This may be an old question that everyone has asked before, would really appreciate the help.
Looking thru the hollow core planks catalog for my project, I noticed that the planks may have 1" camber in it.
1. What does this really mean for the topping slab? Should I increase the topping slab...
Ron: I would really like to go that way.
Brad805: What kind of gypcrete thickness you've used in the 4-stories? 3/4" or 1" or 2"?
Thank you all for input. It would have been an easy decision if the code were to forbid the method.
Calculated a maximum ultimate diaphragm shear of 0.8 k/ft...
Kootk: Agreed, you have a good point about the labor to pour topping versus gypcrete. Very insightful discussion and greatly appreciate the opinion. I guess I need to contact the contractor for some pricing exercise.
Well, if we go with 0.75" gypcrete, we save about 18psf per floor, and for 5 stories it's 90 psf, and that's significant.
0.75" Gypcrete = 7 psf
8" bare plank = 54 psf (from Old Castle catalog)
8" plank + 2"topping = 79 psf (from Old Castle catalog)
For buildings in SDC A-C, either method is...
Ron: I appreciate your concern, and I am myself as well. Just want to clarify: you mentioned "I have not seen a multi-story hollow core/masonry project in Florida without a topping slab..." this 'topping slab' that you referenced, do you mean by structural topping slab for diaphragm or just...
Agree, I am all for topping slab, no doubt it's the best practice for a reliable diaphragm, I was just wondering if untopped hollow core plank has been used for multi story structure.
I have also found a project done locally where light weight 2" non structural topping is used.
Ron and KootK,
thank you for the valuable input, greatly appreciate it.
Another alternate to a diaphragm topping slab is physical plank to plank connection with shear ties or embed plates. Totally agree on the chord strength and continuity. Found a good article abstract from FEMA P751 showing...
I am working on a 5 story hollow core plank on CMU wall projects in Florida, ie no seismic. As permitted in PCA hollow core design manual, I managed to get grout filled core to work as diaphragm action lateral load distribution. However, I have heard concerns of reliability of grout filled...
We are working on a high rise hotel with a meeting room space hosting more than 300 people; in our opinion, the structure should be categorized as II. FBC 2010 Risk Category Table 1604.5 clearly states that Risk Cat III is meant for 'structures whose primary occupancy is public assembly', in...
Thanks for all the replies.
KootK and hokie66: the shafts are 48" and 60" in diameter. you have a point about formwork and beam reinforcing labor.
oldrunner: the geotech does not touch on grade beam detailing. they have provided us the shaft capacities.
I am seeking help in detailing of drilled shaft foundation system for concrete shear walls. I have some standard details that have been used but want to make sure it's applicable.
Structure is a 14 stories concrete building with stairs and elevators as shear wall cores, i.e. 4 sided box...
Sorry that I was not clear. Yes, the allowable stress was too low that nothing would work. I am just curious if a small tack weld at bottom of beam would cause the whole section to have to use the low weld strength.
Greetings. I am designing a continuous aluminum beam, 2 spans, with square tube section, 6063-T5. the ends of beam and intermediate supports are to be welded to another aluminum beam.
The welded yield strength is much less than the non-welded, and the code specifies that the welded strength...
We have a small one story wood structure, that we are using gypsum board as interior shear walls for wind resistance. We are trying to determine the shear wall deflection, which is a simple calculation for OSB or plywood sheathed shear walls (IBC Section 2305.3), but we could not find the Gt...
I am a building structural engineer trying to design a fiberglass sheet to withstand some loading. I am not sure if I got my head straight on this; I am so excited that I found this forum where all the experts in plastic/fiberglass talk:
Basically, it's a 12'x12' sheet, supported at every 4'...
I am running a fast non-linear analysis (FNA) in SAP2000 on a simple shear wall building. I noticed that the base shear is much larger than the summation of internal shear, almost 2.5 times more. This is very weird. Is this normal or what could I have missed in the analysis?
Thanks for your...
I am designing a grade beam-drilled shaft foundation system for a 4 story condo, and was wondering how would the foundation details look like for this type of system. If you could shed some lights into this, i would appreciate it.
Detail 1. 18"x24" grade beam spanning between drilled shafts...
Found a very good article from attendance to a seminar by PTI. The speaker was Dr. Bijan O. Aalami, who is a very well known researcher in post tension slab. the article address the same crack pattern as described.
"Restraint Cracks and their mitigation in unbonded post-tensioned building...
Thanks hokie66, dowel action is the correct term.
see attached simplified diagram for confidentiality of the project.
the clouded areas are the cracked region.
as you can see, the stair cores are located at each end of the banded tendon. banded tendons are running plan left-right direction...
Lion06
Shear friction is purely the shear capacity of the bars. Slab will bear on top of wall with dowels into walls. Wall verticals extend from tier below to above slab engaging the slab dowels. No contribution from concrete friction is considered, just like hollow core plank on cmu wall...
