Cover [PDF]

Standards [PDF]

Foreword [PDF]

Acknowledgements [PDF]

Dedication [PDF]

Contents [PDF]

Chapter 1 General

Chapter 2 Combinations of Loads

Chapter 3 Dead Loads, Soil Loads, and Hydrostatic Pressure

Chapter 4 Live Loads

Chapter 5 Flood Loads

Chapter 6 Reserved for Future Provisions

Chapter 7 Snow Loads

Chapter 8 Rain Loads

Chapter 9 Reserved for Future Provisions

Chapter 10 Ice Loads - Atmospheric Icing

Chapter 11 Seismic Design Criteria

Chapter 12 Seismic Design Requirements for Building Structures

Chapter 13 Seismic Design Requirements for Nonstructural Components

Chapter 14 Material Specific Seismic Design and Detailing Requirements

Chapter 15 Seismic Design Requirements for Nonbuilding Structures

Chapter 16 Seismic Response History Procedures

Chapter 17 Seismic Design Requirements for Seismically Isolated Structures

Chapter 18 Seismic Design Requirements for Structures with Damping Systems

Chapter 19 Soil-Structure Interaction for Seismic Design

Chapter 20 Site Classification Procedure for Seismic Design

Chapter 21 Site-Specific Ground Motion Procedures for Seismic Design

Chapter 22 Seismic Ground Motion Long-Period Transition and Risk Coefficient Maps

Chapter 23 Seismic Design Reference Documents

Chapter 24

Chapter 25

Chapter 26 Wind Loads: General Requirements

Chapter 27 Wind Loads on Buildings‒MWFRS (Directional Procedure)

Chapter 28 Wind Loads on Buildings‒MWFRS (Envelope Procedure)

Chapter 29 Wind Loads on Other Structures and Building Appurtenances‒MWFRS

Chapter 30 Wind Loads ‒ Components and Cladding (C&C)

Chapter 31 Wind Tunnel Procedure

Appendix 11A Quality Assurance Provisions

Appendix 11B Existing Building Provisions

Appendix C Serviceability Considerations

Appendix D Buildings Exempted from Torisional Wind Load Cases

The provisions of this appendix shall apply to the design and construction of alterations and additions and to existing structures with a change in use.
An addition that is structurally independent from an existing structure shall be designed and constructed in accordance with the seismic requirements for new structures.
Where an addition is not structurally independent from an existing structure, the addition and alterations to the existing structure shall be designed and constructed such that the entire structure conforms to the seismic force-resistance requirements for new structures.

     EXCEPTIONS: The entire structure shall not be required to comply with the seismic force-resistance requirements for new structures where all of the following conditions are met:
  1. The addition complies with the requirements for new structures.
  2. The addition does not increase the seismic forces in any structural element of the existing structure by more than 10% unless the capacity of the element subject to the increased forces is still in compliance with this standard.
  3. The addition does not decrease the seismic resistance of any structural element of the existing structure unless the reduced resistance is equal to or greater than that required for new structures.
Alterations may be made to any structure without requiring the existing structure to comply with this standard, provided the alterations comply with the requirements for a new structure . Alterations that increase the seismic force in any existing structural element by more than 10% or decrease the design strength of any existing structural element to resist seismic forces by more than 10% shall not be permitted unless the entire seismic force-resisting system is determined to comply with this standard for a new structure.

     EXCEPTIONS: Alterations to existing structural elements or additions of new structural elements that are not required by this standard and are initiated for the purpose of increasing the strength or stiffness of the seismic force-resisting system of an existing structure shall not be required to be designed for forces in accordance with this standard provided that an engineering analysis is submitted indicating the following:
  1. The design strengths of existing structural elements required to resist seismic forces are not reduced.
  2. The seismic force to required existing structural elements is not increased beyond their design strength.
  3. New structural elements are detailed and connected to the existing structural elements as required by this standard.
  4. New or relocated nonstructural elements are detailed and connected to existing or new structural elements as required by this standard.
  5. The alteration does not create a structural irregularity or make an existing irregularity more severe.
Where a change of use results in a structure being reclassified to a higher occupancy category as defined in Table 1.5-1 of this standard, the structure shall conform to the seismic requirements for new construction.

     EXCEPTIONS:
  1. Where a change of use results in a structure being reclassified from Occupancy Category I or II to Occupancy Category III and the structure is located in a seismic map area where SDS < 0.33, compliance with the seismic requirements of this standard is not required.
  2. Specific seismic detailing requirements of this standard for a new structure need not be met where it can be shown that the level of performance and seismic safety is equivalent to that of a new structure . Such analysis shall consider the regularity, overstrength, redundancy , and ductility of the structure within the context of the existing and retrofit (if any) detailing provided.
Resources