Nonlinear Performance Based Seismic Assessment for Low-Rise Buildings

In May 2004 the Ministry of Education of British Columbia (Ministry) announced a $1.5 billion seismic mitigation program for public K-12 school buildings. The goal of this program is to achieve the seismic mitigation of the most hazardous school buildings within a reasonable length of time. The development of innovative, cost effective assessment and mitigation design is being prepared under contract with the Ministry through a cooperative agreement between the Association of Professional Engineers and Geoscientists of British Columbia (APEGBC) and the Department of Civil Engineering of the University of British Columbia (UBC). The unique approach to develop a new cost effective seismic mitigation program within a reasonable period of time is a real challenge. The basic concepts of the approach and preliminary data were generated and released to the design community in November 2006. Internally this document is referred to as the Bridging Guidelines. However, the official title of the copyrighted document is Performance-Based Seismic Assessments and Retrofit Design Concepts — Second Edition. In March 2007 the Ministry announced the availability of $254 million in funding for capital construction. The Ministry required that the funds for this program be utilized for the assessment and structural seismic retrofit designs of the school buildings. Non-structural seismic mitigation was in a separate program. APEGBC and UBC are continuing the program development. The concepts and ideas given herein are a combination of those released in November 2006 and more recent developments. This paper is intended to be consistent with the new, significantly improved version of the program. However, as new concepts continue to be developed this paper cannot assure the reader that what is presented will be the final approved program.