Waqas Haider

Thank you very much bhai.

Correct. I don't know if reserve strength is the right word but simply put it this way that we want plastic hinge formation in beams, which shall require full fy development thus no ld reduction.
Thanks.

It simply means that bent up bars are allowed. Thats what I understand. If anyone has a different opinion please post.

Thanks.

as a whole we dont go in tiny details like adjusting cardinal points....remember that there are 100 ways to pass a failed member but just dont do it..its not practical to adjust each and every beam and column by selecting appropriate cardinal points..just do center to center...struc analsyis is based on center to center..there are ways and means to be on the safer side.. I mean you should limit your interaction reatio for columns upto 0.8 not more than that instead of 0.99...So put more attention on the results rather being lost in model making perfection (like what i used to be in past )

Aoa,
 
Sir Umar!
 
 
Firstly, I totally agree with the idea of "Consistent Design", for the Pakistani Engineers.
 
BTW, What is the progress achieved on this idea so far?
 
Secondly, IMHO this idea of Consistent Design may be made even more useful, keeping in view following comments:
 
1. What I have understood from your post, your basic idea is limited to consistent design for UBC-97 and earthquake resistant design ONLY.  IMO, this should extend to all other design types, based either on material (concrete, steel, wood etc) or the nature of loading (earthquake, wind, snow, etc) as well.
 
2. According to my knowledge, although in our country mostly US Design Codes are being used by private consultants or government departments, there is generally no consensus among the structural engineers as to which design codes (British or US) are to be adopted, even for common materials like concrete and steel.  In this context, first of all we should decide a standard or 'Consistent' Structural Design Criteria for the proposed 'Consist Design'. This design criteria should include both 'Material design Codes' for the various structural materials (concrete, steel, wood etc) and the 'Loading Codes' (for dead, live, earthquake, wind, snow etc).
 
My recommendations regarding 'Consistent Structural Design Criteria', are as follows:
 
a. We should use US Material Design and Loading codes, being more advanced and progressive. And, also because our national building code, Building Code of Pakistan, is based on US codes.
 
b. In line with above recommendation, specific Material Design codes should be:
 
   (1) ACI 318 for Reinforced Concrete Design
  
   (2) AISC 360 for Structural Steel Design
 
   (3) AISI for Cold-Formed Steel Design
 
c. Specific Loading codes should be:
 
   (1) Building Code of Pakistan (Seismic Provisons-2007) and UBC-1997 for Earthquake (Seismic) Loads
 
   (2) ASCE 7 for all other (Dead, Live, Wind, Snow) Loads
 
 
Thirdly, this is a very important and special topic. As such, it should be allotted a separate full forum, and all the relevant posts should be placed in this new forum.
 
 
Thanks.

SIR, 
surely this will give a very much clear picture of things and make concept very much clear....the problems which i faced today surely everone face those at their initial stages, but sometime we are lucky to get a good senior in our office to guide us in the right way , but you are not lucky evertym , sometym you just have to follow the usual practice that is going on in your office without getting proper concept behind those things, and if there is something new we got and stuck in that, our seniors just simply say " you are doing wrong" without explaining the main reason behind....
sir i appreciate your Idea and i wish more experience people join you in this cause ..............

Salaam All,
 
Looking forward to develop a series of articles under the title of "SEFP Consistent Design". 
 
The aim is to provide simple and lucid examples for our Pakistani Engineers that use UBC 97; examples will serve as quick reference and try to clarify misconceptions prevalent in design offices. Anyone, who would like to volunteer on this is most welcome. 
 
As the name indicates, "consistent design" is meant to spread common understanding of complex code clauses that a design engineer faces on a day to day basis. e.g., calculating story stiffness, or designing a flexible diaphragm. Examples would be pure, and written by authors with copyrights to SEFP.
 
Current target is to have at least 2 examples published per month. I hope this will help young engineering to develop a rock-solid understanding and design the right thing rather than saying yes to whatever they are told to follow.That's my goal. 
 
Any ideas, input, volunteering in appreciated. 
 
Thanks.

Dear AbdurRasheed, 
Regarding this, i want to say you. Some go in design, some go in field, some go for higher study etc etc. But i believe no one is in loss ultimately. What thing matters is YOUR INTEREST. If you have interest in Designing, you should go for it. At start you may get less salary. But when you will become experienced, or you will get chance for abroad (Remember, Life is toooooo Long and Circumstances change a lot), u may get higher salaries. But the only thing is your interest. Otherwise you will get bore of your job one day. I am a design Engineer (Obviously you know because we are friends since last 6 years ) But i never get tired of my work because i love design job and it is a type of hobby for me. So ask your self, MAZA KIS ME ATA HE APKO? Baqi baten sham ko mil kr kren ge...

