UmarMakhzumi

Leave it to the default value (8 seconds). For your structure, any number more than 2 seconds will not change the design force. So this parameter is useless for your purposes.

I'd likely try to develop two separate lateral load resisting elements in 'both halves' of the structure and isolate the connection at the top.  How are the lateral loads resisted?  What is the height? and what is the approximate height from floor to floor?

Moment release in SAFE doesn't work regardless the model. probably a bug in the program. checked it with another model and lap top.

Thanks by the way

Can anyone guide the general principles to be considered for designing of Concrete Pad / Strip footing for Steel Columns? I would really appreciate if group can refer some relevant material or excel sheets.  

well explain by Baz but i want add to it
1.) Load Patterns refer to the types of load which will be used like Dead, Super Dead ,Live , Earth Quack etc.
2.) Load Cases refer to the Analysis 
3.) Load Combinations refers to Design 

Gentlemen,
I just joined this esteemed forum. Let me introduce myself. I am a structural engineer have more that 35 years of experience in structural design. I have a YouTube Chanel also. Here is a link of one of my lectures.
 
Please watch and send me your comments. Now I am working on designing the same building as per BCP-2021.
Best Regards,
Sajjad
 
 

Hi Groszni,
There are a number of ways in which it can be done depending upon what kind of forces need to be transferred.
1) For Pinned End Beams
The primary force to transfer is shear. You can embed a steel plate in concrete column with anchor studs (industry practise is to use Nelson Studs D2L or D3L Mild Steel Studs). The beam would get welded on the face of embeded plate. In that manner you can transfer the desired force in concrete. To develop concrete for applied shear force you would need to use equations outlined in ACI Code Appendix D.
2) For Moment and Shear Transfer
For this case, you need to transfer tension compression force couple as well as shear. The best thing to do would be either to weld rebars as shown below or provide anchor bolts where high capacities are required. Shear shall be transferred by studs. Use ACI Appendix D for required equations. Figure one is shown for presentation purpose only. A web connected beam won't be transferring any moment in the column.
Hope that helps.
Thanks.
Figure 1:

Figure 2

 

W.salaam.
Since we normally don't consider soil structure interaction in structural analysis, therefore I am quite certain that the statement quoted by you about choice of pin or fixed based on soil type is flawed. Anyhow, for concrete columns unless special detailing is done at coulmn joints, they would always transfer moment that should be accounted in the design. Using fixed based would likely result in conservative design for structural members than using pinned base. The real response would stand somewhere inbetween a pin and fixed base.
Thanks.

FEMA P-2012/2018 Assessing Seismic Performance of Buildings with Configuration Irregularities is now available.
Thanks.
FEMA_P-2012_508.pdf

Source: https://www.fema.gov/media-library-data/1551300980344-8e2d825576db50c85ea48448ede5bd90/FEMA_P-2012_508.pdf
 

I have worked with some engineers that like to assign high stiffness modifiers to rafts to get conservative flexural and shear design of foundation. Assigning modifiers would increase amount of rebar in your raft.  I personally think that this is good practice as nothing is perfectly rigid and cracking in inevitable, which would result in loss of inertia and high flexural stresses.
The general procedure is to create two models. One with no stiffness modifiers and one with modifiers for foundation/ raft. You should use the first model to calculate piles reactions and the second to do flexural and shear design. 
Thanks.

Part of the reason the forum went quiet as I found out recently was our Anti-Spam system. Almost all new users that registered on the website are now tagged for manual approval by Admins. Since that takes some time, therefore, the new users don’t get approved right away and by the time they get approved, the question for which they wanted to come to the forum is probably solved. We are looking into it. Apart from that, this forum focuses on a very small subset of Civil Engineering professionals - we also do admit that participation level is low as target audience is very limited and there are some challenges that we need to overcome. 
Thanks. 

AA.  Soil bearing capacity is provided by the client in the shape of site-specific soil investigation report (SSSIR), prepared by a geotechnical engineer for the site area where building is to be constructed. If SSSIR is not available, client should be asked to arrange the same for proper design of foundation. 
Regards.

