Development of Seismic Design Methodologies for Rigid Wall Flexible Diaphragm Structures

Evidence indicates that the dynamic behavior of Rigid Wall – Flexible Diaphragm (RWFD) structures is dominated by the diaphragm’s response instead of the walls’ response, and this is a significant departure from the underlying assumptions of the widely used equivalent lateral force method in current building codes. RWFD buildings are common in North America and other parts of the world, and incorporate rigid in-plane concrete or masonry walls and flexible in-plane wood or steel roof diaphragms. With the use of a numerical computer modeling framework developed specifically for this type of building, this study sets out to investigate the seismic response of a variety of building archetypes with the intent to develop a simpler, more rational approach to the engineering design of RWFD buildings. A representative list of building archetypes is developed accounting for a variety of common parameters found in North America involving the building size, shape, diaphragm material, and diaphragm connections. Archetype designs are developed under ASCE/SEI 7-10 and this study’s proposed approach to develop design methodologies uses the FEMA P-695 methodology to evaluate building performance. In addition, two separate seismic force levels were utilized during the assessment representing both moderate and high seismic exposures to evaluate the impact of these parameters. Assistant Professor, Dept. of Architectural Engineering, California Polytechnic State University, San Luis Obispo, CA 93422 Principal, Simpson Gumpertz & Heger, Waltham, MA 02453 Ph.D. Candidate, Dept. of Civil, Structural and Environmental Engineering, University at Buffalo, State University of New York, Buffalo, NY 14260 Professor, Dept. of Civil, Structural and Environmental Engineering, University at Buffalo, State University of New York, Buffalo, NY 14260 Lawson J, Kelly DJ, Koliou M, Filiatrault A. Development of Seismic Design Methodologies for Rigid Wall – Flexible Diaphragm Structures. Proceedings of the 10 National Conference in Earthquake Engineering, Earthquake Engineering Research Institute, Anchorage, AK, 2014. Tenth U.S. National Conference on Earthquake Engineering Frontiers of Earthquake Engineering July 21-25, 2014 10NCEE Anchorage, Alaska DEVELOPMENT OF SEISMIC DESIGN METHODOLOGIES FOR RIGID WALL-FLEXIBLE DIAPHRAGM STRUCTURES J. Lawson, D. J. Kelly, M. Koliou and A. Filiatrault