// CODE SNIPPET

# 1605.4 Special Seismic Load Combinations

Jump To Full Code Chapter

For both allowable stress design and strength design methods, where specifically required by Sections 1613 through 1622 or by Chapters 18 through 23, elements and components shall be designed to resist the forces calculated using Equation 16-19 when the effects of the seismic ground motion are additive to gravity forces and those calculated using Equation 16-20 when the effects of the seismic ground motion counteract gravity forces.

where:

1.2

*D*+*f*+_{1}L*E*_{m}**(Equation 16-19)**
0.9

*D*+*E*_{m}**(Equation 16-20)**where:

E_{m} |
= | The maximum effect of horizontal and vertical forces as set forth in Section 1617.1. |

f_{1} |
= | 1.0 for floors in places of public assembly, for live loads in excess of 100 psf (4.79 kN/m^{2}) and for parking garage live load. |

f_{1} |
= | 0.5 for other live loads. |

### Related Code Sections

1605.4 Structural Design, Special Seismic Load Combinations

of the

*seismic*ground motion are additive to gravity forces and those calculated using Equation 16-20 when the effects of the*seismic*ground motion ...1620.2.9 Structural Design, Elements Supporting Discontinuous Walls or Frames

of Table 1616.5.1.1 or vertical irregularity Type 4 of Table 1616.5.1.2 shall have the design strength to resist

*special**seismic**load**combinations*...NYC Building Code 2008 > 16 Structural Design > 1620 Earthquake Loads — Design, Detailing Requirements and Structural Component Load Effects > 1620.2 Structural Component Design and Detailing (For Use in the Simplified Analysis Procedure of Section 1617.5) > 1620.2.9 Elements Supporting Discontinuous Walls or Frames

1617.1 Structural Design, Seismic Load Effect E and EM

The maximum

*seismic**load*effect,Em, for use in the*special**seismic**load**combination*of Section 1605.4 shall be the*special**seismic**load*determined from ...1620.4 Structural Design, Seismic Design Category D

are determined using the

*special**seismic**load**combinations*of Section 1605.4 ...Section 1620 Structural Design, Earthquake Loads — Design, Detailing Requirements and Structural Component Load Effects

Type 4 of Table 1616.5.1.2 shall have the design strength to resist

*special**seismic**load**combinations*of Section 1605.4. The connections from ...