Attached is another solution. You can add new beams. Red and Blue.

The end condition for Red beams can be pinned/ moment released. For Blue, the end towards the red beam can be pinned/ moment released only. The size of blue beam should be same as balcony beam. 

Thanks.

Wsalaam WR WB,

Welcome aboard Fikri. We are very pleased to have you.

Thank you.

On 5/26/2020 at 2:11 AM, M.Arslan Umar said:

AoA

Dear members, I have a few questions regarding the topic mentioned above. 

Is there possibility of resting an RCC flat slab over steel columns? Is there any research paper/article regarding that? What and how will the connection be made?  What will be the connection response against sesimic activity? 

Thanks and regards 

The situation here is very similar to where foundations are placed on steel piles (although there is no continuity for piles to top like columns can have another column on top of slab). I can explain to you what is done for the pile connection. Normally a cap plate is used on top of the pile and dowels are welded to the cap plate that get embedded in the foundation concrete. The dowels can be designed for shear and tension forces (Moment is resolved into tension). I haven't done a configuration in slab but for piles, I have done a lot of these.

Regards,

Makhzumi.

This is a very powerful feature and a great question asked. Please see the following video:

Thanks.

I would suggest reading this book, as it has a lot of case studies on famous high rise buildings.

Structural Analysis and Design of Tall Buildings: Steel and Composite Construction - 1st Edition

You need to create a new topic to be consistent with Forum Posting Guidelines. We have a lot of people on forum that are experienced with SAFE. They will answer.

Thanks.

Makhzumi!

One of the biggest life lessons that I have learned is on focusing what not to do, rather than focusing on what to do. As the great Molana Rumi said, The art of knowing is to know what to ignore.

I would suggest you to read about structural failures as that will shift your thinking to what should not be done. A good starting book would be - Why Structures Fall Down.

Thanks.

Makhzumi!

Ali,

I will need to dig up the reference but I think what I read a few years ago, if my memory serves me right is that beams need to be twice as stiff as slabs.

Thanks.

On 4/3/2020 at 6:04 PM, shazeb mirza said:

• how yo use ACI 314 in concrete design ?
•  how to take advantage from these code ?

can someone guide me please?

From the website, where you can download this as well fo free.

Quote

DESCRIPTION

Members of ACI Committee 314, Simplified Design of Concrete Buildings, have created and reviewed a series of helpful design aids for reinforced concrete. Download this documents for quick and easy reference during design or to refresh one’s memory on the basics of concrete design.

On 2/16/2020 at 2:53 AM, callmeismail said:

Is this correct to calculate Buoyancy force only for 2' depth? shouldnt be the buoyancy force equivalent to the confined heigth of water? say if EGL is 8' above the Raft, then the buoyancy force should be 8*62.4 psf upward. correct me please.

Normally what I have seen is that almost all Client Specifications require buoyancy checks to be done assuming GWT is at grade irrespective of where it is  (to account for seasonal fluctuations and also because the approach is conservative). You only need to consider buoyancy for the volume of concrete that is displacing the water (assuming water table is at grade). For soil, you will have submerged unit weight that accounts the buoyancy affects.

Thanks.

You are better off using a different foundation system if your bearing capacity is super low than expected. Have you considered piling? You can use friction piles if loads are low.

Thanks.

Built up sections are custom sections. You are better off adding plates to increase the capacity to meet the demand. Trial and error.

Thanks.

This is a great question. I will share what I have been using:

On 12/23/2019 at 4:53 AM, Simple Structures said:

Which codes do you use for 'structural design of elements’?

1. Wind Loading -?

Mostly ignored it while working in Pakistan as seismic governed. For cases where had to consider UBC 97 was used. At some project I also used IBC as I had a supplement that provided the environmental parameters for wind, seismic and snow.

2.  Concrete design -?

ACI 318-02

3. Steelwork Design -?

AISC 360

4. Masonry design -?

Zilch

5. Timber design -?

Never did.

6. Geotechnical design -?

Consultant in all the cases.

7. Earthquake design?

ACI 318-2, UBC 97 mix

& so on etc etc.

In addition to above, I once got the chance to use Eurocode for a British Embassy Project but that was exception to the rule.

On 12/23/2019 at 4:53 AM, Simple Structures said:

Should Pakistan be adopting Eurocodes with the Turkey's Nationally Determined Parameters? 

Pakistan should work on improving it's own code. We would be better off improving on American codes as people are more familiar with them. 

On 12/23/2019 at 4:53 AM, Simple Structures said:

Who is the custodian of the design codes ruling in Pakistan? PEC (another of the country's quango that is more interested in ticks box exercise, or am I wrong is that assumption) or is there another body that one can look to for guidance?

I think you can get contact information on this if you have a copy of Pakistan Building Code. please see the following link for more details:

https://www.pec.org.pk/building_code_pakistan.aspx

It would be great to see what others have been using in Pakistan.

Thanks.

Hi Rummaan17, 

Great questions.

On 12/9/2019 at 4:36 AM, rummaan17 said:

1. What would be the case if Shear resistance is greater than bending resistance? its not explicitly defined in the guide.

