VERTICAL LOAD-CARRYING CAPACITY OF CONTINUOUS COLUMNS IN MULTISTORY REINFORCED-CONCRETE FRAMES SUBJECTED TO LATERAL LOADING REVERSALS

A simplified analytical method based on equivalent elastic stability theory has been developed to evaluate the vertical load-carrying capacity of continuous columns in multistory reinforced concrete frames, after subjection to lateral loading reversals. The analytical method has been verified through experimental works, employing different lateral loading histories on seven reinforced concrete model frame structures of weak beam-strong column types with two different numbers of stories. The necessity to determine the design level of long-term axial load of columns is discussed to secure the required safety factor on the premise of the continued serviceability of buildings after major or extreme earthquakes.