Generalization of research for CFT structures and estimation of performance of CFT frames

研究成果总结如下：1.研究成果综述。对钢管混凝土结构的各种标准、建议和参考文献进行了研究，提出了钢管混凝土结构在截面、构件、节点、柱脚、抗震构件、框架等方面的结构性能评估公式及其应用。钢管混凝土框架的抗震性能为了说明钢管混凝土框架具有良好的抗震性能，通过抗震分析，研究了钢管混凝土框架的抗震性能，并与钢骨混凝土框架、钢筋混凝土框架和钢骨框架进行了比较。为了研究钢管混凝土框架在地震作用下的弹塑性性能，进行了7个试件的试验研究。试件为三层1跨钢管混凝土柱-H型钢梁框架及内嵌钢剪力墙框架。试验参数为1)梁柱连接形式(外横隔式或竖向加劲肋式)，2)带缝剪力墙类型(不带或3种类型之一)，3)作为柱的构件(钢管混凝土或空钢管)。通过对三层一跨钢管混凝土结构的加载试验，得出了以下认识：1)新提出的竖向加强板连接形式，其结构性能与实际中常见的连接形式相当或更好。这种连接类型允许相邻的梁或柱进行刚性连接，这意味着框架的刚度将仅根据框架构件的刚度进行估计。2)带缝剪力墙是提高结构强度、刚度和吸能能力的有效装置，钢管混凝土框架和带缝剪力墙的组合是一种良好的结构体系。

Summary of research results is as follows.1. Study on comparison of standards and recommendationsAll of standards, recommendations and references for CFT structures was studie d. And then evaluation formulae and applications were proposed, on structural performance of cross section, members, connections, column base, earthquake resisting elements, and frames.2. Seismic behavior of CFT framesIn order to propose that CFT frames show good earthquake resistant properties, the seismic behavior of frames composed of CFT was studied by seismic analysis and compared with the other frames of SRC, RC and steel.3. Test of 3 story CFT framesIn order to study elastic-plastic behavior of CFT frames under earthquake loading, seven specimens were tested. The specimens were 3-story 1-span frames con sisting of CFT columns and H-shaped steel beam and such frames with steel shear wall embedded. Experimental parameters are 1) beam to column connection type (external diaphragm type or vertical stiffener type), 2) type of shear wall with slits (non or one of 3 types), and 3) member used as columns (CFT or vacant steel tube). Loading test on 3-story 1-span CFT structures gave the following knowledge ; 1) Newly proposed connection type, Vertical Stiffener connection, possesses structural performance equal or better than connection types common in practice. This connection type allows adjacent beams or columns to be connected rigidly, which means stiffness of the frame will be estimated only reflecting stiffness of frame members. 2) Steel Shear Wall with Slits is an effective device to improve structural performance of structures---strength, stiffness and energy absorption capacity---and the combination of CFT frame and the shear wall with slits is a good structural system viable for rehabilitation.