In my opinion the key parameter is 14 and 28 days strength and curing periods are recommendations to achieve the strength. Generally industry practice is to open forms at 14 days and load members post 28 days and curing periods might help achieve those strength in required number of days but the can only help. 
I have used early high strength concrete mixes like Lafarge Chronolia (https://www.lafarge.ca/en/chronolia), that can achieve the desired 28 days strength in 3 days due to higher C3A contents in the design mix. So curing is dependeted on what the target is being tried to be met and should not be looked independently of strength. If desired strength can be obtained earlier by using higher C3A content cement or water reducers, curing recommendations are just helping in bigger scheme of things. 
Thanks.

Yes. We can 
10.3.1.2 For columns with cross sections larger than
required by considerations of loading, it shall be permitted
to base gross area considered, required reinforcement, and
design strength on a reduced effective area, not less than
one-half the total area.
but need to be considered the following as well
This provision shall not apply to columns in special moment frames or columns not part of
the seismic-force-resisting system required to be designed in
accordance with Chapter 18.
 
 

Yes, You can reduce. ACI 318 calls them Architectural Columns, See following sections of ACI 318-14
ACI 318-14 (R10.3.1.2)
But, you need to be careful in areas where ductility demand is high.

There is huge gap between the two in Pakistan, engineering graduates comes in field and almost know nothing about industry practices, engineering graduates required to have field knowledge and a fair understanding of there trade, they must know their basic discipline, after two years of engineering degree, they must be exposed to practical jobs, they must be doing part-time practical work near there institute, if they are doing so while graduating they will jump straight into the field, this will give them clarity of mind about there engineering studies and their interest.
At the moment engineering students coming from university need at least 6 months to one year to develop basic understanding of the engineering practices.
At the start of career engineering graduate shall define their interest very clearly (yes/no rule), they shall go to seniors in the field, have meetings and request someone near you to mentor you, consult different career paths this could make the path easier and vectored.

P.S. No engineering is out of scope at any stage, if you have interest and willingness to learn, you can grow, success is yours.

Design your floor system by checking the "ignore vertical offsets in non P/T Models". It is performing incorrect analysis when you uncheck this option; you can compare the shape of bending moment diagram in beams as a reference. It gives a weird shape when you uncheck this option.
 
Ignoring or considering the 2D analysis only will have negligible effect.

For gravity loads, and for the purpose of deflection check ( which needs to be checked against gravity loads), it is reasonable to use 2D analysis option. Even if your are using 3D analysis by unchecking this option, your results should approximately be the same, as you are using gravity loads only. Another scenario where this option can lead to considerably different results is when you have angled columns.
Vertical offsets are used to model raised and depressed slab panels. If you have not modelled them, it does not matter if that option is checked or not.
How much is the difference in results in terms of percentage? I doubt if your results are  differing by considerable amount.

Use ACI 530-11 for the reference.
You do not need a software for these structures, unless you want to know the design shear on individual wall panels.
For most masonry buildings (rectangular shape with no vertical irregularities, normal size rooms, and only the normal size window and door openings) you do not even need to consult any code or use software. You should be able to design these kind of structures in 30 minutes.
 

"There is no favorable wind for sailor who does not know where to go". You are asking wrong questions. Whatever I write, will misguide you.

Study the PMM diagram. For column at top floor, small axial load coupled with relatively large moment is causing your PMM ratio to shoot up.

Assalam O Alaikum!
Hoping everyone is fine and busy in their daily routine. I am here for some advice related to research proposal. I have been approaching various professors through email for research assistantship. Luckily I got few responses but problem is that I don't have any research proposal and all of them required a research proposal. I have been googling about the temperature effect on structure (mostly MS Structures) but I have not been able to come up with unique topic within this domain. Need guidance related to topic selection and what to write in proposal. 
Thanks in advance!

Go through relevant literature (means research papers), and read recommendation part to find the research gap. Then highlight this gap and write proposal accordingly.
 
For your reference, you can download this paper. If interested in this topic, you can find similar papers from references of the same article.

https://www.worldscientific.com/doi/10.1142/S0219455419501396

Hii...
I am using Etabs 2016 in saudi arabia, but now i want to add Saudi Building Code to Etabs for design but there is no such code there now. Can anyone please guide me how  to add SBC

Asssalam-o-alaikum!
 
You might need to increase your main member (pipe) size (thereby increasing stiffness), or to add brackets and bracing, to reduce deflection.
 
BTW... I am unable to understand, why are modelling pipe as shell, instead of frame? What is its basis, and to what advantages it may lead to?
 
Regards.