DYNAMIC RESTORING FORCE CHARACTERISTICS AND MODEL OF REINFORCED CONCRETE COLUMN UNDER VARYING AXIAL LOAD

Dynamic loading tests of reinforced concrete columns (RC columns) under the varying axial load were carried out and the complicated restoring force characteristics including the effects of varying axial load and loading rate have been obtained. On the basis of the test results the dynamic restoring force model of RC column under seismic load is derived. The model expresses the effects of varying axial load and loading rate and can be applied easily to seismic response analysis. It is also ascertained that the presented model is useful by comparing it quantitatively with the dynamic loading test results.