Incorporation of full-scale testing and nonlinear connection analyses into the seismic upgrade of a 15-story steel moment frame building

摘要

This paper summarizes the seismic analysis and rehabilitation design of a 15-story steel moment-resisting nframe building constructed with connection details that were found to be vulnerable to fracture in the 1994 nNorthridge earthquake. This building is located in Oakland, California, less than 5 miles from the Hayward nFault. Previous testing of the existing moment connections demonstrated that the beam fl ange to column nfl ange complete joint penetration groove welds were vulnerable to fracture, and consequently, the building npresented a risk to life safety in the event of a major earthquake. Seismic rehabilitation to meet the require-nments of the State of California, Department of General Services resulted in a retrofi t scheme, including a ncombination of moment connection strengthening and addition of viscous dampers. Because of the deep nW27 column and very large W36 beam sections present in the special moment-resisting frames, a series nof four full-scale tests were conducted to evaluate the performance of the proposed rehabilitation schemes. nSophisticated analysis techniques were performed in the rehabilitation design, including nonlinear time nhistory analyses. These models included a nonlinear fi ber element that approximated the fracture behavior nobserved in the existing connection tests and incorporated results from the test program to model the nstrengthened connection behavior. Copyright © 2011 John Wiley & Sons, Ltd.