan and cracks in the box girders have commonly appeared in some long-span prestressed concrete box girder bridges after a period of operation,reducing the serviceability and durability of the bridges.The causes of cracks and excessive deflection are still not clear.Long-span prestressed concrete box girder bridges are studied from several aspects,such as longitudinal prestress design,vertical prestress design,vertical prestress loss,composition design,configuration of stirrups,characteristics of concrete.Two methods of longitudinal prestress design are compared,and the study indicates that the layout of bent-down tendons is an effective means for avoiding diagonal cracks in the webs.Moreover,the influences of shear deformation and development of diagonal cracks in thin-walled box girders on long-term deflection could not be ignored.
出处
《土木工程学报》
EI
CSCD
北大核心
2010年第1期22-28,共7页
China Civil Engineering Journal
基金
陕西省教育厅专项基金(06JK260)
陕西省西自然基金(2003E230)
关键词
钢拱
大跨度结构
现场试验
稳定
初始缺陷
box girder
prestressed concrete
bent-down tendon in the web
crack
deflection
