Performance-Based Seismic Design of Steel Moment Frame Buildings with Supplemental Passive Dampers
Mentor:Felipe Perez, Assistant Professor, Civil Engineering Department, California State Polytechnic University Pomona
The performance-based design of structures with supplemental passive damper systems can alleviate the need for cost-effective seismic hazard mitigation in new buildings. The use of passive damping systems can increase the seismic performance of conventional steel frames by providing an additional source of energy dissipation, reducing damage in the primary lateral load resisting system and by controlling drift. Lehigh University proposes a simplified design procedure (SDP) for the seismic design of buildings with supplemental dampers which this study applies to design a four story prototype building located in a high seismic area in order to validate its use as a practical design procedure. The performance-based seismic design procedure fits in the design of the damping system with the seismic design of resisting frames for specified performance objectives of story drift and member response. The frames are designed using current methods used in practice and the damping system is designed within the SDP. This study looks into implementing dampers by introducing damped brace frames (DBFs) to work alongside moment frames as well as implementing the dampers by introducing them inside the moment frame bays. Special moment resisting frames (SMRFs) were designed to strictly satisfy strength criteria (resulting in smaller members) for 100% and 75% of the code-based force demands. In accordance with the SDP, supplemental dampers were introduced to reduce drift levels to satisfy code limits. Results indicate that it is possible to undersize SMRFs for strength and introduce supplemental dampers for drift control. The SDP, which precludes the use of an advanced analysis, is shown to be an effective tool for the seismic design of buildings with SMRFs and supplemental dampers. This study may lead to the adoption of the SDP into future building codes for use by most practicing engineers.