Is it a multi-story structure? are you removing ALL the load bearing walls? If not, you're potentially creating an inverted pendulum lateral system. but maybe that is a moot point. Also, are there bar joists? Most structures that want to remove LB walls will place the new steel frame "inside" of the skin from the wall. This can be very complicated if its bar joists. if you're placing the new flame in the same plane as the masonry, you have to consider temporary framing to hold up the existing roof/floor system. Still a mess if bar joists frame the horizontal planes. Also, with multi-story buildings, the diaphrams wil frequently be broken by continuous LB walls. Consequently you'll need create a band-aid across those "gaps" and reanalyze the affected diaphrams. . . or place a steel frame at each occurence with its own lateral support. Of course that is still complicated because the LB wall can vary in width from probably 6" to 12"+. the beams will generally have 6 inch-ish flanges. is there actually adequate seating of the horizontal members on the new steel flange. if the bays on each side are significantly different spans, a cap plate to provide suitable seating may induce a lot of torsion. And then there is deflection if its multi-story and you're only removing say one floor of LB wall. L/600 or 0.3" is difficult to get with long spans and/or short (vs tall) beams. how much clearance do you need beneath your steel that you're doing this? How long of a span is needed or desired that this is an option?
Anyway, those are the initial thoughts that crossed my mind. I could probably think of more pitfalls if I spent another hour on it.
Oh! spread footings for the columns could be a bitch too.
-Nathan
------------------------------
Nathan Smith P.E., M.ASCE
Engineer
Greensboro NC
------------------------------
Original Message:
Sent: 11-14-2023 07:58 AM
From: Ahmad Jamal Khan
Subject: Can we convert Load bearing structure to Frame Structure?
What are the potential risks associated with the conversion of Load bearing structure to Frame Structure, and how can they be mitigated?
------------------------------
Ahmad Jamal Khan S.M.ASCE
Abbottabad
------------------------------