Regarding point # 3, suppose at any support strength requirement shows 3 #6 bars,here to counteract ldh you  provide greater area i.e greater bars for ex if you provide 6 # 6 bars then ldh should be multiplied with As-3#6/As-6#6 i.e 0.5.
 
Concept behind this provision is that if at any support say half ldh is available for stressed bars then these bars will develop half of their strength through bonding in concrete and will be able to take stresses till 0.5xFy,if you add up same no of bars with same ldh then they will also bear stresses upto 0.5xFy and as a whole you will get the required resistance Fy. 

Waqas,
 
First note that development length in indicated case is only the straight length as shown in figure and doesn't include bent portion and secondly this requirement can be fulfilled as follows,
 
1,you can use greater no of lesser dia bars complying ldh requirement and if beam width is insufficient to accommodate greater no of bars then you can distribute them in effective flange width (ACI 318-11 section 10.6.6).
 
2. you can multiply ldh by 0.8 if you tie hooked end reinforcing bar with ties parallel or perpendicular to the bar, spaced not greater than 2db (db = hooked bar diametre).(ACI 318-11 figure R12.5.3).
 
3, You can provide excessive reinforcement and multiply ldh by As req/As prov.
 
4, You can multiply ldh by 0.7 by maintaining minimum side cover to the longitudinal bar to 2.5".

It will require two plastic hinges to develop mechanism, as it act as propped beam, and it can still redistribute moment. You are not relying on plastic strength of the structure to carry gravity loads.
If , in a particular frame, your reliability/redundancy factor is less than 1, excluding  the bay which contains propped beam, and your drifts are under control, then you can use a propped beam in one bay of that frame.
If you can afford a non-moment resisting bay, which means your drifts are under control and your structure has adequate redundancy, then you don't have to worry about integrity of that one joint. Other joints and bays of the frame can take care of that.

Dear senior brothers!
I have one year experience as a site engineer and 5 months as a project coordinator.I am getting 38,000 rupees per month.But i have keen interest in design job from the very beginning.I may get one opportunity where i will get up-to 25,000 rupees per month.But  experience there is good.So kindly suggest which alternative should i choose out of them???? I need your valuable suggestions and advice....
Thanks brother
 
Regards,
Rasheed

https://www.daad.de/de/is your gateway to Germany.
http://www.pk.emb-japan.go.jp/Education.htmlis your gateway to Japan.
And there are a lot more scholarships that can get you a foreign degree(like US Fulbright) but you will have to return home after your degree is completed. AIT offers a similar scholarship too. I would share with you what I thought and did when I was out of university.
After working for two years in Islamabad as a Structural Engineer, one thing that I was certain was that the usefulness of a foreign degree could not be maximized unless I have worked abroad as an engineer. I was also confused about to do a research thesis or just a degree program. Well, on one of the projects I did for USAID, I happened to meet Kazami Sahab(SMK Associates) and after discussing with him I went for a degree program and no-scholarship.
Today, I am glad that my understanding of working abroad was correct and I am also grateful to Kazmi Sahab for convincing me not to do a thesis program as that saved me 1.5 years of salary. I can tell you the you won't get the max out of your degree unless you have worked in a different and more robust environment than Pakistan. However, having said that if you go for a thesis or PHD, the challenges involved in the degree would open up your mind and help you take on things with a different approach.
Set your goals and go achieve them.
Good Luck.

Assalam o alaikum.
According to ACI 12.5.2,
development length for fc' = 3000, fy=60000, for normal weight concrete and epoxy less reinforcement, The required development length comes out to be
for #3 = 8.2 inch
for #4 = 10.95 inch
for #6 = 16.42 inch
for #8 = 21.9 inch
 
And if in my case, ACI 12.5.3 is not fulfilled, it means now i have to provide ldh as mentioned above. ldh is STRAIGHT EMBEDMENT LENGTH + RADIUS OF BEND + ONE BAR DIAMETER as shown in figure attached. Now my question is, if in my case, main reinforcement of beam is of #6 and #4, minimum column size required will be 18 inch and 12 inch respectively. Lets say by any means, i can not select #4, #3 bars and size of column where bars are to be terminated is 12 inch, how to fullfil this development length???

Assalam-o-alaikum!
 
 
All of the courses and other relevant material (formulas, tables etc) you have mentioned in your post, are necessary for your professional development. Which of them you will actually use in your professional life, will depend upon nature of practical problems you will come across and have to find solutions thereof.  In general, you will need and use them, MUCH MORE in STRUCTURAL ENGINEERING, than in any other field of civil engineering. 
 
As regards planning to do masters from and working abroad, IMHO you may obtain sufficient information from the internet, about the scope of civil engineers not only in Australia, but in other advanced countries (like USA and Germany etc.) as well. And, it will probably help you select a better option if you check your prospects in more than one country, and make your final decision keeping in view advantages and disadvantages in each case.
 
