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1617.6.2.3 Combinations of Framing Systems
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Where different seismic-force-resisting systems are used along the two orthogonal axes of the structure, the appropriate response modification coefficient,R, system over-strength factor, Ω0, and deflection amplification factor,Cd, indicated in Table 1617.6.2 for each system shall be used.
The response modification coefficient, R, in the direction under consideration at any story shall not exceed the lowest response modification coefficient, R, for the seismic-force-resisting system in the same direction considered above that story, excluding penthouses. The system over-strength factor, 0, in the direction under consideration at any story, shall not be less than the largest value of this factor for the seismic-force-resisting system in the same direction considered above that story. In structures assigned to Seismic Design Category D, if a system with a response modification coefficient, R, with a value less than five is used as part of the seismic-force-resisting system in any direction of the structure, the lowest such value shall be used for the entire structure.
- Detached one-and two-family dwellings constructed of light framing.
- The response modification coefficient, R, and system over-strength factor, Ω0, for supported structural systems with a weight equal to or less than 10 percent of the weight of the structure are permitted to be determined independent of the values of these parameters for the structure as a whole.
- The following two-stage static analysis procedure is permitted to be used for structures having a flexible upper portion supported on a rigid lower portion where both portions of the structure considered separately can be classified as being regular, the average story stiffness of the lower portion is at least 10 times the average story stiffness of the upper portion and the period of the entire structure is not greater than 1.1 times the period of the upper portion considered as a separate structure fixed at the base:
- shall be designed as a separate structure using the appropriate values of R and
- The rigid lower portion shall be designed as a separate structure using the appropriate values of R and ρ. The reactions from the upper portion shall be those determined from the analysis of the upper portion amplified by the ratio of,R/ρ, of the upper portion over, R/ρ, of the lower portion. This ratio shall not be less than 1.0.
The detailing requirements of Section 1620 required by the higher response modification coefficient, R, shall be used for structural components common to systems having different response modification coefficients.
Related Code Sections
1617.6.2.3 Structural Design, Combinations of Framing Systems
for the entire structure.
Detached one-and two-family dwellings constructed of light framing.
The response modification coefficient, R , and system ...
NYC Building Code 2008 > 16 Structural Design > 1617 Earthquake Loads — Minimum Designlateral Force and Related Effects > 1617.6 Seismic-Force-Resisting Systems > 1617.6.2 Seismic-Force-Resisting Systems (For Use in the Simplified Analysis Procedure of Section 1617.5) > 1617.6.2.3 Combinations of Framing Systems
1620.2.9 Structural Design, Elements Supporting Discontinuous Walls or Frames
that can be transmitted to the element by the lateral-force-resisting system at yield.
Concrete slabs supporting light-framed walls.
...
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
2403.3 Glass and Glazing, Framing
To be considered firmly supported, the framing members for each individual pane of glass shall be designed so the deflection of the edge of the glass ...
NYC Building Code 2014 > 24 Glass and Glazing > 2403 General Requirements for Glass > 2403.3 Framing
2403.3 Glass and Glazing, Framing
To be considered firmly supported, the framing members for each individual pane of glass shall be designed so the deflection of the edge of the glass ...
NYC Building Code 2008 > 24 Glass and Glazing > 2403 General Requirements for Glass > 2403.3 Framing
1617.6 Structural Design, Seismic-Force-Resisting Systems
For a dual system, the moment frame shall be capable of resisting at least 25 percent of the design forces. The total seismic force ...
NYC Building Code 2008 > 16 Structural Design > 1617 Earthquake Loads — Minimum Designlateral Force and Related Effects > 1617.6 Seismic-Force-Resisting Systems