Distinguished Webinar Series in Earthquake Engineering and Seismology
Organized by the Canadian Association of Earthquake Engineering
Seismic Retrofit of Non-Ductile Concrete Frames and Masonry Walls
Wednesday, March 1, 2023, 3:00 p.m. EDT
Registration Link: Zoom Webinar
Abstract
Non-ductile reinforced concrete frame buildings and unreinforced masonry (URM) infill or load bearing walls suffer significant damage when subjected to strong earthquakes. A viable seismic risk mitigation strategy for such structures involves seismic retrofits either at the element level or at the global structural level. The former approach aims to increase strength and deformability of seismically deficient elements, and the latter approach focuses on lateral bracing of structures for lateral drift control, thereby minimizing damage to brittle elements while also increasing lateral strength, and possibly enhancing lateral deformability. The presentation will provide an overview of experimental and analytical research conducted at the University of Ottawa. The results of large-scale tests under simulated seismic loading will be presented. Lateral bracing of non-ductile reinforced concrete frames, representative of older buildings designed prior to the enactment of modern seismic codes, will be discussed. The bracing techniques will include diagonal bracing of concrete frames by means of high-strength prestressing strands, specially developed buckling restraining braces (BRB) and the use of carbon fibre reinforced polymer (CFRP) sheets on infill walls to brace the frames. At the element level, the retrofit techniques will include transverse prestressing of existing columns to introduce active and passive confinement pressures to increase flexural deformability, to control diagonal tension cracks caused by seismic shear while also increasing transverse shear reinforcement, as well as to generate lateral clamping forces for improved bond in seismically deficient lap splice regions. Column research also includes CFRP jacketing methodology and the design procedure that was incorporated in CSA S806 Standard. The use of surface bonded CFRP sheets is extended to URM infill and load bearing walls, with and without the introduction of boundary elements in URM walls by inserting rebars or prestressing strands. Relevant design concepts will be presented and discussed for use in practice.
Murat Saatcioglu, PhD, Distinguished University Professor
Department of Civil Engineering of the University of Ottawa, Ottawa, Canada
Fellow of the Canadian Academy of Engineers, Engineering Institute of Canada, American Concrete Institute (ACI),
and the Canadian Society for Civil Engineering (CSCE)
Website: http://muratsaatcioglu.ca/
Short Bio: Dr. Murat Saatcioglu’s research interests include analysis, design, and retrofit of structures subjected to extreme loads, including those caused by earthquakes and bomb blasts. He has conducted extensive experimental and analytical research on earthquake and blast resistant structures, and contributed towards the development of codes and standards, nationally and internationally.
Professor Saatcioglu is the recipient of numerous national and international research and teaching awards and medals, including the 2015 A.B. Sanderson Award of CSCE for outstanding contributions to the development and practice of structural engineering in Canada; the 2014 Whitman Wright Award of CSCE for significant contributions to the advancement of innovation and information technology in civil engineering; the 2001, 2004 and 2015 Casimir Gzowski Medals for best papers in the Canadian Journal of Civil Engineering; the 2004 Wason Medal of ACI, the 2000 Raymond C. Reese Research Prize of the American Society of Civil Engineers for outstanding contributions to the application of structural engineering research, the 2005 CCEDS-1 Award for Best Paper from McMaster University; and the 1989 Charles Whitney Medal of ACI. In 2021 he was listed among the World’s Top 2% Scientists in all categories by Stanford University.