Regards.

This is a critical analysis about approach of codes to reduce seismic forces in terms of over strength factor. 
overstrength theory.PDF

waqar...thats a nice question....i would like to add that after reading what Ayesha posted...do think about the difference between an inverted and dropped beam design in ETABS....if facing difficulties post it here 

Assalam-o-alaikum!
 
Shear reinforcement values indicated on the column member are generally the maximum values for the two shear axes, whether these are from on load combo or from two different load combos. Right-cIick on the member reinforcement diagram generally leads straight to load combo resulting in the maximum longitudinal or maximum shear  reinforcement. However, as you have indicated, I am unsure, why this does not always happen. Surely, someone else might be able to explain this.
 
Interpretation of shear reinforcement value 'Av/s', given by ETABS, is not very difficult.
 
Since your units are 'kip-in", Av (i.e. cross-sectional area of ties) is in 'sq.in.' and s (i.e., spacing) in 'inches'.
 
For your case,  Av/s = 0.045.
 
For 2-legged #3 ties, Av = 0.11x 2 = 0.22 sq. in.
 
Substitution of value of Av in above equation, results in required tie spacing,  s = 0.22 / 0.045 = 4.88 in.
 
 
Regards.

First , I am Very Happy to Participate in Forum Such As This Forum , I need to Make Engineering Discussion With These Questions
 
1.       Why We Make Scale Factor Between Static And Dynamic Seismic Analysis ?
2.       After Scale Factor We Design By Load Combinations Included Dynamic Cases Only
          Or Static Load Only Or Dynamic And Static ?
3.       What is Diaphragm And What is Importance of Diaphragm In Seismic And Wind?
4.       When We Define Diaphragm? And We Define As Rigid Or Semi Rigid And What is the Different Between Them?
5.       Different Between Displacement And Drift Due to Seismic ?
6.       Displacement Due to Seismic Results From Etabs We Multiply it X 0.70 X R ,Why And What About Drift ?
7.       We Make 3 Cases For Each Case ( X AND Y ) in Static Analysis What About Dynamic Same Or Not
          Static Analysis
          Ex
          Ex With + Eccentricity
          Ex With – Eccentricity
          Ey
          Ey With + Eccentricity
          Ey With – Eccentricity
8.       Why We Don't Combine Seismic And Wind in Load Combinations?
9.       In Dynamic Analysis , Forces Cause Mode Shapes Or Mode Shapes Cause Forces?
10.   Difference Between Response Spectrum ( Dynamic ) And Time History , Which Best?
11.   What is the Effect of Seismic in Slabs And Beams?
12.   Design Of Slabs And Beams By Load Combination Included Seismic Right Or Wrong?
13.   After Finishing 3D Model , What are the Checks For Seismic?
14.   Slab On Grade , I Put In Etabs Or Not ?
15.   How Building Make Damping For Seismic ,What is Factors Damping Depend on?
16.   Different Between Point Drift – Story Drift – Diaphragm Drift ?
 

Yes, slab connects all the lateral forces resisting elements and acts as diaphragm.
 
Further Reading:
http://www.sepakistan.com/topic/87-diaphragm/
http://www.sepakistan.com/topic/1480-diaphragm-flexibility/
 
Thanks.

Assalam-o-alaikum!
 
Umair is right. According to ACI 318-11 Section 21.1.4.1, the requirements of section 21.1.4 apply to special moment frames, special structural walls and all components of special structural walls, including coupling beams and wall piers.
 
Since slabs and footings are not mentioned, probably 2500 psi concrete (minimum as per ACI section 1.1.1) may be used for these elements.
 
However, according to ACI section 4.1.1, minimum value of specified concrete compressive (fc′) shall be the greatest of the values required by following three criteria:
 
a. ACI section 1.1.1 requirement i.e., 2500 psi minimum
b. Requirement for durability, as per ACI Chapter 4, and
c. Actual requirement, from structural strength point of view        
 
As such, most likely 3000psi may be likely choice in many cases. On the other hand, use of 2500 psi and 3000psi concrete for most of the small scale projects might not result in appreciable saving in the project cost. From construction point of view also, it will generally be time saving and preferable to use concrete of one compressive strength, as compared to the opposite.
 
 
 
Regards.

Good suggestions have been provided to you. IMHO, you will get ample time after graduation to use softwares. You should improve your understanding of subjects that are being taught to you. Remember, as an engineer, you can't design what you can't understand and visualize. Studies are very important, and you should focus on them. What is your GPA?

It is applicable to SMRF i.e beams & columns and structural walls with their coupling beams.In general all members effective in resisting lateral force.

Aoa.
 
 
In case you get some useful data, please do share at this forum for the benefit of all of us.
 
 
Thanks.

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.