Models of non-slip-type restoring force characteristics for steel exposed column base
Exposed column base
Restoring force characteristics
Generally, an exposed column base consists of anchor bolts and an elastic thick base plate. Restoring force characteristics of the column base are observed to be slip-type due to a gap between a nut of the anchor bolt and the base plate, caused by the plastic elongation of the anchor bolt. A new technique for improving the slip-type behavior has been proposed by the authors. This exposed column base with wedge devices shows non-slip-type restoring force characteristics instead of slip-type ones. In this paper, models of the new restoring force characteristics are proposed and compared with experimental results. The following conclusions are drawn. 1) The models of restoring force characteristics for new exposed column bases under monotonic loading can be calculated from the bending resistance of all anchor bolts. 2) The models of cyclic characteristics for the exposed column bases can be shown as non-slip-type ones, which are build-up-from-origin-type and are formulated by use of the models under monotonic loading. 3) Because the models of the characteristics for the column bases with wedge devices can be simply predicted, they can be easily applied to seismic response analysis.