Seismic performance of encased CFT column base connections
Concrete-filled tubular (CFT) column has been quite often used in the high-rise buildings,because of its high strength and good performance against seismic loading. In a seismic design of CFT struc-tures, column bases form highly important connections which must ensure smooth transferring of internal forces from column to foundation. So far, encased column base connection is becoming popular in the CFT buildings of China. The rigidity of this type of column base has been widely studied under static loads, but few investigations have been reported for the hysteretic behavior of the connections subjected to cyclic loading. This paper examines the cyclic performance of two encased concrete-filled tubular (CFT) column to base connec-tions. Among the two, one is an encased CFT base plate connection with traditional detail, the other is a new type of encased CFT column base proposed by the authors which is strengthened by central reinforcing bars going through base plate into foundation concrete. Each specimen was subjected to increasing horizontal drift amplitude under a predetermined condition of axial compression. The experimental results clearly show that (1) stable restoring force characteristics are obtained for these two column bases, (2) use of central reinforcing bars can yield larger deformation capacity and higher strength than that of traditional encased CFT column bases, and (3) encased CFT column bases of these two types may be expected to have excellent properties for progressive collapse prevention since they all keep a stable residual load-bearing capacity though drastic encased concrete crush and reinforcing bar rupture occur. Finally, an analytical model for base strength estima-tion is proposed for design references.
W.Wang Y.Y.Chen Y.Wang Y.J.Xu X.D.Lv
Tongji University, Shanghai China China Northwest Building Design Research Institute, Xian, China
国际会议
第12届钢管结构国际学术会议(The 12th International Symposium on Tubular Structures)
上海
英文
235-241
2008-10-08（万方平台首次上网日期，不代表论文的发表时间）