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

研究结果总结如下：1。标准与建议的比较研究研究了CFT结构的所有标准、建议和参考，然后提出了截面、构件、连接、柱基础、抗震单元和框架结构性能的评价公式和应用。CFT框架的抗震性能为了证明CFT框架具有良好的抗震性能，通过地震分析对CFT框架的抗震性能进行了研究，并与其他框架（SRC、RC和钢）进行了比较。3层CFT框架的试验为了研究CFT框架在地震荷载作用下的弹塑性性能，对7个试件进行了试验。试件为3层1跨CFT柱- h型钢梁框架及预埋钢剪力墙框架。试验参数为：1)梁柱连接型式（外隔膜型式或竖向加筋型式），2)带缝剪力墙型式（无缝或三种型式之一），3)构件作为柱（CFT或空钢管）。对3层1跨CFT结构进行加载试验，得出以下结论：1)新提出的连接方式竖向加劲连接，其结构性能等于或优于实际常用的连接方式。这种连接方式允许相邻的梁或柱进行刚性连接，这意味着仅反映框架构件的刚度即可估计框架的刚度。2)带缝钢剪力墙是提高结构强度、刚度和吸能性能的有效装置，CFT框架与带缝钢剪力墙相结合是一种具有修复可行性的良好结构体系。

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.