uising fema 310 and ibc 2006 to analyze an existing building
uising fema 310 and ibc 2006 to analyze an existing building
(OP)
I have a 100 year old building (six story) that requires a global analysis. We were going to use IBC 2006 for the loading and model and analyze the structure using SAP2000 version 11. However, the owner recommends that we use FEMA 310 (ASCE 31) to perform the seismic analysis. Does the FEMA 310 analysis generate seismic forces to be inserted into the SAP2000 loading conditions similar to forces generated from IBC 2006. We believe we will be going into Tier 2 evaluation of FEMA 310 to generate this analysis. Is there compatibility here?






RE: uising fema 310 and ibc 2006 to analyze an existing building
RE: uising fema 310 and ibc 2006 to analyze an existing building
RE: uising fema 310 and ibc 2006 to analyze an existing building
How does a pre-standard like this apply to buildings legally? Technically the building code is the governing document and I always see the FEMA documents as more a source or support to the code. Is this right?
Do engineers actually use FEMA do design by? Bypassing the IBC or whatever code is adopted?
RE: uising fema 310 and ibc 2006 to analyze an existing building
If the owner decides to undertake a seismic rehabilitation project, we typically use ASCE 41 (supercedes FEMA 356) for the design. The IBC sets minimum standards for new construction and is generally insufficient for performance-based seismic upgrades for existing buildings. ASCE 41 is the state-of-the-art for seismic rehabilitation design and is generally considered "deemed to comply" by building officials.
Seismic rehabilitations are usually voluntary undertakings so as long as the existing building condition is not being worsened, most building officials will not have a problem with them. We usually have this conversation up-front so that all parties understand and agree.
RE: uising fema 310 and ibc 2006 to analyze an existing building
There is some language in the IBC about existing buildings (i.e. don't reduce seismic load carrying capacity by more than 10% etc.) I think it is in the later chapters of the IBC. How does that relate to the use of ASCE 31 and 41?
RE: uising fema 310 and ibc 2006 to analyze an existing building
RE: uising fema 310 and ibc 2006 to analyze an existing building
As previou8sly stated, it is for evaluation of existing structures, not their design. The buildings are evaluated to either the "Life Safety" or "Immediate Occupancy" Performamnce Level.
It further states in the commentary that "Mitigation strategies for rehabilitating buildings found to be deficient are not included in this Handbook." It mentions that additionaql resources need to be used for this.
Mike McCann
McCann Engineering
RE: uising fema 310 and ibc 2006 to analyze an existing building
(Is that a correct phrase?)