Lateral load resisting frame question
Lateral load resisting frame question
(OP)
hi, is it possible to use a flat slab + RC column as lateral force resisting frame? (without shear walls). if so what "R value" will be used for the seismic load computation. will this kind of system follow the requirements of SMRF?






RE: Lateral load resisting frame question
RE: Lateral load resisting frame question
RE: Lateral load resisting frame question
slickdeals is probably correct that in higher seismic conditions such a system would either not be allowed or not acceptable.
RE: Lateral load resisting frame question
I think the comments already provided are pretty much on point. It's system sometimes used but is really limited in seismic performance potential. In a normal configuration it has initially low and quickly degrading stiffness for lateral displacements. And the potential failure mechanism can be petty catastrophic, punching shear failure at the slab-column joint. Under the best of circumstances it should be considered only as a last chance back-up to something more robust in seismic application.
That said it is interesting that when you look at the lateral behavior particularly for highrise building using a shear wall core and flat slab/plate floors the cumulative effect of the slab frames acting as outriggers can be pretty significant. So even if you designate the lateral forces to another system it's worth looking at the behavior and interaction of slab frames with the LFRS.
regards,
Michel
RE: Lateral load resisting frame question
I would try to find a system where the slab is not part of the moment resisting frame.
RE: Lateral load resisting frame question
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Lateral load resisting frame question
Assuming i am in a moderate to high seismic zone, say zone 3 or 4
So if I add a shear wall in the flat slab + RC column framing system. will that type of structural system work? if yes, will it follow special detailing requirments such as those with SMRFs?
FYI, I have mostly dealt with my projects using SMRF's. or dual system SMRF + shear wall. Hence, i am not that familiar with other lateral systems
RE: Lateral load resisting frame question
SDC A & B ~ UBC Zones 0 & 1, SDC C ~ Zone 2, and SDC D, E, & F ~ Zones 3 & 4.
RE: Lateral load resisting frame question
Can we generally define areas with peak ground acceleration < 0.8 m/s^2 as low hazard areas.
@DST148... for those of us outside US we're lost in acronyms. This is what I could translate:
(SMRF) San Marcos River Foundation
(IMRF) International Maritime Rescue Federation
(OMRF) Oklahoma Medical Research Foundation
Thanks.
RE: Lateral load resisting frame question
OMRF - Ordinary Moment Resisting Frame
IMRF - Intermediate Moment Resisting Frame
SMRF - Special Moment Resisting Frame
LFRS - Lateral Force Resisting System
SDC - Seismic Design Category
RE: Lateral load resisting frame question
follow up question, In order for me to utilize the R value for dual systems (say RC frame + shear wall) does the shear wall + RC frame need to be present at every bay of the structure for the direction of the EQ load being considered??? because it is quite difficult to have a shear wall at every bay of the structure (esp if it is irregular in shape or if the architect does not allow it).
RE: Lateral load resisting frame question
Shear wall + Frame need not be present in every bay. Typically the concrete slab acting as a diaphragm can carry the lateral loads to vertical elements of the LFRS.
RE: Lateral load resisting frame question