EARTHQUAKE RESPONSE OF STRENGTHENED STEEL SPECIAL MOMENT-RESISTING FRAMES

This paper presents the response of steel moment resisting frames with damage to their welded connections for two repair options: (1) reweld only; and (2) reweld and strengthen connection. Two different nonline ar dynamic analysis programs are used to research the effect of repair ing and strengthening these weld failures and also for predicting the expected building response assuming that the connection is not repaire d. The effect on response is studied for connections where weld failur e reduces the capacity to 50, 20 and 5% of the original moment capacit y. The frames selected for the research are in a real building damaged during the Northridge earthquake. They are subjected to an ensemble o f artificial earthquake records that have an equal probability of occu rring at the site for comparative studies. (C) 1997 by John Wiley & So ns, Ltd.