kam22
Structural
- Mar 11, 2024
- 3
For cantilevered column system design axial load is as follows:
1. ASCE 7 Section 12.2.5.2: Cantilever column
systems are permitted as indicated in Table 12.2-1 and as
follows. The required axial strength of individual cantilever
column elements, considering only the load combinations that
include seismic load effects, shall not exceed 15% of the
available axial strength, including slenderness effects.
2.AISC 341 Section E5.2: Columns shall be designed using the load combinations including the overstrength
seismic load. The required axial strength, Prc, shall not exceed 15% of the available
axial strength, Pc, for these load combinations only.
ASCE 7 says considering seismic load combinations, AISC 341 says considering seismic overstrength with omega. My question is how can the vertical load be influenced by omega when the load combinations including omega come from ASCE 7 Section 2.3.6. Ev and Emh are per 12.4.3. Only Emh includes Omega and this is a horizontal load not vertical. How can the horizontal load cause vertical load in the column for a cantilevered column? --> If it doesnt then why does AISC 341 specifically say including Omega for this type of system?
1. ASCE 7 Section 12.2.5.2: Cantilever column
systems are permitted as indicated in Table 12.2-1 and as
follows. The required axial strength of individual cantilever
column elements, considering only the load combinations that
include seismic load effects, shall not exceed 15% of the
available axial strength, including slenderness effects.
2.AISC 341 Section E5.2: Columns shall be designed using the load combinations including the overstrength
seismic load. The required axial strength, Prc, shall not exceed 15% of the available
axial strength, Pc, for these load combinations only.
ASCE 7 says considering seismic load combinations, AISC 341 says considering seismic overstrength with omega. My question is how can the vertical load be influenced by omega when the load combinations including omega come from ASCE 7 Section 2.3.6. Ev and Emh are per 12.4.3. Only Emh includes Omega and this is a horizontal load not vertical. How can the horizontal load cause vertical load in the column for a cantilevered column? --> If it doesnt then why does AISC 341 specifically say including Omega for this type of system?
