RESTORING FORCE CHARACTERISTICS OF NON-SLIP-TYPE EXPOSED COLUMN-BASE WITH MULTI-ROWS OF ANCHOR BOLTS : Self-centering performance in case of no-axial force

Abstract

Steel buildings generally use anchor − bolt − yie］ d − type exposed colurnn − bases ． Thes ¢ colUmn ・ bases show slip − type restering force char ・ acteristics ， and the cyclic behavior of column ・ bases with multi ・ rQws of anchor ・ bolts becomes very complicated ． The authors have proposed non − slip − typ¢ coiumn − bases using a wedge device to minimize shp ． This paper describes an experimcntaE study on both non − slip − type and slip ・ type column − bases subjected to cyclic loadings fc 〕r comparison with models ofrestoring fi)rce charactcristics pro −． posed by the authors ． The following observations were made ： 1)The non − s置 ip − type column − bases showed no slip behavior ． 2) The non ・ slip − typ巳 column −bases with multi −rews ol ' anchor bolts provided self −centering performance ． 3) The slip − type column − bases with multi − rows ofanchor bolts showed complicated cyclic curves ． Howeve口 he cyclicbehavior ofthe non ・ slip − type column − bases was very slmp 且 e ． κ 砂 脚 r お ' Exposed CO ' 躍 η η 一 base， Anchor −bolt − yield 一 り ， pe ， 丿-es ' 0 跏 9 ／ brce eharacteristiCS ，

Effectiveness of repairing yielding anchor rods in exposed column bases in steel structures

“…13 The penalty to the base shear is due to the limited energy dissipating capacity of anchor-yielding type exposed column bases with slip-type behavior compared to the column yielding with bi-linear hysteresis. 14 Previous studies have investigated the influence of column base flexibility on the overall frame behavior. A reduction in column base fixity will result in an increase of the displacement demand and a change of the first mode shape such that deformations are concentrated in the first story of the frame.…”

“…Prior yielding of the anchor rods and base plates is allowed, given assured ductility to anchor rods and increase slightly the base shear demand to the lowest story 13 . The penalty to the base shear is due to the limited energy dissipating capacity of anchor‐yielding type exposed column bases with slip‐type behavior compared to the column yielding with bi‐linear hysteresis 14 . Previous studies have investigated the influence of column base flexibility on the overall frame behavior.…”