| dc.description.abstract | This study is focused on the seismic performance of concrete filled steel tube (CFT) column foundation. Results from nine specimens tested under combined axial and lateral forces were used to define the relationships between seismic performance and structural parameters, such as the embedment depth, anchor bolts and stiffeners. The specimens can be classified to serial U, serial S and serial SN based on their foundation connections. Alphabet U indicates ＂unstiffened＂, maens the base plate without stiffeners. Alphabet S indicates ＂stiffened＂, means using stiffeners between the base plate and the CFT column. And N indicates ＂no anchor＂, which means the base plate without anchor bolts. Furthermore, the specimens are also classified into four different embedment depth : unbedded, 0.5D, 1.0D and 1.5D (D is the width of the CFT column), indicated by number 00, 05, 10 and 15. The result of tests shows the critical depth of embedded of U serial specimens is around 35㎝ (1D), and the damage is controlled by the CFT column when embedded deeper than critical depth. Meanwhile, the critical depth of embedded of S serial specimens is around 17.5㎝ (0.5D). The small critical depth number shows the employ of stiffener can reduce the damage level of foundation and enhance the economy and reliability of foundation design. The comparison of serial SN, serial S and serial U shows the effect on anchor by stiffeners is similar to anchor bolts. The rigidity of foundation differs by foundation connection and enlarged by the increase of the embedment depth. Therefore the relationship between the embedment depth and the rigidity of foundation can be established by foundation connection. The analysis principle can be obtained then appropriate for foundation design reference. | en_US |