This Global Topics Report is the third in a series of reports chronicling the development of the FEMA 273 NEHRP Guidelines for the Seismic Rehabilitation of Buildings into the FEMA 356 Prestandard and Commentary for the Seismic Rehabilitation of Buildings. The purpose of this report is to provide a narrative discussion and permanent record of the technical changes made to Guidelines as the document evolved into the Prestandard. It is the vehicle by which new technical information was introduced into the Prestandard, as issues were identified and, when possible, resolved by the Prestandard Project Team. For completeness, this report also includes a brief discussion of new concepts introduced to the engineering profession in the publication of the original FEMA 273 Guidelines and FEMA 274 Commentary documents.
As the Guidelines were used by the industry, questions arose regarding application of certain procedures, interpretation of some provisions, and results stemming from portions of the methodology. These questions have been formulated into statements, termed global issues, and recorded in this report for reference during the prestandard project and future revisions of the document.
At the time the Guidelines were published, it was known that additional research was needed to refine the accuracy and applicability of certain procedures, and analytical studies were required to test and substantiate certain new concepts and philosophical themes. Unresolved issues, reported by BSSC to be present at the time of publication, are incorporated into this report and identified with the designation ‘previously unresolved’ in the classification of the issue.
The purpose of Global Topics Report 1, Identification of Global Issues, dated April 12, 1999, was to formulate a statement and classify global issues that had been identified as of the date of the report. The issues identified in that report were presented and discussed at the ASCE Standards Committee Meeting on March 3, 1999, in San Francisco. The discussions resulted in clarifications to some of the issues, as well as a consensus on the recommended classification of each issue. Comments from Standards Committee members were incorporated into the report, and were used by the Project Team in moving issues toward
resolution.
Global Topics Report 2 was published on March 22, 2000. The purpose of the second report was to formulate statements for new global issues identified since Global Topics Report 1, and to document resolution of issues that were incorporated into the Second Draft of the Prestandard.
This third and final Global Topics Report contains new global issues identified since the publication of the previous two reports, and final resolutions of previously identified issues. The appendices to this report contain the results of special focused studies, which serve as back-up data to the resolution of selected issues. These studies are referenced in the body of this report, where applicable, and included in the appendices for future reference.
Upon completion of the Case Studies Project, the final report FEMA 343 Case Studies: An Assessment of the NEHRP Guidelines for the Seismic Rehabilitation of Buildings was made available to the Prestandard Project Team. Issues identified in FEMA 343 have been incorporated as global issues in this report, and a cross-reference to these issues is contained in Appendix C.
In April, 2000, a Prestandard draft document was distributed to the ASCE Standards Committee on the Seismic Rehabilitation of Buildings in an unofficial letter ballot. Ballot comments were reviewed and considered by the Project Team, and changes, were incorporated into the Prestandard. The results of that balloting are documented in the Ballot Comment Resolution Report on the Unofficial Letter Ballot on the Second Draft of FEMA 356 Prestandard for the Seismic Rehabilitation of Existing Buildings, included in Appendix L of this report.
This report is organized based on the chapter numbering and sequence of information contained in the original Guidelines. New section numbers are referenced for information that was relocated during the development of the Prestandard. Included in the body of this report are global technical or editorial issues that merited expanded discussion. Each issue was classified as one or more of the following:
Technical Revision — Issue requiring a revision or clarification of the technical content of the Prestandard
Editorial Revision — Issue requiring a revision or clarification of the technical verbiage of the Prestandard that does not substantially change the technical content.
Commentary Revision — Issue requiring a revision, clarification or expanded discussion in the Commentary
FEMA 343 Case study Consensus Revision — Issue resolved with the help of information gained from the FEMA 343 Case Study Project
Application of Published Research — Issue for which additional research has been published and can be used to supplement the Prestandard
Recommended for Basic Research — Issue that requires more information and further detailed study before a resolution can be reached.
Non-persuasive — Issue that was reviewed by the Project Team and the resolution resulted in no change to the Prestandard.
Once classified, issues were presented to the Project Team for resolution. Issues that were successfully resolved with the consensus of the Project Team were then incorporated into the Prestandard document. Resolved or not, the history of each issue that was identified over the course of the prestandard project is recorded in this report for future reference. Appendix B contains a summary of unresolved issues recommended for future research. It is the hope of the Prestandard Project Team that this Global Topics Report will serve as a resource and a reference for improvements to the FEMA 356 Prestandard and Commentary for the Seismic Rehabilitation of Buildings as the document is developed into a standard and incorporated into the practice of seismic rehabilitation.
