Switching from CBF to EBF
Switching from CBF to EBF
(OP)
New building code has changed R factor for a CBF from 5 to 3.25 which is causing an increase in overall seismic base shear of more than 30%. Our thought is to change from a CBF to an EBF braced structure to utilize the R = 7 or 8 factor and reduce overall base shear.
We understand the theory of EBF, but this structure is fully designed CBF and not sure how much redesign would be required to switch to EBF - asides from tweaking bracing angles, link beam stiffeners, etc. How much is likely to change? ie. columns, beams, foundations to ensure strength greater than the link beam itself?
Any help, tips, thoughts are appreciated.
Thank you.
We understand the theory of EBF, but this structure is fully designed CBF and not sure how much redesign would be required to switch to EBF - asides from tweaking bracing angles, link beam stiffeners, etc. How much is likely to change? ie. columns, beams, foundations to ensure strength greater than the link beam itself?
Any help, tips, thoughts are appreciated.
Thank you.






RE: Switching from CBF to EBF
RE: Switching from CBF to EBF
RE: Switching from CBF to EBF
OCBF has hardly any ductility. EBF is inherently better, but more expensive to design, and more expensive to fabricate due to connection requirements (overstrength). For one and two story buildings, EBF may be overkill except for very high seismic areas.
RE: Switching from CBF to EBF