Table of Contents Preface.- .. i 1 Introduction- 1 1.1 Origin and Purpose.- .. 1 1.2 Issue Development- .. 2 1.3 Issue Objectives ..- 3 1.4 Categories of Issues and Their Relationship 3 1.5 Priorities and Importance- 6 1.6 Issues Presentation- .. 6 1.7 A Preliminary Concept of the Guidelines.. 7 2 Scope Issues.. 15 2.1 Definition of Building- 17 2.2 Determination of Applicability 19 2.3 Damage or Deterioration- .. 20 2.4 Non-engineered Approaches 21 2.5 Seismic Isolation and Energy Dissipation. 23 3 Implementation and Format Issues.. 2 5 3.1 Document Title..- 27 3.2 Audience and Use- 28 3.3 Involvement of Codes and Standards Development Groups 30 3.4 Implementation Methods .31 3.5 Document Format..- .. 32 3.6 Prescriptive Versus Analytical Provisions..,..33 3.7 Revising and Updating the Guidelines35 4Issues of Coordination With Other Efforts.. 3 7 4.1 Relationship to Parallel Efforts ..39 4.2 Relationship to Building Evaluation Methods..40 4.3 Relationship to Strengthening Techniques Studies.42 4.4 Relationship to Studies of Costs and Benefits. 43 4.5 Other Natural Hazards.- ..45 5 Legal and Political Issues.. 47 5.1 Standards of Care 49 5.2 Liability- .52 5.3 Standards for New Versus Existing Buildings 54 5.4 Impact Variation- .. 56 5.5 Due Process and Taking Principles .. 58 6Social Issues.. 6 1 6.1 Affordable Housing.- . 63 6.2 Social Impacts ..- 65 7 Economic Issues 67 7.1 Direct Cost of Strengthening- .. 68 7.2 Performance Benefit-Cost Relationships.. 70 7.3 Social and Economic Implications of Alternative Standards 72 7.4 Local Government Economic Effects. 74 7.5 Associated Non-Seismic Requirements76 ATC-28 Contents iii 8 Historic Building Issues .. 77 8.1 Inclusion or Exclusion of Historic Buildings..79 8.2 Standards for Historic Buildings. 81 9 Research and New Technology Issues.. 8 3 9.1 Innovative Risk Reduction Methods.. 85 9.2 Dependence on Recent and Future Research.. 88 10 Seismicity and Mapping Issues. 91 10.1 Defining Ground Shaking Hazard93 10.2Soil Instability and Other Geologic Hazards.. 94 10.3Soil AmplificatJon..,.- 96 11 Issues of Engineering Philosophy and Goals .97 11.1 Definition of Life Safety 99 11.2 Performance Goals 102 11.3 Incremental Strengthening- .. 105 11.4 Voluntary Strengthening- 106 11.5 Strengthening Provisions for Different Seismic Zones 107 11.6 Remaining Life of Building 108 11.7 Occupancy- .. 109 11.8 Contribution of Nonstructural Elements.110 12 Issues in the Development of Specific Provisions.. I 1 1 12.1 Minimum Quality Standards and Testing 113 12.2 Strength Versus Working Stress Design 115 12.3 Force Level Definition Procedure ..116 12.4 Drift Limits..- .. 118 12.5 Consideration of Detailing of Existing Systems ..119 12.6 Detailing For New Elements 120 12.7 Compatibility of Old and New Construction.121 12.8 Foundations- .. 122 12.9 Unreinforced Masonry Partitions 124 12.10 Adjacency Conditions- 126 12.11 Exterior Falling Hazards 128 12.12 Alternative and Advanced Analysis Methods 129 12.13 Quality Control.- 130 13 NonstructuralElement Issues.. 131 13.1 Inclusion or Exclusion of Nonstructural Elements 133 13.2Standards for Nonstructural Elements .. 134 14 References- . 137 Appendix A:Project Participants..141 Appendix B: Users Workshop Participants.145 Appendix C: ASCE Consensus Approval Participants..149 iv Contents ATC-28