Abstract
In this study, a method to control the differential column shortening by placing additional reinforcement was proposed and the optimum distribution of reinforcement for reducing the differential column shortening was investigated. To reduce the differential column shortening, the axial stiffness of the columns below the story in which maximum differential column shortening occurred should be increased. The axial stiffness can be increased by placing additional reinforcement. The amount of reduction in differential column shortening of 2-bays frame structure according to four reinforcement distribution schemes were examined to find out the most effective reinforcement distribution scheme. We investigated the efficiency between the proposed distribution schemes when they were applied to the 2-bays frame structure with outrigger by comparing the reduction in maximum differential column shortening. As a result, the distribution scheme determined by considering the stiffness of the outriggers was the most efficient in terms of amount of reduction in differential column shortening and the required quantity of reinforcement.