Nulukkizdin
Structural
All,
This will be a fairly vague question as we're still trying to figure out systems, but I just wanted to see if I could get some input while we were still planning. We've got a 5 story building that will be somewhere in the ballpark of 4 stories of wood on top of 1 story of steel or concrete. So basically a big concrete platform with a wood building on top. We're hoping to utilize some two stage analysis techniques (which I will need to study more once we go down that road) to help out the overall system.
My question stems from how people are typically modeling this type of structure and what software they are utilizing. I am very used to RAM SS, and use it for a lot of my steel and concrete jobs. It seems like if we were to use RAM SS for our application, we'd model our typical framing (joists on beams/bearing walls) above and bring all of that down to the concrete plinth. We'd have to design the wood elements separately, but could use this to bring our gravity loads down to the plinth. Then RAM SS could be used to size the plinth level and the columns below. From a lateral side, I'm not sure we'd see the same continuity as we'd have to fake in the lateral shear walls, and I'm not sure we'd be getting the same T&C forces from overturning that we'd really want to be applying. That said, it seems like we're doing most of the work outside of RAM SS and might be better off only modeling the first floor plinth, applying all of our gravity and lateral loads to this model. This gets weird in itself, as we have a really hard time adding EQ point loads to beams in Systems...
That said, are there other programs that deal with this (fairly common) problem more directly? I was going to dive into RISA a bit, but know that they definitely have some limitations in their wood shear wall design. Anything else that has worked better in the past? How about if we're going with cold formed instead of wood?
Any thoughts would be helpful! Just trying to get a good idea of the best approach for this type of thing.
This will be a fairly vague question as we're still trying to figure out systems, but I just wanted to see if I could get some input while we were still planning. We've got a 5 story building that will be somewhere in the ballpark of 4 stories of wood on top of 1 story of steel or concrete. So basically a big concrete platform with a wood building on top. We're hoping to utilize some two stage analysis techniques (which I will need to study more once we go down that road) to help out the overall system.
My question stems from how people are typically modeling this type of structure and what software they are utilizing. I am very used to RAM SS, and use it for a lot of my steel and concrete jobs. It seems like if we were to use RAM SS for our application, we'd model our typical framing (joists on beams/bearing walls) above and bring all of that down to the concrete plinth. We'd have to design the wood elements separately, but could use this to bring our gravity loads down to the plinth. Then RAM SS could be used to size the plinth level and the columns below. From a lateral side, I'm not sure we'd see the same continuity as we'd have to fake in the lateral shear walls, and I'm not sure we'd be getting the same T&C forces from overturning that we'd really want to be applying. That said, it seems like we're doing most of the work outside of RAM SS and might be better off only modeling the first floor plinth, applying all of our gravity and lateral loads to this model. This gets weird in itself, as we have a really hard time adding EQ point loads to beams in Systems...
That said, are there other programs that deal with this (fairly common) problem more directly? I was going to dive into RISA a bit, but know that they definitely have some limitations in their wood shear wall design. Anything else that has worked better in the past? How about if we're going with cold formed instead of wood?
Any thoughts would be helpful! Just trying to get a good idea of the best approach for this type of thing.
