Seismic Behavior of Diaphragm-Through Connections of Concrete-Filled Square Steel Tubular Columns and H-Shaped Steel Beams

Based on the introductions of a type of diaphragm-through connection between concrete-filled square steel tubular columns (CFSSTCs) and H-shaped steel beams,a finite element model of the connection is developed and used to investigate the seismic behavior of the connection.The results of the finite element model are validated by a set of cyclic loading tests.The cyclic loading tests and the finite element analyses indicate that the failure mode of the suggested connections is plastic hinge at the beam with inelastic rotation angle exceeding 0.04 rad.The suggested connections have sufficient strength,plastic deformation and energy dissipation capacity to be used in composite moment frames as beam-to-column rigid connections.

Influence of Axial Load Ratio on Shear Behavior of Through-Diaphragm Connections of Concrete-Filled Square Steel Tubular Columns

Nonlinear finite element analysis and parametric studies were carried out to study the influence of axial load ratio on the shear behavior of the through-diaphragm connections of concrete-filled square steel tubular columns. The analysis reveals that smaller axial load ratio can improve the shear bearing capacity and ductility while larger axial load ratio will decrease the shear behavior of the through-diaphragm connections. The parametric studies indicate that the axial load ratio should be limited to less than 0.4 and its influence should be considered in the analysis and design of such connections.

Low cyclic fatigue performance of concrete-filled steel tube columns

Eight concrete-filled steel tubular(CFT) columns were tested subjected to cyclic loading under constant axial load. Experimental parameters included axial compression ratio, loading sequences, and strength of concrete and steel. The seismic performance of CFT columns and failure modes were analyzed. The test results show that different axial load ratios and loading sequences have effects on the load carrying capacity, ductility and energy dissipation capacity of CFT columns, as well as the failure modes of the CFT columns. The failure pattern can be categorized into two types: local buckling failure of steel tube in compression zone, and low cycle fatigue tearing rupture failure of steel tube. The seismic behavior was evaluated through the energy index obtained from each cycle.

钢管柱全位置自动焊接装置研究及应用

研发了一种轨道式管道全位置自动焊接装置,针对现场复杂焊接作业工况改进了密封防尘的水平/高低滑块、多维调节焊枪摆动机构、齿条式快速拆装导轨等关键机构部件的设计。使用该自动焊装置进行了多组GMAW管道自动焊接试验,获得了成熟的焊接工艺参数,并进行了宏观金相、拉伸、侧弯、冲击等测试。工艺评定结果表明,该装置可用于桥梁钢管立柱的全位置对接自动焊中。目前该装置已应用于黄陵项目现场桥梁钢管立柱对接自动焊接作业中。

公铁合建超深车站施工方法比选

针对武汉地铁7号线徐家棚站基坑工程,对明挖顺作和盖挖逆作施工方法进行比选研究。通过数值计算、设计分析和工程实践经验总结,得到如下结论:一是开创"先逆后顺再拓"新型逆作工法,相对于同等厚度(1 500 mm)围护地连墙明挖法施工,节省投资占土建总投资的7.3%;相对于1 200 mm厚地连墙明挖法施工,节省投资占土建总投资的5.3%;二是采用新型逆作法,安全可靠,投资较省,工期较优,绿色环保,是一种可持续发展和绿色建造的施工方法;三是开创钢管混凝土柱"两点机械定位工法",施工便利,精度可控,最高精度可达1/500H以上,满足设计和工程受力要求。

矩形钢管混凝土柱-H型钢梁边跨节点有限元分析

基于ABAQUS有限元软件,对空鼓下的内隔板式钢管混凝土柱-H型钢梁边跨节点进行数值分析获得试件的荷载-位移滞回曲线,通过与试验结果对比,二者吻合较好,验证了部件之间相互约束、接触作用、材料本构关系等设定的精确性和合理性。且又进一步模拟分析了空鼓占比大小及位置、内隔板厚等参数对存在空鼓的试件节点承载能力与抗震性能的影响规律,结果表明随着空鼓占比大小以及内隔板厚的增加,节点极限承载力会逐渐降低,此外钢管混凝土梁柱节点连接处的焊缝质量,对试件节点的抗震性能有较大的影响,通过上述模拟分析,为今后该类节点在实际工程中的应用提供了理论依据。

钢管混凝土柱导向式施工安装技术

城市化建设步伐逐渐加快的今天,对建筑安全性、稳定性提出了更高的要求,为了构建出更加安全、稳定的建筑物,建筑领域开始对钢管混凝土柱导向式安装技术进行应用。基于此,以某工程作为研究对象,对钢管混凝土柱导向式安装技术进行了介绍,并以此为基础,提出了施工质量保障措施,为更好完成钢管混凝土柱导向式安装施工活动提供支持。