Design of Structures with Dampers per ASCE 7-16 and Performance for Large Earthquakes

An impediment to the use of seismic protection devices has been the difficulty for practicing engineers to design buildings with isolation system or damping devices. ASCE/SEI task committees charged with development of new generation of codes for seismic design and retrofit of buildings have updated the relevant code sections with one goal being to encourage the use of such devices. An effort was undertaken to develop a step-by-step design guideline for such design. Following the preparation of guideline, incremental analysis of four steel SMF building models was undertaken. The benchmark model was designed using the strength and drift requirements of ASCE 7-16. The other models were based on provisions of Chapter 18 of ASCE 7-16. For one model the lower base shear value was used, and for a third model, the drift ratios were further limited to obtain enhanced performance. Lower- and upper-bound analyses as required by ASCE 7-16 were conducted to size the dampers. The models were then subjected to incremental nonlinear analysis and key response parameters were evaluated. In all cases, the use of dampers resulted in reduction in the hinging of SMF members. It was notes that the best performing model was the model designed for 100% of nominal base shear and above minimum effective damping had superior performance, remaining elastic at design earthquake, and having almost no residual displacement at very large earthquakes.