This can happen. However, just to keep things simple you can size your section to make sure bending resistance is > than shear resistance. I know this answer is not very neat but I have been out of touch with this so don't exactly remember the details here.

On 12/9/2019 at 4:36 AM, rummaan17 said:

2. If there is two way slab, what would be the case?

You might have to refresh me here about where does this come in play? 

On 12/9/2019 at 4:36 AM, rummaan17 said:

3. How are we comparing the strength of the section to applied load? does it has to with stand peak on side over pressure (Pso) or reflected pressure (Pr) for front wall. I am not clear about if section strength is compared to any loading .

I think the example that I have provided only talks about the period calculation, not the strength. You are right. Do you have a criteria provided by the Client company to meet? There might be details there about what load combinations to use and what checks need to be done for blast loading for strength design.

On 12/9/2019 at 4:36 AM, rummaan17 said:

4. If I model this scenario as Linear Time history analysis in STAAD and check support rotation limit of 2 degree. Is it correct

Could be, but I haven't done it. 

You have got some excellent questions here. I wish I could answer you better but to be honest, blast loading is a complete criteria in itself. Normally a good starting point would be client specifications that you have to meet as they should specify they load cases, acceptance limit states under strength and serviceability and any other items that need to be considered. If you don't have a governing criteria, then the next best thing would be to get a book on the subject and follow a design example and establish the limit sates. Let me know.

Thanks.

Welcome aboard Syahrul, 

We are very happy to have you here.

Thanks.

Wsalaam Fatima,

On 11/18/2019 at 2:50 PM, Fatima Khalid said:

In case of analysis/seismic assessment, Do we need to consider this storey as a storey while distributing base shear. OR should we consider only RC structure as a storey and take load of steel roof on the existing columns?

 

Definition of Storey is based on if a diaphragm is provided or not. So for cases, where there is a concrete moment resisting frame system, that has a steel truss roof, if the roof has sufficient horizontal bracing (which is normally the case or the structure would be unstable), then it will act as diaphragm, and you can consider that construction up to roof as one story and any extensions above as another storey.

Now for cases where you have concrete column extending a bit from roof and steel columns are used, in my opinion (I could be wrong as I am out of touch from seismic since long), you can simply your design by still assuming 2 stories, one till steel roof and other to top of new construction, and design the connection between steel and concrete column with using over strength factors. This is the most simple answer I could give you without looking at the sketch. 

Thanks.

Yes, please scale it down.

The question is very general and there can be numerous answers.

You can try different layout of beams to see which one way direction provides the least quantity of reinforcement and concrete volume. 

On 10/8/2019 at 3:04 AM, Nawaz Qasim said:

What should be the variables (Rho , Depth) ?

These values would be based on applied loads so discussing these parameters is open ended. 

Thanks.

Earthquake loads as generally considered in one direction at a time (unlike wind). There are some exceptions to it like when you have a non-orthogonal system. The requirements on condition where you have to consider earthquake loads simultaneously in both directions are generally provided in the building code that you are following. So, I would recommend you to look up your building code.

If your question is about a regular Seismic Lateral Frame Resisting System, then, the answer is to consider one direction at one time. P+Myy and P+ Mxx ( Check for both cases independently) 

Thanks.

Quote

SAP2000

The SAP2000 analysis & design application

 is written by Computers & Structures, Inc. Full product details can be found on their website.

• The SAP2000 analysis & design application can export and import cis/2 and ifc
   files, and export SDNF files.

• If Tekla Structures and SAP2000 are installed on the same computer, then a direct link can be used.

• It is important that you run SAP2000 for the first time as a standalone application before your load the link. Just start SAP2000 and create a new model, save it and close SAP2000. This will then update your registry which is needed by the link.

To get more information and to download, go to Tekla Warehouse.

Good question. For further details please see: https://teklastructures.support.tekla.com/2016/en/int_sap2000

Thanks.

On 10/12/2019 at 11:05 PM, Tufail Mabood said:

Adding to to the above discussion, Can i provide shear reinforcement in two or more different spans in SAP2000 in a simply supported beam?

The posted video above by Ayesha answers the question.

Thanks.

1 hour ago, Hamza Ahmad said:

Can we perform RSA on two story building have vertical irregularity in zone-2?

You can look up the code that you are designing too and it lists down all the irregularities that require RSA. There is a topic on this forum that explains how to do RSA in ETABS. See the following:

1 hour ago, Hamza Ahmad said:

What should be the preference of desinger, shear wall to avoid it or go for RSA ?

Depends on layout to layout and what are you trying to avoid. For example to control torsion, shear walls need to be located as far from the center of mass as possible.

Thanks.

Sleeves are common. General engineering practice is to place them at location of least moment along the span. You can get that location from your structural analysis software. Once you have located the sleeve, you need to make sure  that you satisfy the shear and flexural strength of the beam at that location. 

Thanks.

You need to check a reference code like AASHTO or talk to Client to see what specifications they want you to use to determine these factors.

Great, some real useful information added here. 

Thanks.