Recent content by mkrei

Another question. I have very large thick footings below the shear wall. In keeping with the .6 dl do I need to reduce my concrete weight to 87 pcf. That really starts to whack things out. Also most of the dead load coming down on the footing is from the concrete shear walls above. Seems...

Some of the issue is how to apply the lateral loads at the base of the wall. This footing is supporting a C-shaped shearwall around an elevator shaft. So I am considering how to add for the additional depth of the walls below the slab on grade. When I add the lateral load in and add a moment...

I have a question about the .6DL+WL overturning check. When I run the numbers I get a FS for overturning greater than 1 for this load with equates to the old 1.5 (1.667) d+wl. However my soil pressures get way out of whack with the .6dl +wl. Is the .6dl+wl purely an overturning check or does...

Yes a vapor retarder is present so friction between slab and subgrade is minimal.

It is being tied into a concrete composite slab 6 1/2" thick normal weight concrete. From my experience the 5 kip/ft I need in the 45' return wall will be working that slab hard. I may need to reinforce that zone. I don't think designing as a cantilever is an option because at some point it is...

The equivalent fluid pressure is 60 psf per the geotech. I think that is high also but....... Also in response to the other posts. No perpendicular walls. The batter piles might work but are costly and dont engage unless vertical load is applied to the pile. Thanks so much for all the...

I have a basement for a hospital facility with 16' tall walls. Assuming a restrained retaining wall with pinned supports at the first floor slab and basement slab I am getting about 5000 lb of load per foot in the basement slab. The opposite walls is over 150' away to provide the balancing...

I ran it in Risa originally so it was run as a frame.

It is not a fixed end as the column is flexible so it acts some place between a beam with simple supports and a cantilever on each end and a beam with the ends fixed. The center span has a higher moment than the moment over the support.

Center spann controls design.

I have a situation where I need the column to not be interupted but I also need to make the beams framing into the web of the column behave like they are continuous. This is a elevated walkway with 14' cantilever on one end, 88' center span and 8' cantilever on the other end. The columns need...

I dug into the final shop drawings that were submitted for the elevator based on the actual elevator and the beam will work unbraced for the 17'. I was using loads that matched up to elevators I had used in the past and they were slightly larger. You would think the elevator people would...

my question is a bearing plate required on top of the pile. I am assuming this is a 100 ton pile. How does the bearing of the steel section on the concrete in the pile cap work. Can get some pretty high bearing values. I have not seen bearing plates used but it seems like they should be. I...

Thanks for the reply. I have spoken to the elevator installation people and they have assured me that the machine beams are indeed welded to the tops of the support beams therefore my assumption of a lateral brace is verified and the beams work fine at the unbraced length equal to the spacing...

I have a steel beam supporting (4) elevator hoist beams (two cars). I am not sure if the contractor welded the elevator hoist beams to the supporting steel beam to provide a brace point. One end of the hoist beam is pocketed into a concrete wall with bearing plate the other end is bearing on...